Virtual graph test structure and test method thereof

Abstract

The invention provides a virtual graph test structure and a test method thereof. The virtual graph test structure comprises at least one virtual filling area, the virtual filling area comprises a first extension area extending along a first direction and a second extension area extending along a second direction, one end of the first extension area is connected with one end of the second extension area, the first extension area and the second extension area have the same first width, and the second extension area has the same second width; wherein an included angle is formed between the first direction and the second direction, a virtual graph is filled in the virtual filling area according to a virtual graph filling rule, and the virtual graph in the virtual filling area has a first filling density; and judging whether the virtual graph filling rule meets the process requirement or not by acquiring the first filling density. According to the technical scheme, the quality of the virtual graph filling rule can be evaluated at the initial stage of platform development, and the improvement of the virtual graph filling rule is guided.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, and in particular to a virtual graphic test structure and a test method thereof. Background Art

[0002] In the early stage of chip manufacturing and development, in order to ensure the accuracy of the final wafer graphics (such as active area (OD), polysilicon (PO), back-end metal (Metal), aluminum pad (Al)), improve the defects caused by the process (such as chemical mechanical polishing (CMP)), etc., the chip foundry will design appropriate dummy pattern filling rules (Dummy Insertion Rule) based on its own process conditions. However, there is no corresponding method in the prior art to measure the advantages and disadvantages of dummy pattern filling rules and the filling capabilities of dummy patterns (Dummy Pattern) under different environments.

[0003] Therefore, how to monitor the quality of virtual graphic filling rules and the filling capabilities of virtual graphics under different environments is a problem that needs to be solved at present. Summary of the invention

[0004] The technical problem to be solved by the present invention is how to monitor the quality of virtual graphic filling rules and the filling capabilities of virtual graphics under different environments, and to provide a virtual graphic test structure and a test method thereof.

[0005] In order to solve the above problems, the present invention provides a virtual graphic test structure, including: at least one virtual filling area, including a first extension area extending along a first direction and a second extension area extending along a second direction, one end of the first extension area is connected to one end of the second extension area, the first extension area and the second extension area have the same first width, wherein the first direction forms an angle with the second direction, and a virtual graphic is filled in the virtual filling area according to a virtual graphic filling rule, and the virtual graphic in the virtual filling area has a first filling density; by obtaining the first filling density, it is determined whether the virtual graphic filling rule meets the process requirements.

[0006] In order to solve the above problems, the present invention provides a virtual graphic testing method, comprising the following steps: providing a virtual graphic testing structure, wherein the virtual graphic testing structure adopts the virtual graphic testing structure described in the present invention; obtaining a first filling density of the virtual graphic in a virtual filling area; and judging whether the virtual graphic filling rule meets the process requirements according to the first filling density.

[0007] The above technical solution generates a virtual graphic by running the virtual graphic filling rule in the virtual fill area, and measures the quality of the virtual graphic filling rule by the first filling density of the virtual graphic. The virtual graphic test structure provided by the present invention can evaluate the quality of the virtual graphic filling rule in the early stage of platform development and guide the improvement of the virtual graphic filling rule.

[0008] It should be understood that the above general description and the detailed description below are exemplary and explanatory only and cannot limit the present invention. The techniques, methods and devices known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, the techniques, methods and devices should be considered as part of the authorization specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following is a brief introduction to the drawings required for the description of the specific embodiments. Obviously, the drawings described below are only some specific embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0010] Figure 1 It is a structural diagram of an embodiment of the virtual graphic test structure of the present invention.

[0011] Figure 2 It is a structural diagram of another embodiment of the virtual graphic test structure of the present invention.

[0012] Figure 3 The figure is a flowchart of one embodiment of the virtual graphics testing method of the present invention.

[0013] Figure 4 It is a schematic diagram of the comparison of the first corresponding relationship diagram and the second corresponding relationship diagram of the virtual graphics testing method of the present invention. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0015] See also Figure 1 , which is a schematic diagram of the structure of an embodiment of the virtual graphic test structure of the present invention. Figure 1As shown, the virtual graphic test structure includes: at least one virtual filling area 11 and a virtual graphic 12. The virtual filling area 11 includes a first extension area 111 extending along a first direction D1 and a second extension area 112 extending along a second direction D2. One end of the first extension area 111 is connected to one end of the second extension area 112. The first extension area 111 and the second extension area 112 have the same first width. Herein, the first direction D1 and the second direction D2 form an angle. The virtual graphic 12 is filled in the virtual filling area 11 according to a virtual graphic filling rule, and the virtual graphic 12 in the virtual filling area 11 has a first filling density. By obtaining the first filling density, it is further determined whether the virtual graphic filling rule meets the process requirements.

