Positioning marker group, mask group and photolithography method

Abstract

A positioning mark group, a mask group, and a photolithography method are disclosed. The positioning mark group includes: a first positioning mark, comprising: a first positioning pattern area and a first blank area; and a second positioning mark, comprising: a second positioning pattern area and a second blank area. When the first positioning mark and the second positioning mark are aligned, the first positioning pattern and the second positioning pattern are spliced ​​together, and the first positioning pattern area is aligned and overlapped with at least a portion of the second blank area, and the second positioning pattern area is aligned and overlapped with at least a portion of the first blank area. In the mask group of this invention, different masks are spliced ​​based on the positioning pattern and blank area of ​​the positioning pattern area. The position of the positioning marks in the positioning mark group on the mask can be freely set, which can overcome the limitations of the positioning mark's position on the mask, overcome the limitations of the exposure order, effectively reduce errors, facilitate the expansion of the process window, and help reduce process difficulty.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing, and in particular to a positioning mark set, a mask set, and a photolithography method. Background Technology

[0002] With the continuous development of integrated circuit manufacturing technology, people have increasingly higher requirements for the integration level and performance of integrated circuits. In order to improve integration level and reduce costs, the critical dimensions of components are constantly shrinking, and the circuit density inside integrated circuits is increasing.

[0003] In the process of integrated circuit manufacturing, photolithography is usually used to manufacture semiconductor devices. Through processes such as projection and development, the patterns on the mask are transferred to the semiconductor material, and through processes such as etching and deposition, components such as diodes, transistors, resistors, and capacitors and their interconnections are formed.

[0004] When fabricating chips larger than the maximum exposure area, photolithography using splicing masks is necessary. Multiple exposures are used to stitch together the pattern and complete the fabrication of the large-size chip. However, existing splicing mask sets have strict limitations on the placement of positioning markers on the masks; moreover, during photolithography, there are strict exposure sequence restrictions between different masks. Different positioning marker placements or exposure sequences may result in the positioning markers not being able to be stitched together, thus affecting subsequent processes. Summary of the Invention

[0005] The problem solved by this invention is how to overcome the limitations of the location setting of positioning marks and the limitations of exposure order, thereby reducing the difficulty of aligning stitching masks.

[0006] To address the above problems, the present invention provides a positioning marker set, comprising:

[0007] A first positioning mark is configured to be disposed on a first mask. The first positioning mark includes a first positioning graphic area and a first blank area. The first positioning graphic area has a first positioning graphic, and the first blank area does not have a graphic. A second positioning mark is configured to be disposed on a second mask. The second positioning mark includes a second positioning graphic area and a second blank area. The second positioning graphic area has a second positioning graphic, and the second blank area does not have a graphic. The first positioning mark and the second positioning mark are aligned to achieve the splicing of the graphic of the first mask and the graphic of the second mask. When the first positioning mark and the second positioning mark are aligned, the first positioning graphic and the second positioning graphic are spliced ​​together, and the first positioning graphic area is aligned and overlaps with at least a portion of the second blank area, and the second positioning graphic area is aligned and overlaps with at least a portion of the first blank area.

[0008] Optionally, different positioning markers are relatively accurate, and the corresponding positioning patterns do not overlap.

[0009] Optionally, the positioning graphic includes: an inner sub-graphic and an outer sub-graphic, wherein the inner sub-graphic is located between the outer sub-graphic and the blank area, and wherein the positioning graphic is one of a first positioning graphic and a second positioning graphic.

[0010] Optionally, the positioning markers include: positioning points, the positions of which are used to achieve positional alignment between the positioning markers; the positioning markers are one of a first positioning marker and a second positioning marker.

[0011] Optionally, the positioning point is the geometric center of the shape formed by the splicing of the first positioning shape and the second positioning shape.

[0012] Optionally, it further includes: a third positioning mark, the third positioning mark being configured to be disposed on a third mask, the third positioning mark including: a third positioning graphic area and a third blank area, the third positioning graphic area having a third positioning graphic, the third blank area not having a graphic; the first positioning mark, the second positioning mark and the third positioning mark being aligned to achieve the splicing of the graphics of the first mask, the graphics of the second mask and the graphics of the third mask; when the first positioning mark, the second positioning mark and the third positioning mark are aligned, the first positioning graphic, the second positioning graphic and the third positioning graphic are spliced ​​together, and the first positioning graphic area and the second positioning graphic area are aligned and overlapped with at least a portion of the third blank area, the second positioning graphic area and the third positioning graphic area are aligned and overlapped with at least a portion of the first blank area, and the third positioning graphic area and the first positioning graphic area are aligned and overlapped with at least a portion of the second blank area.

