Mask plates and components thereof, semiconductor structures and methods of forming the same and metrology methods

Abstract

A mask plate and an assembly thereof, a semiconductor structure and a forming method and a measuring method, the mask plate comprising: at least one measuring pattern structure, the measuring pattern structure comprising: at least one of a comb-shaped pattern, a half-chain-shaped pattern and a T-shaped pattern; when measuring the semiconductor structure formed by the mask assembly comprising the mask plate, a splicing offset is measured according to the at least one first positioning pattern and the at least one second positioning pattern. According to the electrical performance test result, the mask splicing condition is monitored, the precision is higher, the pattern alignment condition can be accurately judged, and a monitoring position is added for online defect scanning.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing, and in particular to a photomask and its components, a semiconductor structure and its formation method, and a measurement method. Background Technology

[0002] Charge-coupled devices (CCDs) are widely used in military, industrial monitoring, and security monitoring. With the improvement of process technology, CCDs are developing towards larger pixels and array sizes to meet the growing application requirements. Although the wafers used for large array CCD chips can meet the requirements, the maximum exposure area of ​​the lithography machine cannot meet the needs of CCDs. Therefore, it is necessary to use the splicing exposure method for lithography process fabrication.

[0003] Compared to the interlayer alignment techniques in normal photolithography processes, mask splicing requires consideration of not only interlayer alignment but also alignment of patterns within the same layer. Pattern defects such as deformation, discontinuity, and line widening or narrowing often occur at the splicing points. This is especially true if etching follows photolithography; the subsequent etching steps further amplify these defects, severely impacting the quality of the fabricated pattern and ultimately affecting the performance of large-array CCDs.

[0004] However, existing measurement methods are insufficient to fully monitor the alignment of graphics on the same layer, resulting in low measurement accuracy. Summary of the Invention

[0005] The problem addressed by this invention is how to improve the alignment and measurement accuracy of mask assembly splicing.

[0006] To address the aforementioned problems, the present invention provides a photomask, comprising: at least one measurement pattern structure, the measurement pattern structure including at least one of a comb-shaped pattern, a semi-chain-shaped pattern, and a T-shaped pattern; wherein, the comb-shaped pattern includes: a connecting strip-shaped pattern extending along a first direction; and a plurality of comb-tooth strip-shaped patterns extending along a second direction, one end of which is connected to the connecting strip-shaped pattern, the plurality of comb-tooth strip-shaped patterns being arranged separately and parallel along the first direction, and the second direction being perpendicular to the first direction; the semi-chain-shaped pattern includes: at least one U-shaped pattern arranged separately along the first direction, the openings of the U-shaped patterns having the same orientation along the second direction; the T-shaped pattern includes: a first strip-shaped pattern extending along the first direction; and a second strip-shaped pattern extending along the second direction, one end of which is connected to the midpoint of the first strip-shaped pattern along the first direction.

[0007] Accordingly, the present invention also provides a mask assembly, comprising: a first mask template and a second mask template, wherein the first mask template and the second mask template are both mask templates of the present invention; when the patterns of the first mask template and the second mask template are spliced ​​together to form a complete mask pattern, the patterns of at least one measurement pattern structure of the first mask template and the patterns of at least one measurement pattern structure of the second mask template correspond one-to-one.

[0008] In addition, the present invention also provides a method for forming a semiconductor structure, comprising: providing a substrate and a mask assembly, wherein the mask assembly is the mask assembly of the present invention; transferring the pattern of the mask assembly onto the substrate, wherein the step of transferring the pattern of the mask assembly onto the substrate includes: transferring the pattern of a lower mask onto the substrate, wherein the lower mask is one of a first mask and a second mask; after the pattern of the lower mask is transferred, transferring the pattern of an upper mask onto the substrate, wherein the upper mask is the other of the first mask and the second mask.

[0009] Furthermore, the present invention also provides a method for measuring a semiconductor structure, wherein the semiconductor structure is the semiconductor structure of the present invention; the semiconductor structure includes: at least one first positioning structure, the first positioning structure being formed by transferring at least one measurement pattern structure of a first mask onto a substrate; at least one second positioning structure, the second positioning structure being formed by transferring at least one measurement pattern structure of a second mask onto a substrate; the at least one first positioning structure and the at least one second positioning structure correspond one-to-one; the measurement method includes: measuring the splicing offset based on the at least one first positioning pattern and the at least one second positioning pattern.

[0010] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0011] In this invention, the mask template includes at least one measurement pattern structure, which includes at least one of a comb-shaped pattern, a semi-chain-shaped pattern, and a T-shaped pattern. When measuring the semiconductor structure formed by the mask assembly, the splicing offset is measured based on at least one first positioning pattern and at least one second positioning pattern. By monitoring the mask splicing status based on electrical performance test results, higher accuracy is achieved, enabling accurate judgment of pattern alignment and adding monitoring positions for online defect scanning. Attached Figure Description

[0012] Figure 1 This is a top view of a mask assembly used in a semiconductor structure formation method.

[0013] Figure 2 yes Figure 1 An enlarged structural schematic diagram of a pair of first alignment strips and second alignment strips in the mask assembly shown;

[0014] Figure 3 yes Figure 1 The semiconductor structure formed by the semiconductor structure forming method includes a pair of first positioning patterns and second positioning patterns aligned in the semiconductor structure formed by the semiconductor structure forming method.

[0015] Figure 4 This is a top view of an embodiment of the mask template of the present invention;

[0016] Figure 5 This is a top view of an embodiment of the mask assembly of the present invention;

[0017] Figure 6 yes Figure 5 A schematic diagram of the structure of the first test pattern in the first mask template in the mask assembly embodiment shown;

[0018] Figure 7 yes Figure 5 A schematic diagram of the structure of the second test pattern in the second mask template in the mask assembly embodiment shown;

[0019] Figure 8 yes Figure 5 The diagram shows the structure of the first test pattern and the corresponding second test pattern when the first mask pattern and the second mask pattern are spliced ​​together to form a complete mask pattern in the mask component embodiment shown.