[0016] Through the above technical solution, a virtual graphic is generated by running a virtual graphic filling rule in a virtual filling area, and the quality of the virtual graphic filling rule is measured by the first filling density of the virtual graphic. The virtual graphic test structure provided by the present invention can evaluate the quality of the virtual graphic filling rule at the initial stage of platform development and guide the improvement of the virtual graphic filling rule.

[0017] In this embodiment, the first direction D1 and the second direction D2 are perpendicular to each other. The first direction D1 is the vertical direction, and the second direction D2 is the horizontal direction. Considering different insertion directions of the virtual graphic 12, the first extension area 111 extending in the vertical direction and the second extension area 112 extending in the horizontal direction are provided to ensure the severity of the filling environment of the virtual graphic 12 and meet the test requirements.

[0018] It should be noted that parameters such as the shape, size, direction, and density of the virtual graphic 12 are determined by the virtual graphic filling rule. Figure 1 The shape, size, direction, and density of the virtual graphic 12 shown in are only for illustration and do not represent real parameters.

[0019] In some embodiments, the virtual graphic test structure includes a plurality of the virtual filling areas 11 arranged at intervals, and the first widths of the plurality of the virtual filling areas 11 gradually change. Figure 1 The shown embodiment includes 4 virtual filling areas 11, and the first widths of the 4 virtual filling areas 11 are W1, W2, W3, and W4 respectively, and W1, W2, W3, and W4 are all different.

[0020] In some embodiments, the first widths of the plurality of the virtual filling areas 11 gradually increase. In this embodiment, the magnitude order of the first widths of the 4 virtual filling areas 11 is W1 < W2 < W3 < W4. In other embodiments, the first widths of the plurality of the virtual filling areas 11 may also gradually decrease.

[0021] In some embodiments, the first widths of the plurality of virtual filling areas 11 are an arithmetic progression. In this embodiment, the size relationship of the first widths of the four virtual filling areas 11 is W1+3a=W2+2a=W3+a=W4, where a is the tolerance of the arithmetic progression and its value is a constant. In other embodiments, the first widths of the plurality of virtual filling areas 11 can also be set according to process requirements, for example, the first widths of several virtual filling areas with higher usage frequencies are selected according to the actual process, and are sorted according to the size of the usage frequency.

[0022] In some embodiments, a plurality of the virtual filling areas 11 are nested to save space and improve the severity of the filling environment of the virtual pattern 12 .

[0023] See also Figure 2 , which is a structural diagram of another embodiment of the virtual graphic test structure of the present invention. Figure 2 The embodiment shown is Figure 1 The difference from the illustrated embodiment is that a step structure 23 is formed at the connection between the first extension area 211 and the second extension area 212 described in this embodiment, and the step structure 23 includes a plurality of step layers. Figure 2 The step structure 23 in the illustrated embodiment includes two step layers 231 and 232. In other embodiments, the step structure 23 may also include three, four, five or more step layers. In the virtual filling area 21 of this embodiment, the step structure 23 is provided to improve the severity of the filling environment of the virtual pattern 22, so as to cope with more complex layout structures and improve the virtual pattern filling rules to make them more accurate.

[0024] In some embodiments, the step structure 23 has a second width, which is the same as the first width, so as to increase the consistency of the dummy filling area 21 and make the measurement more accurate.

[0025] In other embodiments, the second width may be different from the first width to increase the complexity of the filling environment of the virtual filling area 21 .

[0026] Based on the same inventive concept, an embodiment of the present invention further provides a virtual graphics testing method.

[0027] See also Figure 3 , which is a flowchart of the steps of an embodiment of the virtual graphics testing method of the present invention. Figure 3As shown, the virtual graphic testing method includes the following steps: step S31, providing a virtual graphic testing structure, the virtual graphic testing structure adopts the virtual graphic testing structure described in the present invention; step S32, obtaining the first filling density of the virtual graphic in the virtual filling area; step S33, judging whether the virtual graphic filling rule meets the process requirements according to the first filling density.

