Test structures and semiconductor devices
By designing contact hole test units and test units that do not overlap on the same plane, the problem of separating sample preparation in dense and sparse areas was solved, enabling simultaneous sample preparation of different layer structures of semiconductor devices, thus improving sample preparation efficiency and success rate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GTA SEMICON CO LTD
- Filing Date
- 2022-09-23
- Publication Date
- 2026-05-15
AI Technical Summary
In existing technologies, dense and sparse regions need to be sampled separately during the semiconductor device manufacturing process, and structures of different layers also need to be sampled separately, resulting in waste of manpower and resources and low sample preparation efficiency.
Design a test structure in which contact hole test units and test units are on the same plane without overlapping and located in different layers, including dense and sparse regions. This structure enables simultaneous sample preparation in both dense and sparse regions, and the different layer structures can be split into sections to obtain analytical samples in a single step.
Simultaneous sample preparation in dense and sparse areas saves manpower and resources, improves R&D efficiency, avoids damage to different layers, and enhances sample preparation success rate and efficiency.
Smart Images
Figure CN115458426B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor technology, and in particular to a test structure and a semiconductor device. Background Technology
[0002] With the continuous development of semiconductor process technology, it is necessary to test and analyze various key structural layers during the semiconductor device manufacturing process to evaluate whether their morphology and dimensional data meet the process requirements.
[0003] Currently, when preparing samples for general test structures for structural analysis, the dense and sparse regions need to be prepared separately due to their positional relationship. Similarly, when analyzing structures of multiple different layers on the same wafer, samples of different layers also need to be prepared separately, which consumes a lot of manpower and resources. Summary of the Invention
[0004] Therefore, it is necessary to provide a test structure and semiconductor device to address the issues of dense and sparse regions and the need for separate sample preparation for multiple different layer structures in the aforementioned test structure.
[0005] To achieve the above objectives, this application provides a test structure, which includes a test unit comprising:
[0006] The contact hole testing unit includes a first contact hole testing unit and a second contact hole testing unit. Both the first contact hole testing unit and the second contact hole testing unit include dense areas and sparse areas. The orthographic projections of the first contact hole testing unit and the second contact hole testing unit on the same plane do not overlap.
[0007] The test unit includes a first test unit and a second test unit. Both the first test unit and the second test unit include dense areas and sparse areas. The orthographic projections of the first test unit and the second test unit on the same plane do not overlap.
[0008] The first contact hole test unit, the second contact hole test unit, the first test unit, and the second test unit are all located on different layers; the orthographic projections of the test units and the contact hole test units on the same plane do not overlap.
[0009] In one embodiment, both the dense region and the sparse region of the first contact hole test unit are provided with a plurality of first contact holes. The spacing between adjacent first contact holes in the dense region of the first contact hole test unit is smaller than the spacing between adjacent first contact holes in the sparse region of the first contact hole test unit, and smaller than the spacing between the dense region and the sparse region of the first contact hole test unit.
[0010] In one embodiment, a plurality of second contact holes are provided in both the dense region and the sparse region of the second contact hole test unit. The spacing between adjacent second contact holes in the dense region of the second contact hole test unit is smaller than the spacing between adjacent second contact holes in the sparse region of the second contact hole test unit, and smaller than the spacing between the dense region and the sparse region of the second contact hole test unit.
[0011] In one embodiment, the spacing between adjacent first contact holes in the dense area of the first contact hole test unit and the spacing between adjacent second contact holes in the dense area of the second contact hole test unit both satisfy the minimum design rule.
[0012] In one embodiment, the first test unit includes:
[0013] The first test strip includes the opposing first and second ends;
[0014] The second test strip is parallel to the first test strip and is located between the first test strip and the contact hole test unit, and has a distance from both the first test strip and the contact hole test unit;
[0015] Multiple third test strips are arranged in parallel at intervals on opposite sides of the first test strip, extending from the first end of the first test strip to the second end of the first test strip;
[0016] Multiple fourth test strips are arranged in parallel at intervals on opposite sides of the first test strip, extending from the second end of the first test strip to the first end of the first test strip, and there is a gap between the fourth test strips and the third test strip;
[0017] Multiple fifth test strips are arranged in parallel at intervals on opposite sides of the second test strip, and the length of the fifth test strip is less than the length of the second test strip.
