Test structure and test method

Abstract

A test structure and test method are disclosed. The structure includes: a plurality of first metal wires arranged in a matrix along a first direction and a second direction, wherein the first direction and the second direction are perpendicular to each other; a plurality of interconnection structures, each interconnection structure including a comb handle portion and comb teeth portions electrically connected to the comb handle portion, wherein the comb teeth portions are located at the top of the first metal wires and span the first metal wires, and each first metal wire is electrically connected to the comb teeth portion spanning its top, wherein the comb handle portions of the plurality of interconnection structures are respectively used as test signal loading terminals. This reduces the area occupied by the test structure.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing, and more particularly to a test structure and test method. Background Technology

[0002] In advanced BEOL process nodes, as the area continues to shrink and with the introduction of SAQP process, a large number of metal cut processes will occur. The reliability of metal cut process is becoming a key factor affecting product yield. Therefore, detailed monitoring of the health of metal cut process is becoming increasingly important. Common metal cut process failure modes include cut missing and overcut.

[0003] To fully monitor the health of the metal cut process and simulate various situations that may occur in a real chip, it is often necessary to introduce a large number of test structures to cover all possible scenarios.

[0004] Currently, the area occupied by the test structure still needs to be reduced. Summary of the Invention

[0005] The problem solved by the embodiments of the present invention is to provide a test structure and test method that helps to reduce the area occupied by the test structure.

[0006] To address the aforementioned problems, embodiments of the present invention provide a test structure comprising: a plurality of first metal wires arranged in a matrix along a first direction and a second direction, wherein the first direction and the second direction are perpendicular to each other; a plurality of interconnection structures, each interconnection structure comprising a comb handle portion and comb teeth portions electrically connected to the comb handle portion, wherein the comb teeth portions are located at the top of the first metal wires and span the first metal wires, the first metal wires are electrically connected to the comb teeth portions spanning their tops, and the comb handle portions of the plurality of interconnection structures are respectively used as test signal loading terminals.

[0007] Optionally, the test structure further includes: a first isolation port group, arranged at intervals along the first direction in the first metal line, the first isolation port group including adjacent first isolation ports; and a second isolation port group, located between adjacent first isolation port groups along the first direction, the second isolation port group including adjacent second isolation ports, and the first isolation ports and the second isolation ports are formed in different forming processes.

[0008] Optionally, the plurality of interconnect structures include: a first interconnect structure, a second interconnect structure, and a third interconnect structure; the first interconnect structure includes a first comb tooth portion and a first comb handle portion electrically connected to the first comb tooth portion, the first comb tooth portion being located above a first metal wire between adjacent first partition openings, and the first comb tooth portion being electrically connected to the first metal wire, the first comb handle portion being used as a first test signal loading terminal; the second interconnect structure includes a second comb tooth portion and a second comb handle portion electrically connected to the second comb tooth portion, the second comb tooth portion being located above a first metal wire between adjacent second partition openings, and the second comb tooth portion being electrically connected to the first metal wire, the second comb handle portion being used as a second test signal loading terminal; the third interconnect structure includes a third comb tooth portion and a third comb handle portion electrically connected to the third comb tooth portion, the third comb tooth portion being located above a first metal wire between adjacent first partition opening groups and second partition opening groups, and the third comb tooth portion being electrically connected to the first metal wire, the third comb handle portion being used as a third test signal loading terminal.

[0009] Optionally, the test structure further includes: a first interconnecting through-hole structure located between the first comb teeth and the first metal wire, and between the first comb teeth and the first comb handle, wherein the first comb teeth are electrically connected to the first metal wire through the first interconnecting through-hole structure, and the first comb teeth are electrically connected to the first comb handle through the first interconnecting through-hole structure; a second interconnecting through-hole structure located between the second comb teeth and the first metal wire, and between the second comb teeth and the second comb handle, wherein the second comb teeth are electrically connected to the first metal wire through the second interconnecting through-hole structure, and the second comb teeth are electrically connected to the second comb handle through the second interconnecting through-hole structure; and a third interconnecting through-hole structure located between the third comb teeth and the first metal wire, and between the third comb teeth and the third comb handle, wherein the third comb teeth are electrically connected to the third comb handle through the third interconnecting through-hole structure.

[0010] Optionally, the materials of the first interconnect via structure, the second interconnect via structure, and the third interconnect via structure all include copper, tungsten, cobalt, or ruthenium.

[0011] Optionally, the first comb handle portion and the second comb handle portion are located on the same side, and the third comb handle portion is opposite to the first comb handle portion and the second comb handle portion.

[0012] Optionally, the comb handle portions of the multiple interconnected structures extend in the same direction.

