Test structure
By designing a test structure in the integrated circuit, utilizing the correspondence between the first positioning component and the test finger, and the serpentine extension structure, the problem of inaccurate positioning in traditional testing methods is solved, and accurate detection of metal interconnects is achieved.
Patent Information
- Application Number
- CN202520074283.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-13
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2035-01-13
AI Technical Summary
Traditional testing methods struggle to accurately detect failures between tiny metal structures, especially due to inaccurate localization issues.
A test structure is designed, including a first connecting part and a first test finger. A first positioning component is set to correspond one-to-one with the first test finger. A second test structure with a serpentine extension is used to accurately locate the short circuit position using the first positioning component, and to accurately detect the short circuit by combining the resistance difference of the resistor or diode.
This greatly improves the accuracy of fault location and analysis, and increases the success rate of detection.
Smart Images
Figure CN223829816U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of integrated circuit technology, and in particular to a test structure. Background Technology
[0002] In integrated circuit manufacturing, as technology nodes continue to shrink, the size of metal interconnects is also constantly decreasing. This tiny metal structure makes the connections between metals more susceptible to various factors, such as electromigration and stress migration.
[0003] Traditional testing methods are insufficient for accurately detecting failures in these tiny metallic structures. For example, existing test structures often fail to accurately locate short circuits in metal interconnects, resulting in discrepancies between the detected hotspot and its actual location. Therefore, specialized failure testing structures are needed. Utility Model Content
[0004] Therefore, it is necessary to provide a test structure to address the problem of inaccurate detection of metal interconnects.
[0005] To achieve the above objectives, this utility model provides a test structure, comprising:
[0006] The first test structure includes a first connecting portion and a first test finger. The first connecting portion extends in a first direction, and the first test finger is arranged sequentially at intervals along the first direction on the first connecting portion. The first test finger extends along a second direction. The first direction and the second direction are located in the same plane and are intersected by each other.
[0007] The first positioning component is located on the first connecting part on one side of the first test finger, and is set in a one-to-one correspondence with the first test finger;
[0008] The second test structure extends in a serpentine pattern along the edge of the first test finger and the first connection portion.
[0009] In one embodiment, the test structure further includes:
[0010] First pad, second pad, and third pad;
[0011] The first pad is connected to the first end of the second test structure, and the second pad is connected to the second end of the second test structure;
[0012] The third pad is connected to the first connection part.
[0013] In one embodiment, the first positioning component includes a first resistor or a first diode.
[0014] In one embodiment, the resistance of the first resistor is much greater than the resistance of the first test structure.
[0015] In one embodiment, the test structure further includes:
[0016] The third test structure includes a second connecting part and a second test finger. The second connecting part extends in the first direction, and the second test finger is arranged sequentially at intervals on the second connecting part along the first direction. The second test finger extends in the second direction.
[0017] The second test finger and the first test finger are located between the second connecting portion and the first connecting portion, and in the first direction, the second test finger and the first test finger are arranged alternately at intervals.
[0018] In one embodiment, the test structure further includes:
[0019] The fourth pad is connected to the second connection portion.
[0020] In one embodiment, the second test finger is spaced the same as the first test finger in the first direction.
[0021] In one embodiment, the test structure further includes:
[0022] The second positioning component is located on the second connecting part on one side of the second test finger, and is set in a one-to-one correspondence with the second test finger.
[0023] In one embodiment, the second positioning component includes a second resistor or a second diode.
[0024] In one embodiment, the resistance of the second resistor is much greater than the resistance of the second test structure.
[0025] Compared with existing technologies, the above technical solution has the following advantages:
[0026] In the aforementioned test structure, a first positioning component is provided on the first connecting part of the first test structure, corresponding one-to-one with the first test finger. When a short circuit occurs between the first test structure and the second test structure, the first positioning component can accurately locate the first test finger at the corresponding position, thereby accurately testing the location where the short circuit occurred, greatly improving the accuracy of failure location and enhancing the accuracy and success rate of failure analysis. Attached Figure Description
[0027] 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.
[0028] Figure 1 This application provides a schematic diagram of a test structure.
