Dimension measurement structure and method of forming the same

Abstract

A size measurement structure and a method for forming the same, wherein the structure comprises: a substrate, the substrate comprising a monitoring area; a first monitoring structure on the monitoring area, the first monitoring structure comprising a plurality of mutually separated measurement structures, each measurement structure comprising a first monitoring layer and a second monitoring layer on the first monitoring layer, the first monitoring layer comprising a plurality of first pattern layers and first openings between adjacent first pattern layers, the second monitoring layer comprising a plurality of second pattern layers and second openings between adjacent second pattern layers, thereby improving the accuracy of critical dimension measurement and the accuracy of a photolithography process.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a dimension measurement structure and a method for forming the same. Background Technology

[0002] In semiconductor manufacturing, when the width of the patterned material layer is a critical parameter for the characteristics of the electronic component (or when this width is the smallest among all patterned wafer layers), this width is called the critical dimension (CD). Because variations in the critical dimension have a significant impact on the characteristics of electronic components, the error in the critical dimension must be strictly controlled within a certain range to avoid degrading component quality. To monitor the critical dimension, monitoring patterns, such as critical dimension bars (CD bars), are typically placed within the dicing trace. Measuring the CD bar allows for monitoring of process parameters, ensuring the proper formation of the photolithographic pattern.

[0003] When establishing existing photolithography processes, customer layouts are often very complex, and due to business confidentiality reasons, manufacturers often cannot obtain all design patterns. Typically, they select a few key structures based on product design requirements for process design. In processes with significant substrate step undulations, such as power, BCD (Bipolar-CMOS-DMOS), and RF device processes, the step undulations can even be comparable to the key process parameter of photolithography, the depth of focus (DOF).

[0004] Existing monitoring patterns typically only consider planar designs for critical dimensions, failing to assess situations where parts of the pattern span across the uneven substrate, leading to inaccurate critical dimension measurements. Furthermore, since lithography process conditions are set based on critical dimension measurements, when parts of the pattern span across the uneven substrate, the optimal focus depth of the lithography process and the commonly used process settings are not on the same plane, making it difficult to form some patterns.

[0005] Therefore, existing methods for measuring critical dimensions need further improvement. Summary of the Invention

[0006] The technical problem solved by this invention is to provide a dimension measurement structure and its forming method to optimize the detection means of critical dimensions.

[0007] To solve the above-mentioned technical problems, the present invention provides a size measurement structure, comprising: a substrate, the substrate including a monitoring area; a first monitoring structure located on the monitoring area, the first monitoring structure including a plurality of mutually discrete measurement structures, each measurement structure including a first monitoring layer and a second monitoring layer located on the first monitoring layer, the first monitoring layer including a plurality of first patterned layers and a first opening between adjacent first patterned layers, and the second monitoring layer including a plurality of second patterned layers and a second opening between adjacent second patterned layers.

[0008] Optionally, the plurality of first graphic layers and the plurality of second graphic layers are arranged along a first direction, the first graphic layer having a first size along the first direction, and the periodic arrangement size of the second graphic layer and the second opening along the first direction being a first periodic value, wherein the first size is less than twice the first periodic value.

[0009] Optionally, the plurality of measurement structures include a plurality of first type measurement structures, each of the first type measurement structures including a first pattern layer and a second opening located on the first pattern layer, wherein the second opening exposes a portion of the top surface of the first pattern layer along the first direction.

[0010] Optionally, the plurality of measurement structures include a plurality of second type measurement structures, each of the second type measurement structures including the first opening and a second opening located on the first opening, wherein along the first direction, the projection of the first opening on the substrate surface is located within the projection range of the second opening on the substrate surface.

[0011] Optionally, the plurality of measurement structures include a plurality of third-type measurement structures, each of the third-type measurement structures including a first graphic layer and a second graphic layer located on the first graphic layer, wherein the second graphic layer covers the surface and sidewalls of the first graphic layer along the first direction.

[0012] Optionally, the plurality of measurement structures include a plurality of fourth type measurement structures, each of the fourth type measurement structures including the first opening and the second pattern layer, wherein along the first direction, the second pattern layer is located inside and on the first opening.

[0013] Optionally, the periodic arrangement size of the first graphic layer and the first opening along the first direction is a second periodic value, and the ratio of the second periodic value to the first size ranges from 2:1 to 10:1; the second graphic layer has a second size along the first direction, and the ratio of the first periodic value to the second size ranges from 2:1 to 10:1.

[0014] Optionally, the second graphic layer has a second size along the first direction, and the spacing between adjacent second graphic layers and between adjacent second graphic layers is greater than a minimum design value, and the first size is greater than or equal to the difference between the second size and the minimum design value.