[0013] Optionally, it further includes: a fourth positioning mark, the fourth positioning mark being configured to be disposed on a fourth mask, the fourth positioning mark including: a fourth positioning graphic area and a fourth blank area, the fourth positioning graphic area having a fourth positioning graphic, the fourth blank area not having a graphic; the first positioning mark, the second positioning mark, the third positioning mark and the fourth positioning mark are aligned to achieve the splicing of the graphics of the first mask, the second mask, the third mask and the fourth mask; when the first positioning mark, the second positioning mark, the third positioning mark and the fourth positioning mark are aligned, the first positioning graphic, the second positioning graphic, the third positioning graphic and the fourth positioning graphic are spliced, and the first positioning graphic area, the second positioning graphic area and the third positioning graphic area are aligned and overlapped with the fourth blank area; the second positioning graphic area, the third positioning graphic area and the fourth positioning graphic area are aligned and overlapped with the first blank area; the third positioning graphic area, the fourth positioning graphic area and the first positioning graphic area are aligned and overlapped with the second blank area; the fourth positioning graphic area, the first positioning graphic area and the second positioning graphic area are aligned and overlapped with the third blank area.

[0014] Accordingly, the present invention also provides a mask assembly, comprising:

[0015] A first mask has a first group of positioning marks, which is the positioning mark group of the present invention; a second mask has a second group of positioning marks, which is the positioning mark group of the present invention; the distribution positions of the positioning marks in the first group of positioning marks correspond to the distribution positions of the positioning marks in the second group of positioning marks.

[0016] Optionally, the mask has a splicing area and a non-splicing area; a positioning mark is located in the splicing area, wherein the mask is one of the first mask and the second mask, and the positioning mark is a positioning mark on the mask.

[0017] Optionally, it also includes: a third mask, the third mask having a third positioning mark group, the third positioning mark group being the third positioning mark of the positioning mark group provided by the present invention; the distribution positions of the positioning marks in the first positioning mark group, the distribution positions of the positioning marks in the second positioning mark group and the distribution positions of the positioning marks in the third positioning mark group correspond to each other.

[0018] Optionally, it further includes: a fourth mask, the fourth mask having a fourth positioning mark group, the fourth positioning mark group being the fourth positioning mark of the positioning mark group provided by the present invention; the distribution positions of the positioning marks in the first positioning mark group, the second positioning mark group, the third positioning mark group, and the fourth positioning mark group correspond to each other.

[0019] Optionally, the positioning mark is located at the top corner of the mask, wherein the positioning mark is one of the first positioning mark, the second positioning mark, the third positioning mark and the fourth positioning mark, and the mask is a mask corresponding to the positioning mark.

[0020] Furthermore, the present invention also provides a photolithography method, wherein the photolithography method uses the mask set of the present invention to perform photolithography, comprising: providing a substrate having a material layer to be processed on the substrate; patterning the material layer to be processed using a first mask to form a first patterned layer; and patterning the first patterned layer using a second mask to form a second patterned layer.

[0021] Optionally, the step of using a second mask to graphically represent the first graphic layer includes: aligning the positioning points of the positioning marks in the second positioning mark group of the second mask according to their positions.

[0022] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0023] In the positioning mark group of the present invention, each positioning mark includes a positioning graphic area with a positioning graphic and a blank area without a graphic. When different positioning marks are aligned, the positioning graphics of different positioning marks are spliced ​​together, and the positioning graphic areas and blank areas of different positioning marks are at least partially aligned and overlapped. It can be seen that in the mask group of the present invention, different masks are spliced ​​based on the positioning graphics of the positioning graphic area and the blank area. The position of the positioning marks in the positioning mark group on the mask can be set freely, which can break through the limitation of the position of the positioning marks on the mask, break through the limitation of the exposure order, effectively reduce errors, facilitate the expansion of the process window, and help reduce the difficulty of the process. Attached Figure Description

[0024] Figure 1 It is a positioning mark for splicing mask groups;

[0025] Figure 2 This is a schematic diagram of a positioning mark caused by an incorrect exposure sequence;

[0026] Figure 3 This is a schematic diagram of the splicing of some embodiments of the positioning mark group of the present invention;

[0027] Figures 4 to 7 This is a schematic diagram of the structure of each positioning mark in some embodiments of the positioning mark group of the present invention;

[0028] Figure 8 This is a top view of one of the mask structures in some embodiments of the mask assembly of the present invention;

[0029] Figure 9 This is a schematic diagram of the structure of four masks spliced ​​together in some embodiments of the mask group of the present invention. Detailed Implementation

[0030] As is known from the background art, in existing technologies, there are strict exposure order restrictions on different masks in a stitching mask group. An incorrect exposure order will prevent the positioning marks from being stitched together. The following analysis examines the reasons for this exposure order restriction in the context of positioning marks in a stitching mask group:

[0031] Figure 1 A positioning mark for a splicing mask assembly is shown.

