Patent Application
20060187719
This Non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 2005-001864 filed in Japan on Jan. 6, 2005, the entire contents of which are hereby incorporated by reference.
The present invention belongs to the art relating to identification of semiconductor packages or semiconductor integrated circuit chips.
Conventionally, assignment and allocation of specific numbers to semiconductor integrated circuit chips (hereinafter they may be referred to as semiconductor chips merely) have been examined in view of manufacturing process management. Because, in the case where a plurality of semiconductor chips are taken out by dividing a wafer after formation of semiconductor integrated circuits in a wafer state (i.e., diffusion process), it is necessary to acquire, after shipment of the semiconductor chips, information on, for example, when in the diffusion process a certain chip is formed, from which lot it is obtained, from which wafer it is obtained, where in a wafer it is taken out, and so on. Similarly, it is significant to, after packaging semiconductor chips, assign or allocate specific numbers to the packages.
Under the circumstances, conventional techniques for generating a barcode for a semiconductor chip and the like have been utilized (see Japanese Patent Application Laid Open Publication No. 5-13529A, for example). This conventional technique contemplates increasing production efficiency in manufacture in such a manner that a specific ID code is generate in each semiconductor integrated circuit chip region when a stepper exposure is performed in, for example, an aluminum layer patterning process in the diffusion process for semiconductor integrated circuit in a wafer state. Specifically, the aluminum layer is formed also in the periphery (a code region) of each chip region provided in the semiconductor wafer and the aluminum layer in the code region is patterned into a barcode pattern by stepper exposure in patterning the aluminum layer, thereby generating an ID code within the code region of each chip.
Also, as another conventional technique for allocating specific numbers to semiconductor chips, there was proposed a technique in which specific identification information of semiconductor integrated circuit devices is set based on a magnitude relationship in physical quantity of elements to be identified which corresponds to process variation (see International Publication No. 02/45139). In this technique, a flip flop rise pattern formed due to ununiformity in transistor characteristic, which is yield by process variation, is utilized as specific ID information of each chip.
As described above, assignment of a specific number to a semiconductor chip itself (or a semiconductor package including a semiconductor chip) is very important in view of the manufacturing process management (to acquire information on when in the diffusion process a semiconductor chip is formed, from which lot it is obtained, from which wafer it is obtained, where in a wafer it is taken out, and so on).
However, artificial assignment of a specific number to a semiconductor chip or the like involves problems of counterfeiting of the specific number and the like in view of information security. As such, for recent application to IC money, IC tags, IC cards, and the like, it becomes much important to add a specific number incapable of being changed from outside to a semiconductor chip itself (or a semiconductor package including a semiconductor chip). In short, provision of an artificially unforgeable semiconductor chip is demanded. Further, in order to attain cost reduction, a method simple as far as possible for adding such a specific number to a semiconductor chip or the like is desired.
In addition, the following is also important. Namely, in the case where a semiconductor chip shipped to the market is judged as a failure (hereinafter referred to as a market failure) upon use, the semiconductor chip is recovered and the specific number (specific number guarded by information security) assigned to the semiconductor chip is recognized again for finding a cause of the failure in a short period of term so as to secure customers' trust on the responsibility of a manufacturing maker.
As described above, in assigning a specific number to a semiconductor chip (or a semiconductor package including a semiconductor chip), it is desired to assign an unforgeable number under protection by information security and to easily extract, upon market failure, the specific number of the failed semiconductor chip for immediately providing countermeasures for customers' benefits.
Referring to the conventional technique for generating a barcode for a semiconductor chip (see Japanese Patent Application Laid Open Publication No. 5-13529A, for example), however, a barcode is assigned to a semiconductor chip artificially, involving problems of counterfeiting and the like in view of information security.
Further, in the other conventional technique for setting a specific ID information to a semiconductor integrated circuit device based on the magnitude relationship in physical quantity of elements to be identified which corresponds to process variation (see International Publication No. 02/45139), the process variation is utilized for setting the specific ID information, so that the specific ID information can be obtained which is not assigned artificially, namely, is under protection by information security. However, as described above, this technique requires an additional step of forming a FF (Flip flop) circuit and causes difficulty in obtaining relatively random specific ID information because the variation in electric characteristic of elements to be identified which corresponds to the process variation is utilized for setting the specific ID information. Further, the electric characteristic of the elements to be identified must be evaluated in setting and extracting the specific ID information, and this raises a possibility of degradation or change of the specific ID information because of degradation in the electric characteristic of the recovered semiconductor chip judged as a market failure in comparison with the one at shipment. At the worst, the semiconductor chip may be electrically defective and the circuit itself may be inoperable when the electric characteristic of the semiconductor chip judged as a market failure is evaluated for acquiring the specific ID information thereof. As a result, the specific ID information of the semiconductor chip cannot be acquired due to inoperability of the semiconductor chip.
In view of the above problems, the present invention has its objects of providing an unforgeable random specific ID information which is under protection by information security in assigning a specific ID information to a semiconductor chip (or a semiconductor package including a semiconductor chip) and of extracting a specific ID information of a failed semiconductor chip or the like for immediately providing countermeasures for customer's benefits in the case of market failure of a semiconductor chip or the like.
To attain the above objects, a semiconductor package ID generating system according to the present invention includes: a function of selecting a topographic characteristic to be utilized as specific information from at least one topographic characteristic that a semiconductor package has; a function of measuring the selected topographic characteristic as the specific information; and a function of generating an ID for identification for the semiconductor package based on the measured specific information.
A semiconductor integrated circuit chip ID generating system according to the present invention includes: a function of selecting a topographic characteristic to be utilized as specific information from at least one topographic characteristic that a semiconductor integrated circuit chip has; a function of measuring the selected topographic characteristic as the specific information; and a function of generating an ID for identification for the semiconductor integrated circuit chip based on the measured specific information.
A semiconductor package ID recognizing system according to the present invention includes: a function of selecting a topographic characteristic to be utilized as specific information from at least one topographic characteristic that a semiconductor package has; a function of measuring the selected topographic characteristic as the specific information; a function of generating an ID for identification for the semiconductor package based on the measured specific information; a function of storing the generated ID for identification into a database; and a function of acquiring again the ID for identification of the semiconductor package by re-measuring the selected topographic characteristic as the specific information and comparing the re-measured specific information with data stored in the database.
A semiconductor integrated circuit chip ID recognizing system according to the present invention includes: a function of selecting a topographic characteristic to be utilized as specific information from at least one topographic characteristic that a semiconductor integrated circuit chip has; a function of measuring the selected topographic characteristic as the specific information; a function of generating an ID for identification for the semiconductor integrated circuit chip based on the measured specific information; a function of storing the generated ID for identification into a database; and a function of acquiring again the ID for identification of the semiconductor integrated circuit by re-measuring the selected topographic characteristic as the specific information and comparing the re-measured specific information with data stored in the database.
A first semiconductor package ID recognition method according to the present invention includes the steps of: selecting a topographic characteristic to be utilized as specific information from at least one topographic characteristic that a semiconductor package has; measuring the selected topographic characteristic as the specific information; generating an ID for identification for the semiconductor package based on the measured specific information; storing the generated ID for identification into a database; and acquiring again the ID for identification of the semiconductor package by re-measuring the selected topographic characteristic as the specific information and comparing the re-measured specific information with data stored in the database.