[0013] Optionally, the test structure further includes: a second metal wire arranged in a matrix along the first and second directions, with the second metal wire located on both sides of the first metal wire; and a plurality of third partition openings located between adjacent second metal wires in the first direction.

[0014] Optionally, the second metal wires located on both sides of the third partition opening are electrically connected to the comb teeth of different interconnect structures.

[0015] Optionally, the test structure further includes: a fourth interconnect via structure located between the second metal wire and the comb tooth portion, wherein the second metal wire is electrically connected to the comb tooth portion through the fourth interconnect via structure.

[0016] Optionally, the materials of the fourth interconnect via structure include copper, tungsten, cobalt, or ruthenium.

[0017] Optionally, along the first direction, the distance between adjacent comb teeth is 20 nanometers to 480 nanometers.

[0018] Optionally, the test signal loading terminal is used to measure the current value between adjacent first metal lines.

[0019] Accordingly, this embodiment of the invention also provides a testing method, including: providing the test structure provided in this embodiment of the invention; measuring a first current value between any two test signal loading terminals, and determining whether adjacent first metal lines are short-circuited based on the first current value.

[0020] Optionally, the step of determining whether adjacent first metal lines are short-circuited includes: if the first current value is 0, then it is determined that adjacent first metal lines are not short-circuited; if the first current value is greater than 0, then it is determined that adjacent first metal lines are short-circuited.

[0021] Optionally, the test structure further includes: second metal wires arranged in a matrix along the first and second directions, with the second metal wires located on both sides of the first metal wires; a plurality of third isolation openings located between adjacent second metal wires in the first direction, and the second metal wires located on both sides of the third isolation openings being electrically connected to the comb teeth of different interconnection structures; after determining whether there is a short circuit between adjacent first metal wires based on the current value, the test method further includes: measuring a second current value between the test signal loading terminals electrically connected to the second metal wires, and determining whether there is a short circuit between adjacent second metal wires based on the second current value.

[0022] Optionally, the step of determining whether adjacent second metal lines are short-circuited includes: if the second current value is 0, then it is determined that adjacent second metal lines are not short-circuited; if the second current value is greater than 0, then it is determined that adjacent second metal lines are short-circuited.

[0023] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0024] This invention provides a test structure in which multiple first metal wires are arranged in a matrix along a first direction and a second direction, the first direction and the second direction being perpendicular to each other; multiple interconnection structures, each interconnection structure including a comb handle portion and comb teeth portions electrically connected to the comb handle portion, the comb teeth portions being located at the top of the first metal wires and spanning the first metal wires, the first metal wires being electrically connected to the comb teeth portions spanning their tops, and the comb handle portions of the multiple interconnection structures being used as test signal loading terminals respectively. By setting multiple interconnection structures in one test structure, each interconnection structure being provided with a test signal loading terminal, in the subsequent test method, through... By measuring the current value between any two test signal loading terminals, it is possible to determine whether there is a short circuit between adjacent first metal lines. In other words, by setting multiple test signal loading terminals in the same test structure, and combining the multiple test signal loading terminals in pairs, the test structure can perform electrical tests between a large number of adjacent first metal lines. Compared with the existing method that requires multiple test structures to complete the electrical test between adjacent first metal lines, the embodiment of the present invention only requires one test structure to perform electrical tests between a large number of adjacent first metal lines, thereby reducing the area occupied by the test structure and using the saved area to set up other device structures. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of an embodiment of the test structure of the present invention;

[0026] Figure 2 This is a flowchart of the steps of an embodiment of the testing method of the present invention. Detailed Implementation

[0027] The performance of current test structures needs improvement. To fully monitor the health of the Metal Cut process, test structures are introduced to cover various possible scenarios in the Metal Cut process. The most common scenario in the Metal Cut process is Cut Missing (Cut Missing refers to the fact that the metal wire that should have been cut was not completely cut). As the density of metal wires increases, the density of metal wire isolation interfaces also increases. Due to the performance requirements of photolithography equipment, in order to increase the process window for forming metal wire isolation interfaces, the isolation interfaces need to be formed in different Metal Cut processes. Each metal cut process forms an isolation interface corresponding to a test structure, which is used to perform electrical testing on the isolation interface. Since there are multiple metal cut processes, it means that multiple corresponding test structures need to be formed to perform electrical testing on the isolation interfaces, which results in multiple test structures occupying an excessively large area.

[0028] To address the technical problem, this invention provides a test structure comprising: a plurality of first metal wires arranged in a matrix along a first direction and a second direction, wherein the first direction and the second direction are perpendicular to each other; a plurality of interconnection structures, each interconnection structure comprising a comb handle portion and comb teeth portions electrically connected to the comb handle portion, wherein the comb teeth portions are located at the top of the first metal wires and span the first metal wires, the first metal wires are electrically connected to the comb teeth portions spanning their tops, and the comb handle portions of the plurality of interconnection structures are respectively used as test signal loading terminals.

