Overlay mark, semiconductor structure, and photomask

Abstract

The embodiment of the disclosure provides a set of marking, a semiconductor structure and a photomask, wherein the set of marking comprises a first marking formed by using a first photomask and a second marking formed by using a second photomask, the first marking and the second marking are located in the same horizontal plane; the first marking comprises at least a first marking pattern, and the second marking comprises at least a fourth marking pattern; the first marking pattern and the fourth marking pattern are similar polygons, and the fourth marking pattern is located in the inside of the first marking pattern; and the polygon has at least eight sides.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of semiconductor technology, and relates to, but is not limited to, an overlay mark, a semiconductor structure and a photomask. BACKGROUND

[0002] A photolithography process is a key step in the manufacture of a semiconductor integrated circuit. Overlay accuracy of photolithography is one of the key parameters for measuring the photolithography process, which refers to the offset between upper and lower layer patterns of a wafer, that is, overlay error. The overlay error is usually measured by measuring the offset between overlay marks of the upper and lower layer patterns to evaluate the overlay accuracy.

[0003] At present, due to size limitations, the photomask used by the interposer includes a plurality of small photomasks, each of which forms a pattern at a predetermined position in the interposer until the final required pattern is formed. For example, in a Chip-on-Wafer-on-Substrate (CoWoS) design, a large interposer of 50*55 square millimeters (mm 2 ) requires a 4-in-1 mask stitching to expand the photomask size limit of 26*33 mm 2 . Therefore, the overlay mark in the related art cannot measure the offset between multiple small photomasks. SUMMARY

[0004] In view of this, the embodiments of the present disclosure provide an overlay mark, a semiconductor structure and a photomask.

[0005] In a first aspect, the embodiments of the present disclosure provide an overlay mark, which comprises:

[0006] The overlay mark comprises a first mark formed using a first photomask and a second mark formed using a second photomask, the first mark and the second mark being located on the same horizontal plane;

[0007] The first mark comprises at least a first mark pattern, and the second mark comprises at least a fourth mark pattern; the first mark pattern and the fourth mark pattern are similar polygons, and the fourth mark pattern is located inside the first mark pattern; the polygon has at least eight sides.

[0008] In some embodiments, the first mark pattern comprises at least eight first sub-patterns; the first mark further comprises a second mark pattern positioned in a first direction and a third mark pattern positioned in a second direction;

[0009] The second mark pattern and the third mark pattern are respectively located outside each of the first sub-patterns, and one second mark pattern and one third mark pattern are respectively arranged on both sides of each symmetry axis of the first mark pattern; the first direction is perpendicular to the second direction.

[0010] In some embodiments, the fourth mark pattern comprises at least eight fourth sub-patterns; the second mark further comprises a fifth mark pattern arranged along the first direction and a sixth mark pattern arranged along the second direction;

[0011] The fifth mark pattern and the sixth mark pattern are respectively located outside each of the fourth sub-patterns, and one fifth mark pattern and one sixth mark pattern are respectively arranged on both sides of each symmetry axis of the fourth mark pattern;

[0012] The fifth mark pattern and the sixth mark pattern are both located outside the first mark pattern.

[0013] In some embodiments, the symmetry axes of the first mark pattern and the fourth mark pattern respectively extend along the first direction or the second direction, and a preset angle direction relative to the first direction or the second direction;

[0014] The second mark pattern, the third mark pattern, the fifth mark pattern and the sixth mark pattern located at both ends of the symmetry axis in the preset angle direction are used to determine the offset amount of the first photomask and the second photomask in the preset angle direction; the preset angle at least comprises 45°.

[0015] In some embodiments, the second mark pattern comprises a plurality of second sub-patterns arranged at intervals along the second direction; each of the second sub-patterns comprises a first end and a second end along the first direction; a first virtual connection line formed by connecting the second ends of a plurality of the second sub-patterns has a first included angle with the second direction.

[0016] In some embodiments, the fifth mark pattern comprises a plurality of fifth sub-patterns arranged at intervals along the second direction; each of the fifth sub-patterns comprises a first end and a second end along the first direction; a second virtual connection line formed by connecting the first ends of a plurality of the fifth sub-patterns has a second included angle with the second direction;

[0017] The first included angle is equal to the second included angle, and the first virtual connection line intersects the second virtual connection line.

[0018] In some embodiments, each of the second sub-patterns and the corresponding fifth sub-pattern has a preset offset amount in the first direction;

[0019] The preset offsets include positive offsets, 0, and negative offsets, and the preset offsets increase or decrease in the second direction in turn.

[0020] The second sub-pattern and the fifth sub-pattern are used to determine the offset of the first photomask and the second photomask in the first direction.

[0021] In some embodiments, the third mark pattern includes a plurality of third sub-patterns arranged at equal intervals in the second direction, and the first preset distance is between adjacent third sub-patterns.

[0022] The sixth mark pattern includes a plurality of sixth sub-patterns arranged at intervals in the second direction, and the second preset distance is between adjacent sixth sub-patterns.