[0018] In one embodiment, the second test unit includes:
[0019] The sixth test strip includes the opposing first and second ends;
[0020] The seventh test strip is parallel to the sixth test strip and is located between the sixth test strip and the contact hole test unit, with a distance between it and both the sixth test strip and the contact hole test unit;
[0021] Multiple eighth test strips are arranged in parallel at intervals on opposite sides of the sixth test strip, extending from the first end of the sixth test strip to the second end of the sixth test strip;
[0022] Multiple ninth test strips are arranged in parallel at intervals on opposite sides of the sixth test strip, extending from the second end of the sixth test strip to the first end of the sixth test strip, and there is a gap between the ninth test strip and the eighth test strip;
[0023] Multiple tenth test strips are arranged in parallel at intervals on opposite sides of the seventh test strip, and the length of the tenth test strip is less than the length of the seventh test strip.
[0024] In one embodiment, the spacing between adjacent third test strips, the spacing between adjacent fourth test strips, the spacing between the third test strip and the first test strip, the spacing between the fourth test strip and the first test strip, the spacing between adjacent fifth test strips, the spacing between the fifth test strip and the second test strip, the spacing between adjacent eighth test strips, the spacing between adjacent ninth test strips, the spacing between the eighth test strip and the sixth test strip, the spacing between the ninth test strip and the sixth test strip, the spacing between adjacent tenth test strips, and the spacing between the tenth test strip and the seventh test strip all satisfy the minimum design rule.
[0025] In one embodiment, the first test unit is located on two adjacent sides of the contact hole test unit, and the second test unit is located on the other two adjacent sides of the contact hole test unit.
[0026] In one embodiment, the test structure includes a plurality of first contact hole test units, a plurality of second contact hole test units, a plurality of first test units, and a plurality of second test units; the plurality of first contact hole test units, the plurality of second contact hole test units, the plurality of first test units, and the plurality of second test units are located in different layers.
[0027] This application also provides a semiconductor device including the test structure described in any of the above embodiments.
[0028] The test structure of this application includes: a contact hole test unit and a test unit. The contact hole test unit includes a first contact hole test unit and a second contact hole test unit. The orthographic projections of the first contact hole test unit and the second contact hole test unit on the same plane do not overlap. The test unit includes a first test unit and a second test unit. The orthographic projections of the first test unit and the second test unit on the same plane do not overlap. Both the first contact hole test unit and the second contact hole test unit include dense regions and sparse regions. This can solve the problem that dense regions and sparse regions in the test structure need to be prepared separately during sample preparation, and achieve simultaneous sample preparation of dense regions and sparse regions. The first contact hole test unit, the second contact hole test unit, the first test unit, and the second test unit are all located on different layers, and the orthographic projections of the test units and the contact hole test units on the same plane do not overlap. This can achieve simultaneous sample preparation of different layers of the test structure. Analytical samples of all structural layers can be obtained simultaneously in one section, saving manpower and resources and improving R&D efficiency.
[0029] The semiconductor device of this application includes a test structure, which has the same beneficial effects as the test structure. When preparing samples of this semiconductor device, it is possible to prepare samples of dense and sparse regions at the same time, and it is also possible to prepare samples of different layers of test structures at the same time. One dicing can obtain analytical samples of all structural layers of the semiconductor device at the same time, saving manpower and resources and improving R&D efficiency. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0031] Figure 1 This is a schematic diagram of the test structure provided in one embodiment;
[0032] Figure 2 This is a schematic diagram of the structure of the first contact hole test unit in a test structure provided in one embodiment;
[0033] Figure 3 This is a schematic diagram of the structure of the second contact hole test unit in a test structure provided in one embodiment;
[0034] Figure 4 This is a schematic diagram of the structure of the first test unit in a test structure provided in one embodiment;
[0035] Figure 5 This is a schematic diagram of the structure of the second test unit in a test structure provided in one embodiment.
[0036] Explanation of reference numerals in the attached figures:
[0037] 1. First contact hole test unit; 101. Dense area of the first contact hole test unit; 102. Sparse area of the first contact hole test unit; 11. First contact hole; 2. Second contact hole test unit; 201. Dense area of the second contact hole test unit; 202. Sparse area of the second contact hole test unit; 21. Second contact hole; 3. First test unit; 301. Dense area of the first test unit; 302. Sparse area of the first test unit; 31. First test strip; 32. Second test strip; 33. Third test strip; 34. Fourth test strip; 35. Fifth test strip; 4. Second test unit; 401. Dense area of the second contact hole test unit; 402. Sparse area of the second test unit; 41. Sixth test strip; 42. Seventh test strip; 43. Eighth test strip; 44. Ninth test strip; 45. Tenth test strip. Detailed Implementation
[0038] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate preferred embodiments of the application. However, this application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.
