Through hole test structure, test method and integrated circuit

Abstract

The invention discloses a through hole test structure, a test method and an integrated circuit, and belongs to the technical field of semiconductors, the through hole test structure at least comprises a bottom metal layer, a top metal layer and a middle metal layer; the through hole layer is connected with the two metal layers, the through hole layer comprises a first type of connecting structure and a second type of connecting structure, the first type of connecting structure comprises a first number of through holes, the second type of connecting structure comprises a second number of through holes, and the second number is greater than the first number; wherein the bottom through hole layer or the top through hole layer comprises at least one first type of connecting structure, and at least one first type of connecting structure is additionally arranged at any position of the current through hole layer except the position of the first type of connecting structure of the upper layer in the lamination direction of the through hole layers. Through the through hole test structure, the test method and the integrated circuit provided by the invention, the accuracy of abnormal detection of the through hole can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and in particular relates to a through-hole test structure, a test method and an integrated circuit. Background Art

[0002] In the semiconductor manufacturing process, a through-hole test structure is required to test the through-hole impedance and complete the reliability evaluation of the semiconductor integrated circuit. The through-hole test structure is usually a chain structure or a Kelvin structure.

[0003] The chain structure connects the through holes of the same layer in series through the metal layer. When a through hole is broken, the impedance of the through hole test structure is extremely high. However, a chain structure can only test one layer of through holes. A Kelvin structure only detects the resistance of one through hole. When multiple through holes need to be tested, a Kelvin structure needs to be set at each through hole. Therefore, neither the chain structure nor the Kelvin structure can realize the detection of through hole anomalies in different layers by one test structure. Summary of the invention

[0004] The object of the present invention is to provide a through-hole test structure, a test method and an integrated circuit, which can solve the problem that one test structure cannot detect through-hole anomalies in different layers.

[0005] To solve the above technical problems, the present invention is achieved through the following technical solutions: The present invention provides a through-hole test structure, comprising: A bottom metal layer, including a bottom metal conductor; A top metal layer, comprising a top metal wire, wherein the bottom metal wire and the top metal wire cover all test positions; An intermediate metal layer is disposed between the bottom metal layer and the top metal layer, and the intermediate metal layer includes a plurality of intermediate metal wires, each of which covers one of the test positions; A through-hole layer is arranged between two metal layers to connect the two metal layers, and the through-hole layer includes a first type connection structure and a second type connection structure, wherein the first type connection structure includes a first number of through-holes, and the second type connection structure includes a second number of through-holes, and the second number is greater than the first number; Among them, the bottom through-hole layer or the top through-hole layer includes at least one of the first-type connection structures, and along the stacking direction of the through-hole layer, except for the test position of the first-type connection structure of the previous layer, at least one of the first-type connection structures is added at any position of the through-hole layer in this layer.

[0006] In one embodiment of the present invention, the through-hole test structure comprises: A first intermediate metal layer, disposed on the bottom metal layer; a second intermediate metal layer, disposed on the first intermediate metal layer; a first via layer, disposed between the bottom metal layer and the first intermediate metal layer; A second through-hole layer is arranged between the first intermediate metal layer and the corresponding second intermediate metal layer; A third via layer is arranged between the second intermediate metal layer and the top metal layer; Wherein, the through-hole test structure further includes a first test position, a second test position and a third test position, and the first test position, the second test position and the third test position are arranged side by side; In the first via layer, the first type connection structure is arranged at the first test position, and the second type connection structure is arranged at the second test position and the third test position; In the second through-hole layer, the first type connection structure is arranged at the first test position and the second test position, and the second type connection structure is arranged at the third test position; In the third via layer, the first test location, the second test location, and the third test location are provided with the first type connection structure.

[0007] In one embodiment of the present invention, the first number is equal to one, and the second number of through holes completely covers the surface of the intermediate metal layer.

[0008] The present invention also provides a through-hole testing method, using any one of the through-hole testing structures described above, and the through-hole testing method comprises: Using one end of the top metal layer or the bottom metal layer as a current input end, using one end of the bottom metal layer or the top metal layer opposite to the current input end as a current output end, and obtaining the impedance of the through-hole test structure from the current input end to the current output end; and The via layer where the circuit is broken is determined according to the impedance of the via test structure.