[0023] The second preset distance is greater than the first preset distance, and the second preset distance increases in turn by the same incremental distance in the second direction.

[0024] In some embodiments, one third sub-pattern is aligned with one sixth sub-pattern.

[0025] The third sub-pattern and the sixth sub-pattern are used to determine the offset of the first photomask and the second photomask in the second direction.

[0026] In a second aspect, the embodiments of the present disclosure provide a semiconductor structure, comprising:

[0027] An interposer, and a overlay mark in a lithography stitching area of the interposer; the lithography stitching area includes a stitching area of a first photomask and a second photomask;

[0028] The overlay mark includes a first mark photolithographically formed by the first photomask, and a second mark photolithographically formed by the second photomask.

[0029] The first mark includes at least a first mark pattern, and the second mark includes at least a fourth mark pattern; the first mark pattern and the fourth mark pattern are similar polygons, and the fourth mark pattern is located in the first mark pattern; the polygon has at least eight sides.

[0030] In some embodiments, the lithography stitching area further includes a stitching area of the second photomask and a third photomask, and a stitching area of the third photomask and a fourth photomask.

[0031] The overlay mark is in the stitching area of the second photomask and the third photomask, and the stitching area of the third photomask and the fourth photomask.

[0032] In some embodiments, the overlay mark is not located in a common lithography stitching area of the first photomask, the second photomask, the third photomask, and the fourth photomask.

[0033] In a third aspect, the embodiments of the present disclosure provide a photomask, comprising at least: a first photomask and a second photomask; wherein the first photomask comprises a first mark, and the second photomask comprises a second mark.

[0034] The first mark comprises at least a first mark pattern, and the second mark comprises at least a fourth mark pattern; the first mark pattern and the fourth mark pattern are similar polygons, and a projection area of the fourth mark pattern in a third direction is located inside a projection area of the first mark pattern in the third direction; the polygon has at least eight sides; and the third direction is perpendicular to a plane on which the first photomask is located.

[0035] In some embodiments, the first mark further comprises a second mark pattern located along a first direction, and a third mark pattern located along a second direction; and the second mark further comprises a fifth mark pattern located along the first direction, and a sixth mark pattern located along the second direction.

[0036] The projection area of the second mark pattern along the third direction partially overlaps the projection area of the fifth mark pattern along the third direction; and the projection area of the third mark pattern along the third direction is adjacent to the projection area of the sixth mark pattern along the third direction.

[0037] In some embodiments, the photomask further comprises: a third photomask partially overlapping the second photomask, and a fourth photomask partially overlapping the third photomask and the first photomask.

[0038] The second photomask further comprises the first mark located in an overlapping area of the second photomask and the third photomask.

[0039] The third photomask comprises the second mark located in the overlapping area of the second photomask and the third photomask, and the first mark located in an overlapping area of the third photomask and the fourth photomask.

[0040] The fourth photomask comprises the second mark located in an overlapping area of the third photomask and the fourth photomask.

[0041] The overlay mark, the semiconductor structure and the photomask provided by the embodiments of the present disclosure, wherein the overlay mark comprises a first mark formed by using a first photomask and a second mark formed by using a second photomask, the first mark and the second mark are located in the same horizontal plane; the first mark comprises at least a first mark pattern, and the second mark comprises at least a fourth mark pattern; the first mark pattern and the fourth mark pattern are similar polygons, and the fourth mark pattern is located inside the first mark pattern. Since the alignment or offset of the first photomask and the second photomask can be determined by the first mark pattern in the first mark and the fourth mark pattern in the second mark, thus, the overlay mark provided by the embodiments of the present disclosure can measure the alignment of the stitching area of the first photomask and the second photomask. BRIEF DESCRIPTION OF DRAWINGS

[0042] In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components in different views. Like numerals having different letter suffixes can represent different instances of the components. The drawings illustrate generally, by way of example, various embodiments discussed herein.

[0043] Figure 1 A structural schematic diagram of the overlay mark provided by the embodiments of the present disclosure;

[0044] Figure 2 Another structural schematic diagram of the overlay mark provided by the embodiments of the present disclosure;

[0045] Figure 3 A structural schematic diagram of the second mark pattern and the fifth mark pattern provided by the embodiments of the present disclosure;

[0046] Figure 4 A structural schematic diagram of the third mark pattern and the sixth mark pattern provided by the embodiments of the present disclosure;

[0047] Figure 5 A structural schematic diagram of the semiconductor structure provided by the embodiments of the present disclosure;

[0048] Figure 6 A structural schematic diagram of the photomask provided by the embodiments of the present disclosure. DETAILED DESCRIPTION

[0049] Exemplary embodiments of the present disclosure will be described hereinafter with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0050] In the following description, numerous specific details are set forth to provide a more thorough understanding of the present disclosure. However, it will be apparent to one of skill in the art upon

[0051] In the drawings, the size of layers, regions, elements, and the like can be exaggerated for clarity. Like reference numerals designate like elements throughout the specification.