[0020] Figure 9 This is a top view schematic diagram of an embodiment of the semiconductor structure of the present invention;

[0021] Figure 10 This is a schematic flowchart of an embodiment of the semiconductor structure measurement method of the present invention. Detailed Implementation

[0022] As the background technology shows, existing measurement methods for pattern stitching suffer from low accuracy. This paper analyzes the reasons for this low accuracy problem in pattern stitching measurement methods using a semiconductor structure measurement method as an example.

[0023] In a method for forming a semiconductor structure, firstly, a substrate (not shown in the figure) and a mask assembly 10 (such as...) are provided. Figure 1 The mask assembly 10 includes a first mask template 11 and a second mask template 12. The first mask template 11 has a plurality of first alignment strips 11o, and the second mask template 12 has a plurality of second alignment strips 12i.

[0024] Next, the pattern of the lower mask is transferred to the substrate. The lower mask is one of the first mask 11 and the second mask 12. After the pattern of the lower mask is transferred, the pattern of the upper mask is transferred to the substrate. The upper mask is the other of the first mask 11 and the second mask 12. In the step of transferring the pattern of the upper mask to the substrate, the plurality of first alignment strips 11o of the first mask 11 and the plurality of second alignment strips 12i of the second mask 12 are aligned one-to-one. Specifically, as follows... Figure 2 As shown, the alignment pattern 13o on the first alignment bar 11o and the alignment pattern 13i on the second alignment bar 12i are squares with different side lengths.

[0025] The formed semiconductor structure includes: a plurality of first positioning patterns, which are formed by transferring alignment patterns on a first alignment strip onto a substrate; and a plurality of second positioning patterns, which are formed by transferring alignment patterns on a second alignment strip onto a substrate.

[0026] refer to Figure 3 This shows a pair of first and second positioning patterns aligned in the formed semiconductor structure.

[0027] When the first positioning pattern 14o and the second positioning image 14i are aligned, the second positioning pattern 14 with the larger side length surrounds the first positioning pattern 14o with the smaller side length, that is, the first positioning pattern 14o with the smaller side length is located inside the second positioning pattern 14 with the larger side length.

[0028] The measurement method for semiconductor structures includes: measuring the spacing between corresponding edges of the first positioning pattern 14o and the second positioning image 14i, namely spacing a and spacing b, to obtain the offset of the stitching of the pattern of the first mask 11 and the pattern of the second mask 12.

[0029] This measurement method cannot comprehensively and accurately monitor the alignment of patterns in the same layer, especially when it involves active areas, patterned polysilicon layers, and patterned metal lines, making it even more difficult to monitor their alignment.

[0030] Furthermore, the step of measuring the distance between corresponding sides of the first positioning graphic 14o and the second positioning image 14i is usually performed using a measuring tool, resulting in low measurement accuracy and difficulty in obtaining more accurate alignment information.

[0031] To address the technical problem, the present invention provides a photomask, comprising: at least one measurement pattern structure, the measurement pattern structure including at least one of a comb-shaped pattern, a semi-chain-shaped pattern, and a T-shaped pattern; wherein, the comb-shaped pattern includes: a connecting strip-shaped pattern extending along a first direction; and a plurality of comb-tooth strip-shaped patterns extending along a second direction, one end of which is connected to the connecting strip-shaped pattern, the plurality of comb-tooth strip-shaped patterns being arranged separately and parallel along the first direction, and the second direction being perpendicular to the first direction; the semi-chain-shaped pattern includes: at least one U-shaped pattern arranged separately along the first direction, the openings of the U-shaped patterns facing the same direction along the second direction, and the second direction being perpendicular to the first direction; the T-shaped pattern includes: a first strip-shaped pattern extending along the first direction; and a second strip-shaped pattern extending along the second direction, one end of which is connected to the midpoint of the first strip-shaped pattern along the first direction, and the second direction being perpendicular to the first direction.

[0032] The technical solution of this invention monitors the mask splicing status based on the electrical performance test results, with higher precision, accurately judging the alignment of the pattern, and also adding monitoring positions for online defect scanning.

[0033] To make the above-mentioned objects, features and advantages 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.

[0034] refer to Figure 4 The diagram shows a top view of an embodiment of the mask template of the present invention.

[0035] In this embodiment, the mask template includes at least one measurement pattern structure 100. The measurement pattern structure 100 includes at least one of a comb-shaped pattern 110, a semi-chain-shaped pattern 120, and a T-shaped pattern 130.

[0036] In some embodiments of the present invention, each measurement pattern structure 100 includes multiple patterns from comb-shaped pattern 110, semi-chain-shaped pattern 120 and T-shaped pattern 130; the multiple patterns are arranged separately along the first direction X.

[0037] Specifically, such as Figure 4 In the embodiment shown, the measurement pattern structure 100 includes a comb-shaped pattern 110, a semi-chain-shaped pattern 120, and a T-shaped pattern 130; the comb-shaped pattern 110, the semi-chain-shaped pattern 120, and the T-shaped pattern 130 are arranged sequentially along the first direction X.

[0038] The comb-shaped pattern 110 includes: a connecting strip pattern 111 extending along a first direction X; and a plurality of comb-tooth strip patterns 112 extending along a second direction Y, one end of which is connected to the connecting strip pattern 111. The plurality of comb-tooth strip patterns 111 are arranged separately and parallel along the first direction X, and the second direction Y is perpendicular to the first direction.

[0039] It should be noted that the mask is used to splice with another mask to obtain a complete pattern. Therefore, the direction from one end 112a of the comb-shaped pattern 112 connected to the connecting strip pattern 111 to the other end 112b is consistent with the direction from which the mask points to the other mask to be spliced.

[0040] In some embodiments of the present invention, along the first direction X, the spacing a1 between adjacent comb-shaped patterns 112 is greater than the size b1 of the comb-shaped patterns 112.