[0029] In the test structure provided by this embodiment of the invention, multiple first metal wires are arranged in a matrix along a first direction and a second direction, the first direction and the second direction being perpendicular to each other; multiple interconnection structures, each interconnection structure including a comb handle portion and comb teeth portions electrically connected to the comb handle portion, the comb teeth portions being located at the top of the first metal wires and spanning the first metal wires, the first metal wires being electrically connected to the comb teeth portions spanning their tops, and the comb handle portions in the multiple interconnection structures being used as test signal loading terminals respectively, by setting multiple interconnection structures in one test structure, each interconnection structure being provided with a test signal loading terminal, in the subsequent test method, through By measuring the current value between any two test signal loading terminals, it is possible to determine whether there is a short circuit between adjacent first metal lines. In other words, by setting multiple test signal loading terminals in the same test structure, and combining the multiple test signal loading terminals in pairs, the test structure can perform electrical tests between a large number of adjacent first metal lines. Compared with the existing method that requires multiple test structures to complete the electrical test between adjacent first metal lines, the embodiment of the present invention only requires one test structure to perform electrical tests between a large number of adjacent first metal lines, thereby reducing the area occupied by the test structure and using the saved area to set up other device structures.

[0030] To make the above-mentioned objects, features and advantages of the embodiments of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0031] Figure 1 This is a schematic diagram of an embodiment of the test structure of the present invention.

[0032] The test structure includes: multiple first metal lines 100, along a first direction (e.g., Figure 1 (as shown in the X direction) and the second direction (as shown in the X direction) Figure 1 The interconnects are arranged in a matrix (as shown in the Y direction), with the first and second directions perpendicular to each other; multiple interconnect structures 189, each interconnect structure 189 including a comb handle portion 192 and a comb tooth portion 191 electrically connected to the comb handle portion 192, the comb tooth portion 191 being located at the top of the first metal line 100 and spanning the first metal line 100, the first metal line 100 being electrically connected to the comb tooth portion 191 spanning its top, and the comb handle portion 192 in the multiple interconnect structures 189 being used as a test signal loading terminal respectively.

[0033] It should be noted that by setting multiple interconnect structures 189 in a single test structure, each interconnect structure 189 is provided with a test signal loading terminal. In the subsequent test method, by measuring the current value between any two test signal loading terminals, it can be determined whether there is a short circuit between adjacent first metal lines 100. In other words, by setting multiple test signal loading terminals in the same test structure, and combining the multiple test signal loading terminals in pairs, the test structure can perform electrical tests between a large number of adjacent first metal lines 100. Compared with the existing method that requires multiple test structures to cooperate to complete the electrical test between adjacent first metal lines 100, the embodiment of the present invention only requires one test structure to perform electrical tests between a large number of adjacent first metal lines 100, thereby reducing the area occupied by the test structure and using the saved area to set up other device structures.

[0034] In order to fully monitor the health of the Metal cut process, a test structure is introduced to cover various situations that may occur in the Metal cut process, which means that the health of the Metal cut process is monitored through the test structure.

[0035] Specifically, the test structure is set in the dicing area of ​​the wafer.

[0036] In this embodiment, the first metal wire 100 is in the first direction (e.g., Figure 1 (as shown in the X direction) and the second direction (as shown in the X direction) Figure 1 The matrix arrangement is shown in the Y direction, and the first direction (as shown in the image) is as follows: Figure 1 (as shown in the X direction) and the second direction (as shown in the X direction) Figure 1 (as shown in the Y direction) are perpendicular.

[0037] The first metal line 100 is the metal line in the test structure that has been metal-cut. The first metal line 100 is used to monitor whether a cut missing phenomenon occurs in the metal-cut process.

[0038] Specifically, "cut missing" refers to the fact that the metal wire that should have been cut was not completely cut off.

[0039] As an example, the material of the first metal wire 100 includes one or both of copper and aluminum.

[0040] In this embodiment, the test structure further includes: a first isolation opening group 102, which is arranged at intervals along the first direction in the first metal wire 100, and the first isolation opening group 102 includes adjacent first isolation openings 101.

[0041] It should be noted that the first partition opening 101 in the first partition opening group 102 is the first partition opening 101 formed by cutting the first metal wire 100 by the Metal cut process.

[0042] The test structure further includes: a second isolation port group 105 located between adjacent first isolation port groups 102 along the first direction, the second isolation port group 105 including adjacent second isolation ports 103, and the first isolation ports 101 and the second isolation ports 103 are formed in different forming processes.

[0043] It should be noted that the second partition opening 103 in the second partition opening group 105 is the second partition opening 103 formed by cutting the first metal wire 100 using the Metal cut process.