[0029] Figure 2 This application provides a schematic diagram of a test structure for testing short circuits according to an embodiment of the present application.
[0030] Figure 3 for Figure 2 A schematic diagram of the structure of the first positioning component being the first resistor;
[0031] Figure 4 for Figure 2 The first positioning component in the diagram is a first diode.
[0032] Figure 5 This is a schematic diagram of another test structure provided in an embodiment of this application;
[0033] Figure 6 This is a schematic diagram of another test structure for testing short circuits provided in an embodiment of this application.
[0034] Explanation of reference numerals in the attached drawings: 01-First test structure; 011-First connection part; 012-First test finger; 02-First positioning component; 03-Second test structure; 04-First pad; 05-Second pad; 06-Third pad; 07-Third test structure; 071-Second connection part; 072-Second test finger; 08-Fourth pad; 09-Second positioning component; Q-Failure location; Rs-First resistor; D1-First diode. Detailed Implementation
[0035] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can 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.
[0036] 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.
[0037] It should be understood that when a layer is referred to as "on," "adjacent to," or "connected to" other layers, it can be directly on, adjacent to, or connected to other layers, or there can be intervening layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," or "directly connected to" other layers, there are no intervening layers.
[0038] 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 the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.
[0039] Please refer to Figure 1 , Figure 1 This application provides a schematic diagram of a test structure, which includes a first test structure 01, a first positioning component 02, and a second test structure 03.
[0040] The first test structure 01 includes a first connecting part 011 and a first test finger 012. The first connecting part 011 extends in the first direction X. The first test finger 012 is arranged sequentially at intervals along the first direction X on the first connecting part 011. The first test finger 012 extends along the second direction Y. The first direction X and the second direction Y are located in the same plane and are intersected by the first direction X and the second direction Y.
[0041] The first positioning component 02 is located on the first connecting part 011 on one side of the first test finger 012, and is set in a one-to-one correspondence with the first test finger 012.
[0042] The second test structure 03 extends in a serpentine shape along the edge of the first test finger 012 and the first connecting part 011.
[0043] Specifically, the first connecting portion 011 and the first test finger 012 can be an integral structure, both made of metal. The extending direction of the first test finger 012 intersects the extending direction of the first connecting portion 011. For example, Figure 1 As shown, the first direction X is perpendicular to the second direction Y, that is, the first connecting part 011 is perpendicular to the extension direction of the first test finger 012, so as to form as shown. Figure 1 The first test structure 01 is shown. In addition, the first test finger 012 may also intersect the extension direction of the first connecting part 011 at a preset angle to achieve testing of special structures, which is not specifically limited here.
[0044] The second test structure 03 extends in a serpentine shape along the edge of the first test finger 012 and the first connecting part 011, such as... Figure 1 As shown, the second test structure 03 and the first test structure 01 are spaced at the same distance, which can avoid test deviation caused by the different resistances between the first test structure 01 and the second test structure 03.
[0045] like Figure 1 As shown, there can be multiple first positioning components 02. The first positioning components 02 are located on the first connecting part 011 on one side of the first test finger 012. That is to say, the number of first positioning components 02 is the same as the number of first test fingers 012. Each first positioning component 02 can relatively position one first test finger 012.
[0046] In this embodiment, a first positioning component 02, corresponding one-to-one with the first test finger 012, is provided on the first connecting portion 011 of the first test structure 01. When a short circuit occurs between the first test structure 01 and the second test structure 03, the first positioning component 02 can accurately locate the first test finger 012 at the corresponding position, thereby accurately testing the location where the short circuit occurred, greatly improving the accuracy of failure location and enhancing the accuracy and success rate of failure analysis.
[0047] In another embodiment of this application, the test structure further includes: a first pad 04, a second pad 05, and a third pad 06.
[0048] The first pad 04 is connected to the first end of the second test structure 03, and the second pad 05 is connected to the second end of the second test structure 03.
[0049] The third pad 06 is connected to the first connecting part 011.
[0050] Specifically, the first pad 04, the second pad 05, and the third pad 06 include, but are not limited to, metal pads.