[0041] like Figure 4 In the embodiment shown, the comb-shaped pattern 110 includes: four comb-tooth strip patterns 112; the four comb-tooth strip patterns 112 are equally spaced and parallel to each other on the same side of the connecting strip pattern 111; and the two ends of the connecting strip pattern 111 are respectively connected to two comb-tooth strip patterns 112.

[0042] In some embodiments of the present invention, the dimensions d1 of the plurality of comb-shaped patterns 111 along the second direction Y are equal to ensure the accuracy and precision of the alignment measurement.

[0043] It should be noted that in the comb-shaped graphic 110, at least one of the width c1 of the connecting strip graphic 111 and the width b1 of the comb-tooth strip graphic 112 meets the minimum width requirement of the graphic in the "graphic design rules"; in addition, the interval a1 between adjacent comb-tooth strip graphics 112 also meets the minimum spacing requirement of the graphic in the "graphic design rules".

[0044] Continue to refer to Figure 4 The semi-chain-like pattern 120 includes at least one U-shaped pattern 121 arranged separately along the first direction X, and the openings 123 of the U-shaped pattern 121 facing the same direction along the second direction Y, with the second direction Y perpendicular to the first direction X.

[0045] As mentioned earlier, the mask is used to join with another mask to obtain a complete pattern. Therefore, the direction from the bottom 121a of the opening 123 of the U-shaped pattern 121 to the top 121b is consistent with the direction from which the mask points to the other mask to which it is joined.

[0046] In some embodiments of the present invention, the semi-chain-like pattern 120 includes: a plurality of U-shaped patterns 121, wherein the plurality of U-shaped patterns 121 are U-shaped patterns 121 of the same shape. The plurality of U-shaped patterns 121 are arranged at equal intervals along a first direction X. Figure 4 In the illustrated embodiment, the semi-chain-like pattern 120 includes three U-shaped patterns 121. The three U-shaped patterns 121 are arranged at equal intervals.

[0047] In some embodiments of the present invention, along the first direction X, the size a2 of the opening 123 of the U-shaped pattern 121 and the spacing b2 between adjacent U-shaped patterns 121 are equal, so that the openings 123 of the two U-shaped patterns 121 can be aligned and connected at the ends.

[0048] In addition, such as Figure 4 As shown, in some embodiments of the present invention, the semi-chain pattern 120 further includes a chain tail strip pattern 122 extending along the second direction Y. Along the first direction X, the chain tail strip pattern 122 is located on one side of the plurality of U-shaped patterns 121, that is, the chain tail strip pattern 122 is one side of all the U-shaped patterns 121.

[0049] In some embodiments of the present invention, along the first direction X, the distance c2 between the chain tail strip pattern 122 and the plurality of U-shaped patterns 121 and the size a2 of the opening 123 of the U-shaped pattern 121 are equal, so that the chain tail strip pattern 121 and the adjacent U-shaped pattern 121 can be aligned and connected with the beginning and end ends of another U-shaped pattern 121.

[0050] It should be noted that in the semi-chain-like graphic 120, at least one of the widths of the U-shaped graphic 121 and the chain tail strip graphic 121 meets the minimum width requirement of the graphic design rules. Furthermore, the interval b2 between adjacent U-shaped graphics 121 and the interval c2 between the chain tail strip graphic 121 and its adjacent U-shaped graphic 121 also meet the minimum spacing requirement of the graphic design rules.

[0051] The U-shaped graphic 121 includes a first segment 121a extending along the first X direction and two second segments 121b, wherein the two second segments 121b extend along the second Y direction and are respectively connected to both ends of the first segment 121a. The width of the U-shaped graphic 121 is the width d2 of the first segment 121a and the width e2 of the second end 121b, so the width d2 of the first segment 121a and the width e2 of the second end 121b also meet the minimum width requirement of the graphic in the "graphic design rules".

[0052] It should also be noted that, in some embodiments of the present invention, the opening 123 of the plurality of U-shaped patterns 121 in the semi-chain pattern 120 is oriented in the same direction as the opening of the comb pattern 110. Specifically, as shown below... Figure 4 As shown, the direction from the bottom 121a of the opening 123 of the U-shaped graphic 121 to the top 121b is consistent with the direction from one end 112a of the comb-shaped graphic 112 connected to the connecting strip graphic 111 to the other end 112b.

[0053] Continue to refer to Figure 4 The T-shaped graphic 130 includes: a first strip graphic 131 extending along a first direction X; and a second strip graphic 132 extending along a second direction Y, one end of the second strip graphic 132 being connected to the midpoint of the first strip graphic 131 along the first direction X.

[0054] In this embodiment, in the semi-chain pattern 120, the width of the T-shaped pattern 130 satisfies the "photolithography pattern splicing design rules". That is, at least one of the widths a3 of the first strip pattern 131 and b3 of the second strip pattern 132 satisfies the minimum width requirement of the pattern in the "pattern design rules".

[0055] Furthermore, in the T-shaped pattern 130, the direction in which the first strip pattern 131 points to the second strip pattern 132 is consistent with the direction of the opening 123 of the U-shaped pattern 121, that is, the direction in which the first strip pattern 131 points to the second strip pattern 132 is consistent with the direction in which the bottom 121a of the opening 123 of the U-shaped pattern 121 points to the top 121b.

[0056] It should be noted that the photomask also includes a functional pattern and a test pattern, wherein the functional pattern is used to form a functional structure with electrical functions, and the test pattern is used to form a test structure for testing the functional structure; the test pattern includes at least one measurement pattern structure. In other embodiments of the present invention, the functional pattern includes at least one measurement pattern structure.

[0057] Accordingly, the present invention also provides a mask assembly.

[0058] refer to Figure 5 The diagram shows a top view of an embodiment of the mask assembly of the present invention.

[0059] In this embodiment, the mask assembly includes a first mask template and a second mask template, both of which are mask templates of the present invention; when the first mask template and the second mask template are spliced ​​together to form a complete pattern, at least one measurement pattern structure 200 of the first mask template and at least one measurement pattern structure 300 of the second mask template correspond one-to-one.