[0044] It should also be noted that the first partition opening 101 and the second partition opening 103 are formed in different forming processes, which means that the first metal wire 100 forms the first partition opening 101 and the second partition opening 103 in different metal cut processes.

[0045] Specifically, as the density of metal wires increases, the density of metal wire separation openings also increases. Due to the performance requirements of photolithography equipment, in order to increase the process window for forming metal wire separation openings, the first separation opening 101 and the second separation opening 103 in this embodiment are formed in different metal cut processes.

[0046] Correspondingly, compared to the existing scheme where one test structure corresponds to one partition formed by a metal cut process, and the test structure performs electrical tests on the partition, the test structure in this embodiment can perform electrical tests on partitions formed by multiple metal cut processes, thereby reducing the area occupied by the test structure.

[0047] Specifically, multiple interconnect structures 189 are used to provide test signals to the metal lines under test (i.e., the first metal line 100 and the subsequently configured second metal line 120).

[0048] In this embodiment, the comb handle portions 192 of the plurality of interconnecting structures 189 extend in the same direction.

[0049] It should be noted that the extension direction of the comb handle portion 192 of the multiple interconnection structures 189 is the same. In the subsequent process of loading test signals through the comb handle portion 192, it is beneficial to make the test signal loading end of the comb handle portion 192 of the interconnection structure 189 on the same side, thereby reducing the connection distance between the comb handle portion 192 and the external test interface.

[0050] In this embodiment, the comb handle 192 is used as a test signal loading terminal. The test signal loading terminal is used to measure the current value between adjacent first metal wires 100, so as to determine whether there is an open circuit between adjacent first metal wires 100. In other words, it can determine whether adjacent first metal wires 100 are completely cut off.

[0051] It should be noted that the comb tooth section 191 is used to electrically connect with the first metal line 100, so that the test signal can enter the first metal line 100 through the comb tooth section 191.

[0052] Specifically, the comb tooth portion 191 being electrically connected to the first metal wire 100 means that the comb tooth portion 191 is electrically connected to the first metal wire 100 in the extending direction of the comb tooth portion 191.

[0053] It should also be noted that the distance between adjacent comb teeth 191 along the first direction should not be too small or too large. If the distance between adjacent comb teeth 191 is too small, the probability of short circuits between adjacent comb teeth 191 increases, leading to test structure failure and affecting the accuracy of test results. If the distance between adjacent comb teeth 191 is too large, the area occupied by the test structure is too large, resulting in an excessively large wafer dicing area. Consequently, the area reserved for the chip area in the wafer is too small, which greatly reduces the economic value of the wafer. Therefore, in this embodiment, the distance between adjacent comb teeth 191 along the first direction is 20 nanometers to 480 nanometers.

[0054] As an example, the plurality of interconnect structures 189 include a first interconnect structure 162, a second interconnect structure 132 and a third interconnect structure 152.

[0055] In this embodiment, the first interconnection structure 162 includes a first comb tooth portion 161 and a first comb handle portion 160 electrically connected to the first comb tooth portion 161. The first comb tooth portion 161 is located above the first metal wire 100 between adjacent first partition openings 101, and the first comb tooth portion 161 is electrically connected to the first metal wire 100. The first comb handle portion 160 is used as a first test signal loading end.

[0056] Specifically, the first comb handle portion 160 is used as a first test signal loading terminal for connecting an external test signal, and the first interconnection structure 162 has a plurality of first comb teeth portions 161, and the first comb teeth portions 161 are used for electrical connection with a portion of the first metal wire 100.

[0057] It should be noted that the first comb tooth portion 161 being used for electrical connection with a portion of the first metal wire 100 means that the first comb tooth portion 161 is electrically connected to the first metal wire 100 in the extending direction of the first comb tooth portion 161.

[0058] In this embodiment, the test structure further includes: a first interconnecting through-hole structure 199, located between the first comb tooth portion 161 and the first metal wire 100, and located between the first comb tooth portion 161 and the first comb handle portion 160, wherein the first comb tooth portion 161 is electrically connected to the first metal wire 100 through the first interconnecting through-hole structure 199, and the first comb tooth portion 161 is electrically connected to the first comb handle portion 160 through the first interconnecting through-hole structure 199.

[0059] Specifically, the first interconnect via structure 199 enables the first metal wire 100, the first comb tooth portion 161 and the first comb handle portion 160 to form a test signal path, thereby enabling the test signal to enter the first metal wire 100 between adjacent first isolation openings 101.

[0060] In this embodiment, the material of the first interconnect via structure 199 includes copper, tungsten, cobalt, or ruthenium.

[0061] Specifically, copper, tungsten, cobalt, or ruthenium are all commonly used conductive materials for interconnect vias, which are beneficial for large-area mass production.