[0009] In one embodiment of the present invention, the through-hole test structure comprises: A first intermediate metal layer, disposed on the bottom metal layer; a second intermediate metal layer, disposed on the first intermediate metal layer; a first via layer, disposed between the bottom metal layer and the first intermediate metal layer; A second through-hole layer is arranged between the first intermediate metal layer and the corresponding second intermediate metal layer; A third via layer is arranged between the second intermediate metal layer and the top metal layer; A first test position, a second test position and a third test position, wherein the first test position, the second test position and the third test position are arranged side by side; Among them, in the first through-hole layer, the first type of connection structure is set at the first test position, and the second type of connection structure is set at the second test position and the third test position; in the second through-hole layer, the first type of connection structure is set at the first test position and the second test position, and the second type of connection structure is set at the third test position; in the third through-hole layer, the first type of connection structure is set at the first test position, the second test position and the third test position.

[0010] In one embodiment of the present invention, when all the connection structures in the first via layer, the second via layer and the third via layer are normal, the impedance of the via test structure is obtained according to the following formula: R = 6 (R0 ± r) / 11; Wherein, R0 is the impedance value of the first type connection structure, and r is the impedance fluctuation margin value of each connection structure.

[0011] In one embodiment of the present invention, when the first via layer is broken and the connection structures in the second via layer and the third via layer are normal, the impedance of the via test structure is obtained according to the following formula: R = 2 (R0 ± r) / 3; Wherein, R0 is the impedance value of the first type connection structure, and r is the impedance fluctuation margin value of each connection structure.

[0012] In one embodiment of the present invention, when the second via layer is open circuited and the connection structures in the first via layer and the third via layer are normal, the impedance of the via test structure is obtained according to the following formula: Where, R = R0 ± r; Wherein, R0 is the impedance value of the first type connection structure, and r is the impedance fluctuation margin value of each connection structure.

[0013] In one embodiment of the present invention, when the third via layer is broken and the connection structures in the first via layer and the second via layer are normal, the impedance of the via test structure is a maximum value.

[0014] The present invention also provides an integrated circuit, characterized in that it comprises a through-hole test structure as described in any one of the above items.

[0015] In summary, the method for making a through-hole test structure provided by the present invention has the unexpected effect that: in the through-hole layer, two types of connection structures are set, namely, a first type connection structure including a first number of through-holes and a second type connection structure including a second number of through-holes. By setting the number of through-holes in the connection structure, it is ensured that the first type connection structure is affected by static electricity, while the second type connection structure is not affected by static electricity. Then, by setting the position and number of the first type connection structure and the second type connection structure in each through-hole layer, that is, in the bottom through-hole layer or the top through-hole layer, at least one first type connection structure is set, and along the stacking direction of the through-hole layer, except for the test position where the first type connection structure of the previous layer is located, at least one first type connection structure is added at any position of the through-hole layer of this layer, until the top through-hole layer or the bottom through-hole layer, all test positions are provided with the first type connection structure. When static electricity occurs, when different through-hole layers are affected by static electricity and open circuit occurs, the impedance of the test path that is not open circuit is different. Therefore, after an electrostatic fault occurs, by detecting the impedance of the through-hole test structure, the through-hole layer where the fault occurs can be determined.

[0016] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0018] Figure 1 The distribution of impedance through-hole test structures in the cutting lanes.

[0019] Figure 2 Schematic diagram of a through-hole test structure in one embodiment of the present application.

[0020] Figure 3 FIG. 4 is a circuit diagram of a through-hole test structure in an embodiment of the present application.

[0021] Figure 4 It is a structural diagram of a through-hole test structure in another embodiment of the present application.

[0022] Figure 5 This is a structural diagram of a through-hole test structure in yet another embodiment of the present application.

