CN116449644A - Photomask, photomask set and patterning method - Google Patents

Abstract

The disclosure provides a photomask, a photomask set, and a patterning method. The photomask includes: a plurality of first strip graphics extending along the first direction and a plurality of first auxiliary graphics arranged at intervals along the first direction; the first strip graphics and the The first auxiliary graphics are overlapped and arranged along the first direction, the first auxiliary graphics and the first bar graphics have an overlapping area, and at the edge of the overlapping area, the first auxiliary graphics have The protruding portion covered by the first strip pattern. In the above technical solution, by setting the first auxiliary figure, the first protruding portion is formed on the edge of the first strip figure. By changing the size and shape of the first protruding portion, the shape of the photomask is changed to obtain a photomask with an ideal length ratio between the horizontal direction and the vertical direction.

Description

Reticle, Reticle Set, and Patterning Method

technical field

Embodiments of the present disclosure relate to the field of semiconductor manufacturing, and in particular, to a photomask, a photomask set, and a patterning method.

Background technique

With the continuous development of the semiconductor field, there are higher requirements for the high speed, high integration density and low power consumption of the dynamic memory. Fabrication of contact hole arrays formed by photolithography and etching is a very important technique.

As contact hole size shrinks and array density increases, contact hole patterns are generated on wafers by applying a lithography-etch-lithography-etch approach. For bit line contact holes, the use of this patterning process is limited Due to the size of the active region structure in the dynamic memory, it is impossible to obtain a pattern with an ideal length ratio between the horizontal and vertical etching.

Contents of the invention

The technical problem to be solved in this application is to provide a photomask, a photomask set, and a patterning method, so as to obtain a pattern with an ideal length ratio between the horizontal and vertical etching.

In order to solve the above problems, an embodiment of the present disclosure provides a photomask, including: a plurality of first strip patterns arranged extending along the first direction and a plurality of first auxiliary patterns arranged at intervals along the first direction ; The first bar graphics and the first auxiliary graphics are overlapped and arranged along the first direction, the first auxiliary graphics and the first bar graphics have an overlapping area, and in the overlapping area On the edge, the first auxiliary figure has a protruding part not covered by the first bar figure.

In some embodiments, the photomask includes: the protruding portion includes at least two protruding sub-portions arranged on different sides of the overlapping region.

In some embodiments, the protruding sub-sections are located on opposite sides of the overlapping region.

In some embodiments, the protrusion is polygonal.

In some embodiments, the length of the shortest side of the protruding sub-portion is in the range of 5-10 nm, and the angle between the longest side of the protruding sub-portion and the edge of the overlapping region is in the range of 10-20°.

In some embodiments, the protrusion is polygonal.

An embodiment of the present disclosure also provides a photomask group, including: a first photomask, the first photomask has a plurality of first striped patterns extending along the first direction and a plurality of strip patterns along the first The first auxiliary graphics arranged at intervals in the direction; wherein, the first strip graphics and the first auxiliary graphics are arranged overlapping along the first direction, and the first auxiliary graphics and the first strip graphics The figure has a first overlapping area, and at the edge of the first overlapping area, the first auxiliary figure has a first protruding portion not covered by the first strip figure; a second mask, the second light The cover has a plurality of second striped graphics extending along the second direction and a plurality of second auxiliary graphics arranged at intervals along the second direction; wherein, the second striped graphics and the second auxiliary graphics The graphics are arranged overlappingly along the second direction, the second auxiliary graphics and the second bar graphics have a second overlapping area, and at the edge of the second overlapping area, the second auxiliary graphics have The second protruding part covered by the second strip pattern; during exposure, the first photomask and the second photomask are respectively placed along the first direction and the second direction, and the first The overlapping area and the second overlapping area overlap to form a target overlapping area, and the first protrusion, the second protrusion, the first overlapping area and the second overlapping area overlap to form a target pattern.

In some embodiments, the target pattern includes a critical dimension in the X direction and a critical dimension in the Y direction, the X direction and the Y direction are perpendicular, and the length of the critical dimension in the X direction and the critical dimension in the Y direction is given by The shape and size of the first protrusion, the second protrusion, the first overlapping area, and the second overlapping area are determined, and the ratio of the length of the critical dimension in the X direction to the length of the critical dimension in the Y direction is greater than 1.05.

In some embodiments, the first protrusions and the second protrusions are center-symmetrically distributed along the target overlapping area.