[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
[0040] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, parts, regions, layers, doping types, and / or portions, these elements, parts, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, part, region, layer, doping type, or portion from another element, part, region, layer, doping type, or portion. Therefore, without departing from the teachings of this application, the first element, component, region, layer, doping type, or portion discussed below may be represented as a second element, component, region, layer, or portion; for example, the first doping type may be referred to as the second doping type, and similarly, the second doping type may be referred to as the first doping type; the first doping type and the second doping type are different doping types, for example, the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.
[0041] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.
[0042] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that when the terms “comprise” and / or “comprising” are used in this specification, the presence of the stated feature, integer, step, operation, element, and / or part is established, but the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or groups is not excluded. Meanwhile, when used herein, the term “and / or” includes any and all combinations of the associated listed items.
[0043] With the continuous development of semiconductor process technology, it is necessary to test and analyze various key structural layers during the semiconductor device manufacturing process to evaluate whether their morphology and dimensional data meet the process requirements.
[0044] Currently, when preparing samples for general-purpose test structures for structural analysis, the dense and sparse regions need to be prepared separately due to their positional relationship. Similarly, when analyzing multiple different layers on the same wafer simultaneously, separate sample preparation for each layer is required, consuming significant manpower and resources. Furthermore, preparing a sample for one layer can damage critical structures in other layers, making it impossible to obtain usable samples from all layers simultaneously. Additionally, the small overall length of individual test structures makes over-grinding during cross-sectional sample preparation difficult, rendering these smaller test structures unsuitable for grinding.
[0045] Therefore, it is necessary to provide a test structure and semiconductor device to address the issues of dense and sparse regions and the need for separate sample preparation for multiple different layer structures in the aforementioned test structure.
[0046] To achieve the above objectives, this application provides a test structure, such as... Figure 1 As shown, the test structure includes: a contact hole test unit and a test unit; the contact hole test unit includes a first contact hole test unit 1 and a second contact hole test unit 2, both of which include dense and sparse regions, and their orthographic projections on the same plane do not overlap; the test unit includes a first test unit 3 and a second test unit 4, both of which include dense and sparse regions, and their orthographic projections on the same plane do not overlap; wherein, the first contact hole test unit 1, the second contact hole test unit 2, the first test unit 3, and the second test unit 4 are all located on different layers; the orthographic projections of the test unit and the contact hole test unit on the same plane do not overlap.
[0047] Specifically, see Figure 1 The first contact hole test unit 1 includes a dense region 101 and a sparse region 102, the second contact hole test unit 2 includes a dense region 201 and a sparse region 202, the first test unit 3 includes a dense region 301 and a sparse region 302, and the second test unit 4 includes a dense region 401 and a sparse region 402.
[0048] It should be noted that, because the first contact hole test unit 1, the second contact hole test unit 2, the first test unit 3, and the second test unit 4 are all located on different layers, Figure 1The image shown is an orthographic projection of the first contact hole test unit 1, the second contact hole test unit 2, the first test unit 3, and the second test unit 4 on the same plane (the same projection reference plane). Specifically, the lower surface of the base of the test structure can be used as the projection reference plane, and the lower surface of the base of the test structure is the bottommost lower surface of the entire test structure.
[0049] Among them, still refer to Figure 1 The orthographic projections of the first contact hole test unit 1 and the second contact hole test unit 2 on the same plane do not overlap, meaning there is a gap between the orthographic projections of the first contact hole test unit 1 and the second contact hole test unit 2 on the projection reference plane; the orthographic projections of the first test unit 3 and the second test unit 4 on the same plane do not overlap, meaning there is a gap between the orthographic projections of the first test unit 3 and the second test unit 4 on the projection reference plane; the orthographic projections of the test unit and the contact hole test unit on the same plane do not overlap, meaning there is a gap between the orthographic projections of the first contact hole test unit 1, the second contact hole test unit 2, the first test unit 3, and the second test unit 4 on the projection reference plane.
[0050] Furthermore, the orthographic projection of the first test unit 3 onto the projection reference plane is at least located on one side of the orthographic projection of the contact hole test unit onto the projection reference plane; the orthographic projection of the second test unit 4 onto the projection reference plane and the orthographic projection of the first test unit 3 onto the projection reference plane are respectively located on different sides of the orthographic projection of the contact hole test unit onto the reference plane.