[0052] It should be understood that when an element or layer is referred to as being "on", "adjacent", "connected to" or "coupled to" another element or layer, it can be directly on, adjacent, connected or coupled to the other element or layer, or one or more intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on", "directly adjacent", "directly connected to", or "directly coupled to" another element or layer, then there are no intervening elements or layers present. It will be appreciated that, although terms such as first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are simply used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure and, similarly, a second element, component, region, layer or section discussed below could be termed a first element, component, region, layer or section without departing from the teachings of the present disclosure.

[0053] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0054] The embodiment of the present disclosure provides a mark for overlay, Figure 1 A structure diagram of the mark for overlay provided by the embodiment of the present disclosure is shown in Figure 1As shown, the overlay mark 100 includes a first mark formed using a first photomask and a second mark formed using a second photomask, the first mark and the second mark being located in the same horizontal plane. The first mark includes at least a first mark pattern 101, and the second mark includes at least a fourth mark pattern 201; the first mark pattern 101 and the fourth mark pattern 201 are similar polygons, and the fourth mark pattern 201 is located inside the first mark pattern 101; the polygon has at least eight sides.

[0055] In the embodiments of the present disclosure, the first mark pattern 101 and the fourth mark pattern 201 are both octagons. In other embodiments, the first mark pattern 101 and the fourth mark pattern 201 can also be both n-sided polygons, n being an even number greater than 8, for example, a decagon, a dodecagon, or a hexadecagon.

[0056] In some embodiments, please continue to refer to Figure 1 , the first mark pattern 101 has eight sides, i.e., the first mark pattern 101 includes eight first sub-patterns 101a; the fourth mark pattern 201 has eight sides, i.e., the fourth mark pattern 201 includes eight fourth sub-patterns 201a; the first sub-pattern 101a and the fourth sub-pattern 201a correspond to each other, and each first sub-pattern 101a and the corresponding fourth sub-pattern 201a have a preset distance d1. In the embodiments of the present disclosure, the first mark pattern in the first photomask and the fourth mark pattern in the second photomask are formed in the same layer, when the distance between the first sub-pattern 101a in the first mark pattern 101 and the corresponding fourth sub-pattern 201a in the fourth mark pattern 201 is equal to d1, it indicates that the alignment of the first photomask and the second photomask is good, when the distance between the first sub-pattern 101a in the first mark pattern 101 and the corresponding fourth sub-pattern 201a in the fourth mark pattern 201 is not equal to d1, it indicates that the first photomask and the second photomask have shifted, at this time, the amount of shift of the first photomask and the second photomask needs to be determined by technical means such as an electron microscope.

[0057] In the embodiments of the present disclosure, the alignment or shift of the first photomask and the second photomask can be determined through the first mark pattern and the fourth mark pattern, so that the overlay mark provided by the embodiments of the present disclosure can measure the shift of the first photomask and the second photomask.

[0058] Figure 2This is another schematic diagram of the overlay mark provided in an embodiment of the present disclosure. The overlay mark 100 includes a first mark formed using a first photomask and a second mark formed using a second photomask, with the first mark and the second mark located on the same horizontal plane. The first mark includes a first mark pattern 101, a second mark pattern 102 for positioning along a first direction, and a third mark pattern 103 for positioning along a second direction; the second mark includes a fourth mark pattern 201, a fifth mark pattern 202 for positioning along the first direction, and a sixth mark pattern 203 for positioning along the second direction.

[0059] The first marking pattern 101 and the fourth marking pattern 201 are similar octagons, and the fourth marking pattern 201 is located inside the first marking pattern 101.

[0060] In some embodiments, please continue to see Figure 1 The first marking pattern 101 includes eight first sub-patterns 101a; the fourth marking pattern 201 includes eight fourth sub-patterns 201a; each first sub-pattern 101a corresponds one-to-one with a fourth sub-pattern 201a.

[0061] In this embodiment of the disclosure, within the plane containing the first photomask or the second photomask, two arbitrary perpendicular directions are defined as the first direction and the second direction. For example, the first direction can be... Figure 2 The X-axis direction and the second direction can be Figure 2 The Y-axis direction in the diagram.

[0062] In this embodiment of the disclosure, the second marking pattern 102 is used for positioning in the X-axis direction, and the third marking pattern 103 is used for positioning in the Y-axis direction. The second marking pattern 102 and the third marking pattern 103 are respectively located outside each first sub-pattern 101a, and a second marking pattern 102 and a third marking pattern 103 are respectively provided on both sides of each axis of symmetry of the first marking pattern 101.

[0063] Please continue reading Figure 2 The first marking pattern 101 includes an axis of symmetry along the X-axis, an axis of symmetry along the Y-axis, and an axis of symmetry at 45° to both the X-axis and Y-axis. In this embodiment, a second marking pattern 102 and a third marking pattern 103 are provided on both sides of the first marking pattern 101 along the axis of symmetry along the X-axis, the axis of symmetry along the Y-axis, and the axis of symmetry at 45° to both the X-axis and Y-axis.