[0062] In this embodiment, the second interconnection structure 132 includes a second comb tooth portion 131 and a second comb handle portion 130 electrically connected to the second comb tooth portion 131. The second comb tooth portion 131 is located above the first metal wire 100 between adjacent second partition openings 103. The second comb tooth portion 131 is electrically connected to the first metal wire 100. The second comb handle portion 130 is used as a second test signal loading end.

[0063] Specifically, the second comb handle portion 130 is used as a second test signal loading terminal for connecting an external test signal, and the second interconnection structure 132 has a plurality of second comb teeth portions 131, and the second comb teeth portions 131 are used for electrical connection with a portion of the first metal wire 100.

[0064] It should be noted that the second comb tooth portion 131 is used for electrical connection with a portion of the second metal wire 120, meaning that the second comb tooth portion 131 is electrically connected to the first metal wire 100 in the extending direction of the second comb tooth portion 131.

[0065] In this embodiment, the test structure further includes: a second interconnecting through-hole structure 133, located between the second comb tooth portion 131 and the first metal wire 100, and located between the second comb tooth portion 131 and the second comb handle portion 130, wherein the second comb tooth portion 131 is electrically connected to the first metal wire 100 through the second interconnecting through-hole structure 133, and the second comb tooth portion 131 is electrically connected to the second comb handle portion 130 through the second interconnecting through-hole structure 133.

[0066] Specifically, the second interconnecting via structure 133 enables the first metal wire 100, the second comb tooth portion 131, and the second comb handle portion 130 to form a test signal path, thereby allowing the test signal to enter the first metal wire 100 between adjacent second isolation openings 103.

[0067] In this embodiment, the material of the second interconnect via structure 133 includes copper, tungsten, cobalt, or ruthenium.

[0068] Specifically, copper, tungsten, cobalt, or ruthenium are all commonly used conductive materials for interconnect vias, which are beneficial for large-area mass production.

[0069] In this embodiment, the third interconnection structure 152 includes a third comb tooth portion 151 and a third comb handle portion 150 electrically connected to the third comb tooth portion 151. The third comb tooth portion 151 is located above the first metal wire 100 between adjacent first isolation opening group 102 and second isolation opening group 105, and the third comb tooth portion 151 is electrically connected to the first metal wire 100. The third comb handle portion 150 is used as a third test signal loading terminal.

[0070] Specifically, the third comb handle portion 150 is used as a third test signal loading terminal for connecting an external test signal, and the third interconnection structure 152 has a plurality of third comb teeth portions 151, and the third comb teeth portions 151 are used for electrical connection with a portion of the first metal wire 100.

[0071] It should be noted that the third comb tooth portion 151 is used for electrical connection with a portion of the first metal wire 100, meaning that the third comb tooth portion 151 is electrically connected to the first metal wire 100 in the extending direction of the third comb tooth portion 151.

[0072] In this embodiment, the test structure further includes a third interconnecting via structure 180, located between the third comb tooth portion 151 and the first metal wire 100, and between the third comb tooth portion 151 and the third comb handle portion 150, wherein the third comb tooth portion 151 is electrically connected to the third comb handle portion 150 through the third interconnecting via structure 180.

[0073] Specifically, the third interconnecting via structure 180 enables the first metal wire 100, the third comb tooth portion 151, and the third comb handle portion 150 to form a test signal path, thereby allowing the test signal to enter the first metal wire 100 between the first isolation port group 102 and the second isolation port group 105.

[0074] In this embodiment, the material of the third interconnect via structure 180 includes copper, tungsten, cobalt, or ruthenium.

[0075] Specifically, copper, tungsten, cobalt, or ruthenium are all commonly used conductive materials for interconnect vias, which are beneficial for large-area mass production.

[0076] In this embodiment, the first comb handle portion 160 and the second comb handle portion 130 are on the same side, and the third comb handle portion 150 is opposite to the first comb handle portion 160 and the second comb handle portion 130.

[0077] It should be noted that the first comb handle portion 160 and the second comb handle portion 130 are on the same side, and the third comb handle portion 150 is opposite to the first comb handle portion 160 and the second comb handle portion 130. This makes the third comb handle portion 150 not on the same side as the first comb handle portion 160 and the second comb handle portion 130, which reduces the pattern density of the comb handle portion 192 on the same side and increases the process window for forming the comb handle portion 192.

[0078] In this embodiment, the test structure further includes a second metal wire 120, which is arranged in a matrix along the first direction and the second direction, and the second metal wire 120 is located on both sides of the first metal wire 100.

[0079] Specifically, the second metal line 120 is the metal line in the test structure that has been metal-cut. The second metal line 120 is used to monitor whether a cut missing phenomenon occurs in the metal-cut process.