[0028] Please refer to Figure 1 And step S31, providing a virtual graphic test structure, the virtual graphic test structure adopts the present invention Figure 1 Virtual graphics test structure shown.

[0029] Please refer to Figure 1 And step S32, obtaining the first filling density of the virtual pattern 12 in the virtual filling area 11. When there are multiple virtual filling areas 11, it is necessary to count the first filling density of the virtual pattern 12 in each virtual filling area 11 respectively.

[0030] Please refer to Figure 1 And step S33, judging whether the virtual pattern filling rule meets the process requirement according to the first filling density.

[0031] In some embodiments, the step of judging whether the virtual graphic filling rule meets the process requirements according to the first filling density specifically includes: comparing the first filling density and the density threshold to judge whether the virtual graphic filling rule meets the process requirements. The density threshold can be set according to the process requirements, or it can refer to the parameters already available in the industry. By comparing the first filling density and the density threshold, if the difference between the first filling density and the density threshold is within the error range allowed by the process, it is judged whether the virtual graphic filling rule meets the process requirements; if the difference between the first filling density and the density threshold is large, it is necessary to adjust the virtual graphic filling rule to meet the process requirements.

[0032] like Figure 1 As shown, in some embodiments, the virtual pattern test structure includes a plurality of virtual filling areas 11 arranged at intervals, and the first widths of the plurality of virtual filling areas 11 gradually change, and the step of judging whether the virtual pattern filling rule meets the process requirements according to the first filling density specifically includes: comparing whether the first filling densities of the virtual patterns 12 of the plurality of virtual filling areas 11 are the same, and judging whether the virtual pattern filling rule meets the process requirements. If there is no industry parameter to refer to for the density threshold, the first filling densities of the virtual patterns 12 of the plurality of virtual filling areas 11 can also be compared to make the first filling densities of the virtual patterns 12 of each virtual filling area 11 as consistent as possible, so as to improve the reliability of the virtual pattern filling rule.

[0033] like Figure 1 As shown, in some embodiments, the dummy pattern test structure includes a plurality of dummy filling areas 11 arranged at intervals, and the first widths of the plurality of dummy filling areas 11 gradually change, and the step of judging whether the dummy pattern filling rule meets the process requirements according to the first filling density specifically includes: comparing the first filling density of the dummy pattern 12 of the dummy filling areas 11 with different first widths with the density threshold of the corresponding width, to judge whether the dummy pattern filling rule meets the process requirements. The first filling density of the dummy pattern 12 of the dummy filling areas 11 with different first widths and the density threshold of the corresponding width are compared respectively. In each of the dummy filling areas 11, if the difference between the first filling density and the density threshold is within the error range allowed by the process, it is judged that the filling rule of the dummy pattern filling rule for the first width corresponding to the dummy filling area 11 meets the process requirements; if the difference between the first filling density and the density threshold is large, it is necessary to adjust the filling rule of the dummy pattern filling rule for the first width corresponding to the dummy filling area 11 to meet the process requirements.

[0034] Specifically, Figure 4 As shown, a first correspondence diagram (broken line shown by reference numeral 41) between the first width of the virtual fill area 11 and the first fill density of the corresponding virtual graphic 12 can also be drawn, wherein the horizontal axis is the first width of the virtual fill area 11 and the vertical axis is the first fill density of the corresponding virtual graphic 12; and a second correspondence diagram (broken line shown by reference numeral 42) between the first width of the virtual fill area 11 and the density threshold of the corresponding width can be drawn, wherein the horizontal axis is the first width of the virtual fill area 11 and the vertical axis is the density threshold of the corresponding width. By comparing the two superimposed diagrams, it can be intuitively seen whether the difference between the first fill density generated by the virtual graphic fill rule and the density threshold is too large, and then it can be determined whether the virtual graphic fill rule needs to be adjusted.

[0035] The above technical solution generates a virtual graphic by running the virtual graphic filling rule in the virtual fill area, and measures the quality of the virtual graphic filling rule by the first filling density of the virtual graphic. The virtual graphic test structure provided by the present invention can evaluate the quality of the virtual graphic filling rule in the early stage of platform development and guide the improvement of the virtual graphic filling rule.