[0015] Optionally, the monitoring area includes a first area and a second area, with the first monitoring structure located in the first area; the size measurement structure further includes: a second monitoring structure located in the second area, the second monitoring structure including at least one third opening; and a third monitoring structure located in the second area, the third monitoring structure including at least one fourth graphic layer.

[0016] Optionally, the substrate further includes a dicing region between the chip region and adjacent chip regions; the monitoring region is located within the dicing region.

[0017] Optionally, the size measurement structure further includes: a first device layer located on the chip region and a second device layer located on the first device layer.

[0018] Optionally, it includes: providing a focus depth value, the focus depth value ranging from 0.3 μm to 0.6 μm; and the height range of the first pattern layer being greater than 1 / 3 of the focus depth value.

[0019] Optionally, the first patterned layer includes one or more of the following: gate, source / drain region, metal layer, sidewall, isolation layer, floating gate, and memory gate; the second patterned layer includes one or more of the following: gate, source / drain region, metal layer, sidewall, isolation layer, floating gate, and memory gate.

[0020] Accordingly, the technical solution of the present invention also provides a method for forming a size measurement structure, comprising: providing a substrate, the substrate including a monitoring region; forming a first monitoring structure on the monitoring region, the first monitoring structure including a plurality of mutually discrete measurement structures, each measurement structure including a first monitoring layer and a second monitoring layer located on the first monitoring layer, the first monitoring layer including a plurality of first pattern layers and a first opening between adjacent first pattern layers, and the second monitoring layer including a plurality of second pattern layers and a second opening between adjacent second pattern layers.

[0021] Optionally, the plurality of first graphic layers and the plurality of second graphic layers are arranged along a first direction, the first graphic layer having a first size along the first direction, and the periodic arrangement size of the second graphic layer and the second opening along the first direction being a first periodic value, wherein the first size is less than twice the first periodic value.

[0022] Optionally, the plurality of measurement structures include a plurality of first type measurement structures, each of the first type measurement structures including a first pattern layer and a second opening located on the first pattern layer, wherein the second opening exposes a portion of the top surface of the first pattern layer along the first direction.

[0023] Optionally, the plurality of measurement structures include a plurality of second type measurement structures, each of the second type measurement structures including the first opening and a second opening located on the first opening, wherein along the first direction, the projection of the first opening on the substrate surface is located within the projection range of the second opening on the substrate surface.

[0024] Optionally, the plurality of measurement structures include a plurality of third-type measurement structures, each of the third-type measurement structures including a first graphic layer and a second graphic layer located on the first graphic layer, wherein the second graphic layer covers the surface and sidewalls of the first graphic layer along the first direction.

[0025] Optionally, each of the fourth type of measurement structures includes the first opening and the second patterned layer, wherein the second patterned layer is located within and on the first opening along the first direction.

[0026] Optionally, the periodic arrangement size of the first graphic layer and the first opening along the first direction is a second periodic value, and the ratio of the second periodic value to the first size ranges from 2:1 to 10:1; the second graphic layer has a second size along the first direction, and the ratio of the first periodic value to the second size ranges from 2:1 to 10:1.

[0027] Optionally, the second graphic layer has a second size along the first direction, and the spacing between adjacent second graphic layers and between adjacent second graphic layers is greater than a minimum design value, and the first size is greater than or equal to the difference between the second size and the minimum design value.

[0028] Optionally, the method for forming the first monitoring structure includes: forming the first monitoring layer on the surface of the monitoring area; and forming the second monitoring layer on the surface of the monitoring area and the first monitoring layer.

[0029] Optionally, the monitoring area includes a first area and a second area, with the first monitoring structure located in the first area; the method further includes: forming a second monitoring structure on the second area, the second monitoring structure including at least one third opening; and forming a third monitoring structure on the second area, the third monitoring structure including at least one fourth graphic layer.

[0030] Optionally, the method for forming the second monitoring structure includes: forming the second monitoring structure on the surface of the second region after forming the first monitoring layer; the method for forming the third monitoring structure includes: forming the third monitoring structure on the surface of the second region after forming the first monitoring layer.

[0031] Optionally, the substrate further includes a dicing region between the chip region and adjacent chip regions, and the monitoring region is located within the dicing region.

[0032] Optionally, the method further includes: forming a first device layer and a second device layer located on the first device layer in the chip region.

[0033] Optionally, the first monitoring layer and the first device layer are formed in the same process; the second monitoring layer and the second device layer are formed in the same process.

[0034] Optionally, the method further includes: providing a focus depth value, the focus depth value ranging from 0.3 μm to 0.6 μm; and the height range of the first graphic layer being greater than 1 / 3 of the focus depth value.