[0051] The test structure in the above embodiments includes: a contact hole test unit and a test unit. The contact hole test unit includes a first contact hole test unit 1 and a second contact hole test unit 2. Both the first contact hole test unit 1 and the second contact hole test unit 2 include dense and sparse regions. The test unit includes a first test unit 3 and a second test unit 4. Both the first test unit 3 and the second test unit 4 include dense and sparse regions. This can solve the problem that the dense and sparse regions in the test structure need to be prepared separately during sample preparation, and realize the simultaneous preparation of dense and sparse regions. The first contact hole test unit 1, the second contact hole test unit 2, the first test unit 3, and the second test unit 4 are all located in different layers, and the orthographic projections of the test unit and the contact hole test unit on the same plane do not overlap. This can realize the simultaneous preparation of different layers of the test structure. One dicing can obtain analytical samples of all structural layers at the same time, saving manpower and resources and improving R&D efficiency.
[0052] In some embodiments, the first contact hole test unit 1 may include any one of an interlayer contact hole test unit and a first layer metal hole test unit. The second contact hole test unit 2 may include any one of a second layer metal hole test unit and a top layer metal hole test unit. The first test unit 3 may include any one of an active region test unit and a polysilicon test unit. The second test unit 4 may include any one of a first metal layer test unit and a second metal layer test unit.
[0053] In one embodiment, see Figure 1 and 2 Both the dense area 101 and the sparse area 102 of the first contact hole test unit are provided with a plurality of first contact holes 11. The distance between adjacent first contact holes 11 in the dense area 101 of the first contact hole test unit is smaller than the distance between adjacent first contact holes 11 in the sparse area 102 of the first contact hole test unit, and smaller than the distance between the dense area 101 and the sparse area 102 of the first contact hole test unit.
[0054] Specifically, see Figure 2 If the distance between adjacent first contact holes 11 in the dense area 101 of the first contact hole test unit is a, the distance between adjacent first contact holes 11 in the sparse area 102 of the first contact hole test unit is b, and the distance between the dense area 101 and the sparse area 102 of the first contact hole test unit is c, then a is less than b, and a is less than c.
[0055] In the above embodiment, the distance a between adjacent first contact holes 11 in the dense region 101 of the first contact hole test unit is smaller than the distance b between adjacent first contact holes 11 in the sparse region 102 of the first contact hole test unit, and smaller than the distance c between the dense region 101 and the sparse region 102 of the first contact hole test unit. This allows for the simultaneous acquisition of analytical samples from the sparse and dense regions while minimizing the area occupied by the sparse and dense regions when the first contact hole test unit 1 is cleaved from the same cleavage plane.
[0056] In one embodiment, see Figure 1 and 3 The dense area 201 and the sparse area 202 of the second contact hole test unit are each provided with a plurality of second contact holes 21. The distance between adjacent second contact holes 21 in the dense area 201 of the second contact hole test unit is smaller than the distance between adjacent second contact holes 21 in the sparse area 202 of the second contact hole test unit, and smaller than the distance between the dense area 201 and the sparse area 202 of the second contact hole test unit.
[0057] Specifically, see Figure 3 The distance between adjacent second contact holes 21 in the dense area 201 of the second contact hole test unit is d, the distance between adjacent second contact holes 21 in the sparse area 202 of the second contact hole test unit is e, and the distance between the dense area 201 and the sparse area 202 of the second contact hole test unit is f. Then d is less than e and d is less than f.
[0058] In the above embodiment, the distance d between adjacent second contact holes 21 in the dense region 201 of the second contact hole test unit is smaller than the distance e between adjacent second contact holes 21 in the sparse region 202 of the second contact hole test unit, and smaller than the distance f between the dense region 201 and the sparse region 202 of the second contact hole test unit. This allows for the simultaneous acquisition of analytical samples from the sparse and dense regions while minimizing the area occupied by the sparse and dense regions when the second contact hole test unit 2 is cleaved from the same cleavage plane.
[0059] In one embodiment, see Figures 2 to 3 The spacing 'a' between adjacent first contact holes 11 in the dense area 101 of the first contact hole test unit and the spacing 'd' between adjacent second contact holes 21 in the dense area 201 of the second contact hole test unit both meet the minimum design rule.
[0060] Here, the minimum design rule refers to setting the spacing between the contact holes of the contact hole test unit according to the minimum spacing, while meeting the design requirements of the test structure.
[0061] In the above embodiments, the spacing a between adjacent first contact holes 11 in the dense area 101 of the first contact hole test unit and the spacing d between adjacent second contact holes 21 in the dense area 201 of the second contact hole test unit both meet the minimum design rule, which can reduce the area occupied by the dicing channel and improve the flexibility of the structure placement. The dicing channel is the area used to dicing on the test structure during sample preparation.