[0064] In the embodiments of the present disclosure, the fifth mark pattern 202 is used for positioning in the X-axis direction, and the sixth mark pattern 203 is used for positioning in the Y-axis direction. The fifth mark pattern 202 and the sixth mark pattern 203 are respectively located outside each fourth sub-pattern 201a, and one fifth mark pattern 202 and one sixth mark pattern 203 are respectively arranged on both sides of each symmetry axis of the fourth mark pattern 201.

[0065] Please continue to refer to Figure 2 The fourth mark pattern 201 includes a symmetry axis in the X-axis direction, a symmetry axis in the Y-axis direction, and a symmetry axis in a direction that is 45° to both the X-axis direction and the Y-axis direction. In the embodiments of the present disclosure, one fifth mark pattern 202 and one sixth mark pattern 203 are arranged on both sides of the symmetry axis in the X-axis direction, the symmetry axis in the Y-axis direction, and the symmetry axis in the direction that is 45° to both the X-axis direction and the Y-axis direction of the fourth mark pattern 201.

[0066] In some embodiments, the fifth mark pattern 202 and the sixth mark pattern 203 are both located outside the first mark pattern 101.

[0067] In the embodiments of the present disclosure, the first mark pattern 101 and the fourth mark pattern 201 are used to roughly determine the offset or alignment of the first photomask and the second photomask, and the second mark pattern 102, the third mark pattern 103, the fifth mark pattern 202, and the sixth mark pattern 203 are used to further determine the offset or alignment of the first photomask and the second photomask. The first mark pattern 101, the second mark pattern 102, the third mark pattern 103, the fourth mark pattern 201, the fifth mark pattern 202, and the sixth mark pattern 203 can collectively and accurately determine the alignment or offset of the first photomask and the second photomask. Therefore, the overlay mark provided in the embodiments of the present disclosure can measure the offset of the first photomask and the second photomask.

[0068] In some embodiments, the symmetry axes of the first mark pattern 101 and the fourth mark pattern 201 respectively extend in the first direction or the second direction, and in a direction that is a preset angle to the first direction or the second direction.

[0069] In the embodiments of the present disclosure, the preset angle is related to the number of edges of the first mark pattern 101 and the fourth mark pattern 201. When the first mark pattern 101 and the fourth mark pattern 201 are n-gon, the preset angle is m times of (360 / n) degrees, where n is an even number greater than or equal to 8, and m is a positive integer less than (4 / n)+1. For example, when the first mark pattern 101 and the fourth mark pattern 201 are both similar octagons, the preset angle is 45° or 90°; when the first mark pattern 101 and the fourth mark pattern 201 are both similar decagons, the preset angle is 36°, 72° or 108°; when the first mark pattern 101 and the fourth mark pattern 201 are both similar dodecagons, the preset angle is 30°, 60° or 90°.

[0070] In some embodiments, the second mark pattern 102, the third mark pattern 103, the fifth mark pattern 202 and the sixth mark pattern 203 located at both ends of the symmetry axis in the preset angle direction are used to determine the offset of the first photomask and the second photomask in the preset angle direction.

[0071] For example, please continue to refer to Figure 2 In the embodiments of the present disclosure, the second mark pattern 102, the third mark pattern 103, the fifth mark pattern 202 and the sixth mark pattern 203 located at both ends of the symmetry axis in the direction of 45° with the Y-axis direction are used to determine the offset of the first photomask and the second photomask in the direction of 45° with the Y-axis direction.

[0072] In other embodiments, when the first mark pattern 101 and the fourth mark pattern 201 are decagons, the second mark pattern 102, the third mark pattern 103, the fifth mark pattern 202 and the sixth mark pattern 203 located at both ends of the symmetry axis in the direction of 36° with the Y-axis direction are used to determine the offset of the first photomask and the second photomask in the direction of 36° with the Y-axis direction. When the first mark pattern 101 and the fourth mark pattern 201 are dodecagons, the second mark pattern 102, the third mark pattern 103, the fifth mark pattern 202 and the sixth mark pattern 203 located at both ends of the symmetry axis in the direction of 30° with the Y-axis direction are used to determine the offset of the first photomask and the second photomask in the direction of 30° with the Y-axis direction.

[0073] In the embodiments of the present disclosure, by arranging the second mark pattern 102 and the third mark pattern 103 on both sides of the symmetry axis of the first mark pattern 101, and arranging the fifth mark pattern 202 and the sixth mark pattern 203 on both sides of the symmetry axis of the fourth mark pattern 201, that is, arranging the second mark pattern 102, the third mark pattern 103, the fifth mark pattern 202 and the sixth mark pattern 203 in different directions, the offset amount of the first photomask and the second photomask in different directions can be measured, and the accuracy of the offset amount measurement of the first photomask and the second photomask is improved.

[0074] It should be noted that when the offset amount of the first photomask and the second photomask is measured by the photolithography mark in the embodiments of the present disclosure, the offset amount in multiple different directions can be measured, and reasonable operation is performed to obtain the most accurate offset amount.

