1. Field of the Invention
The present invention relates to a semiconductor substrate, a manufacturing method of a semiconductor device and a testing method of a semiconductor device and, more particularly to a technique to forming a plurality of semiconductor elements (semiconductor chips) on a semiconductor substrate (wafer) in a lump and a testing method of the thus-formed semiconductor device.
2. Description of the Related Art
In order to raise a manufacture efficiency of semiconductor devices, it is a common practice to form a plurality of semiconductor elements (semiconductor chips) on one semiconductor substrate (wafer) in one lump. After, a plurality of semiconductor elements formed on the semiconductor substrate in one lump are subjected to an electric tests, etc., as they are on the semiconductor substrate, and, thereafter, the semiconductor elements are separated into individual elements (individual chip) and are subjected to a packaging process if necessary. Formation of semiconductor elements on the semiconductor substrate includes a preliminary process including a so-called photo-lithography process.
In the photo-lithography process, a reticle (a negative plate for printing) having a pattern for forming a predetermined semiconductor element area or for forming electrodes and wiring is prepared beforehand, and an exposure process is applied to a photosensitive resin layer (photoresist layer) which is formed on a film formed on a main surface of the semiconductor substrate. After performing a developing process on the photosensitive resin layer, the film and the like are selectively removed by etching using the remaining photosensitive resin layer, which results in a pattern of the film formed on the semiconductor substrate.
In recent years, the size of a semiconductor substrate has been increased (8-inch diameter to 100-inch diameter), and it is difficult to cover an entire main surface of a semiconductor substrate by one sheet of reticle. Accordingly, one semiconductor substrate is divided into a plurality of areas so as to perform an exposure process using the reticle on an individual area basis. That is, exposure and printing is performed sequentially on the areas one by one while relatively moving the semiconductor substrate and the reticle to each other. It should be noted that a plurality of patterns, each of which corresponds to one semiconductor element, are formed in one reticle.
The semiconductor elements formed on the semiconductor substrate are individualized by the semiconductor substrate being cut by a dicing blade. Therefore, areas which are cut and removed by the dicing blade, that is, dicing areas are provided between the patterns corresponding to the semiconductor elements that are formed by exposure and printing using the reticle.
Usually, a width of the dicing area is set substantially equal to a width of the dicing blade so that the entire dicing area between adjacent semiconductor elements is cut off and removed by one time of the dicing process. An example of the printing pattern formed on the semiconductor substrate according to the conventional processing method is shown in
As mentioned above, the exposure and printing according to the reticle is performed on a plurality of areas sequentially one by one. Here, 1 time of the exposure printing area by the reticle is called a reticle area. The dicing area shaved off by a dicing blade is referred to a scribe line or a dicing line. In the example shown in
On the other hand, in order to also make a width W2 of the area between the reticle area 2-1 and the adjacent reticle area 2-2 substantially equal to the width W1 of the scribe line W1, a width of the dicing area of an outer peripheral portion of each reticle area is set equal to about ½ (half) of the scribe line in the reticle area. That is, the positions of the reticle areas 2-1 to 2-4 on the semiconductor substrate are adjusted so that the width W2 as a result of connection of the dicing areas on the outer peripheries of adjacent reticle areas is substantially equal to the width of the dicing blade so as to be equal to the width W1 of the scribe line.
The setting of the width of the scribe line is applied not only to the transverse direction W of the pattern 4 corresponding to the semiconductor elements but also to a width L in a longitudinal direction so that all widths of the scribe lines are equal to each other. Conventionally, the intervals (widths W1 and W2, widths L1 and L2) between the patterns 4 corresponding to the semiconductor elements formed on the semiconductor substrate are set equal to a width of a dicing blade so as to attempt to improve an efficiency of dicing.
Moreover, when testing many semiconductor elements formed on a semiconductor substrate before individualizing, an electric connection is made simultaneously to the plurality of semiconductor elements (for example, two elements in the example of
In the example of
It should be noted that such marks are usually provided on scribe lines and are removed when dicing along the scribe lines since the marks are necessary for a manufacturing process but not necessary for completed semiconductor elements. That is, the scribe lines also serve as areas for providing alignment marks and the like. For this reason, the width of the scribe line must be larger than an alignment mark. However, if all scribe lines have a width sufficient to provide alignment marks thereon, the width of the scribe lines are increased, which causes an increase in an area occupied by the scribe lines with respect to the area of the semiconductor substrate and a decrease in the number of semiconductor substrates that can be formed on one sheet of a semiconductor substrate.