[0023] Description of labels: 10. Cutting road; 100. Metal layer; 1001. Intermediate metal wire; 101. Bottom metal layer; 1011. Bottom metal wire; 102. First intermediate metal layer; 103. Second intermediate metal layer; 104. Top metal layer; 1041. Top metal wire; 200. Via layer; 201. First via layer; 202. Second via layer; 203. Third via layer; 301. First type connection structure; 302. Second type connection structure. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0025] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0026] In the present invention, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, if the terms "first" and "second" appear, they are only used for description and distinction purposes, and cannot be understood as indicating or implying relative importance.

[0027] In semiconductor integrated circuits, multiple semiconductor devices are integrated on a silicon wafer. After multiple semiconductor devices are formed on the silicon wafer, multiple metal layers need to be formed, and adjacent metal layers are connected using through-hole layers to electrically connect each semiconductor device according to the designed circuit. The metal layer can be set on the surface of the semiconductor device or on the surface of the silicon wafer away from the semiconductor device. During the semiconductor manufacturing process, electrical testing is required. During the electrical test, the through-hole test structure is used to test whether the through-hole layer is broken. If a break occurs, failure analysis is required to find the break point and analyze it.

[0028] See also Figure 1As shown, the through-hole test structures for testing different metal layers are distributed at different positions of the cutting path 10. If anomalies are prone to occur in a specific area, the through-hole impedance anomalies at different layers of the same test position cannot be monitored due to the limitations of the dispersed distribution of the through-hole test structure. In the semiconductor process, static electricity will affect the connection between the through-hole and the metal layer, resulting in high through-hole impedance or even open circuit. The metal through-hole impedance anomalies caused by static electricity have the characteristics of non-fixed through-hole layer positions, uncertain impedance size, and often regional concentration due to process characteristics. Conventional through-hole test structures are difficult to monitor anomalies caused by this reason.

[0029] See also Figure 2 As shown, the present application provides a through-hole test structure, a test method and an integrated circuit, wherein the through-hole test structure can monitor through-holes of all layers simultaneously. When a through-hole of a layer has a problem due to static electricity, the layer with the problem is determined by measuring the resistance value of the through-hole test structure.

[0030] See also Figure 2 As shown, in one embodiment of the present invention, the through-hole test structure includes a metal layer 100 and a through-hole layer 200, and each through-hole layer 200 is arranged between two metal layers 100 to connect the two metal layers 100. In the present application, the through-hole test structure includes at least three metal layers 100 and at least two through-hole layers 200. Among them, each metal layer 100 includes a plurality of metal wires, and each through-hole layer 200 includes a plurality of connection structures, and each connection structure connects the metal wires at the same test position in the upper and lower metal layers 100. By changing the shape and arrangement of the metal wires and the connection structures, a variety of through-hole test structures can be formed.

[0031] See also Figure 2 As shown, in one embodiment of the present invention, the metal layer 100 includes a top metal layer 104, a bottom metal layer 101 and an intermediate metal layer. The top metal layer 104 and the bottom metal layer 101 are located on both sides of the intermediate metal layer, and each through-hole test structure includes a top metal layer 104, a top metal layer 104 and at least one intermediate metal layer. Moreover, the present application does not limit the positions of the top metal layer 104 and the bottom metal layer 101. The top metal layer 104 and the bottom metal layer 101 are provided only to indicate that the metal layer 100 is provided on both sides of the intermediate metal layer. In this embodiment, the bottom metal layer 101 is located on the side close to the semiconductor device, and the top metal layer 104 is located on the side away from the semiconductor device.

[0032] See also Figure 2As shown, in one embodiment of the present invention, the top metal layer 104 includes a top metal wire 1041, and the bottom metal layer 101 includes a bottom metal wire 1011. The bottom metal wire 1011 and the bottom metal wire 1011 cover all test positions, and connect the connection structure of each position in series to form a through-hole test structure.

[0033] See also Figure 2 As shown, in one embodiment of the present invention, the intermediate metal layer is disposed between the top metal layer 104 and the bottom metal layer 101, and each through-hole test structure includes at least one intermediate metal layer. In some embodiments, one or two intermediate metal layers are disposed between the top metal layer 104 and the bottom metal layer 101. In other embodiments, three or more intermediate metal layers are disposed between the top metal layer 104 and the bottom metal layer 101.