[0060] It should be noted that, Figure 5 The diagram shows a top view of one measurement pattern structure of the first mask and the corresponding two side pattern structures of the second mask when the patterns of the first mask and the second mask are spliced ​​together to form a complete mask pattern.

[0061] It should also be noted that each measurement pattern structure includes: at least one measurement pattern, which is at least one of the following: comb pattern, semi-chain pattern, and T-shaped pattern.

[0062] In some embodiments, each measurement pattern structure includes: multiple measurement patterns; when the pattern of the first mask and the pattern of the second mask are spliced ​​together to form a complete mask pattern, the multiple measurement patterns in the measurement pattern structure of the first mask and the multiple measurement patterns in the corresponding measurement pattern structure of the second mask correspond one-to-one.

[0063] Specifically, Figure 5 In the illustrated embodiment, the measurement pattern structure 200 of the first mask template includes: a comb-shaped pattern 210, a semi-chain-shaped pattern 220, and a T-shaped pattern 230; correspondingly, the measurement pattern structure 300 of the second mask template also includes: a comb-shaped pattern 310, a semi-chain-shaped pattern 320, and a T-shaped pattern 330.

[0064] Furthermore, when the patterns of the first mask template and the second mask template are spliced ​​together to form a complete mask pattern, the comb-shaped pattern 210, the semi-chain-shaped pattern 220 and the T-shaped pattern 230 in the measurement pattern structure 200 of the first mask template correspond one-to-one with the comb-shaped pattern 310, the semi-chain-shaped pattern 320 and the T-shaped pattern 330 in the measurement pattern structure 300 of the second mask template.

[0065] In some embodiments of the present invention, the comb pattern 210 in the measurement pattern structure 200 of the first mask template includes: a connecting strip pattern 211 extending along the first direction X; and a plurality of comb tooth strip patterns 212 extending along the second direction Y, one end of the comb tooth strip pattern 212 being connected to the connecting strip pattern 211, the plurality of comb tooth strip patterns 212 being arranged separately and parallel along the first direction X, and the second direction Y being perpendicular to the first direction.

[0066] Correspondingly, the comb pattern 310 in the measurement pattern structure 300 of the second mask, which corresponds to the comb pattern 210 in the measurement pattern structure 200 of the first mask, includes: a connecting strip pattern 311 extending along the first direction X; and a plurality of comb tooth strip patterns 312 extending along the second direction Y, one end of which is connected to the connecting strip pattern 311, and the plurality of comb tooth strip patterns 312 are arranged separately and parallel along the first direction X.

[0067] like Figure 5 As shown, when the patterns of the first mask template and the second mask template are spliced ​​together to form a complete mask pattern, in the corresponding measurement pattern structure 200 of the first mask template and measurement pattern structure 300 of the second mask template, multiple comb-tooth strip patterns 212 in the comb pattern 210 and multiple comb-tooth strip patterns 312 in the comb pattern 310 are arranged alternately. That is, multiple comb-tooth strip patterns 212 are respectively located between the gaps of adjacent comb-tooth strip patterns 312, and correspondingly, multiple comb-tooth strip patterns 312 are also respectively located between the gaps of adjacent comb-tooth strip patterns 212.

[0068] Specifically, Figure 5 In the embodiment shown, in the measurement pattern structure 200 of the first mask template, the comb pattern 210 includes 4 comb tooth strip patterns 212; in the measurement pattern structure 300 of the second mask template, the comb pattern 310 includes 3 comb tooth strip patterns 312.

[0069] In this embodiment, the four comb-tooth strip patterns 212 have three gaps, and the three comb-tooth strip patterns 312 are located in the three gaps of the four comb-tooth strip patterns 212; the three comb-tooth strip patterns 312 have two gaps, and two of the four comb-tooth strip patterns 212 are located in the two gaps of the three comb-tooth strip patterns 312 respectively, and the other two of the four comb-tooth strip patterns 212 are located on both sides of the three comb-tooth strip patterns 312 respectively.

[0070] It should be noted that, Figure 5In the illustrated embodiment, the length of the connecting strip pattern 211 of the comb pattern 210 in the measurement pattern structure 200 of the first mask is equal to the length of the connecting strip pattern 311 of the comb pattern 310 in the measurement pattern structure 300 of the second mask. Therefore, along the first direction X, the connecting strip pattern 311 of the comb pattern 310 in the measurement pattern structure 300 of the second mask extends to one side of the outermost comb strip pattern 212.

[0071] Continue to refer to Figure 5 In some embodiments of the present invention, the semi-chain pattern 220 in the measurement pattern structure 200 of the first mask template includes at least one U-shaped pattern 221 arranged discretely along the first direction X; correspondingly, the semi-chain pattern 320 in the measurement pattern structure 300 of the second mask template, which corresponds to the semi-chain pattern 220 in the measurement pattern structure 200 of the first mask template, includes at least one U-shaped pattern 321 arranged discretely along the first direction X.

[0072] like Figure 5 As shown, when the patterns of the first mask template and the second mask template are spliced ​​together to form a complete mask pattern, in the corresponding measurement pattern structure 200 of the first mask template and measurement pattern structure 300 of the second mask template, at least one U-shaped pattern 221 of the semi-chain pattern 210 of the first mask template and at least one U-shaped pattern 321 of the semi-chain pattern 310 of the second mask template are connected end to end.

[0073] Specifically, the beginning and end of at least one U-shaped pattern 221 of the semi-chain pattern 210 of the first mask and at least one U-shaped pattern 321 of the semi-chain pattern 310 of the second mask are connected by partial overlap, so the at least one U-shaped pattern 221 of the semi-chain pattern 210 of the first mask and the semi-chain pattern 310 of the second mask constitute a square wave pattern.