[0032] like Figure 1 As shown, the positioning mark group includes positioning mark 11, positioning mark 12, positioning mark 13, and positioning mark 14. Different positioning marks are connected by partial overlap (i.e.,...) Figure 1 Alignment is achieved by filling the intersecting lines in the middle. When positioning marks 11, 12, 13 and 14 are aligned, they are joined to form a cross-shaped graphic within the box.

[0033] Since different positioning marks in the positioning mark group are aligned by overlapping the positioning patterns themselves, there are strict restrictions on the formation order of the positioning marks during the photolithography process. The positioning marks of the mask used in the later patterning must have an overlapping part with the positioning marks of the mask used in the previous patterning. For example, after patterning with a mask with positioning mark 11, only a mask with positioning mark 12 or a mask with positioning mark 13 can be used for patterning.

[0034] If the positioning markers are set in different positions or the exposure order is different, the positioning markers may not be able to be stitched together. Figure 2 As shown, the placement of the positioning markers on the mask and the exposure order of different masks during the graphics process are strictly limited.

[0035] To address the aforementioned technical problems, this invention provides a positioning mark group. The positioning marks in the positioning mark group can be freely positioned, overcoming limitations on the placement of positioning marks on the mask and the exposure sequence, effectively reducing errors, facilitating the expansion of the process window, and reducing process difficulty.

[0036] 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.

[0037] refer to Figures 3 to 7 The diagram illustrates structural schematics of some embodiments of the positioning marker group of the present invention. Figure 3 This is a schematic diagram of the splicing of some embodiments of the positioning mark group of the present invention; Figures 4 to 7 This is a schematic diagram of the structure of each positioning mark in some embodiments of the positioning mark group of the present invention.

[0038] The positioning mark group includes: a first positioning mark 110, configured to be disposed on a first mask, the first positioning mark 110 including: a first positioning graphic area 111 and a first blank area 112, the first positioning graphic area 111 having a first positioning graphic, the first blank area 112 not having a graphic; and a second positioning mark 120, configured to be disposed on a second mask, the second positioning mark 120 including: a second positioning graphic area 121 and a second blank area 122, the second positioning graphic area 121 having a second positioning graphic, the second blank area 122 not having a graphic; the first positioning mark 110 and the second positioning mark 120 are aligned to achieve splicing of the graphic of the first mask and the graphic of the second mask; when the first positioning mark 110 and the second positioning mark 120 are aligned, the first positioning graphic and the second positioning graphic are spliced, and the first positioning graphic area 111 is aligned and overlapped with at least a portion of the second blank area 122, and the second positioning graphic area 121 is aligned and overlapped with at least a portion of the first blank area 112.

[0039] The technical solution of the positioning mark group embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] The first positioning mark 110 and the second positioning mark 120 are used to align with each other to achieve the splicing of the pattern of the first mask and the pattern of the second mask; the pattern spliced ​​by the first positioning mark 110 and the second positioning mark 120 is also used for positioning in subsequent processes.

[0041] like Figure 4 As shown, the first positioning mark 110 includes: a first positioning graphic area 111 with a first positioning graphic and a first blank area 112 without a graphic; as Figure 5 As shown, the second positioning mark 120 includes: a second positioning graphic area 121 with a second positioning graphic and a second blank area 122 without a graphic.

[0042] It should be noted that, Figure 4In the embodiment shown, the first positioning graphic area 111 is shown with a red dashed box, and the first blank area 112 is shown with a blue dashed box; Figure 5 In the embodiment shown, the second positioning graphic area 121 is shown with a red dashed box, and the second blank area 122 is shown with a blue dashed box.

[0043] When the first positioning mark 110 and the second positioning mark 120 are aligned, the first positioning graphic area 111 is aligned and overlaps with at least a portion of the second blank area 122, and the second positioning graphic area 121 is aligned and overlaps with at least a portion of the first blank area 112.