A first semiconductor integrated circuit chip ID recognition method according to the present invention includes the steps of: selecting a topographic characteristic to be utilized as specific information from at least one topographic characteristic that a semiconductor integrated circuit chip has; measuring the selected topographic characteristic as the specific information; generating an ID for identification for the semiconductor integrated circuit chip based on the measured specific information; storing the generated ID for identification into a database; and acquiring again the ID for identification of the semiconductor integrated circuit chip by re-measuring the selected topographic characteristic as the specific information and comparing the re-measured specific information with data stored in the database.
A semiconductor package according to the present invention includes: a specific information reading region for measuring roughness of a surface of the semiconductor package as specific information for generating an ID for identification, wherein a pattern serving as a starting point for measurement is provided within the specific information reading region.
In the semiconductor package, the surface of the semiconductor package in the specific information reading region may be protected physically.
A second semiconductor package ID recognition method according to the present invention includes the steps of: measuring roughness of a surface of a semiconductor package as specific information; generating an ID for identification for the semiconductor package based on the measured specific information and storing the thus generated ID for identification into a database; and acquiring again the ID for identification of the semiconductor package by re-measuring the roughness as the specific information and comparing the re-measured specific information with data stored in the database.
A third semiconductor package ID recognition method according to the present invention includes the steps of: measuring a lead angle of a bonding wire provided in a semiconductor package as specific information; generating an ID for identification for the semiconductor package based on the measured specific information and storing the thus generated ID for identification into a database; and acquiring again the ID for identification of the semiconductor package by re-measuring the lead angle as the specific information and comparing the re-measured specific information with data stored in the database.
A fourth semiconductor package ID recognition method according to the present invention includes the steps of: measuring a contour of a bonding portion provided in a semiconductor package as specific information; generating an ID for identification for the semiconductor package based on the measured specific information and storing the thus generated ID for identification into a database; and acquiring again the ID for identification of the semiconductor package by re-measuring the contour of the bonding portion as the specific information and comparing the re-measured specific information with data stored in the database.
A fifth semiconductor package ID recognition method according to the present invention includes the steps of: measuring a shape of a bump provided in a semiconductor package as specific information; generating an ID for identification for the semiconductor package based on the measured specific information and storing the thus generated ID for identification into a database; and acquiring again the ID for identification of the semiconductor package by re-measuring the shape of the bump as the specific information and comparing the re-measured specific information with data stored in the database.
A first semiconductor integrated circuit chip according to the present invention includes: a specific information reading region provided on an obverse face, a side face, or a reverse face for measuring a topographic characteristic of a constitutional element of the semiconductor integrated circuit chip as specific information for generating an ID for identification.
In the first semiconductor integrated circuit chip, it is possible that the constitutional element is a metal film, the topographic characteristic is an aspect of a grain boundary of the metal film, and at least a part of the metal film is exposed in the specific information reading region.
In the first semiconductor integrated circuit chip, it is possible that the constitutional element is a wire, the topographic characteristic is an edge outline of the wire, and at least a part of the wire is exposed in the specific information reading region.
In the first semiconductor integrated circuit chip, the specific information reading region may be provided in a region other than a region where a bonding pad to which a bonding wire is connected is formed.
In the first semiconductor integrated circuit chip, the metal film may be made of copper, aluminum, tungsten, or an alloy thereof.
A second semiconductor integrated circuit chip ID recognition method according to the present invention includes: a first step of measuring an aspect of grain boundaries of a metal film provided in a semiconductor integrated circuit chip as specific information; a second step of generating an ID for identification for the semiconductor integrated circuit chip based on the measured specific information and storing the generated ID for identification into a database; and a third step of acquiring again the ID for identification of the semiconductor integrated circuit chip by re-measuring the aspect of the grain boundaries as the specific information and comparing the re-measured specific information with data stored in the database.
In the second semiconductor integrated circuit chip ID recognition method, it is possible that the first step includes a step of extracting, after an image of the grain of the metal film is obtained, the aspect of the grain boundaries of the metal film by subjecting the image to image processing and the second step includes a step of extracting a point that connects the grain boundaries with each other, which are extracted in the first step, and storing a position of the extracted point as the ID for identification into the database.
A third semiconductor integrated circuit chip ID recognition method according to the present invention includes the steps of: measuring an edge outline of a wire provided in a semiconductor integrated circuit chip as specific information; generating an ID for identification for the semiconductor integrated circuit chip based on the measured specific information and storing the generated ID for identification into a database; and acquiring again the ID for identification of the semiconductor integrated circuit chip by re-measuring the edge outline as the specific information and comparing the re-measured specific information with data stored in the database.
A fourth semiconductor integrated circuit chip ID recognition method according to the present invention includes the steps of: measuring, as specific information, a profile of roughness or chapping generated in a side surface portion of a semiconductor integrated circuit chip in chip dicing; generating an ID for identification for the semiconductor integrated circuit chip based on the measured specific information and storing the generated ID for identification into a database; and acquiring again the ID for identification of the semiconductor integrated circuit chip by re-measuring the profile of the roughness or the chapping as the specific information and comparing the re-measured specific information with data stored in the database.
A second semiconductor integrated circuit chip according to the present invention includes: a specific information reading region on a reverse face thereof for measuring an aspect of the reverse face as specific information for generating an ID for identification, wherein a pattern serving as a starting point for measurement is provided within the specific information reading region.
A fifth semiconductor integrated circuit chip ID recognition method according to the present invention includes the steps of: measuring an aspect of a reverse face of a semiconductor integrated circuit chip as specific information; generating an ID for identification for the semiconductor integrated circuit chip based on the measured specific information and storing the generated ID for identification into a database; and acquiring again the ID for identification of the semiconductor integrated circuit chip by re-measuring the aspect of the reverse face as the specific information and comparing the re-measured specific information with data stored in the database.
According to the present invention, the topographic characteristic that a semiconductor package or a semiconductor chip (hereinafter they may be referred to as “chip or the like”) has is utilized as specific information of the chip or the like, acquiring physically random specific information. Accordingly, an unforgeable ID (hereinafter it may be referred to as “chip ID or the like”) for identification which exhibits a very strict information security function can be assigned to a chip or the like based on the specific information. Further, for satisfying a demand for speedy countermeasures for customers' benefits upon market failure of a semiconductor chip, a cause of the failure can be found in an early stage by re-extracting the chip ID or the like by measuring again the physically random specific information that the chip or the like has. In addition, a topographic characteristic serving as physically random specific information is utilized as the chip ID or the like, so that the chip ID or the like of a chip or the like electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the chip or the like. Thus, the effects of the present invention are significant.
As described above, when the present invention is utilized for identifying a semiconductor package or a semiconductor integrated circuit chip, an unforgeable ID for identification which exhibits a very strict information security function can be provided, offering useful effects.
A semiconductor package ID generating system according to Embodiment 1 of the present invention will be described below with reference to the drawings.
The most significant feature of the present embodiment lies in that a topographic characteristic that a semiconductor package has is set as the specific information, so that the specific information becomes distinctive and physically random.
A method for identifying a semiconductor package by the ID generating system of the present embodiment will be described below.