[0074] Specifically, such as Figure 5 In the illustrated embodiment, the second U-shaped pattern (such as...) Figure 5 The dashed box 342) and the third U-shaped graphic (such as Figure 5 The dashed boxes 343) are located in the first U-shaped shape (e.g. Figure 5 The dashed frame 241) extends along both sides of the first direction X, wherein the first U-shaped graphic is one U-shaped graphic 221 in the semi-chain graphic 210; the second U-shaped graphic and the third U-shaped graphic are two U-shaped graphics 221 in the semi-chain graphic 310.

[0075] In this embodiment, one second segment 221b of the first U-shaped pattern overlaps with and is connected to the second segment 321b of the second U-shaped pattern that is close to the first U-shaped pattern; another second segment 221b of the first U-shaped pattern overlaps with and is connected to the second segment 321b of the third U-shaped pattern that is close to the first U-shaped pattern.

[0076] In some embodiments of the present invention, the semi-chain pattern 220 further includes a chain tail strip pattern 222 extending along the second direction Y; the semi-chain pattern 320 further includes a chain tail strip pattern 322 extending along the second direction Y.

[0077] Specifically, along the first direction X, the chain tail strip pattern 222 of the semi-chain pattern 220 and the chain tail strip pattern 322 of the semi-chain pattern 320 are located on both sides of the multiple U-shaped patterns 221 and the multiple U-shaped patterns 321, respectively.

[0078] Furthermore, the chain tail strip pattern 222 of the semi-chain pattern 220 overlaps with the outermost second segment 321b of the U-shaped pattern 321 furthest from the chain tail strip pattern 322 to form a connection; the chain tail strip pattern 322 of the semi-chain pattern 320 overlaps with the outermost second segment 221b of the U-shaped pattern 221 furthest from the chain tail strip pattern 222 to form a connection.

[0079] Continue to refer to Figure 5 In some embodiments of the present invention, the T-shaped pattern 230 in the measurement pattern structure 200 of the first mask template includes: a first strip pattern 231 extending along the first direction X; and a second strip pattern 232 extending along the second direction Y; the T-shaped pattern 330 in the measurement pattern structure 300 of the second mask template includes: a first strip pattern 331 extending along the first direction X; and a second strip pattern 332 extending along the second direction Y.

[0080] In this embodiment, when the first mask template and the second mask template are spliced ​​together to form a complete pattern, the second strip pattern 232 of the T-shaped pattern 230 of the first mask template and the second strip pattern 332 of the T-shaped pattern 330 of the second mask template are connected to each other in the corresponding measurement pattern structure 200 and measurement pattern structure 300 of the first mask template.

[0081] Specifically, the second strip pattern 232 of the T-shaped pattern 230 of the first mask and the second strip pattern 332 of the T-shaped pattern 330 of the second mask are connected by partial overlap.

[0082] It should be noted that, as Figure 6 As shown, the first mask template includes: a first test pattern 250 for forming a first test structure, the first test pattern 250 including: at least one measurement pattern structure 251; as Figure 7As shown, the second mask template includes a second test pattern 350 for forming a second test structure, and the second test pattern 350 includes at least one measurement pattern structure 351.

[0083] In addition, such as Figure 8 As shown, the first test pattern 250 further includes a first alignment pattern 252; the second test pattern 350 further includes a second alignment pattern 352; the first alignment pattern 252 and the second alignment pattern 352 are used to align the first mask and the second mask to achieve splicing. Specifically, as... Figure 8 In the embodiment shown, when the first mask template and the second mask template are spliced ​​together to form a complete pattern, the first aligned pattern 252 is located within the range of the corresponding second aligned pattern 352.

[0084] In this embodiment, when the first mask and the second mask are spliced ​​together to form a complete pattern, the measurement pattern structure 251 of the first mask and the corresponding measurement pattern structure 351 of the second mask partially overlap to form an overlapping area 400 (e.g., Figure 5 (As shown).

[0085] Accordingly, the present invention also provides a method for forming a semiconductor structure.

[0086] In this embodiment, the semiconductor structure formation method includes: providing a substrate and a mask assembly, wherein the mask assembly is the mask assembly of the present invention; transferring the pattern of the mask assembly onto the substrate to form a semiconductor structure; wherein the step of transferring the pattern of the mask assembly onto the substrate includes: transferring the pattern of a lower mask onto the substrate to form a first positioning structure, wherein the lower mask is one of a first mask and a second mask; after the pattern of the lower mask is transferred, transferring the pattern of an upper mask onto the substrate to form a second positioning structure, wherein the upper mask is the other of the first mask and the second mask.

[0087] The substrate serves as a platform for process operations and also provides a process foundation for subsequent steps.

[0088] In some embodiments of the present invention, the substrate includes a substrate and a semiconductor structure located on the substrate. The substrate material is selected from monocrystalline silicon, polycrystalline silicon, or amorphous silicon; the substrate material may also be selected from silicon, germanium, gallium arsenide, or silicon-germanium compounds; the substrate material may also be other semiconductor materials. The present invention does not limit this. In other embodiments of the present invention, the substrate may consist only of a substrate.

[0089] In this embodiment, the mask assembly is used to transfer the pattern onto the substrate.

[0090] The mask assembly is the mask assembly of the present invention. Therefore, the specific technical solution of the mask assembly is described in the foregoing embodiments of the mask assembly, and will not be repeated here.

[0091] The step of transferring the pattern of the mask component onto the substrate is used to achieve pattern transfer.

[0092] The mask template also includes: a functional graphic, which is suitable for transfer onto the substrate to form a functional structure.

[0093] In the step of transferring the image of the mask assembly onto the substrate, the functional pattern of the first mask and at least one measurement pattern structure are simultaneously transferred onto the substrate; the functional pattern of the second mask and at least one measurement pattern structure are simultaneously transferred onto the substrate. For example... Figure 5 The diagram shows a top view of an embodiment of the semiconductor structure formation method of the present invention after the pattern of the mask assembly is transferred onto the substrate.