[0044] The alignment and overlap of the positioning graphic and the blank area refers to the fact that when different positioning marks are aligned, the positioning graphic area of ​​different positioning marks partially overlaps with the range of the blank area, and part of the edge of the positioning graphic area coincides with part of the edge of the blank area.

[0045] Specifically, when the first positioning mark 110 and the second positioning mark 120 are aligned, the first positioning graphic and the second positioning graphic are joined together. The first positioning graphic area 111 is aligned and overlaps with a portion of the second blank area 122, and the second positioning graphic area 121 is aligned and overlaps with a portion of the first blank area 112.

[0046] The splicing range of the first positioning graphic area 111 and the first blank area 112 has the same shape and size as the splicing range of the second positioning graphic area 121 and the second blank area 122. When the first positioning mark 110 and the second positioning mark 120 are aligned, the range of the first positioning graphic area 111 and the first blank area 112 completely overlaps with the range of the second positioning graphic area 121 and the second blank area 122; in the same plane, the projection of the first positioning graphic area 111 is located within the projection range of the second blank area 122, and a portion of the edge of the projection of the first positioning graphic area 111 coincides with a portion of the edge of the projection of the second blank area 122; in the same plane, the projection of the second positioning graphic area 121 is located within the projection range of the first blank area 112, and a portion of the edge of the projection of the second positioning graphic area 121 coincides with a portion of the edge of the projection of the first blank area 112.

[0047] In some embodiments of the present invention, the positioning mark group further includes: a third positioning mark 130, the third positioning mark 130 being configured to be disposed on a third mask, the third positioning mark 130 including: a third positioning graphic area 131 and a third blank area 132, the third positioning graphic area 131 having a third positioning graphic, and the third blank area 132 not having a graphic.

[0048] The third positioning mark 130 is used to align with the first positioning mark 110 and the second positioning mark 120 to achieve the splicing of the graphics of the first mask, the second mask, and the third mask. For example... Figure 6 As shown, the third positioning mark 130 includes: a third positioning graphic area 131 with a third positioning graphic and a third blank area 132 without a graphic. Figure 6 In the embodiment shown, the third positioning graphic area 131 is shown with a red dashed box, and the third blank area 132 is shown with a blue dashed box.

[0049] When the third positioning mark 130 is aligned with the first positioning mark 110 and the second positioning mark 120, the third positioning graphic area 131 is aligned and overlapped with a portion of the first blank area 112 and a portion of the second blank area 122, respectively. Moreover, the portions of the third positioning graphic area 131 that are aligned and overlapped with the first blank area 112 and the second blank area 122 do not coincide.

[0050] The splicing ranges of the first positioning graphic area 111 and the first blank area 112, the splicing ranges of the second positioning graphic area 121 and the second blank area 122, and the splicing ranges of the third positioning graphic area 131 and the third blank area 132 have the same shape and equal size. When the first positioning mark 110, the second positioning mark 120, and the third positioning mark 130 are aligned, the ranges of the first positioning graphic area 111 and the first blank area 112, the ranges of the second positioning graphic area 121 and the second blank area 122, and the ranges of the third positioning graphic area 131 and the third blank area 132 completely overlap. Within the same plane, the projection of the third positioning graphic area 131 is located within the projection range of the first blank area 112, and a portion of the edge of the projection of the third positioning graphic area 131 coincides with a portion of the edge of the projection of the first blank area 112; within the same plane, the projection of the third positioning graphic area 131 is located within the projection range of the second blank area 122, and a portion of the edge of the projection of the third positioning graphic area 131 coincides with another portion of the edge of the projection of the second blank area 122.

[0051] In some embodiments, the positioning mark group further includes a fourth positioning mark 140, which is configured to be disposed on a fourth mask. The fourth positioning mark 140 includes a fourth positioning graphic area 141 and a fourth blank area 142, wherein the fourth positioning graphic area 141 has a fourth positioning graphic, and the fourth blank area 142 does not have a graphic.

[0052] The fourth positioning mark 140 is used to align with the first positioning mark 110, the second positioning mark 120, and the third positioning mark 130 to achieve the splicing of the graphics of the first mask, the second mask, the third mask, and the fourth mask. For example... Figure 7 As shown, the fourth positioning mark 140 includes: a fourth positioning graphic area 141 with a fourth positioning graphic and a fourth blank area 142 without a graphic. Figure 7 In the embodiment shown, the fourth positioning graphic area 141 is shown with a red dashed box, and the fourth blank area 142 is shown with a blue dashed box.