[0034] See also Figure 2 As shown, in one embodiment of the present invention, two intermediate metal layers are provided between the top metal layer 104 and the bottom metal layer 101. In this case, the intermediate metal layer includes a first intermediate metal layer 102 and a second intermediate metal layer 103, the first intermediate metal layer 102 is located on the bottom metal layer 101, the second intermediate metal layer 103 is located on the first metal layer 100, and the top metal layer 104 is located on the second intermediate metal layer 103.

[0035] See also Figure 2 As shown, in one embodiment of the present invention, the intermediate metal layer includes a plurality of intermediate metal wires 1001. Specifically, the number of intermediate metal wires 1001 provided in each intermediate metal layer is equal to the number of test positions, and each intermediate metal wire 1001 covers one test position, and adjacent intermediate metal wires 1001 have a preset spacing therebetween.

[0036] See also Figure 2 As shown, in one embodiment of the present invention, a via layer 200 is disposed between two adjacent metal layers 100, and the number of the via layers 200 is determined according to the number of the metal layers 100. In this embodiment, three via layers 200 are disposed between four metal layers 100. In other embodiments, if there are three metal layers 100, two via layers 200 are disposed between the three metal layers 100. If there are two metal layers 100, one via layer 200 is disposed between the two metal layers 100. That is, the number of the via layers 200 is equal to the number of the metal layers 100 minus one.

[0037] See also Figure 2As shown, in one embodiment of the present invention, the via layer 200 includes a first via layer 201, a second via layer 202 and a third via layer 203. The first via layer 201 is arranged between the bottom metal layer 101 and the first intermediate metal layer 102, and the connection structure in the first via layer 201 connects the bottom metal wire 1011 in the bottom metal layer 101 and the intermediate metal wire 1001 in the first intermediate metal layer 102. The second via layer 202 is arranged between the first intermediate metal layer 102 and the second intermediate metal layer 103, and the connection structure in the second via layer 202 connects the intermediate metal wire 1001 in the first intermediate metal layer 102 and the intermediate metal wire 1001 in the second intermediate metal layer 103. The third via layer 203 is arranged between the second intermediate metal layer 103 and the top metal layer 104, and the connection structure in the third via layer 203 connects the intermediate metal wire 1001 in the second intermediate metal layer 103 and the top metal wire 1041 in the top metal layer 104.

[0038] See also Figure 2 As shown, in one embodiment of the present invention, at each test position, each through-hole layer 200 is provided with a connection structure, and the connection structure connects the metal wires in the metal layers 100 on both sides thereof. The metal wires connect the connection structures in each metal layer 100 at the current test position in series to form a test path. The test paths of multiple test positions are connected through the top metal layer 104 and the bottom metal layer 101 to form a through-hole test structure.

[0039] See also Figure 2 As shown, in one embodiment of the present invention, the through-hole layer 200 includes two types of connection structures, namely, a first type connection structure 301 and a second type connection structure 302. Among them, the first type connection structure 301 includes a first number of through holes, and the second type connection structure 302 includes a second number of through holes, and the second number is greater than the first number. Among them, the first number is, for example, 1. The second number is set according to demand, and the second number of through holes covers the surface of the intermediate metal wire 1001. The first through hole and the second through hole are filled with conductive material to form a connection structure. At this time, the resistance of the first type connection structure 301 is much greater than the resistance of the metal wire, and the resistance of the second type connection structure 302 is approximately equal to the resistance of the metal wire. The second type connection structure 302 is equivalent to a section of wire. At this time, when a layer of through-hole layer 200 is affected by static electricity, the first type connection structure 301 will be affected by static electricity and a circuit will be broken. However, the second type connection structure 302 will not be broken by static electricity.

[0040] See also Figure 2As shown, in one embodiment of the present invention, at least one first type connection structure 301 is provided in the bottom via layer or the top via layer, and along the stacking direction of the via layer 200, except for the test position where the first type connection structure 301 of the previous layer is located, at least one first type connection structure 301 is added at any position of the current via layer 200, until the top via layer or the bottom via layer, all test positions are provided with the first type connection structure 301. Among them, the stacking direction of the via layer 200 can be the direction from the bottom metal layer 101 to the top metal layer 104, or it can be the direction from the top metal layer 104 to the bottom metal layer 101. At this time, a first type connection structure 301 is provided in each test path. And the number of first type connection structures 301 in each via layer 200 is different. When static electricity occurs, when different via layers 200 are affected by static electricity and disconnected, the impedance of the test paths that are not disconnected is different. Therefore, after an electrostatic fault occurs, the faulty via layer 200 can be determined by detecting the impedance of the via test structure.