In some embodiments, the first protrusion and the second protrusion are polygonal.

In some embodiments, the length of the shortest side of the first protrusion and the second protrusion is in the range of 5-10 nm, and the angle range between the longest side of the protrusion and the edge of the target overlapping area is 10-20°.

An embodiment of the present disclosure also provides a patterning method, including: providing a photomask set, the photomask set including: a first photomask, the first photomask has a plurality of first photomasks extending along the first direction a bar-shaped figure and a plurality of first auxiliary figures arranged at intervals along the first direction; wherein, the first bar-shaped figure and the first auxiliary figures are arranged overlappingly along the first direction, so The first auxiliary graphic and the first bar graphic have a first overlapping area, and at the edge of the first overlapping area, the first auxiliary graphic has a first protrusion not covered by the first bar graphic part; a second photomask, the second photomask has a plurality of second striped patterns extending along the second direction and a plurality of second auxiliary patterns arranged at intervals along the second direction; wherein, the The second bar graphics and the second auxiliary graphics are arranged overlappingly along the second direction, the second auxiliary graphics and the second bar graphics have a second overlapping area, and in the second overlapping the edge of the region, the second auxiliary pattern has a second protruding portion not covered by the second strip pattern; when exposing, the first mask and the second mask are respectively along the first direction placed in the second direction, the first overlapping area and the second overlapping area are overlapped to form a target overlapping area, the first protrusion, the second protrusion, the first overlapping area and the The second overlapping region is overlapped to form a target pattern; a substrate is provided, and a mask layer is formed on the substrate; the mask layer is exposed by the photomask group, and the target is formed on the mask layer pattern.

In some embodiments, the mask layer includes a first sub-mask layer and a second sub-mask layer, the mask layer is exposed with the mask set, and the target is formed on the mask layer The step of patterning includes: forming a first sub-mask layer on the substrate, exposing the first sub-mask layer with the first photomask, forming a first target in the first sub-mask layer pattern; form a second sub-mask layer on the first sub-mask layer, expose the second sub-mask layer with the second photomask, and form a second sub-mask layer in the second sub-mask layer Target pattern: transferring the second target pattern into the first sub-mask layer, forming the target pattern in the first sub-mask layer.

In some embodiments, the target pattern includes a critical dimension in the X direction and a critical dimension in the Y direction, and the X direction and the Y direction are perpendicular to each other. By adjusting the first protrusion, the second protrusion, and the first overlapping area , and the shape and size of the second overlapping area to change the size and shape of the target graphic, the ratio of the length of the critical dimension in the X direction to the length of the critical dimension in the Y direction is greater than 1.05.

In some embodiments, the first protrusions and the second protrusions are center-symmetrically distributed along the target overlapping area.

In some embodiments, the first protrusion and the second protrusion are polygonal.

In some embodiments, the length of the shortest side of the first protrusion and the second protrusion is in the range of 5-10 nm, and the longest side of the first protrusion and the second protrusion overlaps with the target The angle range of the edge is 10-20°.

In the above technical solution, by setting the first auxiliary figure, the first protruding portion is formed on the edge of the first strip figure. By changing the size and shape of the first protruding portion, the shape of the photomask is changed to obtain a photomask with an ideal length ratio between the horizontal direction and the vertical direction.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. Techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods and devices should be considered part of the Authorized Specification.

Description of drawings

FIG. 1 is a schematic diagram of a photomask in an embodiment of the present disclosure.

FIG. 2 is a schematic diagram of a photomask in another embodiment of the present disclosure.

FIG. 3 is a schematic diagram of a mask set in an embodiment of the present disclosure.

FIG. 4 is a schematic diagram of a first mask a in an embodiment of the present disclosure.

FIG. 5 is a schematic diagram of a second mask b in an embodiment of the present disclosure.

FIG. 6 is a schematic diagram of a target pattern in an embodiment of the present disclosure.

FIG. 7 is a schematic diagram of a graphing method in an embodiment of the present disclosure.

FIG. 8 is a schematic diagram of a graphing method in an embodiment of the present disclosure.

FIG. 9 is a schematic diagram of a graphing method in an embodiment of the present disclosure.

FIG. 10 is a schematic diagram of a graphing method in another embodiment of the present disclosure.

FIG. 11 is a schematic diagram of a graphing method in another embodiment of the present disclosure.

FIG. 12 is a schematic diagram of a graphing method in another embodiment of the present disclosure.