Thus, there is suggested in Japanese Laid-Open Patent Application No. 2000-124185 to arrange alternately a narrow scribe line and to arrange alignment marks only on the wide scribe lines so as to increase the number of semiconductor elements that can be formed on one sheet of the semiconductor substrate. Moreover, Japanese Laid-Open Patent No. 63-250119 suggests that a width of scribe lines extending in a longitudinal direction is different from a width of scribe lines extending in a transverse direction as one in which scribe lines having different widths are formed on one semiconductor substrate.
As mentioned above, according to the arrangement of semiconductor devices in which a width of scribe lines between the semiconductor elements is uniform and the dicing area of the outer periphery of the reticle area is equal to ½ of the scribe line, a scribe area having the same width is formed in all areas between the semiconductor elements formed on the semiconductor substrate. Thus, all scribe lines can be cut by a dicing blade of the same width with the width of the scribe lines, which achieves efficient dicing process.
However, a number of semiconductor elements arranged in one reticle area is not always optimum. In order to set the width of the scribe lines constant, there is a restriction arose in the arrangement of the semiconductor elements in the reticle area, which results in that the number of the semiconductor elements which can be provided in one reticle area cannot be increased further.
In recent years, thickness of semiconductor substrates is tend to be reduced so as to achieve a further miniaturization and integration of semiconductor devices, and, thus, such a semiconductor substrate having a reduced thickness can be cut using a dicing blade having a small thickness (or width). However, as mentioned above, the arrangement of semiconductor elements in which widths of scribe lines are equal to each other in the semiconductor substrate, and, as a result, there are many cases in which a dicing blade having a width larger than a minimum width necessary for cutting the semiconductor substrate having a reduced thickness.
If the dicing blade having the necessary minimum thickness (width) is used, the width and area of the dicing area in a semiconductor substrate can be reduced further and it can become possible to increase the area for forming semiconductor elements, which results in an increase in the number of semiconductor elements formed on one semiconductor substrate. However, as mentioned-above, there is a case in which a dicing blade having a necessary minimum thickness (width) cannot be effectively applied in the arrangement of semiconductor elements in which widths of the scribe lines are equal to each other so as to achieve further efficient dicing, and, thus, there is a problem in which the number of semiconductor elements formed on one semiconductor substrate cannot be increased further.
It is a general object of the present invention to provide an improved and useful semiconductor substrate, an improved and useful manufacturing method and testing method of a semiconductor device in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide a semiconductor substrate and a manufacturing method and testing method of a semiconductor device which eliminates a restriction caused by a width of scribe lines so as to increase a number of semiconductor elements formed on the semiconductor substrate.
In order to achieve the above-mentioned objects, there is provided according to one aspect of the present invention a semiconductor substrate on which a plurality of semiconductor element areas are formed by forming a plurality of unit exposed and printed areas, each of which contains the semiconductor element areas, the semiconductor substrate comprising: a first scribe line extending between the semiconductor element areas formed within the unit exposed and printed area; and a second scribe line extending between the unit exposed and printed areas, wherein a width of the first scribe line is different from a width of the second scribe line.
In the semiconductor substrate according to the present invention, it is preferable that the width of the first scribe line is a minimum width by which the semiconductor substrate can be cut. Additionally, it is preferable that the width of the first scribe line is smaller than the width of the second scribe line. Further it is preferable that the width of the first scribe line is determined based on a thickness of the semiconductor substrate.
In the semiconductor substrate according to the present invention, a plurality of scribe lines may include the first scribe line extend within the each of the unit exposed and printed areas, and widths of the scribe lines may be different from each other. An alignment mark may be arranged on the second scribe line.
Additionally, there is provided according another aspect of the present invention a manufacturing method of a semiconductor device, comprising: a first exposing and printing step of forming a first exposed and printed area on a semiconductor substrate using a reticle having a pattern corresponding to a plurality of semiconductor elements that are separated by a first scribe line; a second exposing and printing step of forming a second exposed and printed area on the semiconductor substrate so that a second scribe line extends between the first exposed and printed area and the second exposed and printed area, which has a width larger than a width of the first scribe line; and a step of individualizing the semiconductor elements by cutting and separating the semiconductor substrate along the first scribe line and the second scribe line. The above-mentioned manufacturing method may further comprise setting the width of the first scribe line to a minimum width by which the semiconductor substrate can be cut.