[0051] Test voltage can be applied to the first pad 04, the second pad 05, or the third pad 06. When a short circuit occurs, a path is formed between the first test structure 01 and the second test structure 03. When current flows through the first positioning component 02, the first positioning component 02 can locate the failure position, thereby achieving precise positioning. It should be noted that other structures can also be used to apply voltage to the first test structure 01 or the second test structure 03; no specific limitation is made.
[0052] In this embodiment, the first pad 04, the second pad 05, and the third pad 06 are used to apply a test voltage, thereby forming a path between the first test structure 01 and the second test structure 03 when short-circuited, and further detecting the failure location.
[0053] In another embodiment of this application, the first positioning component 02 includes a first resistor or a first diode.
[0054] Specifically, the first positioning component 02 includes, but is not limited to, a first resistor or a first diode.
[0055] Taking the first positioning component 02 as the first resistor as an example, when a failure occurs, a path is formed between the first test structure 01 and the second test structure 03. After applying a test voltage to the pad, the location of the short circuit can be detected by the resistance value of the current flowing through the first resistor. Then, using the test results as a reference, a more accurate failure location can be obtained by using the photo-induced resistance change (OBIRCH) mode.
[0056] Taking the first positioning component 02 as the first diode as an example, a path is formed between the first test structure 01 and the second test structure 03. After applying a test voltage to the pad, the first diode through which the current flows will turn on. The location of the short circuit can be detected by testing the turned-on first diode using an optical microscopy (EMMI) microscope.
[0057] In this embodiment, the first positioning component 02 is set as a first resistor or a first diode, which has a simple structure. Furthermore, detecting the resistance value and the on / off state of the diode is relatively simple, improving detection accuracy while ensuring ease of detection.
[0058] In another embodiment of this application, the resistance value of the first resistor is much greater than the resistance value of the first test structure 01.
[0059] Specifically, when the resistance of the first resistor is much greater than the resistance of the first test structure 01, the failure location can be magnified, making the detection of the test structure more accurate. For example, when setting up this test structure, first test the resistance Rm of the first test structure 01, and then record the resistance of Rm as aΩ. At this time, set the resistance of the first resistor on the first connection part 011 to 10aΩ, so that the resistance of the first resistor is much greater than the resistance of the first test structure 01.
[0060] refer to Figure 2 , Figure 2 This application provides a schematic diagram of a test structure for testing short circuits, as shown in the embodiments of the present application; see reference. Figure 3 , Figure 3 for Figure 2 The first positioning component in the diagram is a schematic diagram of the first resistor; see reference. Figure 4 , Figure 4 for Figure 2 The first positioning component is a schematic diagram of the first diode; when a short circuit occurs between the tested metal connecting lines, the failure location Q connects the first test structure 01 and the second test structure 03. At this time, as... Figure 2As shown, the current flows from the first pad 04 along the second test structure 03 to the failure location Q, and then along the first test structure 01 through three first positioning structures to the third pad 06.
[0061] At this time, the resistance value between the first test structure 01 and the second test structure 03 is recorded as 3×10aΩ=30aΩ. Since the resistance value of the first resistor Rs is much greater than the resistance value of the first test structure 01, the resistance value between the third pad 06 and the failure location Q can be used to locate the failure location Q. Then, based on the test results as a reference, OBRICH can be used to obtain a more accurate failure location.
[0062] like Figure 3 In the circuit, the first positioning component 02 is the first resistor Rs. Because the resistance of the first resistor Rs is sufficiently large, it amplifies the detected failure location Q. For example... Figure 4 In the circuit, the first positioning component 02 is the first diode D1. Since only the first diode D1 through which current flows will be turned on, the failure location Q of the test is also amplified.
[0063] In this embodiment, the resistance value of the first resistor Rs is much greater than the resistance value of the first test structure 01, which amplifies the failure location Q during detection, making the detection of the test structure more accurate.
[0064] In another embodiment of this application, reference is made to Figure 5 , Figure 5 This is a schematic diagram of another test structure provided in an embodiment of this application; the test structure further includes:
[0065] The third test structure 07 includes a second connecting part 071 and a second test finger 072. The second connecting part 071 extends in the first direction X, and the second test finger 072 is arranged sequentially at intervals along the first direction X on the second connecting part 071. The second test finger 072 extends in the second direction Y.
