An IMD test structure and semiconductor device

Abstract

The application discloses an IMD test structure and a semiconductor device, and relates to the field of semiconductor manufacturing. The IMD test structure comprises a first solder pad and a second solder pad which are arranged in a relative interval; the first solder pad is connected with a first metal wire layer, and the second solder pad is connected with a second metal wire layer which is arranged in an alternating parallel mode with the first metal wire layer; the first metal wire layer and the second metal wire layer both comprise a first metal part and a second metal part which are arranged in an alternating mode; the first metal part is arranged in a relative mode with the second metal part in the adjacent metal wire layer and partially overlaps the second metal part; the second metal part is arranged in a relative mode with the first metal part in the adjacent metal wire layer and partially overlaps the first metal part, so as to jointly enclose a containing space for filling a metal interlayer dielectric to be tested. The test structure improves the flexibility and accuracy of the test.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing, and more specifically, to an IMD test structure and semiconductor device. Background Technology

[0002] In semiconductor manufacturing, the insulation reliability of the inter-metal dielectric (IMD) directly determines the chip's lifespan. If the upper and lower metal layers of the chip become misaligned due to photolithography alignment errors or other reasons, the effective spacing of the IMD will be shortened, leading to a significant decrease in the dielectric breakdown voltage.

[0003] To capture such risks and assess the breakdown performance of IMDs, existing technologies typically employ a comb-shaped capacitance test structure. This structure includes a first and a second pad spaced apart from each other. The first pad has several parallel first metal lines connected to it, and the second pad has several parallel second metal lines connected to it. The first and second metal lines are interwoven and parallel to each other. The IMD under test is filled between the first and second metal lines, and the breakdown voltage of the IMD is monitored by applying a scanning voltage to the first and second metal lines.

[0004] However, the metal line layer of the existing comb-shaped capacitor test structure extends only in a single direction. Therefore, it can only capture metal displacement perpendicular to the direction of metal line extension and detect the breakdown risk of the IMD under test under metal displacement in this single direction. If the metal displacement occurs in the direction parallel to the rack, it cannot detect the reliability risk caused by process variation in this direction. Furthermore, the tip discharge effect of small metal blocks in actual circuits is difficult to effectively simulate in the existing long straight toothed metal line layer, resulting in a decrease in the accuracy of the test results. Utility Model Content

[0005] The purpose of this invention is to provide an IMD test structure and semiconductor device that can detect the breakdown performance of the IMD under multi-directional metal displacement and simulate the breakdown performance of the IMD under the effect of concentrated electric field at the tip, thereby improving the flexibility of the test process and the accuracy of the test results.

[0006] The embodiments of this utility model are implemented as follows: In one aspect, this utility model provides an IMD test structure, including a first pad and a second pad arranged at relative intervals; the first pad is connected to a first metal wire layer, and the second pad is connected to a second metal wire layer arranged alternately and parallel to the first metal wire layer; both the first metal wire layer and the second metal wire layer include alternating first metal portions and second metal portions; the first metal portion is arranged opposite to and partially overlaps with the second metal portion in the adjacent metal wire layer, and the second metal portion is arranged opposite to and partially overlaps with the first metal portion in the adjacent metal wire layer, so as to jointly enclose and form a accommodating space for filling the interlayer medium of the metal to be tested.

[0007] Optionally, a first metal portion is formed on an upper metal layer, the upper metal layer having a first substrate extending in a first direction and a first extension extending in a second direction, the first extension being perpendicularly disposed at the end of the first substrate, and the opposite ends of the first extension forming the first metal portion; the first direction and the second direction are perpendicular to each other.

[0008] Optionally, a second metal portion is formed on a lower metal layer, the lower metal layer having a second substrate extending in a first direction and a second extension extending in a second direction, the second extension being perpendicularly disposed at the end of the second substrate, and the opposite ends of the second extension being respectively formed as second metal portions.