Additionally, there is provided according to another aspect of the present invention a testing method of a semiconductor device in which a plurality of semiconductor element areas are formed on a semiconductor substrate by forming a plurality of unit exposed and printed areas including a first unit exposed and printed area and a second unit exposed and printed area each of which contains the semiconductor element areas, the testing method comprising: simultaneously testing the semiconductor elements located at corresponding positions in the first unit exposed and printed area and the second unit exposed and printed area. The above-mentioned testing method may further comprise correcting a position at which an electric contact is made to the semiconductor element area within the second exposed and printed area in accordance with a positional error between the first exposed and printed area and the second exposed and printed area.
As mentioned above, according to the present invention, the semiconductor substrate can be cut along the first scribe line between adjacent semiconductor element areas formed in one reticle area (the unit exposed and printed area) using a dicing blade having a necessary minimum thickness (width). Therefore, an area of the semiconductor substrate necessary for dicing (removed by cutting) is reduced, thereby increasing an area for forming semiconductor elements in one sheet of semiconductor substrate is increased. That is, a number of semiconductor elements formed in one reticle area is increased, which results in an increase in the number of semiconductor elements formed in one sheet of semiconductor substrate.
Moreover, according to the testing method of a semiconductor device according to the present invention, since a plurality of semiconductor elements located at corresponding positions in different exposed and printed areas can be tested simultaneously, the plurality of semiconductor elements can be electrically contacted and tested simultaneously even if widths of the scribe lines are different from each other.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.
A description will now be given, with reference to the drawings, of embodiments of the present invention. First, a description will be given, with reference to
In the present invention, a number of the semiconductor elements 12 formed in one reticle area 14 is set to be maximum by selecting suitably, as mentioned later, without making all widths of scribe lines equal to each other. The reticle areas 14 are located in a lattice-like arrangement so as to cover an entire main surface of the semiconductor substrate 14 of a circular shape (normally has an orientation flat 10A). It should be noted that although it is unnecessary or inappropriate to form the semiconductor element 12 in an edge area and areas out of the semiconductor substrate 10 in
An area of the part A containing a plurality of reticle areas 14 in
As mentioned above, recently, a thickness of semiconductor substrates tends to decrease, and a width of a dicing blade by which a semiconductor substrate can be cut has decreased in recent years. For example, if a width of a dicing blade which can cut a semiconductor substrate of a conventional thickness is 120 micrometers, a width of a dicing blade which can cut a semiconductor substrate with a reduced thickness has decreased to even 40 μm-60 μm. Therefore, if a dicing blade of a necessary minimum thickness (width) is used, the area of the semiconductor shaved off by cutting is decreased, thereby correspondingly increasing an area in which semiconductor elements are formed. Thus, a number of semiconductor elements that can form in one reticle area is increased, which results in an increase in the number of semiconductor elements formed in one semiconductor substrate. That is, in the present embodiment, a scribe line width corresponding to the thickness (width) of the dicing blade, which is a minimum size by which a semiconductor substrate can be cut, is set to an area between the plurality of semiconductor elements formed in one reticle area.
Then, the exposure and printing is sequentially applied to the semiconductor substrate using the reticle. In the reticle area, a plurality of semiconductor elements (corresponding printed patterns) are gathered into the center portion thereof, and remaining areas on an outer periphery thereof are scribe line areas of the reticle area concerned. That is, in the present embodiment, a plurality of semiconductor elements are separated and arranged in each reticle area with a necessary minimum interval, which is a minimum scribe line width which can cut the semiconductor substrate, and the remaining area in the peripheral portion of the exposed and printed area is set as scribe lines. At this time, the width of the remaining area in the peripheral portion of each reticle area is a value larger than ½ of the scribe line by which the semiconductor substrate can be cut.
By setting the width of the remaining area in the outer periphery of the reticle area to be larger than ½ of the minimum scribe line width by which the semiconductor substrate can be cut, a width of a scribe line (the scribe line 20 in
As mentioned above, in the semiconductor substrate according to the present embodiment, a plurality of semiconductor elements are formed in each of a plurality of reticle areas, and a width of a second scribe line extending between adjacent exposed and printed areas is different from a width of a first scribe line extending between adjacent semiconductor elements in each exposed and printed area. The width of the first scribe line is determined based on the thickness of the semiconductor substrate, and preferably be a minimum width by which the semiconductor substrate can be cut.