[0053] When the fourth positioning mark 140 is aligned with the first positioning mark 110, the second positioning mark 120, and the third positioning mark 130, the fourth positioning graphic area 141 is aligned and overlapped with portions of the first blank area 112, the second blank area 122, and the third positioning graphic area 131, respectively. Furthermore, the portions of the fourth positioning graphic area 131 that are aligned and overlapped with the first blank area 112, the second blank area 122, and the third blank area 132 do not coincide.

[0054] The splicing ranges of the first positioning graphic area 111 and the first blank area 112, the splicing ranges of the second positioning graphic area 121 and the second blank area 122, the splicing ranges of the third positioning graphic area 131 and the third blank area 132, and the splicing ranges of the fourth positioning graphic area 141 and the fourth blank area 142 have the same shape and the same size.

[0055] When the first positioning mark 110, the second positioning mark 120, the third positioning mark 130 and the fourth positioning mark 140 are aligned, the ranges of the first positioning graphic area 111 and the first blank area 112, the ranges of the second positioning graphic area 121 and the second blank area 122, the ranges of the third positioning graphic area 131 and the third blank area 132, and the ranges of the fourth positioning graphic area 141 and the fourth blank area 142 completely overlap.

[0056] The projection of the fourth positioning graphic area 141 is located within the projection range of the first blank area 112, and a portion of the edge of the projection of the fourth positioning graphic area 141 coincides with a portion of the edge of the projection of the first blank area 112; within the same plane, the projection of the fourth positioning graphic area 141 is located within the projection range of the second blank area 122, and a portion of the edge of the projection of the fourth positioning graphic area 141 coincides with a portion of the edge of the projection of the second blank area 122; within the same plane, the projection of the fourth positioning graphic area 141 is located within the projection range of the third blank area 132, and a portion of the edge of the projection of the fourth positioning graphic area 141 coincides with a portion of the edge of the projection of the third blank area 132.

[0057] like Figures 3 to 7 In some embodiments shown, the positioning mark group is used to stitch together 2×2 masks. The four positioning marks of the positioning mark group are stitched together in a 2×2 array. The positioning graphic area of ​​each positioning mark occupies 1 / 4 of the positioning mark, and the blank area occupies the remaining 3 / 4 of the corresponding positioning mark.

[0058] In some embodiments of the present invention, the positioning graphic includes an inner sub-graphic and an outer sub-graphic, wherein the inner sub-graphic is located between the outer sub-graphic and a blank area, and wherein the positioning graphic is one of a first positioning graphic and a second positioning graphic.

[0059] The positioning marks are relatively accurate, and the graphics formed by splicing the positioning graphics have an outer border and an inner pattern, wherein the outer border surrounds the inner pattern. The inner sub-graphics of different positioning graphics are spliced ​​together to form the inner pattern, and the outer sub-graphics of different positioning graphics are spliced ​​together to form the outer border.

[0060] In some embodiments, the positioning mark group further includes a third positioning pattern and a fourth positioning pattern; the positioning pattern is one of the first positioning pattern, the second positioning pattern, the third positioning pattern, and the fourth positioning pattern.

[0061] Specifically, such as Figures 3 to 7 In some embodiments shown, the outer border of the graphic formed by assembling the positioning graphics is a rectangle, and the inner pattern is a cross shape. The inner sub-graphics of each positioning graphic are smaller L-shaped, and the outer sub-graphics of each positioning graphic are also larger L-shaped. The vertex directions of the corners of the inner sub-graphics and the corner directions of the outer sub-graphics are respectively along the opposite directions of the diagonal of the positioning graphic area.

[0062] In some embodiments of the present invention, different positioning marks are aligned relative to each other, and the corresponding positioning patterns do not overlap. Different positioning marks are aligned through the positioning pattern area and the blank area, avoiding the use of overlapping positioning patterns for alignment. This can overcome the limitations of the alignment process on the order of positioning pattern formation, the limitations of the positioning mark placement on the mask, and the limitations of the exposure order, effectively reducing errors, facilitating the expansion of the process window, and reducing process difficulty.

[0063] Specifically, such as Figure 3 As shown, when the first positioning mark 110, the second positioning mark 120, the third positioning mark 130, and the fourth positioning mark 140 are aligned, the boundaries of the first positioning graphic in the first positioning graphic area of ​​the first positioning mark 110, the second positioning graphic in the second positioning graphic area of ​​the second positioning mark 120, the third positioning graphic in the third positioning graphic area of ​​the third positioning mark 130, and the fourth positioning graphic in the fourth positioning graphic area of ​​the fourth positioning mark 140 coincide but do not overlap.