FIG. 13 is a schematic diagram of a graphing method in another embodiment of the present disclosure.

Detailed ways

The specific implementation manners of the photomask, the photomask set, and the patterning method provided by the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The following description of at least one exemplary embodiment is merely illustrative in nature and not intended as any limitation of the disclosure, its application or uses. That is, those skilled in the art will understand that they illustrate only exemplary ways that may be used in real time, and are not exhaustive. Also, the relative arrangement of components and steps set forth in these embodiments does not limit the scope of the present disclosure unless specifically stated otherwise.

FIG. 1 is a schematic diagram of a photomask in an embodiment of the present disclosure. Please refer to FIG. 1 below. The photomask includes: a plurality of first strip graphics 11 extending along the first direction m and a plurality of first auxiliary graphics 21 arranged at intervals along the first direction m; The strip graphics 11 and the first auxiliary graphics 21 are overlapped and arranged along the first direction m, the first auxiliary graphics 21 and the first strip graphics 11 have an overlapping area 3, and at the edge of the overlapping area 3, the first auxiliary graphics 21 has the protruding portion 4 not covered by the first bar pattern 11 . By changing the size and shape of the first auxiliary pattern 21 to change the size and shape of the protruding portion 4 and the overlapping area 3 , the pattern of the mask is changed.

In this embodiment, the first auxiliary figure 21 is a quadrilateral. After the first auxiliary figure 21 overlaps with the first bar figure 11, a plurality of protruding parts 4 not covered by the first bar figure 11 are formed at the edge of the overlapping area 3, and the protruding parts 4 include at least two The protruding sub-portions 411 on different sides of the overlapping area 3 are distributed on opposite sides of the overlapping area 3, and the protruding sub-portions 411 are triangular in shape.

In some embodiments, the length of the shortest side of the protruding sub-portion is in the range of 5-10 nm, and the angle α between the longest side of the protruding sub-portion and the edge of the overlapping region is in the range of 10-20°.

In other embodiments, the protrusions are polygonal. FIG. 2 is a schematic diagram of a photomask in another embodiment of the present disclosure. Referring to Fig. 2 below, the overlapping first auxiliary graphics 21 arranged along the first direction m and the first strip graphics 11 have an overlapping area 3, and at the edge of the overlapping area 3, the first auxiliary graphics 21 have The protruding part 4 covered by the first strip graphic 11, the protruding part 4 includes at least two protruding sub-parts 411 arranged on different sides of the overlapping area 3, and the protruding sub-parts 411 are distributed on the On the opposite side of the overlapping area 3, the protruding sub-portion 411 is trapezoidal.

In the above technical solution, by providing the first auxiliary figure 21 , the protruding portion 4 is formed on the edge of the first strip figure 11 . By changing the size and shape of the protruding portion 4, the shape of the mask is changed to obtain a mask with an ideal length ratio between the X direction and the Y direction.

FIG. 3 is a schematic diagram of a mask set in an embodiment of the present disclosure. Referring to FIG. 3 below, the photomask set includes: a first photomask a and a second photomask b, and the first photomask a and the second photomask b are respectively placed along the first direction m and the second direction n. FIG. 4 is a schematic diagram of a first mask a in an embodiment of the present disclosure. Referring to Fig. 4 below, the first photomask a has a plurality of first strip patterns 11 extending along the first direction m and a plurality of first auxiliary patterns 21 arranged at intervals along the first direction m; wherein, the first The strip graphics 11 and the first auxiliary graphics 21 are overlapped and arranged along the first direction m, the first auxiliary graphics 21 and the first strip graphics 11 have a first overlapping area 31, and at the edge of the first overlapping area 31 , the first auxiliary figure 21 has a first protruding portion 41 not covered by the first bar figure 11 . The first mask a includes more than two first protrusions 41 centered on the first overlapping area 31 and distributed symmetrically. FIG. 5 is a schematic diagram of a second mask b in an embodiment of the present disclosure. The second mask b has a plurality of second strip graphics 12 extending along the second direction n and a plurality of second auxiliary graphics 22 arranged at intervals along the second direction n; wherein, the second strip graphics 12 and The second auxiliary graphics 22 are overlapped and arranged along the second direction n, the second auxiliary graphics 22 and the second strip graphics 12 have a second overlapping area 32, and at the edge of the second overlapping area 32, the second auxiliary graphics 22 have The second protruding portion 42 covered by the second bar pattern 12 . The second mask b includes more than two second protrusions 42 centered on the second overlapping area 32 and distributed symmetrically.