[0035] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0036] In a method for forming a size measurement structure provided by the present invention, the first monitoring structure includes several mutually independent measurement structures. Each measurement structure includes a first monitoring layer and a second monitoring layer located on the first monitoring layer. The first monitoring layer includes several first patterned layers and a first opening between adjacent first patterned layers. The second monitoring layer includes several second patterned layers and a second opening between adjacent second patterned layers. At least four measurement structures can be obtained by varying the relative arrangement of the second patterned layers and second openings in the second monitoring layer with the first patterned layers and first openings in the first monitoring layer. In addition, the first patterned layer has a smaller size along the first direction and forms a step relative to the substrate. The first patterned layer and the first opening are used in the monitoring area to simulate a substrate surface with step undulations. By measuring the size of the second patterned layer or the second opening in the monitoring area, the key dimensions of the substrate surface pattern with step undulations are obtained, improving the accuracy of key dimension measurement and facilitating the monitoring of photolithography processes. At the same time, the accuracy of key dimension measurement can obtain more accurate photolithography process conditions, reducing the problem of difficult formation of structures with patterns crossing steps within the chip, and improving the accuracy of photolithography processes.

[0037] In the dimension measurement structure provided by the present invention, the first monitoring structure includes several mutually independent measurement structures. Each measurement structure includes a first monitoring layer and a second monitoring layer located on the first monitoring layer. The first monitoring layer includes several first patterned layers and a first opening between adjacent first patterned layers. The second monitoring layer includes several second patterned layers and a second opening between adjacent second patterned layers. At least four measurement structures can be obtained by varying the relative arrangement of the second patterned layers and second openings in the second monitoring layer with the first patterned layers and first openings in the first monitoring layer. In addition, the first patterned layer has a smaller size along the first direction and forms a step relative to the substrate. The first patterned layer and the first opening are used in the monitoring area to simulate a substrate surface with step undulations. By measuring the size of the second patterned layer or the second opening in the monitoring area, the key dimensions of the substrate surface pattern with step undulations are obtained, improving the accuracy of key dimension measurement and facilitating the monitoring of photolithography processes. At the same time, the accuracy of key dimension measurement can obtain more accurate photolithography process conditions, reducing the problem of difficult formation of structures with patterns crossing steps within the chip, and improving the accuracy of photolithography processes. Attached Figure Description

[0038] Figures 1 to 12 This is a schematic diagram of the size measurement structure according to an embodiment of the present invention. Detailed Implementation

[0039] It should be noted that the terms "surface" and "on" in this specification are used to describe the relative spatial position and are not limited to whether there is direct contact.

[0040] As described in the background section, existing monitoring patterns typically only consider planar design of critical dimensions, resulting in inaccurate measurements of these dimensions. Furthermore, the optimal focus depth of the photolithography process and the commonly used process settings are not on the same plane, making it difficult to form some patterns. Existing methods for measuring critical dimensions require further improvement.

[0041] To address the aforementioned issues, this invention provides a measurement structure and its formation method. The first monitoring structure comprises several mutually independent measurement structures. Each measurement structure includes a first monitoring layer and a second monitoring layer located on the first monitoring layer. The first monitoring layer includes several first patterned layers and a first opening between adjacent first patterned layers. The second monitoring layer includes several second patterned layers and a second opening between adjacent second patterned layers. At least four measurement structures can be obtained by varying the relative arrangement of the second patterned layers and second openings within the second monitoring layer with respect to the first patterned layers and first openings within the first monitoring layer. Furthermore, the first patterned layer has a smaller dimension along the first direction, and forms a step relative to the substrate. The first patterned layer and the first opening are used in the monitoring area to simulate a substrate surface with stepped undulations. By measuring the dimensions of the second patterned layer or the second opening in the monitoring area, the key dimensions of the stepped substrate surface pattern are obtained, improving the accuracy of key dimension measurement and facilitating the monitoring of the photolithography process. Simultaneously, the accuracy of key dimension measurement allows for more accurate photolithography process conditions, reducing the difficulty in forming structures where patterns cross steps within the chip, and improving the accuracy of the photolithography process.

[0042] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0043] Figures 1 to 12 This is a schematic diagram of the size measurement structure according to an embodiment of the present invention.

[0044] Please refer to Figures 1 to 12 The measurement structure includes: a substrate 100, the substrate 100 including a monitoring area (not shown in the figure); a first monitoring structure located on the monitoring area, the first monitoring structure including a plurality of mutually discrete measurement structures, each measurement structure including a first monitoring layer I and a second monitoring layer II located on the first monitoring layer I, the first monitoring layer I including a plurality of first patterned layers 101 and a first opening 102 between adjacent first patterned layers 101, the second monitoring layer II including a plurality of second patterned layers 103 and a second opening 104 between adjacent second patterned layers 103.