[0064] It should be noted that, Figure 3 In the illustrated embodiment, the second positioning mark 120, the third positioning mark 130, and the fourth positioning mark 140, which are spliced ​​with the first positioning mark 110, are shown in red dashed lines.

[0065] In some embodiments of the present invention, the positioning mark includes: a positioning point, the position of which is used to achieve position alignment between positioning marks; the positioning mark is one of a first positioning mark 110 and a second positioning mark 120.

[0066] In some embodiments, the positioning mark group further includes a third positioning pattern and a fourth positioning pattern; the positioning pattern is one of the first positioning pattern, the second positioning pattern, the third positioning pattern, and the fourth positioning pattern.

[0067] The positioning points are used to determine the location of the positioning markers and to align the images during the stitching process of different masks.

[0068] In some embodiments, the positioning point is the geometric center of the graphic formed by splicing the first positioning graphic and the second positioning graphic. Setting the geometric center of the spliced ​​graphic as the positioning point can make the distribution of positioning graphics in different positioning marks more uniform, effectively reducing the alignment difficulty and improving the alignment accuracy during the splicing process.

[0069] It should be noted that, Figures 3 to 7 In the illustrated embodiment, the positioning point is shown as a dot filled with red lines on a black background.

[0070] Accordingly, the present invention also provides a mask assembly.

[0071] refer to Figure 8 and Figure 9 ,in Figure 8 A top view of one of the masks in some embodiments of the mask assembly of the present invention is shown; Figure 9 A schematic diagram of the structure of four masks spliced ​​together in some embodiments of the mask group of the present invention is shown.

[0072] The mask group includes: a first mask 201, the first mask 201 having a first positioning mark group, the first positioning mark group being the positioning mark group of the present invention; and a second mask 202, the second mask 202 having a second positioning mark group, the second positioning mark group being the positioning mark group of the present invention; the distribution positions of the positioning marks in the first positioning mark group correspond to the distribution positions of the positioning marks in the second positioning mark group.

[0073] The consistent distribution of positioning marks in different positioning mark groups means that in positioning mark groups of different masks, the same positioning marks are located in the same position on the mask.

[0074] In some embodiments of the present invention, the mask group further includes a third mask 203, the third mask 203 having a third positioning mark group, the third positioning mark group being the positioning mark group of the present invention. The distribution positions of the positioning marks in the first positioning mark group, the distribution positions of the positioning marks in the second positioning mark group, and the distribution positions of the positioning marks in the third positioning mark group correspond to each other.

[0075] In some embodiments, the mask group further includes a fourth mask 204, the fourth mask 204 having a fourth positioning mark group, the fourth positioning mark group being the positioning mark group of the present invention; the distribution positions of the positioning marks in the first positioning mark group, the distribution positions of the positioning marks in the second positioning mark group, the distribution positions of the positioning marks in the third positioning mark group, and the distribution positions of the positioning marks in the fourth positioning mark group correspond to each other.

[0076] Specifically, such as Figure 8 and Figure 9 In some embodiments shown, the first positioning mark of all positioning mark groups is set at the same position on the mask; the second positioning mark of all positioning mark groups is set at the same position on the mask; the third positioning mark of all positioning mark groups is set at the same position on the mask; and the fourth positioning mark of all positioning mark groups is set at the same position on the mask. However, the positions of different positioning marks on the same mask and within the same positioning mark group are not limited, thus breaking through the limitation on the position of positioning marks on the mask.

[0077] In some embodiments of the present invention, the mask has a splicing area 201a and a non-splicing area 201b; a positioning mark is located in the splicing area 201a, wherein the mask is one of the first mask 201 and the second mask 202, and the positioning mark is the positioning mark corresponding to the mask.

[0078] In some embodiments, the mask group further includes a third mask and a fourth mask; the mask is one of the first mask, the second mask, the third mask, and the fourth mask. Specifically, as shown... Figure 8 and Figure 9 As shown, the positioning marks of the first positioning mark group are located in the splicing area of ​​the first mask 201; the positioning marks of the second positioning mark group are located in the splicing area of ​​the second mask 202; the positioning marks of the third positioning mark group are located in the splicing area of ​​the third mask 203; and the positioning marks of the fourth positioning mark group are located in the splicing area of ​​the fourth mask 204.

