Test structure
By adding new ports to the test structure and changing it to a comb-shaped structure, the problem of poor monitoring capabilities of the existing test structure is solved, and more accurate process health judgment and variation monitoring are achieved, reducing manufacturing costs and improving yield and profits.
Patent Information
- Application Number
- CN202420450910.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-08
- Publication Date
- 2025-04-25
- Estimated Expiration
- 2034-03-08
AI Technical Summary
When testing the dual Damascus process technology, the existing test structure has poor monitoring capabilities and cannot accurately monitor electrical performance online, resulting in increased manufacturing costs and reduced profits.
Provide a test structure, by adding a new port to the original device test structure, obtaining three sets of electrical data of the same process, and outputting the set closest to the true value by comparing. At the same time, the original bow chain structure is changed to a comb structure, and the current of each sub-test structure is tested to find out whether there are leakage points in the process.
It improves the accuracy of judging process health, strengthens the monitoring ability of process variation, reduces manufacturing costs, and improves yield and profits.
Smart Images
Figure CN222801807U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor technology, and in particular to a test structure. Background Art
[0002] As the complexity and circuit density of integrated circuits continue to increase, many chip manufacturing processes are becoming more and more complex (for example, the dual damascene process used in the copper process of chip manufacturing). Due to the complexity of the process, the yield of the corresponding process will be unstable. Wafer Acceptance Test (WAT) is an indicator for foundry shipment judgment and a reference for process stability. Whether the electrical data stability of the dual damascene process can be detected by electrical measurement is particularly important.
[0003] At present, when conducting electrical testing on a certain process technology, a corresponding test structure will be formed based on the process technology. A common test structure corresponding to the dual damascene process is a chain structure with multiple bows connected in sequence, and a test pad is formed at each of the two free ends of the test structure; during the test, a test voltage is applied to the two test pads to implement electrical testing of the test structure.
[0004] Since the dual Damascus process is relatively complex and the test method of electrical testing is too simple, the measurement value of the above test structure often deviates from the actual value, and the test result is prone to problems; the above test structure has poor monitoring capabilities and cannot accurately monitor the electrical performance of the corresponding process technology online. When there are abnormalities in the process technology, it cannot be discovered in time, which will lead to increased manufacturing costs and reduced profits. Summary of the invention
[0005] The purpose of this application is to provide a test structure that is conducive to accurately monitoring the electrical properties of the test structure process, improving the accuracy of judging the health of the process, strengthening the ability to monitor process variation, reducing manufacturing costs, and improving yield and profits.
[0006] To achieve the purpose of this application, this application provides the following technical solutions:
[0007] In a first aspect, the present application provides a test structure, comprising:
[0008] The first subtest structure is in the shape of a reciprocating bow;
[0009] The second sub-test structure is located on one side of the first sub-test structure and is in a reciprocating arc shape;
[0010] A first test pad connected to one end of the first sub-test structure;
[0011] a second test pad connected to one end of the second sub-test structure;
[0012] The third test pad is connected to an end of the first sub-test structure away from the first test pad and an end of the second sub-test structure away from the second test pad.
[0013] The test structure of the present application can obtain three sets of electrical data of the same process by adding a new port to the original device test structure. At the same time, based on the comparison of the three sets of electrical data, one set closest to the true value can be output. More data improves the accuracy of judging the health of the process, strengthens the ability to monitor process variation, reduces manufacturing costs, and improves yield and profit.
[0014] In one embodiment, the first sub-test structure and the second sub-test structure both include:
[0015] A plurality of test strips extending along a first direction and arranged at intervals along a second direction, wherein the first direction is perpendicular to the second direction; each of the test strips comprises: a plurality of first wire segments, a plurality of second wire segments, and a plurality of interconnection structures; the plurality of first wire segments and the plurality of second wire segments are arranged at intervals along the first direction, and the second wire segments are located below the first wire segments; the interconnection structure is located between the first wire segments and the second wire segments, so as to alternately connect the first wire segments and the second wire segments located in the same column in sequence;
[0016] A plurality of first connecting line segments and a plurality of second connecting line segments; the first connecting line segments and the second connecting line segments are respectively located at opposite ends of the test strip, and respectively located between different adjacent test strips, and are alternately arranged along the second direction; the first connecting line segment connects the first wire segments in two adjacent test strips, and the second connecting line segment connects the second wire segments in two adjacent test strips.