[0009] Optionally, the upper metal and the lower metal are electrically connected to form a monitoring unit, and there are multiple monitoring units, which are sequentially and alternately connected along the first direction.

[0010] Optionally, both the first metal part and the second metal part are rectangular block structures.

[0011] Optionally, both the upper and lower metal layers are provided with through holes, and any adjacent upper and lower metal layers along the first direction are electrically connected through the through holes.

[0012] Optionally, there may be multiple first metal wire layers, which are arranged in parallel and spaced apart, and the second metal wire layer is located between any two adjacent first metal wire layers.

[0013] Optionally, there may be multiple second metal wire layers, which are arranged in parallel and spaced apart, with the first metal wire layer located between any two adjacent second metal wire layers.

[0014] Optionally, the first pad is connected to an active terminal for applying scanning voltage, and the second pad is connected to a current return reference terminal.

[0015] In another aspect, this invention provides a semiconductor device including the aforementioned IMD test structure.

[0016] The beneficial effects of this utility model include: One aspect of this invention provides an IMD test structure, including a first pad and a second pad arranged at relative intervals. The first and second pads are used to connect voltage to construct a voltage test circuit and apply voltage to the interlayer dielectric under test. The first pad is connected to a first metal line layer, and the second pad is connected to a second metal line layer arranged alternately parallel to the first metal line layer. Both the first and second metal line layers include alternating first and second metal portions. The first metal portion is arranged opposite to and partially overlaps with the second metal portion in the adjacent metal line layer, and the second metal portion is arranged opposite to and partially overlaps with the first metal portion in the adjacent metal line layer, so as to jointly enclose and form an accommodating space for filling the interlayer dielectric under test. By simulating the relative arrangement and partial overlap of the first and second metal portions, the small-volume metal block of an actual chip can be simulated, thereby simulating the tip discharge effect of the small-volume metal block in the actual circuit, improving the accuracy of the test results, and ensuring the formation of an effective electric field; the enclosed accommodating space forms a multi-dimensional electric field concentration region. Therefore, when the first metal wire layer is displaced in the vertical or horizontal direction, it can cause the first metal part to move to compress the spacing between the first metal parts connected to the second metal wire layer, and also cause the second metal part to move to compress the spacing between the second metal parts connected to the second metal wire layer. Similarly, when the second metal wire layer is displaced in the vertical or horizontal direction, it can cause the first metal part to move to compress the spacing between the first metal parts connected to the first metal wire layer, and also cause the second metal part to move to compress the spacing between the first metal parts connected to the second metal wire layer. In this way, the breakdown performance of the IMD under test under multi-directional metal displacement can be detected. Compared with the traditional method that can only detect the breakdown performance of the IMD under test under single-direction metal displacement, this application can improve the flexibility of the testing process and the accuracy of the test results. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 One of the structural schematic diagrams of the IMD test structure provided in the embodiments of this utility model; Figure 2 This is a magnified view of the details at point A; Figure 3 This is the second schematic diagram of the IMD test structure provided in the embodiment of the present utility model; Figure 4 The third schematic diagram of the IMD test structure provided in the embodiment of this utility model; Figure 5 The fourth schematic diagram of the IMD test structure provided in the embodiment of this utility model.

[0019] Icons: 100-IMD test structure; 110-First pad; 111-First metal line layer; 120-Second pad; 121-Second metal line layer; 130-Monitoring unit; 131-Upper metal layer; 1311-First metal part; 131a-First substrate; 131b-First extension; 132-Lower metal layer; 1321-Second metal part; 132a-Second substrate; 132b-Second extension; 133-Gap; 134-Through hole; 140-Accommodation space; 150-Active end; 160-Current return reference end; a-First direction; b-Second direction; c-Third direction. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] Please refer to Figure 1 This embodiment provides an IMD test structure 100, including a first pad 110 and a second pad 120 arranged at relative intervals; the first pad 110 is connected to a first metal wire layer 111, and the second pad 120 is connected to a second metal wire layer 121 arranged alternately parallel to the first metal wire layer 111; both the first metal wire layer 111 and the second metal wire layer 121 include alternating first metal portions 1311 and second metal portions 1321; the first metal portion 1311 is arranged opposite to and partially overlaps with the second metal portion 1321 in the adjacent metal wire layer, and the second metal portion 1321 is arranged opposite to and partially overlaps with the first metal portion 1311 in the adjacent metal wire layer, so as to jointly enclose and form a accommodating space for filling the interlayer medium of the metal to be tested.