[0079] In some embodiments, the positioning marks are located at the apex corners of the mask, wherein the positioning mark is one of the first positioning mark, the second positioning mark, the third positioning mark, and the fourth positioning mark, and the mask is a mask corresponding to the positioning mark. Specifically, in the mask group, the first mask, the second mask, the third mask, and the fourth mask are arranged in a 2×2 array; in each mask, the splicing area surrounds the non-splicing area. The four positioning marks in each positioning mark group are respectively located at the four apex corners of the mask.

[0080] It should be noted that, Figure 8 In some embodiments shown, the first mask 201 is used as an example for illustration. In the first mask 201, the non-splicing area is shown with a dashed box, and the annular splicing area surrounds the non-splicing area.

[0081] It should also be noted that, Figure 9 In some of the embodiments shown, different masks are shown with different fill patterns. Specifically, the first mask 201 is shown with a solid red fill; the second mask 202 and the third mask 203 are shown with diagonal lines in different directions; and the fourth mask 204 is shown with a solid white fill.

[0082] Accordingly, the present invention also provides a photolithography method, wherein the photolithography method uses the mask set of the present invention for photolithography.

[0083] The photoresist method includes: providing a substrate having a material layer to be processed on the substrate; patterning the material layer to be processed using a first mask to form a first patterned layer; and patterning the first patterned layer using a second mask to form a second patterned layer.

[0084] The positioning marks in the mask group can be set freely, which can break through the limitation of the positioning marks on the mask and the limitation of the exposure order, effectively reducing errors. The photolithography method has a larger process window and lower process difficulty.

[0085] In some embodiments of the present invention, the step of using a second mask to pattern the first pattern layer includes: aligning the positioning points of the positioning marks in the second positioning mark group of the second mask according to their positions.

[0086] Specifically, in the step of using a first mask to pattern the material layer to be processed, the first positioning pattern is transferred to the material layer to be processed to form a first positioning pattern, and the first positioning pattern has a first fixed point.

[0087] In the step of aligning according to the position of the positioning point of the positioning mark in the second positioning mark group of the second mask, the position of the positioning point of the positioning mark in the second positioning mark group of the second mask is determined according to the position of the first fixed point for graphical representation.

[0088] Specifically, in the step of determining the position of the positioning point of the positioning mark in the second positioning mark group of the second mask based on the position of the first fixed point, the coordinates of the positioning point of the positioning mark in the second positioning mark group of the second mask are set according to the coordinates of the first fixed point. For example, in the step of setting the coordinates of the positioning point of the positioning mark in the second positioning mark group of the second mask, the coordinates of the positioning point of the positioning mark in the second positioning mark group of the second mask can be set to be the same as the coordinates of the first fixed point.

[0089] In summary, each positioning mark includes a positioning graphic area with a positioning graphic and a blank area without a graphic. When different positioning marks are aligned, the positioning graphics of different positioning marks are spliced ​​together, and the positioning graphic areas and blank areas of different positioning marks are at least partially aligned and overlapped. It can be seen that in the mask group of the present invention, different masks are spliced ​​based on the positioning graphics of the positioning graphic area and the blank area. The position of the positioning marks in the positioning mark group on the mask can be set freely, which can break through the limitation of the position of the positioning marks on the mask, break through the limitation of the exposure order, effectively reduce errors, facilitate the expansion of the process window, and help reduce the difficulty of the process.

[0090] 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 positioning marker set, characterized in that, include: A first positioning mark is configured to be set on a first mask. The first positioning mark includes: a first positioning graphic area and a first blank area. The first positioning graphic area has a first positioning graphic, and the first blank area does not have a graphic. The second positioning mark is configured to be set on the second mask. The second positioning mark includes: a second positioning graphic area and a second blank area. The second positioning graphic area has a second positioning graphic, and the second blank area does not have a graphic. The first positioning mark and the second positioning mark are aligned to achieve the splicing of the pattern of the first mask and the pattern of the second mask; When the first positioning mark and the second positioning mark are aligned, the first positioning graphic and the second positioning graphic are spliced ​​together, and the first positioning graphic area is aligned and overlapped with at least a portion of the second blank area, and the second positioning graphic area is aligned and overlapped with at least a portion of the first blank area; When different positioning marks are relatively accurate, the corresponding positioning graphics only overlap at the edges and do not overlap with each other.

2. The positioning marker group as described in claim 1, characterized in that, The positioning graphic includes an inner sub-graphic and an outer sub-graphic, wherein the inner sub-graphic is located between the outer sub-graphic and the blank area, and wherein the positioning graphic is one of a first positioning graphic and a second positioning graphic.