[0075] Figure 3 The structural schematic diagram of the second mark pattern and the fifth mark pattern provided in the embodiments of the present disclosure is shown in Figure 3 The second mark pattern includes a plurality of second sub-patterns 102a arranged at intervals along the Y-axis direction; each second sub-pattern 102a includes a first end c and a second end d along the X-axis direction; and a first virtual connection line b-b' formed by connecting the second ends d of the plurality of second sub-patterns 102a has a first included angle u with the Y-axis direction.

[0076] In some embodiments, please continue to refer to Figure 3 The fifth mark pattern 202 includes a plurality of fifth sub-patterns 202a arranged at intervals along the Y-axis direction; each fifth sub-pattern 202a includes a first end e and a second end f along the X-axis direction; and a second virtual connection line g-g' formed by connecting the first ends e of the plurality of fifth sub-patterns 202a has a second included angle v with the Y-axis direction.

[0077] In some embodiments, the first included angle u is equal to the second included angle v, and the first virtual connection line b-b' intersects with the second virtual connection line g-g'.

[0078] In some embodiments, each second sub-pattern 102a and the corresponding fifth sub-pattern 202a have a preset offset amount in the X-axis direction; the preset offset amount includes a positive offset amount, 0 and a negative offset amount, and the preset offset amount increases or decreases in turn along the Y-axis direction.

[0079] Please continue to refer to Figure 3 When the patterns in the stitching area of the first photomask and the second photomask have no offset, the second mark pattern 102 and the fifth mark pattern 202 present as Figure 3In the shown positional relationship, at this time, along the Y-axis direction from bottom to top (or from top to bottom), the offset amount of each second sub-pattern 102a and the corresponding fifth sub-pattern 202a in the X-axis direction is sequentially increased (or sequentially decreased), which is -1.3M, -1.2M, -1.1M, -M, 0, M, 1.1M, 1.2M and 1.3M respectively, wherein M is a pre-set value, for example, M can be 0.04-0.4 microns (μm). The second sub-pattern 102a and the fifth sub-pattern 202a are used to determine the offset amount of the first photomask and the second photomask in the X-axis direction.

[0080] Please continue to see Figure 3 When the offset amount of the second sub-pattern 102a and the corresponding fifth sub-pattern 202a in the X-axis direction is 0, it indicates that the second sub-pattern 102a and the fifth sub-pattern are in contact, that is, when the first photomask and the second photomask are not offset, the second sub-pattern 102a in the middle of the second mark pattern in the embodiment of the disclosure (that is, the fifth second sub-pattern along the Y-axis direction from bottom to top in the second mark pattern) is in contact with the fifth sub-pattern 202a in the middle of the fifth mark pattern (that is, the fifth fifth sub-pattern along the Y-axis direction from bottom to top in the fifth mark pattern). When the first photomask and the second photomask are used to form the overlay mark in the embodiment of the disclosure, if the second sub-pattern 102a in the middle is not in contact with the fifth sub-pattern 202a in the middle, it indicates that the first photomask and the second photomask have been offset. When the fourth second sub-pattern 102a along the Y-axis direction from bottom to top in the second mark pattern is in contact with the fourth fifth sub-pattern 202a along the Y-axis direction from bottom to top in the fifth mark pattern, it indicates that the offset amount of the first photomask and the second photomask in the X-axis direction is M. When the seventh second sub-pattern 102a along the Y-axis direction from bottom to top in the second mark pattern is in contact with the seventh fifth sub-pattern 202a along the Y-axis direction from bottom to top in the fifth mark pattern, it indicates that the offset amount of the first photomask and the second photomask in the X-axis direction is 1.1M.

[0081] Figure 4 The structural schematic diagram of the third mark pattern and the sixth mark pattern provided by the embodiment of the disclosure is shown. The third mark pattern includes a plurality of third sub-patterns 103a arranged at equal intervals along the Y-axis direction, and the adjacent third sub-patterns 103a have a first preset distance N. N is a pre-set value, for example, N can be 0.04-0.4 μm. The sixth mark pattern includes a plurality of sixth sub-patterns 203a arranged at intervals along the Y-axis direction, and the adjacent sixth sub-patterns 203a have a second preset distance.

[0082] The second preset distance is greater than the first preset distance N, and the second preset distance increases sequentially along the Y-axis at the same increment. For example, the second preset distance can be 1.1N, 1.2N, 1.3N, 1.4N, 1.5N, 1.6N, etc.

[0083] In this embodiment of the disclosure, a third sub-pattern 103a is aligned with a sixth sub-pattern 203a; the third sub-pattern 103a and the sixth sub-pattern 203a are used to determine the offset between the first photomask and the second photomask in the Y-axis direction.

[0084] Please continue reading Figure 4 When the first and second photomasks are not offset, the third marker pattern 103 and the sixth marker pattern 203 appear as follows: Figure 4 As shown in the positional relationship, the first third sub-pattern 103a from top to bottom along the Y-axis is in contact with the first sixth sub-pattern 203a, while the other third sub-patterns 103a and sixth sub-patterns 203a are staggered. When the overlay marks in this embodiment are formed using the first and second photomasks, if the first third sub-pattern 103a from top to bottom along the Y-axis is not in contact with the first sixth sub-pattern 203a, it indicates that the first and second photomasks have shifted. If the third third sub-pattern 103a from top to bottom along the Y-axis is in contact with the third sixth sub-pattern 203a, it indicates that the shift between the first and second photomasks along the Y-axis is 0.6N. If the sixth third sub-pattern 103a from top to bottom along the Y-axis is in contact with the sixth sixth sub-pattern 203a, it indicates that the shift between the first and second photomasks along the Y-axis is 2.1N.