[0094] In some embodiments of the present invention, the step of transferring the pattern of the mask assembly onto the substrate includes at least one of forming an active region, forming a polysilicon layer, forming a metal layer, and forming a metal silicide layer.

[0095] Since the functional pattern of the photomask and at least one measurement pattern structure are transferred to the substrate simultaneously, the functional structure formed by transferring the functional pattern to the substrate and the semiconductor structure formed by transferring at least one measurement pattern structure to the substrate are of the same type of semiconductor structure.

[0096] Specifically, when the step of transferring the pattern of the mask assembly onto the substrate is a step of forming a doped active region, the functional structure formed by transferring the functional pattern onto the substrate is a doped active region, and the semiconductor structure formed by at least one measurement pattern structure is also a doped active region; when the step of transferring the pattern of the mask assembly onto the substrate is a step of forming a doped polysilicon layer, the functional structure formed by transferring the functional pattern onto the substrate is a doped polysilicon layer, and the semiconductor structure formed by at least one measurement pattern structure is also a doped polysilicon layer; when the step of transferring the pattern of the mask assembly onto the substrate is a step of forming a metal layer, the functional structure formed by transferring the functional pattern onto the substrate is a metal layer, and the semiconductor structure formed by at least one measurement pattern structure is also a metal layer; when the step of transferring the pattern of the mask assembly onto the substrate is a step of forming a metal silicide layer, the functional structure formed by transferring the functional pattern onto the substrate is a metal silicide layer, and the semiconductor structure formed by at least one measurement pattern structure is also a metal silicide layer.

[0097] It should be noted that in the step of transferring the pattern of the upper mask onto the substrate, the image of the previous mask is aligned with the pattern of the lower mask transferred onto the substrate, so that the patterns of the upper and lower masks are stitched together to form a complete mask pattern.

[0098] When the patterns of the first mask template and the second mask template are spliced ​​together to form a complete mask pattern, the patterns of at least one measurement pattern structure of the first mask template and the patterns of at least one measurement pattern structure of the second mask template correspond one-to-one. That is to say, in the complete mask pattern, the patterns of at least one measurement pattern structure of the first mask template and the patterns of at least one measurement pattern structure of the second mask template correspond one-to-one.

[0099] In some embodiments of the present invention, in the step of transferring the pattern of the lower mask onto the substrate, the lower mask is a first mask; in the step of transferring the pattern of the upper mask onto the substrate, the upper mask is a second mask.

[0100] Therefore, in the step of transferring the pattern of the lower mask onto the substrate to form at least one first positioning structure, the first positioning structure is formed by transferring at least one measurement pattern structure of the first mask onto the substrate; in the step of transferring the pattern of the upper mask onto the substrate to form at least one second positioning structure, the at least one measurement pattern structure of the second mask corresponds one-to-one with at least one first positioning structure.

[0101] Furthermore, in the step of transferring the pattern of the upper mask onto the substrate to form the second positioning structure, the second positioning structure is formed by transferring at least one measurement pattern structure of the second mask onto the substrate; therefore, at least one second positioning structure corresponds one-to-one with at least one first positioning structure.

[0102] like Figure 9 As shown, in some embodiments of the present invention, the measurement pattern structure in the photomask forming the semiconductor structure includes at least a plurality of comb-shaped patterns, half-chain-shaped patterns, and T-shaped patterns; therefore, the first positioning structure 500 includes a first comb-shaped positioning pattern 510, a first half-chain positioning pattern 520, and a first T-shaped positioning pattern 530; the second positioning structure 600 includes a second comb-shaped positioning pattern 610, a second half-chain positioning pattern 620, and a second T-shaped positioning pattern 630.

[0103] Accordingly, the present invention also provides a semiconductor structure, which is formed by the semiconductor structure forming method of the present invention.

[0104] The semiconductor structure is formed by the semiconductor structure formation method of the present invention. Therefore, the specific technical solution of the semiconductor structure can be referred to the embodiments of the aforementioned semiconductor structure formation method, and will not be repeated here.

[0105] It should be noted that the semiconductor structure includes: a test structure (testkey) formed by transferring a test pattern onto a substrate, wherein at least one first positioning structure and at least one second positioning structure are located within the test structure. In other embodiments of the present invention, the semiconductor structure has a functional structure formed by transferring a functional pattern onto a substrate, wherein at least one first positioning structure and at least one second positioning structure may also be located within the functional structure.

[0106] like Figure 9 As shown, the semiconductor structure includes: at least one first positioning structure 500, which is formed by transferring at least one measurement pattern structure of a first mask onto a substrate; at least one second positioning structure 600, which is formed by transferring at least one measurement pattern structure of a second mask onto a substrate; the at least one first positioning structure 500 and the at least one second positioning structure 600 correspond one-to-one.

[0107] In some embodiments of the present invention, the measurement pattern structure in the photomask forming the semiconductor structure includes at least a plurality of comb-shaped patterns, half-chain-shaped patterns, and T-shaped patterns; therefore, the first positioning structure 500 includes a first comb-shaped positioning pattern 510, a first half-chain positioning pattern 520, and a first T-shaped positioning pattern 530; the second positioning structure 600 includes a second comb-shaped positioning pattern 610, a second half-chain positioning pattern 620, and a second T-shaped positioning pattern 630.

[0108] like Figure 9 As shown, in some embodiments of the present invention, each positioning structure is connected to a solder pad to realize the loading of voltage or current signals; multiple positioning patterns in the same positioning structure are connected to their corresponding solder pads through different metal layers.

[0109] Specifically, in the first positioning structure 500, the first comb-shaped positioning pattern 510, the first half-chain positioning pattern 520, and the first T-shaped positioning pattern 530 are connected to the solder pads 551, 552, and 553 respectively through different metal layers; in the second positioning structure 600, the second comb-shaped positioning pattern 610, the second half-chain positioning pattern 620, and the second T-shaped positioning pattern 630 are connected to the solder pads 651, 652, and 653 respectively through different metal layers.