In the present embodiment, in a step S101 first, a topographic characteristic of a semiconductor package to be utilized as the physically random specific information is selected and a measurement point of the thus selected topographic characteristic (i.e., the specific information) is set, using the evaluation measurement section/evaluation information setting tool 101. The topographic characteristic of a semiconductor package herein means, for example, roughness that the surface of the package forms (in general, a plastic resin with which a silicon filler is mixed is used as a resin for packaging, forming roughness in the surface portion of a package), an angle of a lead wire (a bonding wire) connected to a semiconductor chip in a package, a contour of a bonding portion where a lead wire is connected to a bonding pad of a semiconductor chip, a shape of a bump (a bump connection part) used in lieu to a lead wire, and the like, and is not limited specifically only if it can be utilized as the physically random specific information.
Next, in a step S102, the topographic characteristic selected in the step S101, that is, the physically random specific information of the semiconductor package is measured and extracted using the measurement tool 102. For observing, for example, roughness that the surface of the package forms, a surface SEM (a surface scanning electron microscope), an AFM (an atomic force microscope), a microscope, and the like can be used as the measurement tool 102 in the present embodiment. Alternatively, for observing the angle of a lead wire, the contour of a bonding portion, and the shape of a bump, a measurement tool capable of radioscopic observation using the X-ray may be used.
Finally, in a step S103, the information (data) measured and extracted in the step S102 is processed for identification using the image processor (specific ID generating tool) 103, thereby generating a specific ID (package ID) for the target semiconductor package. Specifically, the image processor 103 performs image processing of the data (for example, an image of a photo or the like obtained through observation by a surface SEM) measured by the measurement tool 102 and relating to the physically random specific information to allow the thus processed data to be used as a package ID. In this way, the specific ID generation for the semiconductor package is performed.
In a case employing image processing for the specific ID generation for the semiconductor package, a significant effect of data compaction (contraction) can be attained. With this effect, even in a case with a huge number of semiconductor packages to be evaluated, specific IDs can be generated for the semiconductor packages efficiently.
Further, the package ID obtained as above is stored in, for example, a memory device of a computer together with manufacture information on the semiconductor package (a manufacturing factory, a manufacturing line, manufacturing date, a lot number, a wafer number, and a chip number).
As described above, in the present embodiment, a topographic characteristic that a semiconductor package has is utilized as the specific information, acquiring the physically random specific information. Accordingly, an unforgeable package ID exhibiting a high-level information security function can be assigned to a semiconductor package based on the specific information. For immediately providing countermeasures for customers' benefits upon market failure of a semiconductor package, the package ID is re-extracted by measuring again the physically random specific information that the semiconductor package has, enabling speedy failure cause finding. In addition, the package ID of the present embodiment is set based on a topographic characteristic, so that the package ID of a semiconductor package electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor package. Thus, the effects of the present invention are significant.
Needless to say, in the present embodiment, the physically random specific information measured and extracted by the measurement tool 102 may be used directly as the package ID. It is also needless to say that any method other than the image processing may be employed as the ID generation method of the specific information.
A semiconductor integrated circuit chip ID generating system according to Embodiment 2 of the present invention will be described below with reference to the drawings.
The most significant feature of the present embodiment lies in that a topographic characteristic that a semiconductor integrated circuit chip has is set as the specific information, so that the specific information becomes distinctive and physically random.
A method for generating an ID for a semiconductor integrated circuit chip by the ID generating system of the present embodiment will be described below.
In the present embodiment, in a step S201 first, a topographic characteristic of a semiconductor integrated circuit chip to be utilized as physically random specific information is selected and a measurement point of the thus selected topographic characteristic (i.e., the specific information) is set, using the evaluation measurement section/evaluation information setting tool 201. The topographic characteristic of a semiconductor integrated circuit chip herein means, for example, a grain boundary of the surface of a metal layer, an edge outline of a metal wire, a sectional shape of a divided semiconductor integrated circuit chip, surface roughness on the reverse side of a semiconductor integrated circuit chip, and the like and is not limited specifically only if it can be utilized as the physically random specific information.
Next, in a step S202, the topographic characteristic selected in the step S201, that is, the physically random specific information of the semiconductor integrated circuit chip is measured and extracted using the measurement tool 202. For observing a grain boundary of the surface of a metal layer or surface roughness on the reverse side of a semiconductor integrated circuit chip, a surface SEM or an AFM can be used as the measurement tool 202 in the present embodiment. Alternatively, for observing an edge outline of a metal wire or a sectional shape of a divided semiconductor integrated circuit chip, a surface SEM can be used, for example.
Finally, in a step S203, an ID is generated from the information (data) measured and extracted in the step S202 using the image processor (a specific ID generating tool) 203, thereby generating a specific ID (chip ID) for the target semiconductor integrated circuit chip. Specifically, the image processor 203 performs image processing of the data (for example, an image of a photo or the like obtained through observation by a surface SEM) measured by the measurement tool 102 and relating to the physically random specific information to allow the thus processed data to be used as a chip ID. In this way, the specific ID generation for the semiconductor integrated circuit chip is performed.
In a case employing image processing for the specific ID generation for the semiconductor integrated circuit chip, a significant effect of data compaction (contraction) can be attained. With this effect, even in a case with a huge number of semiconductor integrated circuit chips to be evaluated, specific ID chips can be generated for the semiconductor integrated circuit efficiently.
Further, the chip ID obtained as above is stored in, for example, a memory device of a computer together with manufacture information on the semiconductor integrated circuit chip (a manufacturing factory, a manufacturing line, manufacturing date, a lot number, a wafer number, and a chip number).
As described above, in the present embodiment, a topographic characteristic that a semiconductor integrated circuit chip has is utilized as the specific information, attaining the physically random specific information. Accordingly, an unforgeable chip ID exhibiting a high-level information security function can be assigned to a semiconductor integrated circuit chip based on the specific information. For immediately providing countermeasures for customers' benefits upon market failure of a semiconductor integrated circuit, the chip ID is re-extracted by measuring again the physically random specific information that the semiconductor integrated circuit chip has, enabling speedy failure cause finding. In addition, the chip ID of the present embodiment is set based on a topographic characteristic of a semiconductor integrated circuit chip, so that the chip ID of a semiconductor integrated circuit chip electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor integrated circuit chip. Thus, the effects of the present invention are significant.
Needless to say, in the present embodiment, the physically random specific information measured and extracted by the measurement tool 202 may be used directly as the chip ID. Also, it is needless to say that any method other than the image processing may be employed as the ID generation method from the specific information.
A semiconductor package ID recognition method and a semiconductor package ID recognizing system according to Embodiment 3 of the present invention will be described below with reference to the drawing.
In the present embodiment, in a step S301 first, a topographic characteristic of a semiconductor package to be utilized as physically random specific information is selected and a measurement point of the thus selected topographic characteristic (i.e., the specific information) is set. The topographic characteristic of a semiconductor package herein means, for example, roughness that the surface of a package forms (in general, a plastic resin with which a silicon filler is mixed is used as a resin for packaging, forming roughness in the surface portion of a package), an angle of a lead wire (a bonding wire) connected to a semiconductor chip in a package, a contour of a bonding portion where a lead wire is connected to a bonding pad of a semiconductor chip, a shape of a bump (a bump connection part) used in lieu to a lead wire, and the like, and is not limited specifically only if it can be utilized as the physically random specific information.