[0062] In one embodiment, see Figure 1 and 4The first test unit 3 includes: a first test strip 31, a second test strip 32, a plurality of third test strips 33, a plurality of fourth test strips 34, and a plurality of fifth test strips 35; the first test strip 31 includes a first end and a second end opposite to each other; the second test strip 32 is parallel to the first test strip 31 and is located between the first test strip 31 and the contact hole test unit, and has a gap between it and both the first test strip 31 and the contact hole test unit; the plurality of third test strips 33 are arranged in parallel at intervals on opposite sides of the first test strip 31, extending from the first end of the first test strip 31 to the second end of the first test strip 31; the plurality of fourth test strips 34 are arranged in parallel at intervals on opposite sides of the first test strip 31, extending from the second end of the first test strip 31 to the first end of the first test strip 31, and there is a gap between the fourth test strips 34 and the third test strips 33; the plurality of fifth test strips 35 are arranged in parallel at intervals on opposite sides of the second test strip 32, and the length of the fifth test strip 35 is less than the length of the second test strip 32.
[0063] Specifically, in Figure 4 In the diagram, g represents the length of the first test strip 31, h represents the length of the second test strip 32, j represents the length of the third test strip 33, k represents the length of the fourth test strip 34, and m represents the length of the fifth test strip 35. The length m of the fifth test strip 35 is less than the length h of the second test strip 32. The length j of the third test strip 33 and the length k of the fourth test strip 34 are both less than the length g of the first test strip 31. The length j of the third test strip 33 and the length k of the fourth test strip 34 are both less than the length m of the fifth test strip 35.
[0064] In some embodiments, see Figure 4The length g of the first test strip 31 can be 30–34 μm; specifically, the length g of the first test strip 31 can be 30 μm, 31 μm, 32 μm, 33 μm, or 34 μm, or any other length between 30 and 34 μm. The length h of the second test strip 32 can be 30–34 μm; specifically, the length h of the second test strip 32 can be 30 μm, 31 μm, 32 μm, 33 μm, or 34 μm, or any other length between 30 and 34 μm. The length j of the third test strip 33 can be 6–10 μm; specifically, the length j of the third test strip 33 can be 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, or any other length between 6 and 10 μm. The length k of the fourth test strip 34 can be 6–10 μm; specifically, the length k of the fourth test strip 34 can be 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, or any other length between 6 and 10 μm. The length m of the fifth test strip 35 can be 14–18 μm; specifically, the length m of the fifth test strip 35 can be 14 μm, 15 μm, 16 μm, 17 μm, or 18 μm, or any other length between 14 and 18 μm.
[0065] In one embodiment, see Figure 1 and 5 The second test unit 4 includes: a sixth test strip 41, a seventh test strip 42, multiple eighth test strips 43, multiple ninth test strips 44, and multiple tenth test strips 45; the sixth test strip 41 includes a first end and a second end opposite to each other; the seventh test strip 42 is parallel to the sixth test strip 41 and is located between the sixth test strip 41 and the contact hole test unit, and has a gap between it and both the sixth test strip 41 and the contact hole test unit; the multiple eighth test strips 43 are arranged in parallel at intervals on opposite sides of the sixth test strip 41, extending from the first end of the sixth test strip 41 to the second end of the sixth test strip 41; the multiple ninth test strips 44 are arranged in parallel at intervals on opposite sides of the sixth test strip 41, extending from the second end of the sixth test strip 41 to the first end of the sixth test strip 41, and there is a gap between the ninth test strips 44 and the eighth test strips 43; the multiple tenth test strips 45 are arranged in parallel at intervals on opposite sides of the seventh test strip 42, and the length of the tenth test strip 45 is less than the length of the seventh test strip 42.
[0066] Specifically, in Figure 5In the diagram, n represents the length of the sixth test strip 41, p represents the length of the seventh test strip 42, q represents the length of the eighth test strip 43, r represents the length of the ninth test strip 44, and s represents the length of the tenth test strip 45. The length s of the tenth test strip 45 is less than the length p of the seventh test strip 42. The lengths q of the eighth test strip 43 and r of the ninth test strip 44 are both less than the length n of the sixth test strip 41. The lengths q of the eighth test strip 43 and r of the ninth test strip 44 are both less than the length s of the tenth test strip 45.