[0017] In one embodiment, the first connecting line segment and the first conducting line segment are located in the same layer; the second connecting line segment and the second conducting line segment are located in the same layer.
[0018] In one embodiment, the length of the first wire segment is equal to the length of the second wire segment.
[0019] In one embodiment, the first wire segment is parallel to the second wire segment, and the interconnection structure is perpendicular to the first wire segment and the second wire segment.
[0020] In a second aspect, the present application also provides a test structure, including:
[0021] The first sub-test structure includes a first connecting line segment and a plurality of first test strips; the plurality of first test strips extend along a first direction and are arranged at intervals along a second direction; the first connecting line segment is connected to the plurality of first test strips, and the first direction is perpendicular to the second direction;
[0022] The second sub-test structure comprises a second connecting line segment and a plurality of second test strips; the plurality of second test strips extend along the first direction and are arranged alternately and spaced with the first test strips along the second direction; the second connecting line segment is connected to the plurality of first test strips; the first test strip and the second test strip each comprise: a plurality of first wire segments, a plurality of second wire segments and an interconnection structure; the plurality of first wire segments extend along the first direction and are arranged alternately and spaced along the first direction; the plurality of second wire segments extend along the first direction and are arranged alternately and spaced along the first direction; the second wire segment is located below the first wire segment; the interconnection structure is located between the first wire segment and the second wire segment to alternately connect the first wire segment and the second wire segment in the same column in sequence;
[0023] A first test pad connected to an end of the first connecting line segment away from the first test strip;
[0024] The second test pad is connected to an end of the second connecting line segment away from the second test strip.
[0025] In the test structure of the present application, by changing the original bow-shaped chain structure of the device test structure into a comb-shaped structure and testing the current of each sub-test structure, it is possible to better discover whether there are leakage points in the test structure process, thereby improving the accuracy of judging the health of the process, strengthening the ability to monitor process variation, reducing manufacturing costs, and improving yield and profits.
[0026] In one embodiment, the first connecting line segment is located on the same side of the plurality of first conductive line segments; and the second connecting line segment is located on the same side of the plurality of second conductive line segments.
[0027] In one embodiment, the first connecting line segment and the first conducting line segment are located in the same layer; the second connecting line segment and the second conducting line segment are located in the same layer.
[0028] In one embodiment, the length of the first wire segment is equal to the length of the second wire segment.
[0029] In one embodiment, the first connecting line segment is perpendicular to the first wire segment; the second connecting line segment is perpendicular to the second wire segment; the first wire segment is parallel to the second wire segment, and the interconnection structure is perpendicular to both the first wire segment and the second wire segment.
[0030] To summarize, the test structure provided by the present application, by adding a new port to the original device test structure and changing the bow-shaped chain structure of the original device test structure into a comb-shaped structure, has the unexpected effect of: adding a new port can obtain three sets of electrical data of the same process, and at the same time, based on the comparison of the three sets of electrical data, the group closest to the true value can be output and the comb-shaped structure can test the current of each chain, which can better discover whether there are leakage points in the test structure process, improve the accuracy of judging the health of the process, strengthen the monitoring ability of process variation, reduce manufacturing costs, and improve yield and profit. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0032] Figure 1 is a top view of a test structure provided in an embodiment of the present application;
[0033] Figure 2 is a three-dimensional structural schematic diagram of a test structure provided in an embodiment of the present application;
[0034] Figure 3 is a top view of a test structure provided in another embodiment of the present application;
[0035] Figure 4 It is a three-dimensional structural schematic diagram of a test structure provided in another embodiment of the present application.
[0036] Description of Reference Numerals
[0037] 10. Test structure; 101. First sub-test structure; 102. Second sub-test structure; 103. First test pad; 104. Second test pad; 105. Third test pad; 106. Test strip; 1061. First wire segment; 1062. Second wire segment; 1063. Interconnection structure; 107. First connecting wire segment; 108. Second connecting wire segment;
[0038] 20. Test structure; 201. First sub-test structure; 2011. First connecting line segment; 2012. First test strip; 202. Second sub-test structure; 2021. Second connecting line segment; 2022. Second test strip; 203. First conductor segment; 204. Second conductor segment; 205. Interconnection structure; 206. First test pad; 207. Second test pad. DETAILED DESCRIPTION
[0039] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.
[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.