[0027] Specifically, such as Figure 1 As shown, the IMD test structure 100 includes a first pad 110 and a second pad 120. The first pad 110 and the second pad 120 are respectively used to connect voltage to form a voltage test circuit for applying voltage to the interlayer dielectric of the metal under test. In one specific embodiment of this application, as... Figure 5 As shown, the first pad 110 is connected to the active terminal 150 for applying scanning voltage, and the second pad 120 is connected to the current return reference terminal 160. By applying a linear scanning voltage to the first pad 110 and monitoring the leakage current of the second pad 120, when the leakage current jumps from the reference value to the threshold, the voltage at this moment is recorded as the breakdown voltage.

[0028] like Figure 1 As shown, a first metal wire layer 111 is provided on the first pad 110 along the first direction a. One end of the first metal wire layer 111 is electrically connected to the first pad 110, and the other end is at a preset distance from the second pad 120. Optionally, there may be multiple first metal wire layers 111, which are arranged parallel to each other and spaced apart along the second direction b, and the second metal wire layer 121 is disposed between any two adjacent first metal wire layers 111.

[0029] Similarly, as Figure 1 As shown, the second solder pad 120 is provided with a second metal wire layer 121 along the first direction a. One end of the second metal wire layer 121 is electrically connected to the second solder pad 120, and the other end is spaced apart from the first solder pad 110. The first metal wire layer 111 and the second metal wire layer 121 are arranged parallel to each other along the second direction b, and the first direction a and the second direction b are perpendicular to each other. Optionally, there may be multiple second metal wire layers 121, which are arranged parallel to each other and spaced apart along the second direction b, and the first metal wire layer 111 is located between any two adjacent second metal wire layers 121.

[0030] Preferably, there are multiple first metal wire layers 111 and multiple second metal wire layers 121, and the number of first metal wire layers 111 and second metal wire layers 121 is the same, such that the first metal wire layers 111 and the second metal wire layers 121 are alternately arranged along the second direction b. Both the first metal wire layer 111 and the second metal wire layer 121 include a monitoring unit 130, and the monitoring unit 130 includes an upper metal layer 131 and a lower metal layer 132 that are electrically connected. Optionally, there may be multiple monitoring units 130, which are sequentially and alternately connected along the first direction a to improve the accuracy of the test results.

[0031] Existing metal wire layers extend only in a single direction, thus only capturing metal displacement perpendicular to the direction of metal wire layer extension and detecting the breakdown risk of the IMD under test under metal displacement in this single direction. To be able to detect the breakdown resistance of the IMD under test under multi-directional metal displacement, such as... Figure 1 and Figure 2 As shown, the upper metal layer 131 of this application has a first metal portion 1311 protruding along the second direction b, and the lower metal layer 132 has a second metal portion 1321 protruding along the second direction b, such that the upper metal layer 131 and the lower metal layer 132 not only have portions extending along the first direction a, but also portions extending along the second direction b. The first metal portions 1311 and the second metal portions 1321 adjacent along the second direction b are staggered and their projection portions along the third direction c overlap to form an effective electric field. The specific overlapping portion can be adjusted in real time according to the displacement of the first metal line layer 111 and / or the second metal line layer 121. Furthermore, the protrusion of the first metal portion 1311 and the second metal portion 1321 can simulate the small-volume metal block of an actual chip, thereby simulating the tip discharge effect of the small-volume metal block in the actual circuit and improving the accuracy of the test results.