[0067] In some embodiments, see Figure 5 The length n of the sixth test strip 41 can be 30–34 μm; specifically, the length n of the sixth test strip 41 can be 30 μm, 31 μm, 32 μm, 33 μm, or 34 μm, or any other length between 30 and 34 μm. The length p of the seventh test strip 42 can be 30–34 μm; specifically, the length p of the seventh test strip 42 can be 30 μm, 31 μm, 32 μm, 33 μm, or 34 μm, or any other length between 30 and 34 μm. The length q of the eighth test strip 43 can be 6–10 μm; specifically, the length q of the eighth test strip 43 can be 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, or any other length between 6 and 10 μm. The length r of the ninth test strip 44 can be 6 to 10 μm; specifically, the length r of the ninth test strip 44 can be 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, or any other length between 6 and 10 μm. The length s of the tenth test strip 45 can be 14 to 18 μm; specifically, the length s of the tenth test strip 45 can be 14 μm, 15 μm, 16 μm, 17 μm, or 18 μm, or any other length between 14 and 18 μm.
[0068] Specifically, the sample needs to be ground during the sample preparation process. When the sample size is very small, grinding is easy to over-grind when preparing cross-sectional samples, which makes it impossible to obtain accurate morphological information of the test structure. In the currently used test structure, the longest test strip in the test unit is only 8 μm. However, in this application, the lengths of the first test strip 31 (g), the second test strip 32 (h), the sixth test strip 41 (n), and the seventh test strip 42 (p) are all between 30 and 34 μm, which are suitable for preparing samples by grinding. Moreover, grinding will not damage the morphology of the test structure, thus improving the sample preparation success rate and efficiency.
[0069] In one embodiment, see still Figure 4The spacing between adjacent third test strips 33, adjacent fourth test strips 34, the spacing between third test strip 33 and first test strip 31, the spacing between fourth test strip 34 and first test strip 31, the spacing between adjacent fifth test strips 35, the spacing between fifth test strip 35 and second test strip 32, the spacing between adjacent eighth test strips 43, the spacing between adjacent ninth test strips 44, the spacing between eighth test strip 43 and sixth test strip 41, the spacing between ninth test strip 44 and sixth test strip 41, the spacing between adjacent tenth test strips 45, and the spacing between tenth test strip 45 and seventh test strip 42 all meet the minimum design rule.
[0070] Specifically, the spacing between adjacent third test strips 33, adjacent fourth test strips 34, the spacing between the third test strip 33 and the first test strip 31, the spacing between the fourth test strip 34 and the first test strip 31, the spacing between adjacent fifth test strips 35, the spacing between the fifth test strip 35 and the second test strip 32, the spacing between adjacent eighth test strips 43, the spacing between adjacent ninth test strips 44, the spacing between the eighth test strip 43 and the sixth test strip 41, the spacing between the ninth test strip 44 and the sixth test strip 41, the spacing between adjacent tenth test strips 45, and the spacing between the tenth test strip 45 and the seventh test strip 42 all meet the minimum design requirements. Then, it means that the spacing between adjacent third test strips 33, adjacent fourth test strips 34, the spacing between third test strip 33 and first test strip 31, the spacing between fourth test strip 34 and first test strip 31, the spacing between adjacent fifth test strips 35, the spacing between fifth test strip 35 and second test strip 32, the spacing between adjacent eighth test strips 43, the spacing between adjacent ninth test strips 44, the spacing between eighth test strip 43 and sixth test strip 41, the spacing between ninth test strip 44 and sixth test strip 41, the spacing between adjacent tenth test strips 45, and the spacing between tenth test strip 45 and seventh test strip 42 are set according to the minimum spacing.
[0071] In the above embodiments, the spacing between adjacent third test strips 33, the spacing between adjacent fourth test strips 34, the spacing between the third test strip 33 and the first test strip 31, the spacing between the fourth test strip 34 and the first test strip 31, the spacing between adjacent fifth test strips 35, the spacing between the fifth test strip 35 and the second test strip 32, the spacing between adjacent eighth test strips 43, the spacing between adjacent ninth test strips 44, the spacing between the eighth test strip 43 and the sixth test strip 41, the spacing between the ninth test strip 44 and the sixth test strip 41, and the spacing between adjacent tenth test strips 45 are all specified. The spacing between the test strips and the spacing between the tenth test strip 45 and the seventh test strip 42 both satisfy the minimum design rule, so that when the first test unit 3 is split from the same cleavage plane, the analytical samples of the sparse and dense regions of the first test unit 3 can be obtained in one step, while minimizing the area occupied by the sparse and dense regions of the first test unit 3. Similarly, when the second test unit 4 is split from the same cleavage plane, the analytical samples of the sparse and dense regions of the second test unit 4 can be obtained in one step, while minimizing the area occupied by the sparse and dense regions of the second test unit 4.