[0041] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. On the contrary, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, doping types and / or parts, these elements, components, regions, layers, doping types and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, doping type or part from another element, component, region, layer, doping type or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer, doping type or portion discussed below may be represented as a second element, component, region, layer or portion; for example, the first doping type may be referred to as the second doping type, and similarly, the second doping type may be referred to as the first doping type; the first doping type and the second doping type are different doping types, for example, the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.
[0042] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.
[0043] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that when the terms "consisting of" and / or "comprising" are used in this specification, the presence of the features, integers, steps, operations, elements and / or parts can be determined, but the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups is not excluded. At the same time, when used herein, the term "and / or" includes any and all combinations of the relevant listed items.
[0044] Embodiments of the invention are described herein with reference to cross-sectional views which are schematic diagrams of ideal embodiments (and intermediate structures) of the invention, such that variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances are anticipated. Thus, embodiments of the invention should not be limited to the specific shapes of the regions shown herein, but rather include deviations in shapes due to, for example, manufacturing techniques. For example, an implanted region shown as a rectangle typically has rounded or curved features and / or an implant concentration gradient at its edges rather than a binary change from an implanted region to a non-implanted region. Similarly, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation is performed. Thus, the regions shown in the figures are schematic in nature, their shapes do not represent the actual shape of the region of the device, and do not limit the scope of the invention.
[0045] As the complexity and circuit density of integrated circuits continue to increase, many chip manufacturing processes are becoming more and more complex (for example, the Damascus process used in the copper process of chip manufacturing). Due to the complexity of the process, the yield of the corresponding process will be unstable. Wafer Acceptance Test (WAT) is an indicator for foundry shipment judgment and a reference for process stability. Whether the electrical data stability of the dual Damascus process can be detected by electrical measurement is particularly important.
[0046] When conducting electrical testing on a certain process technology, a corresponding test structure will be formed based on the process technology. A currently common test structure corresponding to the Damascus process is a chain structure with multiple bows connected in sequence, and a test pad is formed at each of the two free ends of the test structure; during the test process, a test voltage is applied to the two test pads to implement electrical testing of the test structure.
[0047] Since the Damascus process is relatively complex and the test method of electrical testing is too simple, the measurement value of the above test structure often deviates from the actual value, and the test result is prone to problems; the above test structure has poor monitoring capabilities and cannot accurately monitor the electrical performance of the corresponding process technology online. When there are abnormalities in the process technology, it cannot be discovered in time, which will lead to increased manufacturing costs and reduced profits.
[0048] See also Figure 1 and Figure 2 The embodiment of the present application provides a test structure 10, which may include: a first sub-test structure 101, which is in a reciprocating bow shape; a second sub-test structure 102, which is located on one side of the first sub-test structure 101 and is in a reciprocating bow shape; a first test pad 103, which is connected to one end of the first sub-test structure 101; a second test pad 104, which is connected to one end of the second sub-test structure 102; and a third test pad 105, which is connected to both one end of the first sub-test structure 101 away from the first test pad 103 and one end of the second sub-test structure 102 away from the second test pad 104.
[0049] In the embodiment of the present application, by adding a new port to the original device test structure, three sets of electrical data of the same process can be obtained. At the same time, based on the comparison of the three sets of electrical data, the set closest to the true value can be output. More data improves the accuracy of judging the health of the process, strengthens the monitoring ability of process variation, reduces manufacturing costs, and improves yield and profit.
[0050] In some embodiments, please refer to Figure 1 and Figure 2The first sub-test structure 101 and the second sub-test structure 102 both include: a plurality of test strips 106 extending along a first direction and arranged at intervals along a second direction, wherein the first direction is perpendicular to the second direction; each test strip 106 includes: a plurality of first wire segments 1061, a plurality of second wire segments 1062, and a plurality of interconnecting structures 1063; the plurality of first wire segments 1061 and the plurality of second wire segments 1062 are arranged at intervals along the first direction, and the second wire segments 1062 are located below the first wire segments 1061; the interconnecting structures 1063 are located between the first wire segments 1061 and the second wire segments 1062, so as to alternately connect the first wire segment 1061 and the second wire segment 1062 located in the same column in sequence; a plurality of first connecting wire segments 107 and a plurality of second connecting wire segments 108; the first connecting wire segments 107 and the second connecting wire segments 108 are respectively located at opposite ends of the test strip 106, and are respectively located between different adjacent test strips 106, and are alternately arranged along the second direction; the first connecting wire segment 107 connects the first wire segments 1061 in two adjacent test strips, and the second connecting wire segment 108 connects the second wire segments 1062 in two adjacent test strips 106.
