This application is based on and claims priority to Korean Patent Application 10-2023-0037184, filed Mar. 22, 2023, and Korean Patent Application No. 10-2022-0147239, filed on Nov. 7, 2022, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entireties.
Example embodiments of the disclosure relate to a substrate inspection apparatus and a method of inspecting a substrate using the same, and more particularly, to a substrate inspection apparatus capable of preventing a charge accumulation phenomenon and a method of inspecting a substrate using the same.
A semiconductor device may be manufactured by various processes. For example, the semiconductor device may be manufactured by a photolithography process, an etching process, a deposition process and a test process. Such processes may be performed on a wafer (e.g., a silicon wafer). In the test process, performance of the semiconductor device may be tested. Various apparatuses may be used to test the semiconductor device. For example, a scanning electron microscope (SEM) may be used to test the semiconductor device.
Information disclosed in this Background section has already been known to or derived by the inventors before or during the process of achieving the embodiments of the present application, or is technical information acquired in the process of achieving the embodiments. Therefore, it may contain information that does not form the prior art that is already known to the public.
One or more example embodiments of the disclosure provide a substrate inspection apparatus capable of preventing deformation of a photoresist (PR) by securing a time for which charges escape, and a method of inspecting a substrate using the same.
One or more example embodiments of the disclosure provide a substrate inspection apparatus capable of obtaining an accurate test result, and a method of inspecting a substrate using the same.
One or more example embodiments of the disclosure provide a substrate inspection apparatus capable of quickly performing a test, and a method of inspecting a substrate using the same.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.
According to an aspect of an example embodiment, a method of inspecting a substrate may include providing a substrate on a test stage, the substrate including a plurality of regions, and scanning the substrate using a scanning electron microscope (SEM) column, where the scanning of the substrate may include scanning a first region of the plurality of regions of the substrate, after scanning the first region, scanning a second region of the plurality of regions of the substrate, the second region being spaced apart from the first region, and after scanning the second region, scanning a third region of the plurality of regions of the substrate, the third region being between the first region and the second region, and where the third region is adjacent to the first region.
According to an aspect of an example embodiment, a method of inspecting a substrate may include providing a wafer on a test stage, the wafer including a plurality of regions, scanning the wafer using an SEM column, and forming an image using data generated based on results of the scanning of the wafer, where the scanning of the wafer may include a first scanning of each of the plurality of regions of the wafer, and after the first scanning of each of the plurality of regions of the wafer is completed, a second scanning of each of the plurality of regions of the wafer.
According to an aspect of an example embodiment, a substrate inspecting apparatus may include an SEM column including an SEM housing including a beam generation space, an electron gun in the beam generation space and a deflector under the electron gun, where the deflector may include a first deflector configured to cause an electron beam emitted from the electron gun to travel along a first path, and a second deflector configured to cause the electron beam emitted from the electron gun to travel along a second path that is different from the first path.
The above and other aspects, features, and advantages of certain example embodiments of the present disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
Hereinafter, example embodiments of the disclosure will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and redundant descriptions thereof will be omitted. The embodiments described herein are example embodiments, and thus, the disclosure is not limited thereto and may be realized in various other forms.
As used herein, expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression, “at least one of a, b, and c,” should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.
Referring to
The substrate inspection apparatus A may include a vacuum chamber VC, a scanning electron microscope (SEM) column 3, a test stage ST, a detector 5, a test stage driving unit SA, an SEM control unit C, a detector control unit DC, a total control unit TC, and a display D.
The vacuum chamber VC may include an inspection space Vh. The inspection space Vh may be maintained in a vacuum state. To achieve this, a vacuum pump connected to the inspection space Vh may be provided. The substrate may be disposed or loaded in the vacuum chamber VC. More particularly, the substrate may be disposed or loaded on the test stage ST in the vacuum chamber VC.
At least a portion of the SEM column 3 may be located in the vacuum chamber VC. The SEM column 3 may include an SEM. The SEM column 3 may be configured to emit an electron beam toward the substrate on the test stage ST. The SEM column 3 may emit the electron beam to the substrate to charge a conductor (e.g., an electrode) in the substrate. In other words, the SEM column 3 may be configured to emit a charged electron beam. For example, the electrode in the substrate to which the electron beam having a secondary electron yield greater than 1 is emitted may be charged with positive (+) charges. Alternatively, the electrode in the substrate to which the electron beam having the secondary electron yield less than 1 is emitted may be charged with negative (−) charges. The SEM column 3 may be configured to emit a scanning electron beam toward the substrate on the test stage ST. The electrode of the substrate charged by the charged electron beam may be scanned by the scanning electron beam.