In this embodiment, the first auxiliary figure 21 and the second auxiliary figure 22 are quadrilaterals. After the first auxiliary figure 21 is overlapped with the first bar-shaped figure 11, a plurality of first protruding portions 41 not covered by the first bar-shaped figure 11 are formed on the edge of the first overlapping area 31, and the first protruding portions 41 are formed in a first The overlapping area 31 is symmetrically distributed around the center, and the first protruding portion 41 is triangular in shape. After the second auxiliary figure 22 overlaps with the second strip figure 12, a plurality of second protrusions 42 that are not covered by the second strip figure 12 are formed on the edge of the second overlapping area 32, and the second protrusion 42 is formed in a second shape. The overlapping area 32 is symmetrically distributed around the center, and the second protruding portion 42 is triangular. The length range of the shortest side of the first protrusion 41 and/or the second protrusion 42 is 5-10 nm, and the angle range between the longest side of the first protrusion 41 and/or the second protrusion 42 and the edge of the target overlapping area The range of the angle α being 10-20° is 10-20°. In some other embodiments, the first auxiliary figure may be any kind of polygon, and the second auxiliary figure may have the same shape or size as the first auxiliary figure, or may be different in shape or size from the first auxiliary figure. The first protrusion that forms after the first auxiliary figure overlaps with the first bar-shaped figure can be a polygon such as a trapezoid, and the second protrusion that forms after the second auxiliary figure overlaps with the second bar-shaped figure can be the shape of the first protrusion. Or the same size, it can also be any kind of polygon. In some embodiments, the first protruding parts and the second protruding parts of the mask set are symmetrically distributed along the target overlapping area.

Please continue to refer to FIG. 3 below. During exposure, the first mask a and the second mask b are placed along the first direction m and the second direction n respectively, and the first overlapping area (not shown) and the second overlapping area (not shown) shown) overlap to form the target overlapping area 33 , and the first protrusion 41 , the second protrusion 42 , the first overlapping area (not shown) and the second overlapping area (not shown) overlap to form the target pattern 5 .

FIG. 6 is a schematic diagram of a target pattern in an embodiment of the present disclosure. Please refer to Fig. 6 below, the target pattern includes the key dimension x1 on the X direction and the key dimension y1 on the Y direction, the X direction and the Y direction are perpendicular, by adjusting the first protruding portion 41, the second protruding portion 42, the first overlapping area (not shown), and the shape and size of the second overlapping area (not shown) to change the size and shape of the target figure, the ratio of the length of the key dimension on the X direction to the length of the key dimension on the Y direction greater than 1.05. An example is as follows: when it is necessary to increase the critical dimension x1 in the X direction, the lengths of the first auxiliary figure (not shown) and the second auxiliary figure (not shown) in the X direction can be increased to increase the length of the first auxiliary figure (not shown) The length of the protruding portion 41 and the second protruding portion 42 in the X direction increases the critical dimension x1 of the target figure in the X direction accordingly. When the target figure is an asymmetric figure, it is also possible to only adjust the length of the first auxiliary figure or the second auxiliary figure in the X direction to change the shape of the target figure in the corresponding area. When it is necessary to increase the ratio of the key dimension x1 of the target graphic in the X direction to the key dimension y1 in the Y direction, the distance between the first auxiliary graphic and the first bar graphic and the distance between the second auxiliary graphic and the first bar graphic can be reduced. The angle between the two bar graphics is to reduce the length of the critical dimension y1 of the target graphic in the Y direction, thereby increasing the ratio of the critical dimension x1 of the target graphic in the X direction to the critical dimension y1 of the Y direction.

In the above technical solution, the first protruding portion 41 and the second protruding portion 42 are formed on the edges of the first bar graphic 11 and the second bar graphic 12 by setting the first auxiliary graphic 21 and the second auxiliary graphic 22 . By changing the size and shape of the first protruding portion 41 and the second protruding portion 42 , the shape of the mask set is changed to obtain a mask set with an ideal length ratio between the X direction and the Y direction.

FIG. 7 is a schematic diagram of a graphing method in an embodiment of the present disclosure. Referring to Fig. 7 below, the patterning method includes: step S101, providing a mask set; step S102, providing a substrate, and forming a mask layer on the substrate; step S103, exposing the mask layer with a mask set, and A target pattern is formed on the layer.