[0051] In some examples, an interconnection structure 1063 and the first wire segment 1061 and the second wire segment 1062 connected thereto in the first sub-test structure 101 and the second sub-test structure 102 can be regarded as a test unit, or a first wire segment 1061 in the first sub-test structure 101 and the second sub-test structure 102, the second wire segment 1062 located below the first wire segment 1061, and the interconnection structure 1063 therebetween can be regarded as a test unit.
[0052] In some examples, the first test pad 103 may be applied with a first voltage; the current passing through the second test pad 104 is the first current; the third pad 105 may be applied with a second voltage, and the current passing through the third pad 105 is the second current; based on the first voltage, the first current, and the total number of test units between the first test pad 103 and the second test pad 104, the first resistance of each test unit between the first test pad 103 and the second test pad 104 may be obtained; based on the first voltage, the second current, and the number of test units between the first test pad 103 and the third test pad 105, the second resistance of each test unit between the first test pad 103 and the third test pad 105 may be obtained; based on the second voltage, the first current, and the total number of test units between the first test pad 103 and the third test pad 105, the second resistance of each test unit between the first test pad 103 and the third test pad 105 may be obtained. 04 and the third test pad 105, the third resistance of each test unit between the second test pad 104 and the third test pad 105 can be obtained; more specifically, when at least one of the first resistance, the second resistance or the third resistance is greater than 500 ohms, the output result is 500 ohms; otherwise (that is, the first resistance, the second resistance and the third resistance are not greater than 500 ohms), compare whether the second resistance and the third resistance are equal, and output the value of the first resistance when the second resistance and the third resistance are equal; otherwise (that is, the second resistance is not equal to the third resistance), compare whether the second resistance is greater than the third resistance, and output the third resistance when the second resistance is greater than the third resistance; otherwise (that is, the second resistance is less than or equal to the third resistance), output the value of the first resistance.
[0053] In some embodiments, please refer to Figure 1 and Figure 2 , the first connecting line segment 107 and the first wire segment 1061 can be located in the same layer; the second connecting line segment 108 and the second wire segment 1062 can be located in the same layer. Specifically, the first connecting line segment 107 and the first wire segment 1061 can be obtained by patterning the same conductive layer; the second connecting line segment 108 and the second wire segment 1062 can be obtained by patterning the same conductive layer.
[0054] In some embodiments, please refer to Figure 2 , the length of the first wire segment 1061 can be equal to the length of the second wire segment 1062.
[0055] In some embodiments, please refer to Figure 2 The first wire segment 1061 may be parallel to the second wire segment 1062 , and the interconnect structure 1063 may be perpendicular to both the first wire segment 1061 and the second wire segment 1062 .
[0056] In some embodiments, the first connecting line segment 107 , the second connecting line segment 108 , the first conductive line segment 1061 , the second conductive line segment 1062 , and the interconnection structure 1063 may all be made of metal materials, such as copper, aluminum, nickel, titanium, or gold.
[0057] See also Figure 3 and Figure 4 , the embodiment of the present application further provides a test structure 20, the test structure 20 may include: a first sub-test structure 201, including a first connecting line segment 2011 and a plurality of first test strips 2012; the plurality of first test strips 2012 all extend along the first direction and are arranged at intervals along the second direction; the first connecting line segment 2011 is connected to the plurality of first test strips 2012, and the first direction is perpendicular to the second direction; a second sub-test structure 202, including a second connecting line segment 2021 and a plurality of second test strips 2022; the plurality of second test strips 2022 all extend along the first direction and are arranged alternately with the first test strips 2012 along the second direction; the second connecting line segment 2021 is connected to the plurality of first test strips 2012; the first test strips 2012 and the second test strips 2022 are connected to each other; 022 includes: a plurality of first wire segments 203, a plurality of second wire segments 204 and an interconnection structure 205; the plurality of first wire segments 203 all extend along the first direction and are arranged at intervals along the first direction; the plurality of second wire segments 204 all extend along the first direction and are arranged at intervals along the first direction; the second wire segments 204 are located below the first wire segments 203; the interconnection structure 205 is located between the first wire segments 203 and the second wire segments 204 to alternately connect the first wire segments 203 and the second wire segments 204 located in the same column in sequence; a first test pad 206 is connected to an end of the first connecting wire segment 2011 away from the first test strip 2012; and a second test pad 207 is connected to an end of the second connecting wire segment 2021 away from the second test strip 2022.