[0045] The aforementioned size measurement structure can achieve at least four measurement structures by varying the relative arrangement of the second pattern layer 103 and the second opening 104 within the second monitoring layer II with the first pattern layer 101 and the first opening 102 within the first monitoring layer. Furthermore, the first pattern layer 101 has a smaller dimension along the first direction X, and forms a step relative to the substrate 100. The first pattern layer 101 and the first opening 102 are used in the monitoring area to simulate a substrate surface with stepped undulations. By measuring the dimensions of the second pattern layer 103 or the second opening 104 in the monitoring area, the critical dimensions of the stepped substrate surface pattern are obtained, improving the accuracy of critical dimension measurement and facilitating the monitoring of the photolithography process. Simultaneously, accurate critical dimension measurement allows for more precise photolithography process conditions, reducing the difficulty in forming structures where patterns cross steps within the chip, and improving the accuracy of the photolithography process.

[0046] In this embodiment, the plurality of first graphic layers 101 and the plurality of second graphic layers 103 are arranged along the first direction X. The first graphic layer 101 has a first size d1 along the first direction X. The second graphic layer 103 and the second opening 104 have a periodic arrangement size along the first direction X of a first period value P1. The first size d1 is less than twice the first period value P1.

[0047] In this embodiment, the plurality of measurement structures includes a plurality of first-type measurement structures (such as...) Figure 1 and Figure 2 As shown), each of the first type of measurement structures includes a first pattern layer 101 and a second opening 104 located on the first pattern layer 101. Along the first direction X, the second opening 104 exposes a portion of the top surface of the first pattern layer 101.

[0048] It should be noted that, Figure 1 and Figure 2 Only three Type I measurement structures are shown in the diagram (one Type I measurement structure is indicated by a dashed line). In other embodiments, the number of Type I measurement structures may not be limited.

[0049] In this embodiment, the plurality of measurement structures includes a plurality of second-type measurement structures (such as...) Figure 3 and Figure 4 As shown), each of the second type of measurement structures includes a first opening 102 and a second opening 104 located on the first opening 102. Along the first direction X, the projection of the first opening 102 on the surface of the substrate 100 is located within the projection range of the second opening 104 on the surface of the substrate 100.

[0050] It should be noted that, Figure 3 and Figure 4 The diagram shows three Type II measurement structures (one of which is indicated by a dashed line). In other embodiments, the number of Type II measurement structures may not be limited.

[0051] In this embodiment, the plurality of measurement structures includes a plurality of third-type measurement structures (such as...) Figure 5 and Figure 6 As shown), each of the third type of measurement structures includes a first graphic layer 101 and a second graphic layer 103 located on the first graphic layer 101. Along the first direction X, the second graphic layer 103 covers the surface and sidewalls of the first graphic layer 101.

[0052] It should be noted that, Figure 5 and Figure 6 The diagram shows three third-type measurement structures (one of which is indicated by a dashed line). In other embodiments, the number of said third-type measurement structures is not limited.

[0053] In this embodiment, the plurality of measurement structures includes a plurality of fourth-type measurement structures (such as...). Figure 7 and Figure 8 As shown), each of the fourth type of measurement structures includes the first opening 102 and the second pattern layer 103. Along the first direction X, the second pattern layer 103 is located inside and on the first opening 102.

[0054] It should be noted that, Figure 7 and Figure 8 The diagram shows three fourth-type measurement structures (one of which is indicated by a dashed line). In other embodiments, the number of said fourth-type measurement structures is not limited.

[0055] In this embodiment, the monitoring area includes a first area (not shown in the figure) and a second area (not shown in the figure), and the first monitoring structure is located in the first area.

[0056] In this embodiment, the first monitoring structure includes a plurality of first-type measurement structures, a plurality of second-type measurement structures, a plurality of third-type measurement structures, and a plurality of fourth-type measurement structures. In other embodiments, the first detection structure may include one or more of the plurality of first-type measurement structures, a plurality of second-type measurement structures, a plurality of third-type measurement structures, and a plurality of fourth-type measurement structures.

[0057] In this embodiment, the size measurement structure further includes: a second monitoring structure located on the second region (such as...). Figure 9 and Figure 10 As shown), the second monitoring structure includes at least one third opening 105.

[0058] The dimensions of the third opening 105 along the first direction X are measured to characterize the critical dimensions of the critical pattern located on the relatively flat surface of the substrate 100.

[0059] It should be noted that, Figure 9 and Figure 10 Three third openings 105 are shown. In other embodiments, the number of the second monitoring structures is not limited.