[0085] The overlay markings provided in this embodiment make it easier to calculate the offset between the first and second photomasks at a 45° angle. Specifically, Figure 4 The third and sixth marker patterns are ideal shapes. Each third sub-pattern 103a in the third marker pattern and one sixth sub-pattern 203a in the sixth marker pattern are adjacent (i.e., in contact) but do not overlap, thus avoiding multiple exposures. When the first and second photomasks are offset in the X-axis direction, the third sub-pattern 103a and the sixth sub-pattern 203a will overlap, and the overlapping part will be repeatedly exposed, causing the pattern at the corresponding position of the overlay mark to become coarser. This will affect the reading and measurement of the offset in the Y-axis. In this case, using the second and fifth marker patterns located on both sides of the same axis of symmetry as the third and sixth marker patterns, as well as the second, third, fifth, and sixth marker patterns located on both sides of the axis of symmetry at 45° (or a preset angle), to further assist in the measurement can improve the accuracy of the offset detection of the first and second photomasks.

[0086] In some embodiments, the second, third, fifth, and sixth marker patterns are distributed on both sides of the axis of symmetry of the first and fourth marker patterns. This allows for the measurement of the offset in the direction of the axis of symmetry extension, thereby improving the measurement accuracy of the offset of the first and second photomasks.

[0087] This disclosure provides a semiconductor structure. Figure 5 This is a schematic diagram of the semiconductor structure provided in the embodiments of this disclosure, such as... Figure 5 As shown, the semiconductor structure 600 includes: an interposer 601, and overlay marks 100 located in the photolithographic stitching region of the interposer 601; the photolithographic stitching region includes a stitching region 601a of a first photomask and a second photomask; the overlay marks 100 include: a first mark 100a photolithographically formed using the first photomask, and a second mark 100b photolithographically formed using the second photomask; the first mark 100a includes at least a first mark pattern ( Figure 5 (not shown in the image), the second mark 100b includes at least a fourth mark pattern ( Figure 5 (not shown in the image); the first and fourth marking patterns are similar polygons, and the fourth marking pattern is located inside the first marking pattern; the polygon has at least eight sides.

[0088] In some embodiments, the first marking pattern includes at least eight first sub-patterns; the first marking pattern also includes a second marking pattern positioned along a first direction and a third marking pattern positioned along a second direction; the second marking pattern and the third marking pattern are respectively located outside each of the first sub-patterns, and a second marking pattern and a third marking pattern are respectively provided on both sides of each axis of symmetry of the first marking pattern.

[0089] In some embodiments, the fourth mark pattern includes at least eight fourth sub-patterns; the second mark also includes a fifth mark pattern positioned along a first direction and a sixth mark pattern positioned along a second direction; the fifth mark pattern and the sixth mark pattern are respectively located outside each fourth sub-pattern, and a fifth mark pattern and a sixth mark pattern are respectively provided on both sides of each axis of symmetry of the fourth mark pattern.

[0090] In some embodiments, both the fifth and sixth marking patterns are located outside the first marking pattern.

[0091] In some embodiments, the second marking pattern includes a plurality of second sub-patterns spaced apart along the second direction; each second sub-pattern includes a first end and a second end along the first direction; a first dummy connecting line formed by connecting the second ends of the plurality of second sub-patterns has a first angle with the second direction.

[0092] In some embodiments, the fifth mark pattern comprises a plurality of fifth sub-patterns arranged at intervals along the second direction; each fifth sub-pattern comprises a first end and a second end along the first direction; and a second dummy connection line formed by connecting the first ends of the plurality of fifth sub-patterns has a second included angle with the second direction.

[0093] In some embodiments, the first included angle is equal to the second included angle, and the first dummy connection line intersects the second dummy connection line.

[0094] It should be noted that, Figure 5 The detailed structure of the overlay mark 100 is not shown in

[0095] In some embodiments, please continue to refer to Figure 5 , the photolithography stitching area further comprises a stitching area 601b of the second photomask and the third photomask, and a stitching area 601c of the third photomask and the fourth photomask; the stitching area 601b of the second photomask and the third photomask, and the stitching area 601c of the third photomask and the fourth photomask all have the overlay mark 100.

[0096] In some embodiments, please continue to refer to Figure 5 , the overlay mark 100 is not located in the photolithography stitching area H common to the first photomask, the second photomask, the third photomask, and the fourth photomask.

[0097] In some embodiments, please continue to refer to Figure 5 , the width w1 of the photolithography stitching area 601a and the width w2 of the photolithography stitching area 601b can be the same or different, and the width of the photolithography stitching area 601a and the photolithography stitching area 601c is the same. The width w1 of the photolithography stitching area 601a and the width w2 of the photolithography stitching area 601b can be 5-50 μm, for example, 5 μm, 10 μm, 30 μm, or 50 μm.