[0072] In one embodiment, see still Figure 1 The first test unit 3 is located on both sides adjacent to the contact hole test unit, and the second test unit 4 is located on the other two sides adjacent to the contact hole test unit. This compact arrangement is also intended to minimize the area occupied by the test units and improve the flexibility of test structure placement.
[0073] Specifically, there can be multiple first test units 3. Figure 1 In the example, there are two first test units 3. The first test units 3 being located on either side of the contact hole test unit means that the orthographic projections of the two first test units 3 onto the projection reference plane are respectively located on either side of the orthographic projection of the contact hole test unit onto the projection reference plane. The number of second test units 4 can be multiple. Figure 1 In the example, there are two second test units 4. The second test units 4 are located on the other two sides adjacent to the contact hole test unit, which means that the orthographic projections of the two second test units 4 on the projection reference plane are respectively located on the other two sides of the orthographic projection of the contact hole test unit on the projection reference plane. Further, the orthographic projections of the first test unit 3 on the projection reference plane and the orthographic projections of the second test unit 4 on the projection reference plane are respectively located on different sides of the orthographic projection of the contact hole test unit on the projection reference plane.
[0074] In one embodiment, the test structure may include a plurality of first contact hole test units 1, a plurality of second contact hole test units 2, a plurality of first test units 3, and a plurality of second test units 4.
[0075] In one embodiment, a plurality of first contact hole test units 1, a plurality of second contact hole test units 2, a plurality of first test units 3 and a plurality of second test units 4 are located on different layers.
[0076] Specifically, the multiple first contact hole test units 1, multiple second contact hole test units 2, multiple first test units 3, and multiple second test units 4 are located on different layers, which may include: multiple first contact hole test units 1 are located on different layers, multiple second contact hole test units 2 are located on different layers, multiple first test units 3 are located on different layers, and multiple second test units 4 are located on different layers; or it may include: multiple first contact hole test units 1, multiple second contact hole test units 2, multiple first test units 3, and multiple second test units 4 are located on different layers.
[0077] In some embodiments, the first contact hole test unit 1 may be located above the first test unit 3, the second test unit 4 may be located above the first contact hole test unit 1, and the second contact hole test unit 2 may be located above the second test unit 4.
[0078] Specifically, the first contact hole test unit 1 is located above the first test unit 3. This can include the first contact hole test unit 1 being directly above the first test unit 3, or it can include cases where there are other intermediate layers between the first contact hole test unit 1 and the first test unit 3. The second test unit 4 is located above the first contact hole test unit 1. This can include the second test unit 4 being directly above the first contact hole test unit 1, or it can include cases where there are other intermediate layers between the second test unit 4 and the first contact hole test unit 1. The second contact hole test unit 2 is located above the second test unit 4. This can include the second contact hole test unit 2 being directly above the second test unit 4, or it can include cases where there are other intermediate layers between the second contact hole test unit 2 and the second test unit 4.
[0079] Specifically, the first contact hole test unit 1, the second contact hole test unit 2, the first test unit 3, and the second test unit 4 in each test structure are all located on different layers. This corresponds to the fact that different structures within the device are located on different layers. For example, when the first test unit 3 is an active region test unit, the second test unit 4 is a first metal layer test unit, the first contact hole test unit 1 is an interlayer contact hole test unit, and the second contact hole test unit 2 is a second layer metal hole test unit, the first contact hole test unit 1 is located on the upper layer of the first test unit 3, the second test unit 4 is located on the upper layer of the first contact hole test unit 1, and the second contact hole test unit 2 is located on the upper layer of the second test unit 4. Although the different test units in the test structure of this application are located on different layers, due to the ingenious arrangement of the structure, samples of different layers can be obtained in one dicing step, avoiding the destruction of other layer structures during the preparation of a sample of a certain layer, which greatly improves the sample preparation efficiency and sample preparation success rate.
[0080] This application also provides a semiconductor device (not shown) including the test structure described in any of the above embodiments.
[0081] The semiconductor device in the above embodiments includes the test structure of any of the above embodiments, and has the same beneficial effects as the test structure. When preparing samples of this semiconductor device, it is possible to prepare samples of dense and sparse regions at the same time, and it is also possible to prepare samples of different layer test structures at the same time. One dicing can obtain analytical samples of all structural layers of the semiconductor device at the same time, saving manpower and resources and improving R&D efficiency.