[0060] In this embodiment, the size measurement structure further includes: a third monitoring structure located on the second region (such as...). Figure 11 and Figure 12 As shown in the figure, the third monitoring structure includes at least one fourth graphics layer 107.

[0061] The dimensions of the fourth patterning layer 107 along the first direction X are measured to characterize the critical dimensions of the critical patterns located on the relatively flat surface of the substrate 100.

[0062] It should be noted that, Figure 11 and Figure 12 Three fourth graphics layers 107 are shown. In other embodiments, the number of said fourth graphics layers may not be limited.

[0063] In this embodiment, the substrate further includes a chip region (not shown in the figure) and a dicing region (not shown in the figure) between adjacent chip regions.

[0064] In this embodiment, the monitoring area is located within the dicing area. Placing the monitoring area within the dicing area does not occupy space in the chip area.

[0065] In this embodiment, the size measurement structure further includes: a first device layer (not shown in the figure) located on the chip region and a second device layer (not shown in the figure) located on the first device layer.

[0066] In this embodiment, the method further includes: providing a focus depth value, the focus depth value ranging from 0.3 μm to 0.6 μm; and the height range of the first patterning layer 101 being greater than 1 / 3 of the focus depth value. The purpose of selecting the height range of the first patterning layer 101 is to enable the first patterning layer 101 to form a sufficiently high step on the surface of the substrate 100 to influence the formation structure of the pattern spanning the step, thereby achieving the purpose of monitoring the pattern size on the substrate surface with step undulations.

[0067] In this embodiment, the first patterned layer 101 includes one or more of the following: gate, source / drain region, metal layer, sidewall, isolation layer, floating gate, and memory gate; the second patterned layer 103 includes one or more of the following: gate, source / drain region, metal layer, sidewall, isolation layer, floating gate, and memory gate.

[0068] In this embodiment, the periodic arrangement size of the first graphic layer 101 and the first opening 102 along the first direction X is the second periodic value P2, and the ratio of the second periodic value P2 to the first size d1 ranges from 2:1 to 10:1.

[0069] In this embodiment, the second graphic layer 103 has a second size d2 along the first direction X, and the ratio of the first period value P1 to the second size d2 ranges from 2:1 to 10:1.

[0070] In this embodiment, the second graphic layer 103 has a second dimension d2 along the first direction X, and the spacing between adjacent first graphic layers 101 and adjacent second graphic layers 103 is greater than the minimum design value. The first dimension d1 is greater than or equal to the difference between the second dimension d2 and the minimum design value.

[0071] Accordingly, embodiments of the present invention also provide a method for forming the above-described dimensional measurement structure; please refer to [further details]. Figures 1 to 12 The method for forming the size measurement structure includes:

[0072] A substrate 100 is provided, the substrate 100 including a monitoring region (not shown in the figure);

[0073] A first monitoring structure is formed on the monitoring area. The first monitoring structure includes several mutually independent measurement structures. Each measurement structure includes a first monitoring layer I and a second monitoring layer II located on the first monitoring layer I. The first monitoring layer I includes several first graphic layers 101 and a first opening 102 between adjacent first graphic layers 101. The second monitoring layer II includes several second graphic layers 103 and a second opening 104 between adjacent second graphic layers 103.

[0074] In this embodiment, the plurality of first graphic layers 101 and the plurality of second graphic layers 103 are arranged along the first direction X. The first graphic layer 101 has a first size d1 along the first direction X. The periodic arrangement size of the second graphic layer 103 and the second opening 104 along the first direction X is a first periodic value P. The first size d1 is less than twice the first periodic value P.

[0075] The aforementioned size measurement structure can achieve at least four measurement structures by varying the relative arrangement of the second pattern layer 103 and the second opening 104 within the second monitoring layer II with the first pattern layer 101 and the first opening 102 within the first monitoring layer. Furthermore, the first pattern layer 101 has a smaller dimension along the first direction X, and forms a step relative to the substrate 100. The first pattern layer 101 and the first opening 102 are used in the monitoring area to simulate a substrate surface with stepped undulations. By measuring the dimensions of the second pattern layer 103 or the second opening 104 in the monitoring area, the critical dimensions of the stepped substrate surface pattern are obtained, improving the accuracy of critical dimension measurement and facilitating the monitoring of the photolithography process. Simultaneously, accurate critical dimension measurement allows for more precise photolithography process conditions, reducing the difficulty in forming structures where patterns cross steps within the chip, and improving the accuracy of the photolithography process.

[0076] In this embodiment, the plurality of measurement structures includes a plurality of first-type measurement structures (such as...) Figure 1 and Figure 2 As shown), each of the first type of measurement structures includes a first pattern layer 101 and a second opening 104 located on the first pattern layer 101. Along the first direction X, the second opening 104 exposes a portion of the top surface of the first pattern layer 101.