[0041] See also Figure 2 As shown, in one embodiment of the present invention, the top via layer is the via layer 200 connected to the top metal layer 104, and the bottom via layer is the via layer 200 connected to the bottom metal layer 101. In this embodiment, the bottom via layer is the first via layer 201, and the top via layer is the third via layer 203.

[0042] See also Figure 2 As shown, it should be noted that the present application does not limit the number of test positions, the number of first type connection structures 301 in each via layer 200 , and the number of second type connection structures 302 in each via layer 200 .

[0043] See also Figure 2 As shown, in one embodiment of the present invention, a through-hole test structure having three test positions is used as an example for explanation, and the three test positions are a first test position, a second test position, and a third test position. In the first through-hole layer 200, a first type connection structure 301 is provided, and the first type connection structure 301 is located at the first test position. In the second test position and the third test position, a second type connection structure 302 is provided.

[0044] See also Figure 2As shown, in one embodiment of the present invention, along the stacking direction of the through-hole layer 200, in addition to the test position where the first type connection structure 301 of the previous layer is located, a first type connection structure 301 is added at any position of the through-hole layer 200. A first type connection structure 301 and two second type connection structures 302 are arranged in the first through-hole layer 201, and one first type connection structure 301 is arranged at the first test position, one second type connection structure 302 is arranged at the second test position, and another second type connection structure 302 is arranged at the third test position. Then, two first type connection structures 301 and one second type connection structure 302 are arranged in the second through-hole layer 202, and one first type connection structure 301 is arranged at the first test position, another first type connection structure 301 is arranged at the second test position, and one second type connection structure 302 is arranged at the third test position. In the third through-hole layer 203, three first type connection structures 301 are arranged. That is, the first type connection structure 301 is arranged at the first test position, the second test position and the third test position. At this time, it is equivalent to having Y test positions in the through-hole test structure, and each test position is provided with Y layers of through-hole layers connected in series to connect the bottom metal layer 101 and the top metal layer 104, and the two adjacent through-hole layers are connected to each other through the intermediate metal layer. Among them, at the Xth test position, the Y-layer through-hole layer includes (X-1) second-type connection structures 302 and Y-(X-1) first-type connection structures 301 along the bottom metal layer 101 to the top metal layer 104, X∈[1,Y] and X∈N*.

[0045] See also Figure 4 and Figure 5 As shown, in another embodiment of the present invention, the via test structure includes four metal layers 100 and three via layers 200, and five test positions are provided. Then, in the first via layer 200, one first type connection structure 301 may be provided, in the second via layer 202, three first type connection structures 301 may be provided, and in the third via layer 203, five first type connection structures 301 may be provided. In yet another embodiment of the present invention, the via test structure includes five metal layers 100 and four via layers 200, and four test positions are provided. Then, in the first via layer 200, one first type connection structure 301 may be provided, in the second via layer 202, two first type connection structures 301 may be provided, in the third via layer 203, three first type connection structures 301 may be provided, and in the fourth via layer 200, four first type connection structures 301 may be provided. Therefore, the number of the first type connection structures 301 and the second type connection structures 302 in each via layer 200 can be configured according to the number of metal layers 100 , the number of via layers 200 , and the number of test positions.

[0046] See also Figure 2 and Figure 3 As shown, in one embodiment of the present invention, when the through-hole test structure provided by the present application is used for testing, one end of the top metal layer 104 or the bottom metal layer 101 is used as the current input end, and one end of the bottom metal layer 101 or the top metal layer 104 relative to the current input end is used as the current output end. Current is input from the current input end, and the voltage between the current input end and the current output end is detected to obtain the impedance of the through-hole test structure. Or when current is input into the through-hole test structure, the impedance of the through-hole test structure is directly measured at the impedance sensing end. Afterwards, the through-hole layer 200 with a broken circuit is determined based on the size of the impedance.