Moreover, according to the manufacturing method of the semiconductor device according to the present embodiment, a pattern corresponding to a plurality of semiconductor devices is exposed and printed on a semiconductor substrate so as to form first exposed and printed areas by using one sheet of reticle having the pattern corresponding to the plurality of semiconductor elements separated by first scribe lines, which have a width equal to a minimum width by which the semiconductor substrate can be cut, and, then, the reticle is moved, and a second exposed and printed area is formed adjacent to the first exposed and printed area so that the width of a second scribe line extending on a boundary is larger than the width of the first scribe line. Then, exposure and printing is repeated while moving the reticle so as to form the semiconductor elements over a substantially entire surface of the semiconductor substrate. Thereafter, the semiconductor elements are individualized by dicing (separating by cutting) the semiconductor substrate along the first scribe lines and the second scribe lines. That is, the semiconductor substrate is cut using the dicing blade having a minimum width by which the semiconductor substrate can be cut along the first scribe lines so as to individualize the semiconductor elements.
In the present embodiment, although a thin dicing blade is used for cutting the semiconductor substrate, cutting by a laser light may be used instead of the dicing blade cutting since the semiconductor substrate is thinned. In such a case using a laser light, the width of dicing can be reduced to 20 μm-30 μm. Thus, the number of semiconductor elements formed in one reticle area is increased, which results in a further increase in the number of semiconductor elements formed on one sheet of semiconductor substrate.
A description will now be given of a testing method when performing an electrical test on the semiconductor substrate on which semiconductor elements are formed in the above-mentioned embodiments as a state of the semiconductor substrate.
Conventionally, a plurality of semiconductor elements formed on one sheet of the semiconductor substrate are arranged at equal intervals, and for example, as shown in
Even if the semiconductor elements are present over two (or more) reticle areas when scribe line widths equal to each other in one sheet of semiconductor substrate, the relative positional relationship between the two adjacent semiconductor elements is constant, and, thus, there is no need to change positions at which the electric contact is made. However, in the present invention, if the width of the scribe lines provided around one reticle area differs from the width of the scribe lines between the semiconductor elements as is in the above-mentioned embodiment, the relative positional relationship (distance) between the semiconductor elements differs from a distance between the semiconductor elements in the reticle area.
Thus, although a plurality of semiconductor elements in one reticle area can be tested simultaneously, a test cannot be applied simultaneously to a plurality of semiconductor elements located over adjacent reticle areas, that is, a first semiconductor element positioned at an end of a first reticle area and a second semiconductor element located at an end of a second reticle area adjacent to the first reticle area and facing the first semiconductor element.
Thus, in the present invention, as shown in
Since one sheet of the reticle is moved sequentially so as to form the reticle areas 14, the relative positional relationship between the semiconductor elements within the reticle area 14 is the same between the reticle areas 14. Therefore, if a contactor, which makes the electric contact to the two semiconductor elements indicated by T1, is moved in a transverse direction in the testing method shown in
Although the testing method for two semiconductor elements 12 in the two reticle areas 14 is show in
In the arrangement shown in
A test is applied sequentially to corresponding four semiconductor elements 12 simultaneously, and after the test is completed for the semiconductor elements 12 of one row, an electric contact is shifted to a next row and performs a test simultaneously to corresponding four semiconductor elements in the same manner as applied to the semiconductor elements 12 in the upper row. Then, after completing the test on all the semiconductor elements 12 in the area 141, a test is applied to the semiconductor elements in the four reticle areas of a next area 142 in the same manner as is applied to the semiconductor elements 12 in the area 141.
As mentioned above, in the testing method according to the present invention, even if scribe lines having different widths exist in one semiconductor substrate, a test can be simultaneously applied to a plurality of semiconductor elements located at the same position in each of exposed and printed areas over the plurality of exposed and printed areas.