[0058] The test structure implemented in the present application, by changing the original bow-shaped chain structure of the device test structure into a comb-shaped structure and testing the current of each sub-test structure, can better discover whether the test structure (for example, dual Damascus) process has leakage points, thereby improving the accuracy of judging the health of the process, strengthening the ability to monitor process variation, reducing manufacturing costs, and improving yield and profits.
[0059] In some examples, an interconnection structure 205 and a first wire segment 203 and a second wire segment 204 connected thereto in the first sub-test structure 201 and the second sub-test structure 202 can be regarded as a test unit, or a first wire segment 203 in the first sub-test structure 201 and the second sub-test structure 202, a second wire segment 204 located below the first wire segment 203, and an interconnection structure 205 therebetween can be regarded as a test unit.
[0060] As an example, the first test pad 206 can apply a first voltage, and the current passing through it is a first current; the second test pad 207 can apply a second voltage, and the current passing through it is a second current; the first current and the second current are compared, and the larger of the two is output as a leakage current; for example, if the first current is greater than the second current, the first current is output as a leakage current, and if the first current is less than the second current, the second current is output as a leakage current.
[0061] In some embodiments, see Continue Figure 3 and Figure 4 , the first connecting line segment 2011 can be located on the same side of the multiple first wire segments 203 ; the second connecting line segment 2021 can be located on the same side of the multiple second wire segments 204 .
[0062] In some embodiments, please refer to Figure 3 and Figure 4 , the first connecting line segment 2011 can be located in the same layer as the first wire segment 203; the second connecting line segment 2021 can be located in the same layer as the second wire segment 204. Specifically, the first connecting line segment 2011 and the first wire segment 203 can be obtained by patterning the same conductive layer; the second connecting line segment 108 and the second wire segment 1062 can be obtained by patterning the same conductive layer.
[0063] In some embodiments, see Figure 4 , the length of the first wire segment 203 can be equal to the length of the second wire segment 204.
[0064] In some embodiments, please refer to Figure 3 and Figure 4 , the first connecting line segment 2011 can be perpendicular to the first wire segment 203; the second connecting line segment 2021 can be perpendicular to the second wire segment 204; the first wire segment 203 can be parallel to the second wire segment 204, and the interconnection structure 205 can be perpendicular to both the first wire segment 203 and the second wire segment 204.
[0065] In some embodiments, the first connecting line segment 2011 , the second connecting line segment 2021 , the first conductive line segment 203 , the second conductive line segment 204 and the interconnect structure 205 may all be made of metal materials, such as copper, aluminum, nickel, titanium or gold.
[0066] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features of the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0067] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.
Claims
1. A test structure, characterized in that: include: The first subtest structure is in the shape of a reciprocating bow; The second sub-test structure is located on one side of the first sub-test structure and is in a reciprocating arc shape; A first test pad connected to one end of the first sub-test structure; a second test pad connected to one end of the second sub-test structure; The third test pad is connected to an end of the first sub-test structure away from the first test pad and an end of the second sub-test structure away from the second test pad.
2. The test structure according to claim 1, characterized in that: The first sub-test structure and the second sub-test structure both include: A plurality of test strips extending along a first direction and arranged at intervals along a second direction, wherein the first direction is perpendicular to the second direction; each of the test strips comprises: a plurality of first wire segments, a plurality of second wire segments, and a plurality of interconnection structures; the plurality of first wire segments and the plurality of second wire segments are arranged at intervals along the first direction, and the second wire segments are located below the first wire segments; the interconnection structure is located between the first wire segments and the second wire segments, so as to alternately connect the first wire segments and the second wire segments located in the same column in sequence; A plurality of first connecting line segments and a plurality of second connecting line segments; the first connecting line segments and the second connecting line segments are respectively located at opposite ends of the test strip, and respectively located between different adjacent test strips, and are alternately arranged along the second direction; the first connecting line segment connects the first wire segments in two adjacent test strips, and the second connecting line segment connects the second wire segments in two adjacent test strips.
3. The test structure according to claim 2, characterized in that: The first connecting line segment and the first conducting line segment are located in the same layer; the second connecting line segment and the second conducting line segment are located in the same layer.
4. The test structure according to claim 2, characterized in that: The length of the first wire segment is equal to the length of the second wire segment.
5. The test structure according to claim 2, characterized in that: The first wire segment is parallel to the second wire segment, and the interconnection structure is perpendicular to the first wire segment and the second wire segment.