Next, in a step S302, the topographic characteristic selected in the step S301, that is, the physically random specific information of the semiconductor package is measured and extracted. Herein, for observing surface roughness that a package forms, a surface SEM, an AFM, a microscope, or the like can be used as a tool for measuring the physically random specific information. Alternatively, for observing a lead wire angle, a contour of a bonding portion, or a shape of a bump, a measurement tool capable of radioscopic observation using the X-ray may be used.
Subsequently, in a step S303, the information (data) measured and extracted in the step S302 is processed for identification using, for example, an image processor, thereby generating a specific ID (package ID) for the target semiconductor package. Specifically, the image processor performs image processing of the data measured by the aforementioned measurement tool and relating to the physically random specific information (for example, an image of a photo or the like obtained through observation by a surface SEM) to allow the thus processed data to be used as a package ID. In this way, the specific ID generation for the semiconductor package is performed.
In a case employing image processing for the specific ID generation for the semiconductor package, a significant effect of data compaction (contraction) can be attained. With this effect, even in the case of a huge number of semiconductor packages to be evaluated, specific ID can be generated for the semiconductor packages efficiently.
Further, the package ID obtained as above is stored in, for example, a memory device of a computer together with manufacture information on the semiconductor package (a manufacturing factory, a manufacturing line, manufacturing date, a lot number, a wafer number, and a chip number).
Thereafter, in a step S304, the semiconductor package for which the package ID is set is shipped to the market as a product to be used in general electric equipment.
In conventional semiconductor packages, the product number, the name of the manufacturing maker, and the like are imprinted usually in the surface portion of the package. No problem is involved when the product number, the name of the manufacturing maker, and the like are imprinted in the surface portion of the semiconductor package of the present embodiment in which the physically random specific information is set as the package ID. In this case, the use of the physically random specific information as the package ID in addition to such imprint is the feature of the semiconductor package. In the present embodiment, of course, only the physically random specific information may be used as the package ID without the imprint in the surface portion of the package. In detail, imprint of the product number, the manufacturing maker and the like in the surface portions of the conventional semiconductor packages is forged easily, resulting in being of no use for preventing semiconductor packages including semiconductor integrated circuit chips from being forged. In contrast, the package ID of the present invention, which utilizes the physically random specific information, prevents forging of the semiconductor package reliably.
Next, in the case where a semiconductor package shipped to the market as a product is judged as a market failure, the failed semiconductor package is recovered in a step S305 for investigating the manufacture history thereof.
Then in a step S306, the topographic characteristic selected in the step S301, that is, the physically random specific information of the recovered semiconductor package judged as a market failure is measured and extracted again. Then, the thus measured and extracted physically random specific information is compared with the package ID that has been stored in the database prior to the product shipment so that the package ID of the semiconductor package is acquired again. Thus, the package ID of the recovered semiconductor package judged as a market failure can be recognized again, so that easy investigation of the manufacture history and the like of the semiconductor package is enabled, resulting in speedy failure cause finding.
As described above, in the present embodiment, the topographic characteristic that the semiconductor package has is utilized as the specific information, so that the specific information becomes distinctive and physically random. In consequence, an unforgeable package ID exhibiting a high-level information security function can be assigned to a semiconductor package. Further, for immediately providing countermeasures for customers' benefits upon market failure of a semiconductor package, the package ID is re-extracted by measuring again the physically random specific information that the semiconductor package has, enabling speedy failure cause finding. In addition, the package ID of the present embodiment is set based on a topographic characteristic, so that the package ID of a semiconductor package electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor package. Thus, the effects of the present invention are significant.
Referring to an ID recognizing system for performing the semiconductor package ID recognition method according to the present embodiment may be composed by adding, to the semiconductor package ID generating system according to embodiment 1 shown in
Needless to say, in the present embodiment, the physically random specific information measured and extracted by the measurement tool may be used directly as the package ID. Also, it is needless to say that any method other than the image processing may be employed as the specific ID generation method.
A semiconductor integrated circuit chip ID recognition method and a semiconductor integrated circuit chip ID recognizing system according to Embodiment 4 of the present invention will be described below with reference to the drawing.
In the present embodiment, in a step S401 first, a topographic characteristic of a semiconductor integrated circuit chip to be utilized as physically random specific information is selected and a measurement point of the thus selected topographic characteristic (i.e., the specific information) is set. The topographic characteristic of a semiconductor integrated circuit chip herein means, for example, a grain boundary of the surface of a metal layer, an edge outline of a metal wire, a sectional shape of a divided semiconductor integrated circuit chip, surface roughness on the reverse side of a semiconductor integrated circuit chip, and the like and is not limited specifically only if it can be utilized as the physically random specific information.
Next, in a step S402, the topographic characteristic selected in the step S401, that is, the physically random specific information of the semiconductor integrated circuit chip is measured and extracted. For observing a grain boundary of the surface of a metal layer or surface roughness on the reverse side of a semiconductor integrated circuit chip, for example, a surface SEM or an AFM can be used as the measurement tool in the present embodiment. Alternatively, for observing an edge outline of a metal wire or a sectional shape of a divided semiconductor integrated circuit chip, a surface SEM can be used, for example.
Subsequently, in a step S403, the information (data) measured and extracted in the step S302 is processed for identification using, for example, an image processor, thereby generating a specific ID (chip ID) for the target semiconductor integrated circuit. Specifically, the image processor performs image processing of the data measured by the aforementioned measurement tool and relating to the physically random specific information (for example, an image of a photo or the like obtained through observation by a surface SEM) to allow the thus processed data to be used as a chip ID. In this way, the specific ID generation for the semiconductor integrated circuit chip is performed.
In a case employing image processing for the specific ID generation for the semiconductor integrated circuit chip, a significant effect of data compaction (contraction) can be attained. With this effect, even in a case with a huge number of semiconductor integrated circuit chips to be evaluated, specific ID can be generated for the semiconductor integrated circuit chips efficiently.
Further, the chip ID obtained as above is stored in, for example, a database provided in a memory device of a computer together with manufacture information on the semiconductor integrated circuit chip (a manufacturing factory, a manufacturing line, manufacturing date, a lot number, a wafer number, and a chip number).
Thereafter, in a step S404, the semiconductor integrated circuit chip for which the chip ID is set is shipped to the market as a product to be used in general electric equipment.
In conventional semiconductor integrated circuit chips, the numbers capable of discriminating chips, for example, the product number and the like are not set for each chip. Although a method of setting a barcode to a semiconductor integrated circuit chip has been employed conventionally (see Japanese Patent Application Laid Open Publication No. 5-13529A, for example), such an artificially set number is not useful at all for preventing a semiconductor integrated circuit chip from being forged. In contrast, the chip ID using the physically random specific information in the present embodiment can prevent reliably the semiconductor integrated circuit chip form being forged.
Next, in the case where a semiconductor integrated circuit chip shipped to the market as a product is judged as a market failure, the failed semiconductor package is recovered in a step S405 for investigating the manufacture history thereof.
Then in a step S406, the topographic characteristic selected in the step S401, that is, the physically random specific information of the recovered semiconductor integrated circuit chip judged as a market failure is measured and extracted again. Then, the thus measured and extracted physically random specific information is compared with the chip ID that has been stored in the database prior to the product shipment so that the chip ID of the semiconductor integrated circuit chip is acquired again. Thus, the chip ID of the recovered semiconductor integrated circuit chip judged as a market failure can be recognized again, so that easy investigation of the manufacture history and the like of the semiconductor integrated circuit chip is enabled, resulting in speedy failure cause finding.