[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0083] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A test structure, characterized in that, The test structure includes: The contact hole testing unit includes a first contact hole testing unit and a second contact hole testing unit. Both the first contact hole testing unit and the second contact hole testing unit include dense areas and sparse areas. The orthographic projections of the first contact hole testing unit and the second contact hole testing unit on the same plane do not overlap. The test unit includes a first test unit and a second test unit. Both the first test unit and the second test unit include dense areas and sparse areas. The orthographic projections of the first test unit and the second test unit on the same plane do not overlap. The first contact hole test unit, the second contact hole test unit, the first test unit, and the second test unit are all located on different layers; the orthographic projections of the test units and the contact hole test units on the same plane do not overlap; The longest test strip in the first test unit is between 30 and 34 micrometers in length; the longest test strip in the second test unit is between 30 and 34 micrometers in length.
2. The test structure according to claim 1, characterized in that, Both the dense area and the sparse area of the first contact hole test unit are provided with multiple first contact holes. The distance between adjacent first contact holes in the dense area of the first contact hole test unit is smaller than the distance between adjacent first contact holes in the sparse area of the first contact hole test unit, and smaller than the distance between the dense area and the sparse area of the first contact hole test unit.
3. The test structure according to claim 2, characterized in that, Multiple second contact holes are provided in both the dense area and the sparse area of the second contact hole test unit. The spacing between adjacent second contact holes in the dense area of the second contact hole test unit is smaller than the spacing between adjacent second contact holes in the sparse area of the second contact hole test unit, and smaller than the spacing between the dense area and the sparse area of the second contact hole test unit.
4. The test structure according to claim 3, characterized in that, The spacing between adjacent first contact holes in the dense area of the first contact hole test unit and the spacing between adjacent second contact holes in the dense area of the second contact hole test unit both meet the minimum design rule.
5. The test structure according to claim 1, characterized in that, The first test unit includes: The first test strip includes the opposing first and second ends; The second test strip is parallel to the first test strip and is located between the first test strip and the contact hole test unit, and has a distance from both the first test strip and the contact hole test unit; Multiple third test strips are arranged in parallel at intervals on opposite sides of the first test strip, extending from the first end of the first test strip to the second end of the first test strip; Multiple fourth test strips are arranged in parallel at intervals on opposite sides of the first test strip, extending from the second end of the first test strip to the first end of the first test strip, and there is a gap between the fourth test strips and the third test strip; Multiple fifth test strips are arranged in parallel at intervals on opposite sides of the second test strip, and the length of the fifth test strip is less than the length of the second test strip.
6. The test structure according to claim 5, characterized in that, The second test unit includes: The sixth test strip includes the opposing first and second ends; The seventh test strip is parallel to the sixth test strip and is located between the sixth test strip and the contact hole test unit, with a distance between it and both the sixth test strip and the contact hole test unit; Multiple eighth test strips are arranged in parallel at intervals on opposite sides of the sixth test strip, extending from the first end of the sixth test strip to the second end of the sixth test strip; Multiple ninth test strips are arranged in parallel at intervals on opposite sides of the sixth test strip, extending from the second end of the sixth test strip to the first end of the sixth test strip, and there is a gap between the ninth test strip and the eighth test strip; Multiple tenth test strips are arranged in parallel at intervals on opposite sides of the seventh test strip, and the length of the tenth test strip is less than the length of the seventh test strip.
7. The test structure according to claim 6, characterized in that, The spacing between adjacent third test strips, the spacing between adjacent fourth test strips, the spacing between the third test strip and the first test strip, the spacing between the fourth test strip and the first test strip, the spacing between adjacent fifth test strips, the spacing between the fifth test strip and the second test strip, the spacing between adjacent eighth test strips, the spacing between adjacent ninth test strips, the spacing between the eighth test strip and the sixth test strip, the spacing between adjacent tenth test strips, and the spacing between the tenth test strip and the seventh test strip all satisfy the minimum design rule.
8. The test structure according to claim 1, characterized in that, The first test unit is located on two adjacent sides of the contact hole test unit, and the second test unit is located on the other two adjacent sides of the contact hole test unit.
9. The test structure according to any one of claims 1 to 8, characterized in that, The test structure includes multiple first contact hole test units, multiple second contact hole test units, multiple first test units, and multiple second test units; the multiple first contact hole test units, multiple second contact hole test units, multiple first test units, and multiple second test units are located in different layers.
10. A semiconductor device, characterized in that, Includes the test structure as described in any one of claims 1 to 9.