[0032] like Figure 1 As shown, there is a spacer groove 133 between the first metal portion 1311 and the second metal portion 1321 adjacent along the first direction a, and the adjacent first metal wire layer 111 and the second metal wire layer 121 can connect the adjacent spacer groove 133, and the projection portions of the first metal portion 1311 and the second metal portion 1321 along the third direction c overlap to form a accommodating space 140 for filling the interlayer medium of the metal layer to be tested.

[0033] like Figure 1 and Figure 2 As shown, since the first metal portion 1311 and the second metal portion 1321 adjacent to each other along the second direction b are staggered, when the first metal wire layer 111 is displaced or moves along the first direction a, it can cause the first metal portion 1311 to move along the first direction a to compress the spacing between the first metal portion 1311 adjacent to the second metal wire layer 121, and also cause the second metal portion 1321 to move along the first direction a to compress the spacing between the second metal portion 1321 adjacent to the second metal wire layer 121; similarly, when the second metal wire layer 121 is displaced along the first direction a... The displacement can cause the first metal part 1311 to move along the first direction a to compress the spacing between the first metal parts 1311 adjacent to the first metal wire layer 111, and cause the second metal part 1321 to move along the first direction a to compress the spacing between the first metal parts 1311 adjacent to the second metal wire layer 121. In this way, the breakdown performance of the IMD under test under multi-directional metal displacement can be detected. Compared with the traditional method that can only detect the breakdown performance of the IMD under test under single-direction metal displacement, this application can improve the flexibility of the testing process and the accuracy of the test results.

[0034] It should be noted that, in one possible implementation of this application, such as Figure 1 and Figure 2 As shown, both the first metal part 1311 and the second metal part 1321 are rectangular block structures, which further simulate the tip discharge effect of small metal blocks in actual circuits through the right-angle corners of the first metal part 1311 and the second metal part 1321, thereby improving the accuracy of the test results.

[0035] For example, such as Figure 3As shown, the upper metal 131 has a first substrate 131a extending along a first direction a and a first extension 131b extending along a second direction b. The first extension 131b is vertically disposed at the end of the first substrate 131a, making the upper metal 131 have a T-shaped structure, which facilitates the connection between the upper metal 131 and the lower metal 132. The opposite ends of the first extension 131b respectively form first metal portions 1311, which facilitates the formation of an effective electric field between the upper metal 131 and the lower metal 132 on the left and right sides when the number of the first metal wire layer 111 or the second metal wire layer 121 increases. At the same time, it facilitates the formation of a accommodating space 140 for filling the interlayer medium of the metal to be tested on both the left and right sides.

[0036] For example, such as Figure 3 As shown, the lower metal 132 has a second substrate 132a extending along a first direction a and a second extension 132b extending along a second direction b. The second extension 132b is vertically disposed at the end of the second substrate 132a, making the lower metal 132 have a T-shaped structure, which facilitates the connection between the upper metal 131 and the lower metal 132. The two opposite ends of the second extension 132b respectively form second metal portions 1321, which facilitates the formation of an effective electric field between the lower metal 132 and the layers of metal on the left and right sides when the number of the first metal wire layer 111 or the second metal wire layer 121 increases. At the same time, it facilitates the formation of a accommodating space 140 for filling the interlayer medium of the metal to be tested on both the left and right sides.

[0037] It should be noted that, in addition to the T-shaped structure, the upper metal 131 and the lower metal 132 can also be in other structural forms, such as a Z-shaped structure or an L-shaped structure, as long as the first base 131a has a first metal part 1311 protruding on at least one side along the second direction b, the second base has a second metal part 1321 protruding on at least one side along the second direction b, and the adjacent first metal parts 1311 and second metal parts 1321 along the second direction b are staggered and their projections along the third direction c overlap. This application does not impose any restrictions on this.