[0047] See also Figure 2 and Figure 3 As shown, this application is based on Figure 2 The impedance test circuit shown in FIG. 2 is taken as an example. The impedance of the first type connection structure 301 in the first through-hole layer 201 is set to the first impedance R1, the impedance of the first type connection structure 301 in the second through-hole layer 202 is set to the second impedance R2, and the impedance of the first type connection structure 301 in the third through-hole layer 203 is set to the third impedance R3. The second type connection structure 302 is equivalent to a wire. Then, the following is formed: Figure 3 The test circuit shown. At this time, the first type connection structure 301 in the first through-hole layer 201, the second through-hole layer 202 and the third through-hole layer 203 at the first test position is connected in series through the metal layer 100 to form a test path at the first test position. The first type connection structure 301 in the second through-hole layer 202 and the third through-hole layer 203 at the second test position is connected in series through the metal layer 100 and the second type connection structure 302 in the first through-hole layer 201 to form a test path at the second test position. The first type connection structure 301 in the third through-hole layer 203 at the third test position is connected in series through the metal layer 100 and the second type connection structure 302 in the first through-hole layer 201 and the second through-hole layer 202 to form a test path at the third test position.

[0048] See also Figure 2 and Figure 3 As shown, in one embodiment of the present invention, when all the connection structures in the first via layer 201, the second via layer 202 and the third via layer 203 are normal, the impedance of the via test structure is equal to the impedance of the test path at the first test position, the test path at the second test position and the test path at the third test position in parallel. Therefore, when all the connection structures in the first via layer 201, the second via layer 202 and the third via layer 203 are normal, the impedance of the via test structure can be specifically obtained according to the following formula: R=1 / (1 / (R1+R2+R3)+1 / (R2+R3)+1 / R3 ); Wherein, R is the impedance of the through-hole test structure, R1 is the impedance of the first type connection structure 301 in the first through-hole layer 201 , R2 is the impedance of the first type connection structure 301 in the second through-hole layer 202 , and R3 is the impedance of the first type connection structure 301 in the third through-hole layer 203 .

[0049] When the height and exposure size of through holes in different layers are consistent, the resistance deviation caused by normal process fluctuations is relatively small, and the resistance of through holes in different layers is considered equal, that is, when R1=R2=R3=R0, then R=6R0 / 11. At the same time, considering the fluctuation of the resistance of the connection structure, the impedance of the through hole test structure can be obtained according to the following formula: R = 6 (R0 ± r) / 11; Where r is the impedance fluctuation margin value of each connection structure.

[0050] See also Figure 2 and Figure 3 As shown, in one embodiment of the present invention, when the first via layer 201 is disconnected and all the connection structures in the second via layer 202 and the third via layer 203 are normal, the first type connection structure 301 in the first via layer 201 is disconnected, and the second type connection structure 302 is not disconnected. At this time, the impedance of the via test structure is equal to the impedance of the test path at the second test position and the test path at the third test position in parallel. Therefore, when the first via layer 201 is disconnected and all the connection structures in the second via layer 202 and the third via layer 203 are normal, the impedance of the via test structure can be specifically obtained according to the following formula: R = 1 / (1 / (R2+R3)+1 / R3); Wherein, R is the impedance of the through-hole test structure, R2 is the impedance of the first type connection structure 301 in the second through-hole layer 202 , and R3 is the impedance of the first type connection structure 301 in the third through-hole layer 203 .

[0051] When the height and exposure size of through holes in different layers are consistent, the resistance deviation caused by normal process fluctuations is relatively small, and the resistance of through holes in different layers is considered equal, that is, when R2=R3=R0, then R=2R0 / 3. At the same time, considering the fluctuation of the resistance of the connection structure, the impedance of the through-hole test structure can be obtained according to the following formula: R = 2 (R0 ± r) / 3; Where r is the impedance fluctuation margin value of each connection structure.