[0080] It should be noted that the line width of the second metal line 120 is different from that of the first metal line 100. In other words, the process for forming the first metal line 100 is different from the process for forming the second metal line 120. For example, the process for forming the first metal line 100 is a one-step etching process, while the process for forming the second metal line 120 includes a multi-exposure image transfer process.

[0081] As an example, the material of the second metal wire 120 includes one or both of copper and aluminum.

[0082] In this embodiment, the test structure further includes: a plurality of third isolation openings 108 located between adjacent second metal lines 120 in the first direction, and the second metal lines 120 located on both sides of the third isolation openings 108 being electrically connected to the comb teeth 191 of different interconnection structures.

[0083] Specifically, the third partition opening 108 is the third partition opening 108 formed by cutting the second metal wire 120 using the Metal cut process.

[0084] It should be noted that the second metal wires 120 located on both sides of the third partition opening 108 are electrically connected to the comb teeth 191 with different interconnection structures, thereby enabling electrical testing of adjacent second metal wires 120 through different interconnection structures.

[0085] like Figure 1 As shown, a second metal wire 120 on one side of the third partition opening 108 is electrically connected to the first comb tooth portion 161, and a second metal wire 120 on the other side of the third partition opening 108 is electrically connected to the second comb tooth portion 131.

[0086] It should also be noted that the first comb handle portion 160 and the second comb handle portion 130 serve as both test signal loading terminals for part of the first metal wire 100 and test signal loading terminals for the second metal wire 120. In other words, in the process of measuring whether there is a short circuit between adjacent first metal wires 100 and adjacent second metal wires 120, the test structure reduces the number of test signal loading terminals by sharing test signal loading terminals, thereby further reducing the area occupied by the test structure.

[0087] In this embodiment, the test structure further includes a fourth interconnecting via structure 170, located between the second metal wire 120 and the comb tooth portion 191, and the second metal wire 120 is electrically connected to the comb tooth portion 191 through the fourth interconnecting via structure 170.

[0088] Specifically, the fourth interconnect via structure 170 enables the second metal wire 120 to form a test signal path with the comb tooth portion 191 and the comb handle portion 192, thereby allowing the test signal to enter the second metal wires 120 on both sides of the third isolation port 108. Then, by acquiring the current between the second metal wires 120 on both sides of the third isolation port 108, it can be determined whether the adjacent second metal wires 120 form a short circuit.

[0089] In this embodiment, the material of the fourth interconnect via structure 170 includes copper, tungsten, cobalt, or ruthenium.

[0090] Accordingly, embodiments of the present invention also provide a testing method. To make the above-mentioned objectives, features, and advantages of the embodiments of the present invention more apparent and understandable, the following description is provided in conjunction with... Figures 1 to 2 Specific embodiments of the present invention will be described in detail below. Figure 2 This is a flowchart of the steps of an embodiment of the testing method of the present invention.

[0091] refer to Figure 1 Step S1: Provide the test structure provided in the embodiment of the present invention.

[0092] For a detailed description of the test structure provided in the embodiments of the present invention, please refer to the foregoing description, which will not be repeated here.

[0093] In this embodiment, the test structure further includes a second metal wire 120, which is arranged in a matrix along the first direction and the second direction, and the second metal wire 120 is located on both sides of the first metal wire 100.

[0094] Specifically, the second metal line 120 is the metal line in the test structure that has been metal-cut. The second metal line 120 is used to monitor whether a cut missing phenomenon occurs in the metal-cut process.

[0095] It should be noted that the line width of the second metal line 120 is different from that of the first metal line 100. In other words, the process for forming the first metal line 100 is different from the process for forming the second metal line 120. For example, the process for forming the first metal line 100 is a one-step etching process, while the process for forming the second metal line 120 includes a multi-exposure image transfer process.

[0096] As an example, the material of the second metal wire 120 includes one or both of copper and aluminum.

[0097] In this embodiment, the test structure further includes: a plurality of third isolation openings 108 located between adjacent second metal lines 120 in the first direction, and the second metal lines 120 located on both sides of the third isolation openings 108 being electrically connected to the comb teeth 191 of different interconnection structures.

[0098] Specifically, the third partition opening 108 is the third partition opening 108 formed by cutting the second metal wire 120 using the Metal cut process.

[0099] It should be noted that the second metal wires 120 located on both sides of the third partition opening 108 are electrically connected to the comb teeth 191 with different interconnection structures, thereby enabling electrical testing of adjacent second metal wires 120 through different interconnection structures.

[0100] refer to Figure 1 Step S2: Measure the first current value between any two test signal loading terminals, and determine whether the adjacent first metal lines 100 are short-circuited based on the first current value.