[0036] It should be noted that references in the specification to "an embodiment", "an embodiment", "an exemplary embodiment", "some embodiments", etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, whether or not explicitly described, it is within the knowledge of a technician in the relevant art to implement such feature, structure, or characteristic in conjunction with other embodiments.

[0037] Typically, a term can be understood at least in part from usage in context. For example, the term "one or more" as used herein depends at least in part on the context and can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a combination of features, structures or features in a plural sense. Similarly, terms such as "one", "a" or "the" can also be understood to express singular usage or to express plural usage, depending at least in part on the context. In addition, the term "based on" can be understood to not necessarily be intended to express a set of exclusive factors, but can alternatively, also at least in part depending on the context, allow for the presence of other factors that are not necessarily explicitly described. It should also be noted in this specification that "connected / coupled" refers not only to the direct coupling of one component to another component, but also to the indirect coupling of one component to another component through an intermediate component.

[0038] It should be noted that the terms "including" and "having" and their variations involved in the documents of the present invention are intended to cover non-exclusive inclusions. The terms "first", "second", etc. are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Unless the context clearly indicates otherwise, it should be understood that the data used in this way can be interchanged under appropriate circumstances. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other unless there is a conflict. In addition, in the above description, the description of well-known components and technologies is omitted to avoid unnecessary confusion of the concepts of the present invention. In the above embodiments, each embodiment focuses on the differences from other embodiments, and the same / similar parts between the embodiments can be referred to each other.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A virtual graphics test structure, characterized in that: include: At least one dummy filling region includes a first extension region extending along a first direction and a second extension region extending along a second direction, one end of the first extension region is connected to one end of the second extension region, the first extension region and the second extension region have the same first width, wherein the first direction forms an angle with the second direction, A virtual pattern is filled in the virtual filling area according to a virtual pattern filling rule, and the virtual pattern in the virtual filling area has a first filling density; Whether the virtual pattern filling rule meets the process requirement is determined by acquiring the first filling density.

2. The virtual graphic test structure according to claim 1, characterized in that: The dummy pattern test structure includes a plurality of dummy filling areas that are spaced apart from each other, and first widths of the plurality of dummy filling areas change gradually.

3. The virtual graphic test structure according to claim 2, characterized in that: The first widths of the plurality of dummy filling areas gradually increase.

4. The virtual graphic test structure according to claim 2, characterized in that: The first widths of the plurality of virtual filling areas are an arithmetic progression.

5. The virtual graphic test structure according to claim 2, characterized in that: A plurality of the virtual filling areas are nested.

6. The virtual graphic test structure according to claim 1, characterized in that: A step structure is formed at a connection between the first extension region and the second extension region, and the step structure includes a plurality of step layers.

7. A virtual graphics testing method, characterized in that: The steps include: Providing a virtual graphics test structure, wherein the virtual graphics test structure adopts the virtual graphics test structure as claimed in claim 1; Acquire a first filling density of the virtual graphic in the virtual filling area; It is determined whether the dummy pattern filling rule meets process requirements according to the first filling density.

8. The method according to claim 7, characterized in that The step of judging whether the virtual pattern filling rule meets the process requirements according to the first filling density specifically includes: The first filling density and the density threshold are compared to determine whether the virtual pattern filling rule meets the process requirements.

9. The method according to claim 7, characterized in that: The dummy pattern test structure includes a plurality of dummy filling areas arranged at intervals, and the first widths of the plurality of dummy filling areas gradually change. The step of judging whether the dummy pattern filling rule meets the process requirements according to the first filling density specifically includes: Comparing whether the first filling densities of the dummy patterns in the plurality of dummy filling areas are the same, and determining whether the dummy pattern filling rule meets the process requirements.

10. The method according to claim 7, characterized in that The dummy pattern test structure includes a plurality of dummy filling areas arranged at intervals, and the first widths of the plurality of dummy filling areas gradually change. The step of judging whether the dummy pattern filling rule meets the process requirements according to the first filling density specifically includes: The first filling density of the virtual pattern of the virtual filling area with different first widths is compared with the density threshold of the corresponding width to determine whether the virtual pattern filling rule meets the process requirement.

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