[0077] In this embodiment, the plurality of measurement structures includes a plurality of second-type measurement structures (such as...) Figure 3 and Figure 4 As shown), each of the second type of measurement structures includes a first opening 102 and a second opening 104 located on the first opening 102. Along the first direction X, the projection of the first opening 102 on the surface of the substrate 100 is located within the projection range of the second opening 104 on the surface of the substrate 100.

[0078] In this embodiment, the plurality of measurement structures includes a plurality of third-type measurement structures (such as...) Figure 5 and Figure 6 As shown), each of the third type of measurement structures includes a first graphic layer 101 and a second graphic layer 103 located on the first graphic layer 101. Along the first direction X, the second graphic layer 103 covers the surface and sidewalls of the first graphic layer 101.

[0079] In this embodiment, the plurality of measurement structures includes a plurality of fourth-type measurement structures (such as...). Figure 7 and Figure 8 As shown), each of the fourth type of measurement structures includes the first opening 102 and the second pattern layer 103. Along the first direction X, the second pattern layer 103 is located inside and on the first opening 102.

[0080] In this embodiment, the method for forming the first monitoring structure includes: forming the first monitoring layer I on the surface of the monitoring area; and forming the second monitoring layer II on the surface of the monitoring area and the first monitoring layer I.

[0081] In this embodiment, the monitoring area includes a first area (not shown in the figure) and a second area (not shown in the figure), and the first monitoring structure is located in the first area.

[0082] In this embodiment, the method for forming the size measurement structure further includes: forming a second monitoring structure (such as...) on the second region. Figure 9 and Figure 10 As shown), the second monitoring structure includes at least one third opening 105.

[0083] The dimensions of the third opening 105 along the first direction X are measured to characterize the critical dimensions of the critical pattern located on the relatively flat surface of the substrate 100.

[0084] In this embodiment, the method for forming the second monitoring structure includes: after forming the first monitoring layer, forming the second monitoring structure on the surface of the second region.

[0085] Specifically, the method for forming the second monitoring structure further includes: after forming the first monitoring layer, forming a third patterned material layer on the surface of the substrate 100; etching the third patterned material layer until the surface of the substrate 100 is exposed, forming a third patterned layer 106 and the third opening 105 located in the third patterned layer 106.

[0086] It should be noted that, Figure 9 and Figure 10 Three third openings 105 are shown. In other embodiments, the number of the second monitoring structures is not limited.

[0087] In this embodiment, the method for forming the size measurement structure further includes: forming a third monitoring structure (such as...) on the second region. Figure 11 and Figure 12 As shown in the figure, the third monitoring structure includes at least one fourth graphics layer 107.

[0088] The dimensions of the fourth patterning layer 107 along the first direction X are measured to characterize the critical dimensions of the critical patterns located on the flat substrate surface.

[0089] In this embodiment, the method for forming the third monitoring structure includes: after forming the first monitoring layer, forming the third monitoring structure on the surface of the second region.

[0090] Specifically, the method for forming the third monitoring structure further includes: after forming the first monitoring layer, forming a fourth patterned material layer on the surface of the substrate 100; etching the fourth patterned material layer until the surface of the substrate 100 is exposed, forming a fourth patterned layer 107 and the fourth opening 108 located in the fourth patterned layer 107.

[0091] In this embodiment, after the first monitoring layer is formed, the second monitoring structure and the third monitoring structure are formed simultaneously. In other embodiments, only one of the second monitoring structure and the third monitoring structure may be formed, or neither the second monitoring structure nor the third monitoring structure may be formed, or the second monitoring structure and the third monitoring structure may not be formed simultaneously.

[0092] It should be noted that, Figure 11 and Figure 12 Three fourth graphics layers 107 are shown. In other embodiments, the number of said fourth graphics layers may not be limited.

[0093] In this embodiment, the substrate further includes a chip region (not shown in the figure) and a dicing region (not shown in the figure) between adjacent chip regions, and the monitoring region is located within the dicing region.

[0094] In this embodiment, the method further includes: forming a first device layer (not shown in the figure) and a second device layer (not shown in the figure) located on the first device layer in the chip region.

[0095] In this embodiment, the first monitoring layer and the first device layer are formed in the same process. That is, the first patterned layer can have the same structure as the chip area in the same layer, and may include structures such as gate, source / drain regions, metal layer, sidewall, isolation layer, floating gate, and memory gate.