[0052] See also Figure 2 and Figure 3As shown, in one embodiment of the present invention, when the second via layer 202 is disconnected and all the connection structures in the first via layer 201 and the third via layer 203 are normal, the first type connection structure 301 in the second via layer 202 is disconnected, and the second type connection structure 302 is not disconnected. At this time, the impedance of the via test structure is equal to the impedance of the test path at the third test position. Therefore, when the second via layer 202 is disconnected and all the connection structures in the first via layer 201 and the third via layer 203 are normal, the impedance of the via test structure can be specifically obtained according to the following formula: R=R3; Wherein, R3 is the impedance of the first type connection structure 301 in the third through-hole layer 203 .

[0053] When the height and exposure size of through holes in different layers are consistent, the resistance deviation caused by normal process fluctuations is relatively small, and the resistance of through holes in different layers is considered equal, that is, when R3=R0, then R=R0. At the same time, considering the fluctuation of the resistance of the connection structure, the impedance of the through-hole test structure can be obtained according to the following formula: R = R0 ± r; Where r is the impedance fluctuation margin value of each connection structure.

[0054] See also Figure 2 and Figure 3 As shown, in one embodiment of the present invention, when the third via layer 203 is disconnected and all the connection structures in the first via layer 201 and the second via layer 202 are normal, the first type connection structure 301 in the third via layer 203 is disconnected, and all the test paths are disconnected. At this time, the impedance of the via test structure is a maximum value.

[0055] In addition to the above situations, when there is no through-hole connection break and only the impedance is high (R>6R0 / 11), further judgment can be made by confirming the through-hole size, physical property structure analysis, etc.

[0056] In summary, the present invention provides a through-hole test structure, a test method and an integrated circuit, wherein the through-hole test structure comprises: a bottom metal layer, comprising a bottom metal wire; a top metal layer, comprising a top metal wire, and the bottom metal wire and the top metal wire cover all test positions; an intermediate metal layer, arranged between the bottom metal layer and the top metal layer, and the intermediate metal layer comprises a plurality of intermediate metal wires, and each intermediate metal wire covers a test position; a through-hole layer, arranged between two metal layers, connecting the two metal layers, and the through-hole layer comprises a first type connection structure and a second type connection structure, the first type connection structure comprises a first number of through holes, and the second type connection structure comprises a second number of through holes, and the second number is greater than the first number; wherein the bottom through-hole layer or the top through-hole layer comprises at least one first type connection structure, and along the stacking direction of the through-hole layer, except for the test position of the first type connection structure of the previous layer, at least one first type connection structure is added at any position of the through-hole layer of the current layer. The present invention provides a through-hole test structure, test method and integrated circuit, and the unexpected effect is: in the through-hole layer, two types of connection structures are set, namely, a first type of connection structure including a first number of through-holes and a second type of connection structure including a second number of through-holes. By setting the number of through-holes in the connection structure, it is ensured that the first type of connection structure is affected by static electricity, while the second type of connection structure is not affected by static electricity. Then, by setting the position and number of the first type of connection structure and the second type of connection structure in each through-hole layer, that is, in the bottom through-hole layer or the top through-hole layer, at least one first type of connection structure is set, and along the stacking direction of the through-hole layer, except for the test position where the first type of connection structure of the previous layer is located, at least one first type of connection structure is added at any position of the through-hole layer of this layer, until the top through-hole layer or the bottom through-hole layer, all test positions are provided with the first type of connection structure. When static electricity occurs, when different through-hole layers are affected by static electricity and open circuit occurs, the impedance of the test path that is not open circuit is different. Therefore, after an electrostatic fault occurs, by detecting the impedance of the through-hole test structure, the through-hole layer where the fault occurs can be determined.

[0057] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A through-hole test structure, characterized in that: include: A bottom metal layer, including a bottom metal conductor; A top metal layer, comprising a top metal wire, wherein the bottom metal wire and the top metal wire cover all test positions; An intermediate metal layer is disposed between the bottom metal layer and the top metal layer, and the intermediate metal layer includes a plurality of intermediate metal wires, each of which covers one of the test positions; A through-hole layer is arranged between two metal layers to connect the two metal layers, and the through-hole layer includes a first type connection structure and a second type connection structure, wherein the first type connection structure includes a first number of through-holes, and the second type connection structure includes a second number of through-holes, and the second number is greater than the first number; Among them, the bottom through-hole layer or the top through-hole layer includes at least one of the first-type connection structures, and along the stacking direction of the through-hole layer, except for the test position of the first-type connection structure of the previous layer, at least one of the first-type connection structures is added at any position of the through-hole layer in this layer.