As described above, in the present embodiment, the topographic characteristic that the semiconductor integrated circuit chip has is utilized as the specific information, so that the specific information becomes distinctive and physically random. In consequence, an unforgeable chip ID exhibiting a high-level information security function can be assigned to a semiconductor integrated circuit chip. Further, for immediately providing countermeasures for customers' benefits upon market failure of a semiconductor integrated circuit chip, the chip ID is re-extracted by measuring again the physically random specific information that the semiconductor integrated circuit chip has, enabling speedy failure cause finding. In addition, the chip ID of the present embodiment is set based on a topographic characteristic, so that the chip ID of a semiconductor integrated circuit chip electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor integrated circuit chip. Thus, the effects of the present invention are significant.
Referring to an ID recognizing system for performing the semiconductor integrated circuit chip ID recognition method according to the present embodiment may be composed by adding, to the semiconductor integrated circuit chip ID generating system according to embodiment 2 shown in
Needless to say, in the present embodiment, the physically random specific information measured and extracted by the measurement tool may be used directly as the chip ID. It is also needless to say that any method other than the image processing may be employed as the specific ID generation method.
A semiconductor package according to Embodiment 5 of the present invention will be described below with reference to the drawings.
As shown in
In the present embodiment, the surface roughness of the package is measured and evaluated by, for example, SEM observation using the starting point pattern 19 as, for example, an origin of the X-Y axes, so that specific information of the semiconductor packages different from one another can be acquired. Thus, an unforgeable package ID exhibiting a high-level information security function can be assigned to a semiconductor package based on the specific information. For immediately providing countermeasures for customers' benefits upon market failure of a semiconductor package, the package ID is re-extracted by measuring again the physically random specific information that the semiconductor package has, enabling speedy failure cause finding. In addition, the package ID of the present embodiment is set based on a topographic characteristic, so that the package ID of a semiconductor package electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor package. Thus, the effects of the present invention are significant.
A semiconductor package according to Embodiment 6 of the present invention will be described below with reference to the drawings.
A difference of the present embodiment from Embodiment 5 is that the surface of a package in the specific information reading region 18 is covered with a protection film 20.
According to the present embodiment, the following effects can be obtained in addition to the effects obtained in Embodiment 5. Namely, the protection film 20 prevents the surface of the package in the specific information reading region 18 from being contaminated by human touch after the semiconductor package appears on the market.
It is noted that the protection film 20 may be formed of plastic or the like in the present embodiment but a material other than plastic may be used as the material of the protection film 20 only if the surface of the package in the specific information reading region 18 is out of contact from outside through such a material.
A semiconductor package ID recognition method according to Embodiment 7 of the present invention will be descried below with reference to the drawings.
In the present embodiment, the surface roughness of the semiconductor package is evaluated by, for example, surface SEM analysis (analysis by a secondary electronic scanning electron microscope), thereby obtaining an image shown in
Further, in the present embodiment, the thus obtained image of the aspect of the surface roughness of the semiconductor package, which serves as the physically random specific information, is subjected to edge extraction by image processing to use the result as a package ID.
The reason why the edge extraction is performed to the image obtained by a surface SEM (hereinafter referred to as a surface SEM image) is as follows. Namely, in the case where the physically random specific information is utilized for setting IDs of individual semiconductor packages, the surface SEM image itself may be used as an ID. However, the direct use of the surface SEM image as an ID increases the amount of image data. In contrast, when the data obtained by employing a scheme of edge extraction from the surface SEM image is used as an ID, the data amount is contracted (compacted), attaining efficient storage and comparison of the package ID.
In the present embodiment, as described above, the data obtained by edge extraction, for example, the data shown in
First, in a step S701, specific information of individual semiconductor packages is measured and extracted for generating package IDs as described above, followed by storage of the obtained package IDs into a database provided in a memory device of a computer. In this time, manufacture information on the semiconductor packages (a manufacturing factory, a manufacturing line, manufacturing date, a lot number, a wafer number, and a chip number) or information on the semiconductor chips packaged in the semiconductor packages (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) is stored into the database together with the package IDs.
Thereafter, in a step S702, the semiconductor packages for which the package IDs are set are shipped as products as usual.
No problem is involved when the semiconductor package shipped as a product operates normally. While, when it is judged as a market failure, the failed semiconductor package is recovered in a step S703 to examine it to find a failure cause. Because, immediate failure cause fining and provision of countermeasures thereof are natural duties and responsibility which current companies considering customers first might have.
Specifically, the surface roughness of the package, which serves as the physically random specific information, in the specific information reading region 21 of the semiconductor package shown in
As described above, in the present embodiment, the surface roughness of the semiconductor package is utilized as the specific information, so that the specific information becomes distinctive and physically random. In consequence, an unforgeable package ID exhibiting a high-level information security function can be assigned to a semiconductor package based on the specific information. In other words, an unforgeable semiconductor package (a semiconductor package including a semiconductor integrated circuit chip) exhibiting a high-level information security function can be provided.
Further, for immediately providing countermeasures for customers' benefits upon market failure of a semiconductor package, the package ID is re-extracted by measuring again the surface roughness of the package as the physically random specific information, enabling speedy failure cause finding. In addition, the package ID of the present embodiment is set based on a topographic characteristic of a semiconductor package, so that the package ID of a semiconductor package electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor package.
Thus, the effects of the present invention are significant.
In the present embodiment, it is needless to say that the method for generating an ID from the surface roughness of the package is not limited to edge extraction by image processing.
A semiconductor package ID recognition method according to Embodiment 8 of the present invention will be described below with reference to the drawings.
The most significant feature of the present embodiment lies in that lead angles of lead wires (bonding wires) in a semiconductor package (directions that the bonding wires extend from bonding pads) are set as the physically random specific information.
As shown in
In the present embodiment, the lead angles of the bonding wires 33 are utilized as the physically random specific information and the package ID is set based on deviation of the specific information from a design value.
Specifically, as shown in
In the present embodiment, each lead angle of the bonding wires is measured by radioscopy first.
As described above, after the package IDs are set for individual semiconductor packages, the thus obtained package IDs are stored in a database provided in a memory device of a computer, likewise the case of Embodiment 7. In this time, manufacture information on the semiconductor packages (a manufacturing factory, a manufacturing line, manufacturing date, a lot number, a wafer number, and a chip number) or information on the semiconductor chips packaged in the semiconductor packages (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) is stored into the database together with the package IDs.
Thereafter, the semiconductor packages for which the package IDs are set are shipped as products as usual.
When a semiconductor package shipped as a product is judged as a market failure, the failed semiconductor package is recovered to examine it to find a failure cause. Specifically, the lead angles of the bonding wires in the failed semiconductor package, which serve as the physically random specific information, are measured (re-evaluation using radioscopy in the present embodiment) again. Subsequently, each measured and extracted lead angle of the bonding wires is converted into a numerical value, as shown in
As described above, in the present embodiment, each lead angle of bonding wires in a semiconductor package is utilized as the specific information, so that that the specific information becomes distinctive and physically random. In consequence, an unforgeable package ID exhibiting a high-level information security function can be assigned to a semiconductor package based on the specific information. In other words, an unforgeable semiconductor package (a semiconductor package including a semiconductor integrated circuit chip) exhibiting a high-level information security function can be provided. Further, for immediately providing countermeasures for customers' benefits upon market failure of a semiconductor package, the package ID is re-extracted by measuring again the lead angles of the bonding wires as the physically random specific information, enabling speedy failure cause finding. In addition, the package ID of the present embodiment is set based on a topographic characteristic of a semiconductor package, so that the package ID of a semiconductor package electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor package. Thus, the effects of the present invention are significant.