[0096] In this embodiment, the second monitoring layer and the second device layer are formed in the same process. That is, the second patterned layer can be consistent with the structure in the chip region on the same layer, and may include structures such as gate, source / drain regions, metal layer, sidewall, isolation layer, floating gate, and memory gate.

[0097] In this embodiment, the measurement structure further includes: providing a focusing depth value, the focusing depth value ranging from 0.3 μm to 0.6 μm; and the height range of the first patterning layer 101 being greater than 1 / 3 of the focusing depth value. The purpose of selecting the height range of the first patterning layer 101 is to enable the first patterning layer 101 to form a sufficiently high step on the surface of the substrate 100 to influence the formation structure of the pattern spanning the step, thereby achieving the purpose of monitoring the pattern size on the substrate surface with step undulations.

[0098] In this embodiment, the periodic arrangement size of the first graphic layer 101 and the first opening 102 along the first direction X is the second periodic value P2, and the ratio of the second periodic value P2 to the first size d1 ranges from 2:1 to 10:1.

[0099] In this embodiment, the second graphic layer 103 has a second size d2 along the first direction X, and the ratio of the first period value P1 to the second size d2 ranges from 2:1 to 10:1.

[0100] In this embodiment, the second graphic layer 103 has a second dimension d2 along the first direction X, and the spacing between adjacent first graphic layers 101 and adjacent second graphic layers 103 is greater than the minimum design value. The first dimension d1 is greater than or equal to the difference between the second dimension d2 and the minimum design value.

[0101] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A size measuring structure, characterized in that, include: Substrate, the substrate including a monitoring region; A first monitoring structure located on the monitoring area, the first monitoring structure includes several mutually independent measurement structures, each measurement structure includes a first monitoring layer and a second monitoring layer located on the first monitoring layer, the first monitoring layer includes several first graphic layers and a first opening between adjacent first graphic layers, the second monitoring layer includes several second graphic layers and a second opening between adjacent second graphic layers; A first device layer is located on a substrate and a second device layer is located on the first device layer. The first monitoring layer is on the same layer as the first device layer, and the second monitoring layer is on the same layer as the second device layer.

2. The dimension measuring structure as described in claim 1, characterized in that, The plurality of first graphic layers and the plurality of second graphic layers are arranged along a first direction. The first graphic layer has a first size along the first direction. The periodic arrangement size of the second graphic layer and the second opening along the first direction is a first periodic value. The first size is less than twice the first periodic value.

3. The dimension measuring structure as described in claim 2, characterized in that, The plurality of measurement structures include a plurality of first type measurement structures, each of the first type measurement structures including a first pattern layer and a second opening located on the first pattern layer, wherein the second opening exposes a portion of the top surface of the first pattern layer along the first direction.

4. The dimension measuring structure as described in claim 2, characterized in that, The plurality of measurement structures include a plurality of second type measurement structures, each of the second type measurement structures including a first opening and a second opening located on the first opening, wherein, along the first direction, the projection of the first opening on the substrate surface is located within the projection range of the second opening on the substrate surface.

5. The dimension measuring structure as described in claim 2, characterized in that, The plurality of measurement structures include a plurality of third-type measurement structures, each of the third-type measurement structures including a first graphic layer and a second graphic layer located on the first graphic layer, wherein along the first direction, the second graphic layer covers the surface and sidewalls of the first graphic layer.

6. The dimension measuring structure as described in claim 2, characterized in that, The plurality of measurement structures include a plurality of fourth type measurement structures, each of the fourth type measurement structures including the first opening and the second graphic layer, wherein along the first direction, the second graphic layer is located inside and on the first opening.

7. The dimension measuring structure as described in claim 2, characterized in that, The periodic arrangement size of the first graphic layer and the first opening along the first direction is a second periodic value, and the ratio of the second periodic value to the first size ranges from 2:1 to 10:1; the second graphic layer has a second size along the first direction, and the ratio of the first periodic value to the second size ranges from 2:1 to 10:

1.

8. The dimension measuring structure as described in claim 2, characterized in that, The second graphic layer has a second size along the first direction, and the spacing between adjacent second graphic layers and between adjacent second graphic layers is greater than the minimum design value. The first size is greater than or equal to the difference between the second size and the minimum design value.

9. The dimension measuring structure as described in claim 1, characterized in that, The monitoring area includes a first area and a second area, with the first monitoring structure located in the first area; the size measurement structure further includes: a second monitoring structure located in the second area, the second monitoring structure including at least one third opening; and a third monitoring structure located in the second area, the third monitoring structure including at least one fourth graphic layer.

10. The dimension measuring structure as described in claim 1, characterized in that, The substrate further includes a dicing region between the chip region and adjacent chip regions; the monitoring region is located within the dicing region.