[0066] The second test finger 072 and the first test finger 012 are located between the second connecting part 071 and the first connecting part 011, and in the first direction X, the second test finger 072 and the first test finger 012 are arranged alternately at intervals.
[0067] Specifically, the second connecting part 071 and the second test finger 072 can be an integral structure, both made of metal. The extending direction of the second test finger 072 intersects the extending direction of the second connecting part 071. For example, Figure 5 As shown, the first direction X is perpendicular to the second direction Y, that is, the second connecting part 071 is perpendicular to the extension direction of the second test finger 072, so as to form as shown. Figure 5The second test structure 03 is shown. In addition, the second test finger 072 may also intersect the extension direction of the second connecting part 071 at a preset angle to achieve testing of special structures, which is not specifically limited here.
[0068] It should be noted that the second test finger 072 and the first test finger 012 are located between the second connecting part 071 and the first connecting part 011, forming an alternating arrangement. At this time, as... Figure 5 As shown, the second test structure 03 extends in a serpentine pattern between the first test finger 012, the second test finger 072, the first connecting part 011, and the second connecting part 071.
[0069] In this application, the first test structure 01, the second test structure 03, and the third test structure 07 work together to expand the detection range and allow the test structures to detect a wider range of metal connecting wires.
[0070] In another embodiment of this application, the test structure further includes a fourth pad 08, which is connected to the second connection portion 071.
[0071] Specifically, the material of the fourth pad 08 includes, but is not limited to, metal pads. The fourth pad 08 can apply a test voltage to the third test structure 07 via the second connection portion 071. When a short circuit occurs, a path is formed between the third test structure 07 and the second test structure 03. It should be noted that other structures can also be used to apply voltage to the third test structure 07; no specific limitation is made.
[0072] In this embodiment, a test voltage is applied to the third test structure 07 using the fourth pad 08, so that the third test structure 07 and the second test structure 03 form a path when short-circuited, and the failure location is further detected.
[0073] In another embodiment of this application, such as Figure 5 As shown, the test structure also includes a second positioning component 09, which is located on the second connecting part 071 on one side of the second test finger 072 and is set in a one-to-one correspondence with the second test finger 072.
[0074] Specifically, there can be multiple second positioning components 09. The second positioning components 09 are located on the second connecting part 071 on one side of the second test finger 072. That is to say, the number of second positioning components 09 and second test fingers 072 is the same, and each second positioning component 09 can be relative to one second test finger 072.
[0075] In this embodiment, a second positioning component 09 corresponding to the second test finger 072 is provided on the second connecting part 071 of the second test structure 03. When a short circuit occurs between the third test structure 07 and the second test structure 03, the second positioning component 09 can accurately locate the second test finger 072 at the corresponding position, thereby accurately detecting the location of the short circuit and improving the detection accuracy of the test structure.
[0076] In another embodiment of this application, the second positioning component 09 includes a second resistor or a second diode.
[0077] Specifically, the second positioning component 09 includes, but is not limited to, a second resistor or a second diode (not shown in the figure).
[0078] Taking the second positioning component 09 as the second resistor as an example, when the failure location appears, a path is formed between the third test structure 07 and the second test structure 03. After applying a test voltage to the pad, the location of the short circuit can be detected by the resistance value of the current flowing through the second resistor. Then, using the test results as a reference, a more accurate failure location can be obtained by using the photo-induced resistance change (OBIRCH) mode.
[0079] Taking the second positioning component 09 as the second diode as an example, a path is formed between the third test structure 07 and the second test structure 03. After applying a test voltage to the pad, the second diode through which the current flows will turn on. The location of the short circuit can be detected by testing the turned-on second diode using an optical microscopy (EMMI) microscope.
[0080] In this embodiment, the second positioning component 09 is configured as a second resistor or a second diode, which has a simple structure. Furthermore, detecting the resistance value and the on / off state of the diode is relatively simple, improving detection accuracy while ensuring ease of detection.