[0098] The overlay mark in the embodiments of the present disclosure is similar to the overlay mark in the above-mentioned embodiments. For technical features not disclosed in detail in the embodiments of the present disclosure, please refer to the above-mentioned embodiments for understanding. Here, no further description is given.

[0099] In addition, the embodiments of the present disclosure also provide a photomask, Figure 6 The structure diagram of the photomask provided by the embodiments of the present disclosure is shown in Figure 6 The photomask 700 at least comprises: a first photomask 701 and a second photomask 702; wherein the first photomask 701 comprises a first mark 100a, and the second photomask 702 comprises a second mark 100b; the first mark 100a at least comprises a first mark pattern (not shown in Figure 6 ), and the second mark 100b at least comprises a fourth mark pattern (not shown inFigure 6 The first mark pattern and the fourth mark pattern are similar polygons, and a projection area of the fourth mark pattern in the third direction is located inside a projection area of the first mark pattern in the third direction; the polygon has at least eight sides; and the third direction is perpendicular to a plane in which the first photomask is located.

[0100] It should be noted that the first photomask and the second photomask in the embodiments of the present disclosure partially overlap, and the first mark and the second mark are both located in the overlapping area of the first photomask and the second photomask.

[0101] In some embodiments, the first mark further includes a second mark pattern positioned along the first direction and a third mark pattern positioned along the second direction; the second mark further includes a fifth mark pattern positioned along the first direction and a sixth mark pattern positioned along the second direction; a projection area of the second mark pattern along the third direction partially overlaps a projection area of the fifth mark pattern along the third direction; and a projection area of the third mark pattern along the third direction is contiguous with a projection area of the sixth mark pattern along the third direction.

[0102] It should be noted that the detailed structure of the first mark and the second mark is not shown in the embodiments of the present disclosure, and the specific structure of the first mark and the second mark can be understood with reference to the above embodiments.

[0103] In some embodiments, please continue to refer to Figure 6The photomask 700 further comprises a third photomask 703 partially coinciding with the second photomask 702, and a fourth photomask 704 partially coinciding with the third photomask 703 and the first photomask 701; the second photomask 702 further comprises the first mark 100a in the coinciding area of the second photomask 702 and the third photomask 703, the third photomask 703 further comprises the second mark 100b in the coinciding area of the second photomask 702 and the third photomask 703, and the first mark 100a in the coinciding area of the third photomask 703 and the fourth photomask 704, and the fourth photomask 704 further comprises the second mark 100b in the coinciding area of the third photomask 703 and the fourth photomask 704. The first mark 100a in the first photomask 701 and the second mark 100b in the second photomask 702 are used to measure the offset between the first photomask 701 and the second photomask 702, the first mark 100a in the second photomask 702 and the second mark 100b in the third photomask 703 are used to measure the offset between the second photomask 702 and the third photomask 703, and the first mark 100a in the third photomask 703 and the second mark 100b in the fourth photomask 704 are used to measure the offset between the third photomask 703 and the fourth photomask 704, so that the offset between the first photomask 701 and the fourth photomask 704 can also be obtained, and the alignment of the photomask in the embodiment of the present disclosure can be determined.

[0104] The photomask provided by the embodiment of the present disclosure comprises at least a first mark and a second mark in the coinciding area of a first photomask and a second photomask, and the first mark and the second mark can be used to measure the offset between the first photomask and the second photomask.

[0105] The above description is only some embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present disclosure, which should be covered in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A type of overprinted mark, characterized in that, The overlay markings include: a first marking formed using a first photomask, and a second marking formed using a second photomask, wherein the first marking and the second marking are located on the same horizontal plane; The first mark includes at least a first mark pattern, and the second mark includes at least a fourth mark pattern; the first mark pattern and the fourth mark pattern are similar polygons, and the fourth mark pattern is located inside the first mark pattern; the first mark also includes a second mark pattern positioned along a first direction and a third mark pattern positioned along a second direction, and the second mark also includes a fifth mark pattern positioned along the first direction and a sixth mark pattern positioned along the second direction; the axes of symmetry of the first mark pattern and the fourth mark pattern extend along the first direction, the second direction, and a direction at a preset angle to the first direction or the second direction; the second mark pattern, the third mark pattern, the fifth mark pattern, and the sixth mark pattern located at both ends of the axis of symmetry in the preset angle direction are used to determine the offset of the first photomask and the second photomask in the preset angle direction; When the similar polygon is an octagon, the preset angle is 45° or 90°; when the similar polygon is a decagon, the preset angle is 36°, 72° or 108°; when the similar polygon is a dodecagon, the preset angle is 30°, 60° or 90°.

2. The overprinting mark according to claim 1, characterized in that, The first marking pattern includes at least eight first sub-patterns; The second marking pattern and the third marking pattern are respectively located outside each of the first sub-patterns, and a second marking pattern and a third marking pattern are respectively provided on both sides of each axis of symmetry of the first marking pattern; the first direction is perpendicular to the second direction.