[0038] Optionally, such as Figure 4 As shown, both the upper metal layer 131 and the lower metal layer 132 are provided with through-holes 134. Any adjacent upper metal layer 131 and lower metal layer 132 along the first direction a are electrically connected through the through-holes 134. The through-holes 134 can connect the upper metal layer 131 and the lower metal layer 132 into a whole electrode, making the potentials of the upper metal layer 131 and the lower metal layer 132 equal. This allows the upper metal layer 131 and the lower metal layer 132 to work together to simulate the complex wiring of the actual chip, improving the accuracy and reliability of the test results.

[0039] In another aspect, this invention provides a semiconductor device including the aforementioned IMD test structure 100. This semiconductor device, through the configuration of the IMD test structure 100, can flexibly and accurately test the breakdown performance of the inter-metal dielectric to evaluate chip yield. The specific structure and beneficial effects of the aforementioned IMD test structure 100 have been described in detail above and will not be repeated here.

[0040] The above description is merely an optional embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0041] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.

Claims

1. An IMD test structure, characterized by, The device includes a first solder pad (110) and a second solder pad (120) arranged at relatively intervals; the first solder pad (110) is connected to a first metal wire layer (111), and the second solder pad (120) is connected to a second metal wire layer (121) arranged alternately and parallel to the first metal wire layer (111); both the first metal wire layer (111) and the second metal wire layer (121) include an alternately arranged first metal portion (1311) and a second metal portion (1321); the first metal portion (1311) is arranged opposite to and partially overlaps with the second metal portion (1321) in the adjacent metal wire layer, and the second metal portion (1321) is arranged opposite to and partially overlaps with the first metal portion (1311) in the adjacent metal wire layer, so as to jointly enclose and form a accommodating space (140) for filling the interlayer medium of the metal layer to be tested.

2. The IMD test structure of claim 1, wherein, The first metal portion (1311) is formed on the upper metal layer (131), the upper metal layer (131) has a first base (131a) extending along a first direction (a) and a first extension (131b) extending along a second direction (b), the first extension (131b) is perpendicularly disposed at the end of the first base (131a), and the first metal portion (1311) is formed at opposite ends of the first extension (131b); the first direction and the second direction are perpendicular to each other.

3. The IMD test structure of claim 2, wherein, The second metal portion (1321) is formed on the lower metal layer (132), which has a second base (132a) extending along a first direction (a) and a second extension (132b) extending along a second direction (b). The second extension (132b) is perpendicularly disposed at the end of the second base (132a), and the second metal portion (1321) is formed at the opposite ends of the second extension (132b).

4. The IMD test structure of claim 3, wherein, The upper metal (131) and the lower metal (132) are electrically connected to form a monitoring unit (130), and there are multiple monitoring units (130) that are sequentially and alternately connected along the first direction (a).

5. The IMD test structure according to claim 1, characterized in that, Both the first metal part (1311) and the second metal part (1321) are rectangular block structures.

6. The IMD test structure of claim 4, wherein, Both the upper metal layer (131) and the lower metal layer (132) are provided with through holes (134), and any adjacent upper metal layer (131) and lower metal layer (132) along the first direction (a) are electrically connected through the through holes (134).

7. The IMD test structure of claim 1, wherein, The number of the first metal wire layers (111) is multiple, and the multiple first metal wire layers (111) are arranged in parallel and spaced apart. The second metal wire layer (121) is located between any two adjacent first metal wire layers (111).

8. The IMD test structure of claim 1, wherein, The number of the second metal wire layers (121) is multiple, and the multiple second metal wire layers (121) are arranged in parallel and spaced apart, and the first metal wire layer (111) is located between any two adjacent second metal wire layers (121).

9. The IMD test structure of claim 1, wherein, The first pad (110) is connected with an active end (150) for applying a scanning voltage, and the second pad (120) is connected with a current return reference end (160).

10. A semiconductor device, characterized by comprising: The IMD test structure (100) according to any one of claims 1-9.

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