[0081] In another embodiment of this application, reference is made to Figure 6 , Figure 6 This is a schematic diagram of another test structure for testing short circuits provided in an embodiment of this application; the resistance value of the second resistor is much greater than the resistance value of the second test structure 03.
[0082] Specifically, when the resistance of the second resistor is much greater than the resistance of the second test structure 03, the failure location can be magnified, making the detection of the test structure more accurate. For example, when setting up this test structure, first test the resistance Rm of the second test structure 03, and then record the resistance of Rm as aΩ. At this time, set the resistance of the second resistor on the second connection part 071 to 10aΩ, so that the resistance of the second resistor is much greater than the resistance of the second test structure 03.
[0083] When a short circuit occurs between the tested metal connecting wires, the failure location Q connects the third test structure 07 and the second test structure 03. At this time, as... Figure 6 As shown, the current flows from the first pad 04 along the second test structure 03 to the failure location Q, and then along the third test structure 07 through the three second positioning components 09 to the fourth pad 08.
[0084] At this point, the resistance between the third test structure 07 and the second test structure 03 is recorded as 3 × 10aΩ = 30aΩ. Since the resistance of the second resistor is much greater than that of the second test structure 03, the resistance between the fourth pad 08 and the failure location Q can be used to locate the failure location Q. Then, based on the test results as a reference, OBRICH can be used to obtain a more accurate failure location.
[0085] When the second positioning component 09 is a second resistor, the formed circuit amplifies the test failure location Q because the resistance value of the second resistor is large enough. When the second positioning component 09 is a second diode, the formed circuit also amplifies the test failure location Q because only the second diode through which current flows will turn on.
[0086] In this embodiment, the resistance value of the second resistor is much larger than that of the second test structure 03, which amplifies the failure location Q during detection, making the detection of the test structure more accurate.
[0087] In another embodiment of this application, in the first direction X, the interval between the second test finger 072 and the first test finger 012 is the same.
[0088] Specifically, when the spacing between the first test finger 012 and the second test finger 072 is the same, the test structure is tested more uniformly, and when detecting failure locations, the uniform spacing can ensure that no detection is missed, further improving the test accuracy of the test structure.
[0089] In the description of this specification, references to terms such as "some embodiments," "another embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.
[0090] 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.
[0091] 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, include: The first test structure includes a first connecting portion and a first test finger. The first connecting portion extends in a first direction, and the first test finger is arranged sequentially at intervals along the first direction on the first connecting portion. The first test finger extends along a second direction. The first direction and the second direction are located in the same plane and are intersected by each other. The first positioning component is located on the first connecting part on one side of the first test finger, and is set in a one-to-one correspondence with the first test finger; The second test structure extends in a serpentine pattern along the edge of the first test finger and the first connection portion.
2. The test structure according to claim 1, characterized in that, The test structure also includes: First pad, second pad, and third pad; The first pad is connected to the first end of the second test structure, and the second pad is connected to the second end of the second test structure; The third pad is connected to the first connection part.
3. The test structure according to claim 1, characterized in that, The first positioning component includes a first resistor or a first diode.
4. The test structure according to claim 3, characterized in that, The resistance of the first resistor is much greater than the resistance of the first test structure.
5. The test structure according to claim 1, characterized in that, The test structure also includes: The third test structure includes a second connecting part and a second test finger. The second connecting part extends in the first direction, and the second test finger is arranged sequentially at intervals on the second connecting part along the first direction. The second test finger extends in the second direction. The second test finger and the first test finger are located between the second connecting portion and the first connecting portion, and in the first direction, the second test finger and the first test finger are arranged alternately at intervals.
6. The test structure according to claim 5, characterized in that, The test structure also includes: The fourth pad is connected to the second connection portion.
7. The test structure according to claim 5, characterized in that, In the first direction, the interval between the second test finger and the first test finger is the same.
8. The test structure according to claim 5, characterized in that, The test structure also includes: The second positioning component is located on the second connecting part on one side of the second test finger, and is set in a one-to-one correspondence with the second test finger.
9. The test structure according to claim 8, characterized in that, The second positioning component includes a second resistor or a second diode.
10. The test structure according to claim 9, characterized in that, The resistance of the second resistor is much greater than the resistance of the second test structure.