Step S101, providing a mask set. FIG. 3 is a schematic diagram of a mask set in an embodiment of the present disclosure. Referring to FIG. 3 below, the photomask set includes: a first photomask a and a second photomask b, and the first photomask a and the second photomask b are respectively placed along the first direction m and the second direction n. FIG. 4 is a schematic diagram of a first mask a in an embodiment of the present disclosure. Referring to Fig. 4 below, the first photomask a has a plurality of first strip patterns 11 extending along the first direction m and a plurality of first auxiliary patterns 21 arranged at intervals along the first direction m; wherein, the first The strip graphics 11 and the first auxiliary graphics 21 are overlapped and arranged along the first direction m, the first auxiliary graphics 21 and the first strip graphics 11 have a first overlapping area 31, and at the edge of the first overlapping area 31 , the first auxiliary figure 21 has a first protruding portion 41 not covered by the first bar figure 11 . The first mask a includes more than two first protrusions 41 centered on the first overlapping area 31 and distributed symmetrically. FIG. 5 is a schematic diagram of a second mask b in an embodiment of the present disclosure. The second mask b has a plurality of second strip graphics 12 extending along the second direction n and a plurality of second auxiliary graphics 22 arranged at intervals along the second direction n; wherein, the second strip graphics 12 and The second auxiliary graphics 22 are overlapped and arranged along the second direction n, the second auxiliary graphics 22 and the second strip graphics 12 have a second overlapping area 32, and at the edge of the second overlapping area 32, the second auxiliary graphics 22 have The second protruding portion 42 covered by the second bar pattern 12 . The second mask b includes more than two second protrusions 42 centered on the second overlapping area 32 and distributed symmetrically.

In this embodiment, the first auxiliary figure 21 and the second auxiliary figure 22 are quadrilaterals. After the first auxiliary figure 21 is overlapped with the first bar-shaped figure 11, a plurality of first protruding portions 41 not covered by the first bar-shaped figure 11 are formed on the edge of the first overlapping area 31, and the first protruding portions 41 are formed in a first The overlapping area 31 is symmetrically distributed around the center, and the first protruding portion 41 is triangular in shape. After the second auxiliary figure 22 overlaps with the second strip figure 12, a plurality of second protrusions 42 that are not covered by the second strip figure 12 are formed on the edge of the second overlapping area 32, and the second protrusions 42 overlap for the second time. The area 32 is distributed centrally symmetrically with the center, and the second protruding portion 42 is triangular in shape. The length of the shortest side of the first protrusion 41 and/or the second protrusion 42 ranges from 5 to 10 nm, and the angle between the longest side of the first protrusion 41 and/or the second protrusion 42 and the edge of the target overlapping area The range of α is 10-20°. In some other embodiments, the first auxiliary figure may be any kind of polygon, and the second auxiliary figure may have the same shape or size as the first auxiliary figure, or may be different in shape or size from the first auxiliary figure. The first protrusion that forms after the first auxiliary figure overlaps with the first bar-shaped figure can be a polygon such as a trapezoid, and the second protrusion that forms after the second auxiliary figure overlaps with the second bar-shaped figure can be the shape of the first protrusion. Or the same size, it can also be any kind of polygon. The photomask set includes more than two first protruding parts centered on the first overlapping area and/or more than two centrally symmetrically distributed second protruding parts centered on the second overlapping area. In some embodiments, the first protruding parts and the second protruding parts of the mask set are symmetrically distributed along the target overlapping area.

Step S102, providing a substrate, and forming a mask layer on the substrate. In this embodiment, the mask layer includes a first sub-mask layer and a second sub-mask layer.

Step S103 , exposing the mask layer with a mask set to form a target pattern on the mask layer. FIG. 8 is a schematic diagram of a graphing method in an embodiment of the present disclosure. Referring to FIG. 8 below, the step of exposing the mask layer with a mask set, and forming the target pattern on the mask layer includes: step S201, forming a first sub-mask layer on the substrate, and exposing the first sub-mask layer with a first mask. A sub-mask layer, forming a first target pattern in the first sub-mask layer; step S202, forming a second sub-mask layer on the first sub-mask layer, exposing the second sub-mask layer with a second photomask , forming a second target pattern in the second sub-mask layer; step S203 , transferring the second target pattern to the first sub-mask layer, and forming the target pattern in the first sub-mask layer.