3. The overprinting mark according to claim 2, characterized in that, The fourth marking pattern includes at least eight fourth sub-patterns; The fifth and sixth marking patterns are located outside each of the fourth sub-patterns, and a fifth marking pattern and a sixth marking pattern are respectively provided on both sides of each axis of symmetry of the fourth marking pattern; Both the fifth and sixth marking patterns are located outside the first marking pattern.

4. The overprinting mark according to claim 1 or 3, characterized in that, The second marking pattern includes a plurality of second sub-patterns spaced apart along the second direction; each second sub-pattern includes a first end and a second end along the first direction; a first dummy connecting line formed by connecting the second ends of the plurality of second sub-patterns has a first angle with the second direction.

5. The overprinting mark according to claim 4, characterized in that, The fifth marking pattern includes a plurality of fifth sub-patterns spaced apart along the second direction; each fifth sub-pattern includes a first end and a second end along the first direction; a second dummy connecting line formed by connecting the first ends of the plurality of fifth sub-patterns has a second angle with the second direction; The first included angle is equal to the second included angle, and the first dummy connecting line intersects with the second dummy connecting line.

6. The overprinting mark according to claim 5, characterized in that, Each of the second sub-patterns and the corresponding fifth sub-patterns has a preset offset in the first direction; The preset offset includes positive offset, 0, and negative offset, and the preset offset increases or decreases sequentially along the second direction; The second sub-pattern and the fifth sub-pattern are used to determine the offset between the first photomask and the second photomask in the first direction.

7. The overlay mark according to claim 1 or 3, characterized in that, The third marking pattern includes a plurality of third sub-patterns arranged at equal intervals along the second direction, with a first preset distance between adjacent third sub-patterns; The sixth marking pattern includes a plurality of sixth sub-patterns arranged at intervals along the second direction, with a second preset distance between adjacent sixth sub-patterns; The second preset distance is greater than the first preset distance, and the second preset distance increases sequentially along the second direction with the same incremental distance.

8. The overprinting mark according to claim 7, characterized in that, One of the third sub-patterns is aligned with one of the sixth sub-patterns; The third sub-pattern and the sixth sub-pattern are used to determine the offset between the first photomask and the second photomask in the second direction.

9. A semiconductor structure, characterized in that, include: An interposer layer and overlay marks located in the photolithographic stitching region of the interposer layer; the photolithographic stitching region includes the stitching region of the first photomask and the second photomask; The overprint mark is the overprint mark as described in claim 1.

10. The semiconductor structure according to claim 9, characterized in that, The photolithography stitching area also includes the stitching area between the second photomask and the third photomask, and the stitching area between the third photomask and the fourth photomask; The overlay mark is present in the stitching area between the second photomask and the third photomask, and in the stitching area between the third photomask and the fourth photomask.

11. The semiconductor structure according to claim 10, characterized in that, The overlay mark is not located in the stitching area shared by the first photomask, the second photomask, the third photomask, and the fourth photomask.

12. A photomask, characterized in that, At least including: A first photomask and a second photomask; wherein the first photomask includes a first mark, and the second photomask includes a second mark; The first mark includes at least a first mark pattern, and the second mark includes at least a fourth mark pattern; the first mark pattern and the fourth mark pattern are similar polygons, and the projection area of ​​the fourth mark pattern in a third direction is located inside the projection area of ​​the first mark pattern in that third direction; the third direction is perpendicular to the plane where the first photomask is located. The first mark further includes a second mark pattern positioned along a first direction and a third mark pattern positioned along a second direction. The second mark further includes a fifth mark pattern positioned along the first direction and a sixth mark pattern positioned along the second direction. The axes of symmetry of the first mark pattern and the fourth mark pattern extend along the first direction, the second direction, and a direction at a preset angle to the first direction or the second direction. The second mark pattern, the third mark pattern, the fifth mark pattern, and the sixth mark pattern located at both ends of the axis of symmetry in the preset angle direction are used to determine the offset of the first photomask and the second photomask in the preset angle direction. When the similar polygon is an octagon, the preset angle is 45° or 90°; when the similar polygon is a decagon, the preset angle is 36°, 72° or 108°; when the similar polygon is a dodecagon, the preset angle is 30°, 60° or 90°.

13. The photomask according to claim 12, characterized in that, The projection area of ​​the second marking pattern along the third direction partially overlaps with the projection area of ​​the fifth marking pattern along the third direction; the projection area of ​​the third marking pattern along the third direction connects with the projection area of ​​the sixth marking pattern along the third direction.

14. The photomask according to claim 13, characterized in that, Also includes: A third photomask that partially overlaps with the second photomask, and a fourth photomask that partially overlaps with both the third photomask and the first photomask; The second photomask also includes a first mark located in the overlapping region of the second photomask and the third photomask; The third photomask includes a second mark located in the overlapping region of the second photomask and the third photomask, and a first mark located in the overlapping region of the third photomask and the fourth photomask; The fourth photomask includes a second mark located in the overlapping region of the third and fourth photomasks.

Images