A single SEM column is illustrated and described in
The test stage ST may be located under the SEM column 3. The test stage ST may support the substrate. The substrate may be disposed on a top surface of the test stage ST. The test stage ST may include a chuck for fixing the substrate. For example, the test stage ST may include an electrostatic chuck configured to fix the substrate using electrostatic force, or a vacuum chuck configured to fix the substrate using vacuum pressure. The test stage ST may be movable in a horizontal direction with respect to the SEM column 3. Thus, the substrate on the test stage ST may also be movable in the horizontal direction with respect to the SEM column 3.
The detector 5 may be configured to detect secondary electrons and/or backscatter electrons, generated by the electron beam. For example, the detector 5 may detect secondary electrons generated from the substrate irradiated by the scanning electron beam. Data on the secondary electrons detected by the detector 5 may be transmitted to the total control unit TC.
The test stage driving unit SA may be configured to move the test stage ST. For example, the test stage driving unit SA may move the test stage ST, on which the substrate is disposed, in the horizontal direction.
The SEM control unit C may be configured to control the SEM column 3. For example, the SEM control unit C may control an irradiation angle, the secondary electron yield and an irradiation time of the electron beam emitted by the SEM column 3. In addition, the SEM control unit C may control a path of the electron beam emitted by the SEM column 3. This will be described later in more detail.
The detector control unit DC may be configured to control the detector 5. The detector control unit DC may transmit data detected from the detector 5 to the total control unit TC. The total control unit TC may control the SEM control unit C, the detector control unit DC, and the test stage driving unit SA. The total control unit TC may form an image using the data on the secondary electrons received from the detector control unit DC. For example, the total control unit TC may form a voltage contrast image (VC image). Alternatively, the total control unit TC may form numerical data on the amount of the secondary electrons using the data on the secondary electrons received from the detector control unit DC. In other words, the total control unit TC may form numerical data on electrical signals by the secondary electrons received from the detector control unit DC. The display D may be connected to the total control unit TC. The display D may output the image formed by the total control unit TC. A user may check the image outputted in the display D to determine the status of the substrate (e.g., failure, success, etc.).
Referring to
The SEM housing 31 may include a beam generation space 31h. The SEM housing 31 may protect the electron gun 33.
The electron gun 33 may be located in the beam generation space 31h. The electron gun 33 may be configured to emit an electron beam. The electron beam emitted from the electron gun 33 may move to the outside of the SEM housing 31 through the deflector 37.
The first condenser lens CL1 may be located under the electron gun 33. The second condenser lens CL2 may be located under the first condenser lens CL1. Two condenser lenses are illustrated and described in
The deflector 37 may be located under the electron gun 33. More particularly, the deflector 37 may be located under the first condenser lens CL1 and/or the second condenser lens CL2. The deflector 37 may be configured to bend or change a path of the electron beam emitted from the electron gun 33. For example, the path of the electron beam emitted downward from the electron gun 33 and traveling straight may be bent or changed while the electron beam passes through the deflector 37. Thus, the deflector 37 may direct the electron beam to a desired place. The deflector 37 may be provided in plurality. For example, as shown in
The blocking deflector 35 may be located between the electron gun 33 and the deflector 37. For example, the blocking deflector 35 may be located between the first condenser lens CL1 and the deflector 37. The blocking deflector 35 may be configured to selectively block the electron beam emitted from the electron gun 33. To achieve this, the blocking deflector 35 may include an electromagnet and/or an electric condenser. The blocking deflector 35 will be described later in more detail.
Referring to
The scanning of the substrate of operation S2 may include scanning a first region in operation S21, scanning a second region in operation S22, and scanning a third region in operation S23.
Hereinafter, the method S300 of inspecting a substrate of
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The scanning of the second region of operation S22 may include emitting an electron beam to the second region 72, and detecting particles emitted from the second region 72. The scanning of the second region of operation S22 may be performed after the scanning of the first region of operation S21 is completed. The second region 72 may be spaced apart from the first region 71. In other words, the first region 71 and the second region 72 may not be adjacent to each other. In other words, another region or regions may be positioned between the first region 71 and the second region 72. Put alternatively, the region that is scanned second may not be a region that is adjacent to a region that is scanned previously, such that another region is positioned between the region scanned first and the region scanned second. For example, when viewing first region 71 and second region 72, other regions, such as regions 74, 78, and 75, are between the first region 71 and the second region 72, such that the first region 71 and the second region 72 may not be considered to be adjacent (i.e., both spaced apart and not adjacent).