In the present embodiment, it is needless to say that the method for generating an ID from lead angles of bonding wires is not limited to the numerical value conversion as shown in
A semiconductor package ID recognition method according to Embodiment 9 of the present invention will be descried with reference to the drawings.
The most significant feature of the present embodiment lies in that the contour of a bonding portion (a portion for connecting a bonding wire and a bonding pad) in a semiconductor package is utilized as the physically random specific information.
In the present embodiment, first, the aspect of the bonding portions to serve as the specific information are shot by a microscope, a surface SEM, or the like and the thus shot image is subjected to image processing so that the edge contours 32a of the bonding portions 32 are extracted as shown in
After the package IDs are set for individual semiconductor packages as described above, the thus obtained package IDs are stored in a database provided in a memory device of a computer, likewise the case of Embodiment 7. In this time, manufacture information on the semiconductor packages (a manufacturing factory, a manufacturing line, manufacturing date, a lot number, a wafer number, and a chip number) or information on the semiconductor chips packaged in the semiconductor packages (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) is stored into the database together with the package IDs.
Thereafter, the semiconductor packages for which the package IDs are set are shipped as products as usual.
When a semiconductor package shipped as a product is judged as a market failure, the failed semiconductor package is recovered to examine it to find a failure cause. Specifically, each contour of the bonding portions in the failed semiconductor package, which serves as the physically random specific information, is measured again (re-evaluation using a microscope or a surface SEM in the present embodiment). Subsequently, each contour of the bonding portions thus measured and extracted is compared with the package ID that has been stored in the database prior to the product shipment to acquire again the package ID of the semiconductor package. Whereby, the information on the semiconductor chip packaged in the semiconductor package (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) can be acquired immediately based on the re-acquired package ID, enabling speedy failure cause fining. Further, the package ID is set using the physically random specific information, so that only the company that manufactured the semiconductor package can acquire again the various kinds of information on the semiconductor package including the package ID.
As described above, in the present embodiment, each contour of bonding portions in a semiconductor package is utilized as the specific information, so that the specific information becomes distinctive and physically random. In consequence, an unforgeable package ID exhibiting a high-level information security function can be assigned to a semiconductor package based on the specific information. In other words, an unforgeable semiconductor package (a semiconductor package including a semiconductor integrated circuit chip) exhibiting a high-level information security function can be provided. Further, for immediately providing countermeasures for customers' benefits upon market failure of a semiconductor package, the package ID is re-extracted by measuring again the contours of the bonding portions as the physically random specific information, enabling speedy failure cause finding. In addition, the package ID of the present embodiment is set based on a topographic characteristic of a semiconductor package, so that the package ID of a semiconductor package electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor package. Thus, the effects of the present invention are significant.
In the present embodiment, it is needless to say that the method for generating an ID from the contours of the bonding portions is not limited to edge extraction by image processing.
A semiconductor package ID recognition method according to Embodiment 10 of the present invention will be described below with reference to the drawings.
The most significant feature of the present embodiment lies in that the shape of a bump in a semiconductor package is utilized as the physically random specific information.
In the present embodiment, each shape of the bumps 43 (Au bumps 43a) of the C-CSP 40 formed as above is utilized as the physically random specific information. The reason why the shapes of the bumps 43 are utilized is that, as shown in
In the present embodiment, first, the shapes of the Au bumps 43A, which serve as the physically random specific information, are measured and evaluated by radioscopy. The radioscopy can project the side of a package with the X-ray, which means that each shape of the bumps can be measured even after completion of the C-CSP. In the present embodiment, data of the thus extracted bump shapes or data thereof subjected to image processing is utilized as a package ID.
After package IDs are set for individual semiconductor packages as described above, the thus obtained package IDs are stored in a database provided in a memory device of a computer, likewise the case of Embodiment 7. In this time, manufacture information on the semiconductor packages (a manufacturing factory, a manufacturing line, manufacturing date, a lot number, a wafer number, and a chip number) or information on the semiconductor chips packaged in the semiconductor packages (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) is stored into the database together with the package IDs.
When a semiconductor package shipped as a product is judged as a market failure, the failed semiconductor package is recovered to examine it to find a failure cause.
Specifically, the shapes of the bumps in the failed semiconductor package, which serve as the physically random specific information, are measured again (re-evaluation by radioscopy in this present embodiment). Subsequently, each bump shape thus measured and extracted is compared with the package ID that has been stored in the database prior to the product shipment to acquire again the package ID of the semiconductor package.
Whereby, the information on the semiconductor chip packaged in the semiconductor package (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) can be acquired immediately based on the re-acquired package ID, enabling speedy failure cause fining.
Further, the package ID is set using the physically random specific information, so that only the company that manufactured the semiconductor package can acquire again the various kinds of information on the semiconductor package including the package ID. As described above, in the present embodiment, the shapes of the bumps in the semiconductor package are utilized as the specific information, so that the specific information becomes distinctive and physically random. In consequence, an unforgeable package ID exhibiting a high-level information security function can be assigned to a semiconductor package based on the specific information. In other words, an unforgeable semiconductor package (a semiconductor package including a semiconductor integrated circuit chip) exhibiting a high-level information security function can be provided.
Further, for immediately providing countermeasures for customers' benefits upon market failure of a semiconductor package, the package ID is re-extracted by measuring again the shapes of the bumps as the physically random specific information, enabling speedy failure cause finding. In addition, the package ID of the present embodiment is set based on a topographic characteristic of a semiconductor package, so that the package ID of a semiconductor package electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor package. Thus, the effects of the present invention are significant.
A semiconductor integrated circuit chip (a semiconductor device) according to Embodiment 11 of the present invention will be described below with reference to the drawings. While the package ID assignment to a semiconductor package has been described in Embodiments 5 to 10, assignment of a chip ID to a semiconductor integrated circuit chip will be described in the present embodiment and the following embodiments. Specifically, a topographic characteristic that a semiconductor integrated circuit chip has is utilized as the physically random specific information.
In a semiconductor integrated circuit chip 50 shown in
In a semiconductor integrated circuit chip 50 shown in
In a semiconductor integrated circuit chip 50 shown in
The semiconductor integrated circuit chips (semiconductor devices) shown in
A semiconductor integrated circuit chip (a semiconductor device) according to Embodiment 12 of the present invention will be described below with reference to the drawings.
As shown in
The most significant feature of the present embodiment lies in that the opening portion for exposing at least a part of a metal film (for example, a Cu film, an Al film, and the like) 56 composing a wire on the substrate 50A is formed in the passivation film 52 so that a grain boundary of the surface of the metal film can be observed. Specifically, in the semiconductor integrated circuit chip of the present embodiment, a specific information reading region 51 for measuring the shape of the grain boundary of the metal film 56 as the specific information for generating a chip ID is provided on the surface of the chip. Wherein, neither a lead wire (bonding wire) nor a bump is connected to the metal film 56 exposed in the specific information reading region 51, that is, a pattern for grain boundary observation.