2. The through-hole test structure according to claim 1, characterized in that: The through-hole test structure comprises: A first intermediate metal layer, disposed on the bottom metal layer; a second intermediate metal layer, disposed on the first intermediate metal layer; a first via layer, disposed between the bottom metal layer and the first intermediate metal layer; A second through-hole layer is arranged between the first intermediate metal layer and the corresponding second intermediate metal layer; A third via layer is arranged between the second intermediate metal layer and the top metal layer; Wherein, the through-hole test structure further includes a first test position, a second test position and a third test position, and the first test position, the second test position and the third test position are arranged side by side; In the first via layer, the first type connection structure is arranged at the first test position, and the second type connection structure is arranged at the second test position and the third test position; In the second through-hole layer, the first type connection structure is arranged at the first test position and the second test position, and the second type connection structure is arranged at the third test position; In the third via layer, the first test location, the second test location, and the third test location are provided with the first type connection structure.

3. The through-hole test structure according to claim 1, characterized in that: The first number is equal to one, and the second number of through holes covers the entire surface of the intermediate metal layer.

4. A through-hole testing method, characterized in that: Using the through-hole test structure described in any one of claims 1 to 3, and the through-hole test method comprises: Using one end of the top metal layer or the bottom metal layer as a current input end, using one end of the bottom metal layer or the top metal layer opposite to the current input end as a current output end, and obtaining the impedance of the through-hole test structure from the current input end to the current output end; and The via layer where the circuit is broken is determined according to the impedance of the via test structure.

5. The through-hole testing method according to claim 4, characterized in that: The through-hole test structure comprises: A first intermediate metal layer, disposed on the bottom metal layer; a second intermediate metal layer, disposed on the first intermediate metal layer; a first via layer, disposed between the bottom metal layer and the first intermediate metal layer; A second through-hole layer is arranged between the first intermediate metal layer and the corresponding second intermediate metal layer; A third via layer is arranged between the second intermediate metal layer and the top metal layer; A first test position, a second test position and a third test position, wherein the first test position, the second test position and the third test position are arranged side by side; Among them, in the first through-hole layer, the first type of connection structure is set at the first test position, and the second type of connection structure is set at the second test position and the third test position; in the second through-hole layer, the first type of connection structure is set at the first test position and the second test position, and the second type of connection structure is set at the third test position; in the third through-hole layer, the first type of connection structure is set at the first test position, the second test position and the third test position.

6. The through-hole testing method according to claim 5, characterized in that: When all the connection structures in the first via layer, the second via layer and the third via layer are normal, the impedance of the via test structure is obtained according to the following formula: R = 6 (R0 ± r) / 11; Wherein, R0 is the impedance value of the first type connection structure, and r is the impedance fluctuation margin value of each connection structure.

7. The through-hole testing method according to claim 5, characterized in that: When the first via layer is broken and the connection structures in the second via layer and the third via layer are normal, the impedance of the via test structure is obtained according to the following formula: R = 2 (R0 ± r) / 3; Wherein, R0 is the impedance value of the first type connection structure, and r is the impedance fluctuation margin value of each connection structure.

8. The through-hole testing method according to claim 5, characterized in that: When the second via layer is broken and the connection structures in the first via layer and the third via layer are normal, the impedance of the via test structure is obtained according to the following formula: Where, R = R0 ± r; Wherein, R0 is the impedance value of the first type connection structure, and r is the impedance fluctuation margin value of each connection structure.

9. The through-hole testing method according to claim 5, characterized in that: When the third via layer is broken and the connection structures in the first via layer and the second via layer are normal, the impedance of the via test structure is a maximum value.

10. An integrated circuit, characterized in that: The method comprises the through-hole test structure as claimed in any one of claims 1 to 3.

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