3. The positioning marker group as described in claim 1, characterized in that, The positioning markers include: positioning points, the positions of which are used to achieve alignment between positioning markers; the positioning marker is one of a first positioning marker and a second positioning marker.

4. The positioning marker group as described in claim 3, characterized in that, The positioning point is the geometric center of the graphic formed by splicing the first positioning graphic and the second positioning graphic.

5. The positioning marker group as described in claim 1, characterized in that, Also includes: The third positioning mark is configured to be set on the third mask. The third positioning mark includes a third positioning graphic area and a third blank area. The third positioning graphic area has a third positioning graphic, and the third blank area does not have a graphic. The first positioning mark, the second positioning mark, and the third positioning mark are aligned to achieve the splicing of the graphics of the first mask, the second mask, and the third mask; When the first positioning mark, the second positioning mark, and the third positioning mark are aligned, the first positioning graphic, the second positioning graphic, and the third positioning graphic are spliced ​​together, and the first positioning graphic area and the second positioning graphic area are aligned and overlapped with at least a portion of the third blank area, the second positioning graphic area and the third positioning graphic area are aligned and overlapped with at least a portion of the first blank area, and the third positioning graphic area and the first positioning graphic area are aligned and overlapped with at least a portion of the second blank area.

6. The positioning marker group as described in claim 5, characterized in that, Also includes: The fourth positioning mark is configured to be set on the fourth mask. The fourth positioning mark includes: a fourth positioning graphic area and a fourth blank area. The fourth positioning graphic area has a fourth positioning graphic, and the fourth blank area does not have a graphic. The first positioning mark, the second positioning mark, the third positioning mark, and the fourth positioning mark are aligned to achieve the splicing of the graphics of the first mask, the second mask, the third mask, and the fourth mask; When the first positioning mark, the second positioning mark, the third positioning mark, and the fourth positioning mark are aligned, the first positioning graphic, the second positioning graphic, the third positioning graphic, and the fourth positioning graphic are joined together, and the first positioning graphic area, the second positioning graphic area, and the third positioning graphic area are aligned and overlapped with the fourth blank area; the second positioning graphic area, the third positioning graphic area, and the fourth positioning graphic area are aligned and overlapped with the first blank area; the third positioning graphic area, the fourth positioning graphic area, and the first positioning graphic area are aligned and overlapped with the second blank area; and the fourth positioning graphic area, the first positioning graphic area, and the second positioning graphic area are aligned and overlapped with the third blank area.

7. A mask assembly, characterized in that, A first mask, the first mask having a first positioning mark group, the first positioning mark group as described in any one of claims 1 to 4; A second mask, the second mask having a second positioning mark group as described in any one of claims 1 to 4; The distribution positions of the positioning marks in the first positioning mark group correspond to the distribution positions of the positioning marks in the second positioning mark group.

8. The mask assembly as claimed in claim 7, characterized in that, The mask has a splicing area and a non-splicing area; a positioning mark is located in the splicing area, wherein the mask is one of the first mask and the second mask, and the positioning mark is a positioning mark on the mask.

9. The mask assembly as claimed in claim 7, characterized in that, Also includes: A third mask, wherein the third mask has a third positioning mark group as described in claim 5; The distribution positions of the positioning marks in the first positioning mark group, the second positioning mark group, and the third positioning mark group correspond to each other.

10. The mask assembly as claimed in claim 9, characterized in that, Also includes: A fourth mask, wherein the fourth mask has a fourth positioning mark group as described in claim 6; The distribution positions of the positioning marks in the first positioning mark group, the second positioning mark group, the third positioning mark group, and the fourth positioning mark group correspond to each other.

11. The mask assembly as claimed in claim 10, characterized in that, The positioning mark is located at the top corner of the mask, wherein the positioning mark is one of the first positioning mark, the second positioning mark, the third positioning mark and the fourth positioning mark, and the mask is the mask corresponding to the positioning mark.

12. A photolithography method, characterized in that, The photolithography method uses the mask set according to any one of claims 7 to 11 for photolithography, including: A substrate is provided, on which a layer of material to be processed is disposed; The material layer to be processed is patterned using a first mask to form a first patterned layer; The first graphic layer is patterned using a second mask to form a second graphic layer.

13. The photolithography method as described in claim 12, characterized in that, The steps of using a second mask to graphically represent the first graphics layer include: Alignment is performed based on the position of the positioning point of the positioning mark in the second positioning mark group of the second mask.

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