In this way, in the present embodiment, in order to measure the grain boundary of the metal film 56 as the physically random specific information of the semiconductor integrated circuit chip and assign the specific chip ID based on the measured result, the metal film 56 as a pattern for grain boundary observation is exposed in the specific information reading region 51, resulting in easy observation of the grain boundary.
It is noted that the material of the metal film 56 is not specified particularly and copper (Cu), aluminum (Al), tungsten (W), or an alloy containing at least two of them may be used.
In addition, in the present embodiment, if the specific information reading region 51 is provided in a region other than the region on the surface of the chip where the bonding pad 53 is formed, measurement of the grain boundary is further facilitated.
A semiconductor integrated circuit chip (a semiconductor device) according to Embodiment 13 of the present invention will be described below with reference to the drawings.
Similar to Embodiment 12, the surface of a substrate 50A serving as the semiconductor integrated circuit chip is covered with a passivation film 52 made of polyimide or the like, as shown in
The most significant feature of the present embodiment lies in that a wire 57 is formed for observation of the edge outline thereof after being etched and the opening portion for exposing at least a part of the wire 57 is formed in the passivation film 52 so that the edge outline of the wire 57 can be observed. Specifically, in the semiconductor integrated circuit chip of the present embodiment, a specific information reading region 51 for measuring the edge outline of the wire 57 as the specific information for generating a chip ID is provided on the surface of the chip.
In this way, in the present embodiment, in order to measure the edge outline of the wire 57 as the physically random specific information of the semiconductor integrated circuit chip and assign the specific chip ID based on the measured result, the wire 57 as a pattern for wire edge outline observation is exposed in the specific information reading region 51, resulting in easy observation of the edge outline.
It is noted that the material of the wire 57 is not specified particularly and Cu, Al, W, or an alloy containing at least two of them may be sued.
In addition, in the present embodiment, if the specific information reading region 51 is provided in a region other than the region on the surface of the chip where the bonding pad 53 is formed, measurement of the edge outline is further facilitated.
A semiconductor integrated circuit chip ID recognition method according to Embodiment 14 of the present invention will be described below with reference to the drawings.
Wherein, a semiconductor integrated circuit chip (a semiconductor device) used in the present embodiment is the same as the semiconductor integrated circuit chip (see
In the present embodiment, the metal film 56 exposed in the specific information reading region 51 in the semiconductor integrated circuit chip (see
In the semiconductor integrated circuit chip ID recognition method according to the present embodiment, the grain boundary of the metal film 56 provided in the semiconductor integrated circuit chip is measured as the physically random specific information, followed by assignment of a chip ID to the semiconductor integrated circuit chip based on the measured value.
Specifically, as described above, the surface SEM observation is performed first to obtain a surface SEM photo of the grain boundaries of the metal (Cu) film 56, which serve as the specific information of the semiconductor integrated circuit chip. Then, the grain boundaries 56a of the metal (Cu) film 56 are extracted, as shown in
After the chip IDs are set for individual semiconductor integrated circuit chips as described above, the thus obtained chip IDs are stored in a database provided in a memory device of a computer, likewise the case of Embodiment 7. In this time, information on the chips (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) is stored into the database together with the chip IDs.
Thereafter, the semiconductor integrated circuit chips for which the chip IDs are set are shipped as products as usual.
When a semiconductor integrated circuit chip shipped as a product is judged as a market failure, the failed semiconductor integrated circuit chip is recovered to examine it to find a failure cause. Specifically, the grain boundary of the metal film 56, which serves as the physically random specific information, is measured again (re-evaluation using a surface SEM in the present embodiment). Subsequently, the grain boundary thus measured and extracted is compared with the chip ID that has been stored in the database prior to the product shipment to acquire again the chip ID of the semiconductor integrated circuit chip. Whereby, the information on the semiconductor chip (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) can be acquired immediately based on the re-acquired chip ID, enabling speedy failure cause fining. Further, the chip ID is set using the physically random specific information, so that only the company that manufactured the semiconductor package can acquire again the various kinds of information on the semiconductor chip including the chip ID.
As described above, in the present embodiment, the grain boundary of the metal film in the semiconductor integrated circuit chip is utilized as the specific information, so that the specific information becomes distinctive and physically random. In consequence, an unforgeable chip ID exhibiting a high-level information security function can be assigned to a semiconductor integrated circuit chip based on the specific information. In other words, an unforgeable semiconductor integrated circuit chip exhibiting a high-level information security function can be provided. Further, for immediately providing countermeasures for customers' benefits upon market failure of a semiconductor integrated circuit chip, the chip ID is re-extracted by measuring again the grain boundary of the metal film as the physically random specific information, enabling speedy failure cause finding. In addition, the chip ID of the present embodiment is set based on a topographic characteristic of a semiconductor integrated circuit chip, so that the chip ID of a semiconductor integrated circuit chip electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor integrated circuit chip. Thus, the effects of the present invention are significant.
In the present embodiment, it is needless to say that the method for generating an ID from a grain boundary of a metal film is not limited to the method by image processing.
A semiconductor integrated circuit chip ID recognition method according to Embodiment 15 of the present invention will be described below with reference to the drawings.
Wherein, a semiconductor integrated circuit chip (a semiconductor device) used in the present embodiment is the same as the semiconductor integrated circuit chip (see
In short, in the present embodiment, the edge outline (rough outline of the edge portion) of the wire (metal wire) 57 is utilized as the physically random specific information and a chip ID is set based on the numerical value of the edge outline.
In the semiconductor integrated circuit chip in Embodiment 13, which is used also in the present embodiment, the wire 57 for observation of the edge outline thereof after being etched is formed and the opening portion through which at least a part of the wire 57 is exposed is formed in the passivation film 52 in a wire formation process so that the edge outline of the wire 57 can be observed. In short, a specific information reading region 51 for measuring the edge outline of the wire 57 as specific information for generating a chip ID is provided on the surface of the chip.
In the present embodiment, the wire 57 exposed in the specific information reading region 51 of the semiconductor integrated circuit chip (see
After the chip IDs are set for individual semiconductor integrated circuit chips as described above, the thus obtained chip IDs are stored in a database provided in a memory device of a computer, likewise the case of Embodiment 7. In this time, information on the chips (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) is stored into the database together with the chip IDs.
Thereafter, the semiconductor integrated circuit chips for which the chip IDs are set are shipped as products as usual.
When a semiconductor integrated circuit chip shipped as a product is judged as a market failure, the failed semiconductor integrated circuit chip is recovered to examine it to find a failure cause. Specifically, the edge outline of the wire 57, which serves as the physically random specific information, is measured again (re-evaluation using a surface SEM in the present embodiment). Subsequently, the edge outline thus measured and extracted is compared with the chip ID that has been stored in the database prior to the product shipment to acquire again the chip ID of the semiconductor integrated circuit chip. Whereby, the information on the semiconductor chip (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) can be acquired immediately based on the re-acquired chip ID, enabling speedy failure cause fining. Further, the chip ID is set using the physically random specific information, so that only the company that manufactured the semiconductor chip can acquire again the various kinds of information on the semiconductor chip including the chip ID.