[0110] In some embodiments of the present invention, all positioning structures in the semiconductor structure are connected to their corresponding pads through different metal layers.

[0111] like Figure 9In the illustrated embodiment, the first comb-shaped positioning pattern 510, the first half-chain positioning pattern 520, and the first T-shaped positioning pattern 530 in the first positioning structure 500, and the second comb-shaped positioning pattern 610, the second half-chain positioning pattern 620, and the second T-shaped positioning pattern 630 in the second positioning structure 600 are respectively connected to pads 551, 552, 553, 651, 652, and 653 through different metal layers.

[0112] In some embodiments of the present invention, in the corresponding first positioning structure and second positioning structure, the distance between the two pads of the corresponding positioning pattern is equal to the distance between the needle tips on the test needle card.

[0113] like Figure 9 In the illustrated embodiment, the distances between the solder pads 551 of the first comb-shaped positioning pattern 510 and the solder pads 651 of the second comb-shaped positioning pattern 610, the distances between the solder pads 552 of the first half-chain positioning pattern 520 and the solder pads 652 of the second half-chain positioning pattern 620, and the distances between the solder pads 553 of the first T-shaped positioning pattern 530 and the solder pads 653 of the second T-shaped positioning pattern 630 are all equal to the distances between the needle tips on the test needle card.

[0114] Furthermore, the present invention also provides a method for measuring semiconductor structures, wherein the semiconductor structure is the semiconductor structure of the present invention.

[0115] refer to Figure 10 The diagram shows a flowchart of an embodiment of the semiconductor structure measurement method of the present invention.

[0116] Reference Figure 9 The diagram shows a top view of the semiconductor structure.

[0117] like Figure 9 As shown, the semiconductor structure includes: at least one first positioning structure 500, which is formed by transferring at least one measurement pattern structure of a first mask onto a substrate; at least one second positioning structure 600, which is formed by transferring at least one measurement pattern structure of a second mask onto a substrate; the at least one first positioning structure 500 and the at least one second positioning structure 600 correspond one-to-one; as shown... Figure 9 As shown, the measurement method includes: performing step S100, measuring the splicing offset based on at least one first positioning structure 500 and at least one second positioning structure 600.

[0118] In some embodiments of the present invention, the measurement pattern structure includes a comb-shaped pattern; the first positioning structure 500 includes a first comb-shaped positioning pattern 510, which is formed by transferring the comb-shaped pattern of the measurement pattern structure of the first mask onto the substrate; the corresponding second positioning structure 600 includes a second comb-shaped positioning pattern 610, which is formed by transferring the comb-shaped pattern of the corresponding measurement pattern structure of the second mask onto the substrate.

[0119] Therefore, the step of performing step S100, measuring the splicing offset, includes performing step S110, measuring at least one of the leakage current and breakdown voltage between the first comb positioning pattern 510 and the second comb positioning pattern 610 to obtain the splicing offset.

[0120] like Figure 9 As shown, the first comb-shaped positioning pattern 510 and the second comb-shaped positioning pattern 610 can form a capacitor structure; the offset of the pattern splicing will affect the distance between the structures formed by the comb-shaped patterns on different photomasks, and will affect the thickness of the dielectric layer between the structures formed by the comb-shaped patterns on different photomasks, thereby affecting the leakage current or breakdown voltage between the two; therefore, the specific situation of the pattern splicing can be obtained by measuring at least one of the leakage current and breakdown voltage between the two.

[0121] Specifically, voltage signals are applied to the first comb-shaped positioning pattern 510 and the second comb-shaped positioning pattern 610 respectively to measure leakage current, or current signals are applied to the first comb-shaped positioning pattern 510 and the second comb-shaped positioning pattern 610 respectively to measure breakdown voltage, thereby obtaining the splicing offset.

[0122] Continue to refer to Figure 5 In some embodiments of the present invention, the measurement pattern structure includes: a semi-chain pattern; the first positioning structure 500 includes: a first semi-chain positioning pattern 520, which is formed by transferring the semi-chain pattern of the measurement pattern structure of the first mask onto the substrate; the corresponding second positioning structure 600 includes: a second semi-chain positioning pattern 620, which is formed by transferring the semi-chain pattern of the corresponding measurement pattern structure of the second mask onto the substrate.

[0123] Therefore, the step of performing step S100, measuring the splicing offset, includes performing step S120, measuring the resistance values ​​of the first half-chain positioning pattern 520 and the second half-chain positioning pattern 620 to obtain the splicing offset.

[0124] like Figure 9As shown, the first half-chain positioning pattern 520 and the second half-chain positioning pattern 620 are connected to form a conductive connection. The offset of the pattern splicing will affect the overlap between the structures formed by the U-shaped patterns on different photomasks, and will affect the width and length between the structures formed by the U-shaped patterns on different photomasks, thereby affecting the resistance value between the two. Therefore, the specific situation of the pattern splicing can be obtained by measuring the resistance value between the two.

[0125] Specifically, voltage signals are applied to the first half-chain positioning pattern 520 and the second half-chain positioning pattern 620 respectively to measure the resistance, thereby obtaining the splicing offset.

[0126] Continue to refer to Figure 5 In some embodiments of the present invention, the measurement pattern structure includes a T-shaped pattern; the first positioning structure 500 includes a first T-shaped positioning pattern 530, which is formed by transferring the T-shaped pattern of the measurement pattern structure of the first mask onto the substrate; the corresponding second positioning structure 600 includes a second T-shaped positioning pattern 630, which is formed by transferring the T-shaped pattern of the corresponding measurement pattern structure of the second mask onto the substrate.

[0127] Therefore, the step of performing step S100, measuring the splicing offset, includes performing step S130, measuring the resistance values ​​of the first T-shaped positioning pattern 530 and the second T-shaped positioning pattern 630 to obtain the splicing offset.