The emitting of the electron beam to the second region 72 may include emitting the electron beam EB (see
The scanning of the third region of operation S23 may include emitting an electron beam to the third region 73, and detecting secondary electrons emitted from the third region 73. The scanning of the third region of operation S23 may be performed after the scanning of the second region of operation S22 is completed. The third region 73 may be spaced apart from the second region 72. In other words, the third region 73 and the second region 72 may not be adjacent to each other (i.e., intermediate regions may be present between the second region 72 and the third region 73 as described above and shown in the figures). In other words, another region or regions may be positioned between the third region 73 and the second region 72.
Scanning processes may be performed on the fourth region 74, the fifth region 75, the sixth region 76, the seventh region 77, the eighth region 78 and the ninth region 79 by the method described above. At this time, two regions continuously irradiated by the electron beam may not be adjacent to each other. In other words, the scanning processes may be performed along a non-linear path.
Referring again to
According to the substrate inspection apparatus and the method of inspecting a substrate using the same in the embodiments of the disclosure, a plurality of regions may be scanned in a non-linear order. For example, the electron beam may be emitted to a first region, and then, the electron beam may be emitted to a region adjacent to the first region after a predetermined amount of time. Between the emitting of the electron beam to the first region and the emitting of the electron beam to the adjacent region, the electron beam may be emitted to a region spaced apart from the first region and the adjacent region. Thus, the electron beam may be prevented from being continuously emitted to the first region and the region adjacent to the first region. For example, the PR may be located between two regions adjacent to each other. The electron beam may be prevented from being continuously emitted to the PR. Thus, charges may be prevented from being accumulated in the PR. In other words, a time for which the charges emitted to the PR escape from the PR may be secured. If the charges are accumulated in the PR, deformation (e.g., shrinkage of the PR) may be caused. According to the disclosure, the deformation (e.g., the shrinkage of the PR) may be prevented. Thus, accurate test results may be obtained.
According to the substrate inspection apparatus and the method of inspecting a substrate using the same in the embodiments of the disclosure, two or more paths may be implemented in the single SEM column using the deflector. Thus, the electron beam may be quickly emitted to positions spaced apart from each other. For example, immediately after the electron beam is emitted to the first region, the electron beam may be emitted to the second region spaced apart (i.e., not adjacent to) from the first region. Thus, a quick test may be performed.
Hereinafter, the descriptions that are the same or similar to features described with reference to
Referring to
The scanning of the wafer of operation Sa2 may include a first scanning in operation Sa21 and a second scanning in operation Sa22.
The forming of the image of operation Sa3 may include forming a first image in operation Sa31, forming a second image in operation Sa32, and combining the first image with the second image in operation Sa33.
Hereinafter, the method S800 of inspecting a substrate of
Hereinafter, the descriptions that are the same or similar to features described with reference to
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The forming of the second image of operation Sa32 may include forming the second image of the plurality of regions using data on results of the second scanning. The second image may be an image on an entire portion of the substrate Wa in the wafer shape.
The combining of the first image with the second image of operation Sa33 may include combining or composing the first image and the second image with each other. The first image and the second image may be combined with each other to obtain a total test result image.
In the above embodiments, two scanning processes are performed and described, but embodiments of the disclosure are not limited thereto. In some embodiments, three or more scanning processes may be performed. In this case, three or more images may be combined with each other.
According to the substrate inspection apparatus and the method of inspecting a substrate using the same in the embodiments of the disclosure, the second scanning may be performed after the first scanning of the whole of the wafer is completed. Thus, the electron beam may be prevented from being continuously emitted to a single die and/or a single region. As a result, a time for which charges escape from the PR may be sufficiently secured. In other words, the charges may be prevented from being accumulated in the PR. Thus, shrinkage deformation of the PR may be prevented.
According to the substrate inspection apparatus and the method of inspecting a substrate using the same in the embodiments of the disclosure, the same substrate may be repeatedly scanned a plurality of times to obtain a plurality of images, and the plurality of images may be combined with each other to obtain a single image. Thus, accurate test results may be obtained.
According to the substrate inspection apparatus and the method of inspecting a substrate using the same in the embodiments of the disclosure, a time for which charges escape may be secured to prevent the deformation of the PR.
According to the substrate inspection apparatus and the method of inspecting a substrate using the same in the embodiments of the disclosure, the accurate test results may be obtained.
According to the substrate inspection apparatus and the method of inspecting a substrate using the same in the embodiments of the disclosure, the quick test may be performed.
Each of the embodiments provided in the above description is not excluded from being associated with one or more features of another example or another embodiment also provided herein or not provided herein but consistent with the disclosure.
While the disclosure has been particularly shown and described with reference to embodiments thereof, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope of the following claims.
Number | Date | Country | Kind |
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10-2022-0147239 | Nov 2022 | KR | national |
10-2023-0037184 | Mar 2023 | KR | national |