As described above, in the present embodiment, the edge outline of a wire in a semiconductor integrated circuit chip is utilized as the specific information, so that the specific information becomes distinctive and physically random. In consequence, an unforgeable chip ID exhibiting a high-level information security function can be assigned to a semiconductor integrated circuit chip based on the specific information. In other words, an unforgeable semiconductor integrated circuit chip exhibiting a high-level information security function can be provided. Further, for immediately providing countermeasures for customers' benefits upon market failure of a semiconductor integrated circuit chip, the chip ID is re-extracted by measuring again the edge outline of the wire as the physically random specific information, enabling speedy failure cause finding. In addition, the chip ID of the present embodiment is set based on a topographic characteristic of a semiconductor integrated circuit chip, so that the chip ID of a semiconductor integrated circuit chip electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor integrated circuit chip. Thus, the effects of the present invention are significant.
In the present embodiment, it is needless to say that the method for extracting an edge outline of a wire is not limited to the method by image processing.
A semiconductor integrated circuit chip ID recognition method according to Embodiment 16 of the present invention will be described below with reference to the drawings.
As shown in
The most significant feature of the present embodiment lies in that, as shown in
In the present embodiment, a SEM image obtained by observing the chip side face by a surface SEM is subjected to image processing to extract the edge profile of the roughness and the like of the chip side face and the thus extracted edge profile is used as a chip ID.
After the chip IDs are set for individual semiconductor integrated circuit chips as described above, the thus obtained chip IDs are stored in a database provided in a memory device of a computer, likewise the case of Embodiment 7. In this time, information on the chips (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) is stored into the database together with the chip IDs.
Thereafter, the semiconductor integrated circuit chips for which the chip IDs are set are shipped as products as usual.
When a semiconductor integrated circuit chip shipped as a product is judged as a market failure, the failed semiconductor integrated circuit chip is recovered to examine it to find a failure cause. Specifically, the edge profile of the roughness and the like of the chip side face, which serves as the physically random specific information, is measured again (re-evaluation using a surface SEM in the present embodiment). Subsequently, the edge profile thus measured and extracted is compared with the chip ID that has been stored in the database prior to the product shipment to acquire again the chip ID of the semiconductor integrated circuit chip. Whereby, information on the chip (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) can be acquired immediately based on the re-acquired chip ID, enabling speedy failure cause fining. Further, the chip ID is set using the physically random specific information, so that only the company that manufactured the chip can acquire again the various kinds of information on the semiconductor chip including the chip ID.
As described above, in the present embodiment, the edge profile of the roughness and the like of the side face of a semiconductor integrated circuit chip which is generated in chip dicing is utilized as the specific information, so that the specific information becomes distinctive and physically random. In consequence, an unforgeable chip ID exhibiting a high-level information security function can be assigned to a semiconductor integrated circuit chip based on the specific information. In other words, an unforgeable semiconductor integrated circuit chip exhibiting a high-level information security function can be provided. Further, for immediately providing countermeasures for customers' benefits upon market failure of a semiconductor integrated circuit chip, the chip ID is re-extracted by measuring again the edge profile of the roughness and the like of the chip side face as the physically random specific information, enabling speedy failure cause finding. In addition, the chip ID of the present embodiment is set based on a topographic characteristic of a semiconductor integrated circuit chip, so that the chip ID of a semiconductor integrated circuit chip electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor integrated circuit chip. Thus, the effects of the present invention are significant.
In the present embodiment, it is needless to say that the method for extracting an edge profile of the roughness and the like of a chip side face is not limited to the method by image processing. Further, any topographic characteristic other than the edge profile of the roughness and the like may be utilized as the physically random specific information, of course.
A semiconductor integrated circuit chip (a semiconductor device) according to Embodiment 17 will be described below with reference to the drawings.
As shown in
According to the semiconductor integrated circuit chip of the present embodiment, a semiconductor integrated circuit chip ID recognition method according to Embodiment 18, which is described next, can be reduced into practice.
A semiconductor integrated circuit chip ID recognition method according to Embodiment 18 of the present invention will be described below with reference to the drawings.
Back grinding to the reverse face of the semiconductor integrated circuit chip 42, which is performed before packaging the chip 42, generates flaws 49 all over the reverse face of the chip 42.
In the present embodiment, the flaws 49 out of the profiles of the reverse face of the semiconductor integrated circuit chip 42 is utilized particularly as the physically random specific information and a chip ID is set based on a measured value of an aspect of the flaws 49. Wherein, the flaws 49 can be detected easily by a microscope, a surface SEM or the like.
In the present embodiment, after the flaws 49 by back grinding the reverse face of the chip are observed by a microscope or a surface SEM, an image obtained by the observation is subjected to image processing to extract the aspect of the flaws 49 as shown in
After the chip IDs are set for individual semiconductor integrated circuit chips as described above, the thus obtained chip IDs are stored in a database provided in a memory device of a computer, likewise the case of Embodiment 7. In this time, information on the chips (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) is stored into the database together with the chip IDs.
Thereafter, the semiconductor integrated circuit chips for which the chip IDs are set are shipped as products as usual.
When a semiconductor integrated circuit chip shipped as a product is judged as a market failure, the failed semiconductor integrated circuit chip is recovered to examine it to find a failure cause. Specifically, the aspect of the flaws (flaws generated in back grinding) in the reverse face of the chip, which serves as the physically random specific information, is measured again (re-evaluation using a surface SEM in the present embodiment). Subsequently, the aspect of the flaws thus measured and extracted is compared with the chip ID that has been stored in the database prior to the product shipment to acquire again the chip ID of the semiconductor integrated circuit chip. Whereby, information on the chip (time when the diffusion process is performed for the semiconductor chip, a lot number, a wafer number, a chip address in the wafer, and the like) can be acquired immediately based on the re-acquired chip ID, enabling speedy failure cause fining. Further, the chip ID is set using the physically random specific information, so that only the company that manufactured the chip can acquire again the various kinds of information on the chip including the chip ID.
As described above, in the present embodiment, an aspect of flaws generated in back grinding of the reverse face of a semiconductor integrated circuit chip is utilized as the specific information, so that the specific information becomes distinctive and physically random. In consequence, an unforgeable chip ID exhibiting a high-level information security function can be assigned to a semiconductor integrated circuit chip based on the specific information. In other words, an unforgeable semiconductor integrated circuit chip exhibiting a high-level information security function can be provided. Further, for immediately providing countermeasures for customers' benefits upon market failure of a semiconductor integrated circuit chip, the chip ID is re-extracted by measuring again the aspect of the flaws on the reverse face of the chip as the physically random specific information, enabling speedy failure cause finding. In addition, the chip ID of the present embodiment is set based on a topographic characteristic of a semiconductor integrated circuit chip, so that the chip ID of a semiconductor integrated circuit chip electrically inoperable due to market failure can be re-extracted independently from the electric circuit operation of the semiconductor integrated circuit chip. Thus, the effects of the present invention are significant.
In the present embodiment, it is needless to say that the method for extracting an aspect of flaws on the reverse face of a chip is not limited to the method by image processing. Further, any topographic characteristic other than the aspect of the flaws generated in back grinding may be utilized as the physically random specific information, of course.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-001864 | Jan 2005 | JP | national |