[0101] Specifically, by measuring the current value between any two test signal loading terminals, it can be determined whether there is a short circuit between adjacent first metal lines 100. In other words, by setting multiple test signal loading terminals in the same test structure, and combining the multiple test signal loading terminals in pairs, the test structure can perform electrical tests between a large number of adjacent first metal lines 100. Compared with the existing method that requires multiple test structures to cooperate to complete the electrical test between adjacent first metal lines 100, the embodiment of the present invention only requires one test structure to perform electrical tests between a large number of adjacent first metal lines 100, thereby reducing the area occupied by the test structure and using the saved area to set up other device structures.

[0102] It should also be noted that, specifically, as the density of the metal wires increases, the density of the metal wire separation openings also increases. Due to the performance requirements of the photolithography equipment, in order to increase the process window for forming the metal wire separation openings, the first separation opening 101 and the second separation opening 103 in this embodiment are formed in different metal cut processes.

[0103] Correspondingly, compared to the existing scheme where one test structure corresponds to one partition formed by a metal cut process, and the test structure performs electrical tests on the partition, the test structure in this embodiment can perform electrical tests on partitions formed by multiple metal cut processes, thereby reducing the area occupied by the test structure.

[0104] In this embodiment, the step of determining whether adjacent first metal lines 100 are short-circuited includes: if the first current value is 0, then it is determined that adjacent first metal lines 100 are not short-circuited; if the first current value is greater than 0, then it is determined that adjacent first metal lines 100 are short-circuited.

[0105] Specifically, a current value of 0 means that there is a complete break between adjacent first metal lines 100, and there is no interconnection between adjacent first metal lines 100; a current value greater than 0 means that there is a path between adjacent first metal lines 100, which means that the adjacent first metal lines 100 are not completely cut off, that is, there is a short circuit between adjacent first metal lines 100.

[0106] As an example, such as Figure 1 As shown, the presence of a short circuit between adjacent first metal lines 100 is determined by obtaining the second current value between the third test signal loading terminal and the second test signal loading terminal, as well as the second current value between the first test signal loading terminal and the third test signal loading terminal.

[0107] refer to Figure 1 Step S3: After determining whether there is a short circuit between adjacent first metal lines 100 based on the current value, the test method further includes: measuring the second current value between the test signal loading terminals electrically connected to the second metal line 120, and determining whether there is a short circuit between adjacent second metal lines 120 based on the second current value.

[0108] Specifically, by determining whether there is a short circuit between adjacent second metal wires 120, it is determined whether the third isolation opening 108 in the second metal wire 120 is completely cut off.

[0109] In this embodiment, the step of determining whether adjacent second metal lines 120 are short-circuited includes: if the second current value is 0, then it is determined that adjacent second metal lines 120 are not short-circuited; if the second current value is greater than 0, then it is determined that adjacent second metal lines 120 are short-circuited.

[0110] Specifically, a current value of 0 means that there is a complete break between adjacent first metal lines 100, and there is no interconnection between adjacent first metal lines 100; a current value greater than 0 means that there is a path between adjacent first metal lines 100, which means that the adjacent first metal lines 100 are not completely cut off, that is, there is a short circuit between adjacent first metal lines 100.

[0111] As an example, such as Figure 1 As shown, by obtaining the second current value between the first test signal loading terminal and the second test signal loading terminal, it is determined whether the third isolation outlet 108 in the second metal wire 120 is completely cut off.

[0112] It should be noted that, in the process of measuring whether there is a short circuit between adjacent first metal line 100 and adjacent second metal line 120, the test structure reduces the number of test signal loading terminals by sharing the test signal loading terminal, thereby further reducing the area occupied by the test structure.

[0113] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A test structure, characterized by, include: Multiple first metal lines are arranged in a matrix along a first direction and a second direction, wherein the first direction and the second direction are perpendicular. Multiple interconnect structures, each interconnect structure including a comb handle portion and comb teeth portions electrically connected to the comb handle portion, the comb teeth portions being located on top of and spanning the first metal wire, the first metal wire being electrically connected to the comb teeth portions spanning its top, and the comb handle portions in the multiple interconnect structures being used as test signal loading terminals respectively.

2. The test structure as described in claim 1, characterized in that, The test structure further includes: a first isolation outlet group, which is arranged at intervals along the first direction in the first metal wire, and the first isolation outlet group includes adjacent first isolation outlets; The second partition opening group is located between adjacent first partition opening groups along the first direction. The second partition opening group includes adjacent second partition openings, and the first partition openings and the second partition openings are formed in different forming processes.