11. The dimension measuring structure as described in claim 1, characterized in that, include: Provide a depth-of-focus value, the depth-of-focus value being in the range of 0.3µm to 0.6µm; The height range of the first graphic layer is greater than 1 / 3 of the focus depth value.

12. The dimension measuring structure as described in claim 1, characterized in that, The first patterned layer includes one or more of the following: gate, source / drain region, metal layer, sidewall, isolation layer, floating gate, and memory gate; the second patterned layer includes one or more of the following: gate, source / drain region, metal layer, sidewall, isolation layer, floating gate, and memory gate.

13. A method for forming a dimension measuring structure, characterized in that, include: A substrate is provided, the substrate including a monitoring region; A first monitoring structure is formed on the monitoring area. The first monitoring structure includes several mutually independent measurement structures. Each measurement structure includes a first monitoring layer and a second monitoring layer located on the first monitoring layer. The first monitoring layer includes several first graphic layers and a first opening between adjacent first graphic layers. The second monitoring layer includes several second graphic layers and a second opening between adjacent second graphic layers. The method for forming the first monitoring structure includes: forming the first monitoring layer on the surface of the monitoring area; and forming the second monitoring layer on the surface of the monitoring area and the first monitoring layer. A first device layer and a second device layer located on the first device layer are formed on the substrate. The first monitoring layer and the first device layer are formed in the same process, and the second monitoring layer and the second device layer are formed in the same process.

14. The method for forming the dimension measuring structure as described in claim 13, characterized in that, The plurality of first graphic layers and the plurality of second graphic layers are arranged along a first direction. The first graphic layer has a first size along the first direction. The periodic arrangement size of the second graphic layer and the second opening along the first direction is a first periodic value. The first size is less than twice the first periodic value.

15. The method for forming the dimension measuring structure as described in claim 14, characterized in that, The plurality of measurement structures include a plurality of first type measurement structures, each of the first type measurement structures including a first pattern layer and a second opening located on the first pattern layer, wherein the second opening exposes a portion of the top surface of the first pattern layer along the first direction.

16. The method for forming the dimension measuring structure as described in claim 14, characterized in that, The plurality of measurement structures include a plurality of second type measurement structures, each of the second type measurement structures including a first opening and a second opening located on the first opening, wherein, along the first direction, the projection of the first opening on the substrate surface is located within the projection range of the second opening on the substrate surface.

17. The method for forming the dimension measuring structure as described in claim 14, characterized in that, The plurality of measurement structures include a plurality of third-type measurement structures, each of the third-type measurement structures including a first graphic layer and a second graphic layer located on the first graphic layer, wherein along the first direction, the second graphic layer covers the surface and sidewalls of the first graphic layer.

18. The method for forming the dimension measuring structure as described in claim 14, characterized in that, The plurality of measurement structures include a plurality of fourth type measurement structures, each of the fourth type measurement structures including the first opening and the second graphic layer, wherein along the first direction, the second graphic layer is located inside and on the first opening.

19. The method for forming the dimension measuring structure as described in claim 14, characterized in that, The periodic arrangement size of the first graphic layer and the first opening along the first direction is a second periodic value, and the ratio of the second periodic value to the first size ranges from 2:1 to 10:1; the second graphic layer has a second size along the first direction, and the ratio of the first periodic value to the second size ranges from 2:1 to 10:

1.

20. The method for forming the dimension measuring structure as described in claim 14, characterized in that, The second graphic layer has a second size along the first direction, and the spacing between adjacent second graphic layers and between adjacent second graphic layers is greater than the minimum design value. The first size is greater than or equal to the difference between the second size and the minimum design value.

21. The method for forming the dimension measuring structure as described in claim 20, characterized in that, The monitoring area includes a first area and a second area, and the first monitoring structure is located in the first area; the method further includes: forming a second monitoring structure on the second area, the second monitoring structure including at least one third opening; forming a third monitoring structure on the second area, the third monitoring structure including at least one fourth graphic layer.

22. The method for forming the dimension measuring structure as described in claim 21, characterized in that, The method for forming the second monitoring structure includes: forming the second monitoring structure on the surface of the second region after forming the first monitoring layer; the method for forming the third monitoring structure includes: forming the third monitoring structure on the surface of the second region after forming the first monitoring layer.

23. The method for forming the dimension measuring structure as described in claim 13, characterized in that, The substrate further includes a dicing region between the chip region and adjacent chip regions, and the monitoring region is located within the dicing region.

24. The method for forming the dimension measuring structure as described in claim 13, characterized in that, The method further includes: providing a focus depth value, the focus depth value ranging from 0.3µm to 0.6µm; the height range of the first graphics layer being greater than 1 / 3 of the focus depth value.

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