[0128] like Figure 9 As shown, the first T-shaped positioning pattern 530 and the second T-shaped positioning pattern 630 are connected to form a conductive connection. The offset of the pattern splicing will affect the overlap between the first T-shaped positioning pattern 530 and the second T-shaped positioning pattern 630, and will affect the width and length of the first T-shaped positioning pattern 530 and the second T-shaped positioning pattern 630, thereby affecting the resistance value between them. Therefore, the specific situation of the pattern splicing can be obtained by measuring the resistance value between them.

[0129] Specifically, voltage signals are applied to the first T-shaped positioning pattern 530 and the second T-shaped positioning pattern 630 respectively to measure the resistance, thereby obtaining the splicing offset.

[0130] In summary, the photomask includes at least one measurement pattern structure, which includes at least one of a comb-shaped pattern, a semi-chain-shaped pattern, and a T-shaped pattern. When measuring the semiconductor structure formed by the photomask assembly, the splicing offset is measured based on at least one first positioning pattern and at least one second positioning pattern. Monitoring the photomask splicing based on electrical performance test results provides higher accuracy, accurately determines pattern alignment, and adds monitoring positions for online defect scanning.

[0131] 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 photomask, characterized in that, include: At least one measurement pattern structure, the measurement pattern structure including at least one of a comb pattern and a T-shaped pattern; wherein, the comb pattern includes: a connecting strip pattern extending along a first direction; a plurality of comb tooth strip patterns extending along a second direction, one end of the comb tooth strip pattern being connected to the connecting strip pattern, the plurality of comb tooth strip patterns being arranged separately and parallel along the first direction, and the second direction being perpendicular to the first direction; The T-shaped pattern includes: a first strip-shaped pattern extending along the first direction; and a second strip-shaped pattern extending along the second direction, one end of which is connected to the midpoint of the first strip-shaped pattern along the first direction. The measurement pattern structure is used to transfer to the substrate, and a positioning pattern consistent with the measurement pattern structure is formed on the substrate, so as to use the formed positioning pattern to monitor the mask splicing accuracy. The mask template is used to splice with the second mask template to form a mask assembly. When the patterns of the mask template and the second mask template are spliced ​​to form a complete mask pattern, in the corresponding measurement pattern structure of the mask template and the measurement pattern structure of the second mask template, when the measurement pattern structure includes a comb-shaped pattern, the multiple comb-tooth strip patterns of the comb-shaped pattern of the mask template and the multiple comb-tooth strip patterns of the comb-shaped pattern of the second mask template are arranged alternately; when the measurement pattern structure includes a T-shaped pattern, the second strip pattern of the T-shaped pattern of the mask template and the second strip pattern of the T-shaped pattern of the second mask template are connected to each other.

2. The mask template as described in claim 1, characterized in that, Each of the measurement pattern structures includes multiple patterns from comb-shaped patterns and T-shaped patterns; Multiple figures are arranged sequentially along the first direction.

3. The mask template as described in claim 1, characterized in that, Along the first direction, the spacing between adjacent comb-tooth strip patterns is greater than the size of the comb-tooth strip patterns.

4. A mask assembly, characterized in that, include: The first mask template and the second mask template are both as described in any one of claims 1 to 3; When the patterns of the first mask template and the second mask template are spliced ​​together to form a complete mask pattern, in the corresponding measurement pattern structure of the first mask template and the measurement pattern structure of the second mask template, when the measurement pattern structure includes a comb-shaped pattern, the multiple comb-tooth strip patterns of the comb-shaped pattern of the first mask template and the multiple comb-tooth strip patterns of the comb-shaped pattern of the second mask template are arranged alternately; when the measurement pattern structure includes a T-shaped pattern, the second strip pattern of the T-shaped pattern of the first mask template and the second strip pattern of the T-shaped pattern of the second mask template are connected to each other.

5. A method for forming a semiconductor structure, characterized in that, include: A substrate and a mask assembly are provided, the mask assembly being as described in claim 4; The pattern of the mask assembly is transferred onto the substrate to form a semiconductor structure; The step of transferring the pattern of the mask assembly onto the substrate includes: transferring the pattern of the lower mask onto the substrate to form a first positioning structure, wherein the lower mask is one of the first mask and the second mask; after the pattern of the lower mask is transferred, transferring the pattern of the upper mask onto the substrate to form a second positioning structure, wherein the upper mask is the other of the first mask and the second mask.

6. The forming method as described in claim 5, characterized in that, The step of transferring the pattern of the mask assembly onto the substrate further includes: forming at least one of the following on the substrate: forming a doped active region, forming a doped polysilicon layer, forming a metal layer, and forming a metal silicide layer.

7. A semiconductor structure, characterized in that, The semiconductor structure is formed by the method for forming a semiconductor structure as described in claim 5 or 6.

8. A method for measuring semiconductor structures, characterized in that, include: According to the first positioning structure and the second positioning structure of the semiconductor structure as described in claim 7, the splicing offset is measured, wherein the first positioning structure and the second positioning structure correspond to each other. Wherein, when the measurement pattern structure includes a comb pattern, the first positioning structure includes: a first comb positioning pattern, which is formed by transferring the comb pattern of the measurement pattern structure of the first mask onto the substrate; the corresponding second positioning structure includes: a second comb positioning pattern, which is formed by transferring the comb pattern of the corresponding measurement pattern structure of the second mask onto the substrate; the step of measuring the splicing offset includes: measuring at least one of the leakage current and breakdown voltage between the first comb positioning pattern and the second comb positioning pattern to obtain the splicing offset; When the measurement pattern structure includes a T-shaped pattern, the first positioning structure includes: a first T-shaped positioning pattern, which is formed by transferring the T-shaped pattern of the measurement pattern structure of the first mask onto the substrate; the corresponding second positioning structure includes: a second T-shaped positioning pattern, which is formed by transferring the T-shaped pattern of the corresponding measurement pattern structure of the second mask onto the substrate; the step of measuring the splicing offset includes: measuring the resistance values ​​of the first T-shaped positioning pattern and the second T-shaped positioning pattern to obtain the splicing offset.

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