The above-mentioned testing method is applicable to a case where scribe lines of different widths exist in one reticle area as shown in
In
For example, in a so-called test element group (TEG), there is a case where patterns corresponding to different semiconductor elements (different in size, different in function) are formed in one reticle. Additionally, there is a case in which the same kind of semiconductor elements are gathered into a part and a width of a scribe line is increased between groups of different kinds of semiconductor elements. In addition, it is possible to provide scribe lines of different widths in one reticle area in other cases. According to the above-mentioned testing method, since the semiconductor elements arranged at the same position in each reticle area are the same kind of semiconductor element among the semiconductor elements arranged in a reticle unit, a plurality of semiconductor elements can be tested simultaneously over a plurality of reticle areas. In the above-mentioned testing method, an electric contact is made simultaneously to the semiconductor elements located at corresponding positions in a first reticle area and a second reticle area (other reticle areas) so as to perform a test simultaneously on the semiconductor elements.
A so-called prober is used in order to make an electric contact. When simultaneously making a contact with corresponding semiconductor elements in a plurality of reticle areas, probes (contact needles) of a prober are arranged in accordance with a plurality of semiconductor elements to be tested simultaneously in consideration of a size of the reticle area so that the probes can be moved all together to positions corresponding to semiconductor elements to be tested subsequently.
The above-mentioned testing method is on the assumption that the reticle can be moved with high accuracy so that a plurality of exposed and printed areas according the reticle. However, assuming that an accuracy of movement of the reticle is deteriorated for some reasons and the accuracy in positioning of the exposed and printed areas is deteriorated, it is needed to correct the positions of the probes. That is, although the positional relationship between the semiconductor elements formed in each reticle area is not changed, the positional relationship between the semiconductor elements in different reticle areas that are tested simultaneously may be changed. Thus, a change in the relative positions of the reticle areas containing the semiconductor elements tested simultaneously is equal to a change in the relative positions of corresponding semiconductor elements. Then, it is preferable to monitor or detect the positional accuracy between the reticle areas so as to correct positions of the probes when the positional accuracy between the reticle areas is deteriorated.
The correction of the positions of the probes can be achieved by correcting, with respect to probes corresponding to a semiconductor element formed in a first reticle area as a reference, positions of the semiconductor elements formed in a second reticle area in accordance with an offset of position of the reticle concerned.
The prober shown in
The XYθ-moving mechanism 60 is capable of minutely moving the movable axis 62 in the X-direction and the Y-direction that are parallel to a main surface of the semiconductor substrate, and also minutely rotatable in the O-direction within the X-Y plane. In order to drive the movable axis 62 as shown in
The micro-actuator 64-1 causes the probe card 52-2 to minutely move in the X-direction by minutely moving the drive axis 62 in the X-direction. The micro-actuator 64-2 causes the probe card 52-2 to minutely move in the Y-direction by minutely moving the drive axis 62 in the Y-direction. The micro-actuators 64-3 and 64-4 causes the probe card 52-2 to rotate in the θ-direction by rotating the drive axis 62 in the θ-direction by pressing a protruding pin 62a protruding in a radial direction from the drive axis 62.
According to the prober shown in
It should be noted that although not shown in
As mentioned above, according to the present embodiment, an electric contact is made simultaneously to a plurality of semiconductor elements at corresponding positions in each of a plurality of exposed and printed areas so as to simultaneously test the semiconductor elements to which the electric contact has been made. Moreover, when an electric contact is made simultaneously to the plurality of semiconductor elements, the position to make the contact is corrected with respect to at least one of the semiconductor elements in accordance with a positional error between the exposed and printed areas.
As mentioned above, in the semiconductor substrate formed by the manufacturing method of a semiconductor substrate according to the present invention, an interval between adjacent semiconductor elements in one reticle area (exposed and printed area) is selectively set to a minimum width (width of a first scribe line) by which the semiconductor substrate can be cut, and a width of a second scribe line formed between adjacent reticle areas is set larger than the width of the first scribe line. Therefore, a number of semiconductor elements formed on the semiconductor substrate can be increased as compared with the conventional method.
Additionally, according to the testing method of the semiconductor device according to the present invention, semiconductor elements located at corresponding positions are tested simultaneously in a plurality of reticle areas arranged with a wider scribe line therebetween. That is, even if the scribe lines have different widths on the semiconductor substrate, a contact is made simultaneously to a plurality of semiconductor elements located at corresponding positions in a plurality of reticle areas and a test is performed simultaneously to the plurality of semiconductor elements.
The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention.
The present application is based on
Japanese priority application No. 2004-328061 filed Nov. 11, 2004, the entire contents of which are hereby incorporated herein by reference.
Number | Date | Country | Kind |
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2004-328061 | Nov 2004 | JP | national |