3. The test structure as described in claim 2, characterized in that, The plurality of interconnect structures include: a first interconnect structure, a second interconnect structure, and a third interconnect structure; The first interconnection structure includes a first comb tooth portion and a first comb handle portion electrically connected to the first comb tooth portion. The first comb tooth portion is located above a first metal wire between adjacent first partition openings, and the first comb tooth portion is electrically connected to the first metal wire. The first comb handle portion is used as a first test signal loading end. The second interconnection structure includes a second comb tooth portion and a second comb handle portion electrically connected to the second comb tooth portion. The second comb tooth portion is located above a first metal wire between adjacent second partition openings. The second comb tooth portion is electrically connected to the first metal wire. The second comb handle portion is used as a second test signal loading terminal. The third interconnection structure includes a third comb tooth portion and a third comb handle portion electrically connected to the third comb tooth portion. The third comb tooth portion is located above a first metal wire between adjacent first and second isolation outlet groups, and the third comb tooth portion is electrically connected to the first metal wire. The third comb handle portion is used as a third test signal loading terminal.

4. The test structure as described in claim 3, characterized in that, The test structure further includes: a first interconnecting through-hole structure, located between the first comb tooth portion and the first metal wire, and located between the first comb tooth portion and the first comb handle portion, wherein the first comb tooth portion is electrically connected to the first metal wire through the first interconnecting through-hole structure, and the first comb tooth portion is electrically connected to the first comb handle portion through the first interconnecting through-hole structure. The second interconnecting through-hole structure is located between the second comb tooth portion and the first metal wire, and between the second comb tooth portion and the second comb handle portion. The second comb tooth portion is electrically connected to the first metal wire through the second interconnecting through-hole structure, and the second comb tooth portion is electrically connected to the second comb handle portion through the second interconnecting through-hole structure. The third interconnecting through-hole structure is located between the third comb tooth portion and the first metal wire, and between the third comb tooth portion and the third comb handle portion, and the third comb tooth portion is electrically connected to the third comb handle portion through the third interconnecting through-hole structure.

5. The test structure as described in claim 4, characterized in that, The materials of the first interconnect via structure, the second interconnect via structure and the third interconnect via structure all include copper, tungsten, cobalt or ruthenium.

6. The test structure as described in claim 3, characterized in that, The first comb handle portion and the second comb handle portion are on the same side, and the third comb handle portion is opposite to the first comb handle portion and the second comb handle portion.

7. The test structure as described in claim 1, characterized in that, The comb handles of the multiple interconnected structures extend in the same direction.

8. The test structure as described in claim 1, characterized in that, The test structure further includes: a second metal wire, which is arranged in a matrix along the first direction and the second direction, and the second metal wire is located on both sides of the first metal wire; Multiple third partition openings are located between adjacent second metal wires in the first direction.

9. The test structure as described in claim 8, characterized in that, The second metal wires located on both sides of the third partition opening are electrically connected to the comb teeth of different interconnect structures.

10. The test structure as described in claim 8, characterized in that, The test structure further includes a fourth interconnecting via structure located between the second metal wire and the comb teeth, wherein the second metal wire is electrically connected to the comb teeth through the fourth interconnecting via structure.

11. The test structure as described in claim 10, characterized in that, The materials used in the fourth interconnect via structure include copper, tungsten, cobalt, or ruthenium.

12. The test structure as described in claim 1, characterized in that, Along the first direction, the distance between adjacent comb teeth is 20 nanometers to 480 nanometers.

13. The test structure as described in claim 1, characterized in that, The test signal loading terminal is used to measure the current value between adjacent first metal lines.

14. A testing method, characterized in that, include: Provide a test structure as described in any one of claims 1 to 13; Measure the first current value between any two test signal loading terminals, and determine whether there is a short circuit between adjacent first metal lines based on the first current value.

15. The test method as described in claim 14, characterized in that, The step of determining whether adjacent first metal lines are short-circuited includes: if the first current value is 0, then it is determined that adjacent first metal lines are not short-circuited; if the first current value is greater than 0, then it is determined that adjacent first metal lines are short-circuited.

16. The test method as described in claim 14, characterized in that, The test structure further includes: a second metal wire, which is arranged in a matrix along the first direction and the second direction, and the second metal wire is located on both sides of the first metal wire; Multiple third partition openings are located between adjacent second metal lines in the first direction, and the second metal lines located on both sides of the third partition openings are electrically connected to the comb teeth of different interconnection structures. After determining whether there is a short circuit between adjacent first metal lines based on the current value, the test method further includes: measuring a second current value between the test signal loading terminal electrically connected to the second metal line, and determining whether there is a short circuit between adjacent second metal lines based on the second current value.

17. The test method as described in claim 16, characterized in that, The steps for determining whether adjacent second metal lines are short-circuited include: if the second current value is 0, then it is determined that adjacent second metal lines are not short-circuited; if the second current value is greater than 0, then it is determined that adjacent second metal lines are short-circuited.

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