In some other embodiments, exposing the mask layer with a photomask set, and forming the target pattern on the mask layer includes: exposing the mask layer with a first photomask, forming a first target pattern in the mask layer; The second photomask exposes the mask layer to form a target pattern in the mask layer.

FIG. 9 is a schematic diagram of a graphing method in an embodiment of the present disclosure. Referring to FIG. 9 , a substrate 6 is provided, and the substrate 6 is a silicon substrate, on which a first sub-mask layer (not shown) is formed. The first sub-mask layer is exposed with a first photomask, and a first target pattern 81 is formed in the first sub-mask layer. Cover the first mask layer 71 on the first target pattern 81, form a second sub-mask layer (not shown) on the first mask layer 71, expose the second sub-mask layer with a second photomask, and A second target pattern 82 is formed in the second sub-mask layer. The second mask layer 72 is covered on the second target pattern 82 . FIG. 10 is a schematic diagram of a graphing method in another embodiment of the present disclosure. Please refer to FIG. 10 below. Before covering the second mask layer 72 on the second target pattern 82, an oxide layer 9 is deposited on the surface of the second target pattern 82. In this embodiment, the oxide layer 9 is two layers. silicon oxide layer. FIG. 11 is a schematic diagram of a graphing method in another embodiment of the present disclosure. Referring to FIG. 11 below, part of the oxide layer 9, the first mask layer 71 and the first target pattern 81 are etched downward along the sidewall of the second target pattern 82, and the second target pattern 82 is transferred to the In the first mask layer 71 , a target pattern 101 is formed in the first mask layer 71 . In some embodiments, the third mask layer 73 is formed on the target pattern 101 , and the above steps are repeated to form other target patterns. FIG. 12 is a schematic diagram of a graphing method in another embodiment of the present disclosure. Please refer to FIG. 12 below. The patterning method further includes forming an active region 111 on the substrate 6 before forming the first sub-mask layer, and forming the target pattern 101 in the above-mentioned manner. FIG. 13 is a schematic diagram of a graphing method in another embodiment of the present disclosure. Referring to FIG. 13 , the target pattern 101 is transferred to the active region 111 and filled with the polysilicon layer 121 .

In some embodiments, when exposing the mask layer, the first photomask is placed across the second photomask. Please continue to refer to FIG. 3 below, the first mask a and the second mask b are placed along the first direction m and the second direction n respectively, the first overlapping area (not shown) and the second overlapping area (not shown) The target overlapping area 33 is formed by overlapping, and the first protrusion 41 , the second protrusion 42 , the first overlapping area (not shown) and the second overlapping area (not shown) are overlapped to form the target pattern 5 .

FIG. 6 is a schematic diagram of a target pattern in an embodiment of the present disclosure. Please refer to Fig. 6 below, the target pattern includes the key dimension x1 on the X direction and the key dimension y1 on the Y direction, the X direction and the Y direction are perpendicular, by adjusting the first protruding portion 41, the second protruding portion 42, the first overlapping area (not shown), and the shape and size of the second overlapping area (not shown) to change the size and shape of the target figure, the ratio of the length of the key dimension on the X direction to the length of the key dimension on the Y direction greater than 1.05. An example is as follows: when it is necessary to increase the critical dimension x1 in the X direction, the lengths of the first auxiliary figure (not shown) and the second auxiliary figure (not shown) in the X direction can be increased to increase the length of the first auxiliary figure (not shown) The length of the protruding portion 41 and the second protruding portion 42 in the X direction increases the critical dimension x1 of the target figure in the X direction accordingly. When the target figure is an asymmetric figure, it is also possible to only adjust the length of the first auxiliary figure or the second auxiliary figure in the X direction to change the shape of the target figure in the corresponding area. When it is necessary to increase the ratio of the key dimension x1 of the target graphic in the X direction to the key dimension y1 in the Y direction, the distance between the first auxiliary graphic and the first bar graphic and the distance between the second auxiliary graphic and the first bar graphic can be reduced. The angle between the two bar graphics is to reduce the length of the critical dimension y1 of the target graphic in the Y direction, thereby increasing the ratio of the critical dimension x1 of the target graphic in the X direction to the critical dimension y1 of the Y direction.

In the above technical solution, the first protruding portion 41 and the second protruding portion 42 are formed on the edges of the first bar graphic 11 and the second bar graphic 12 by setting the first auxiliary graphic 21 and the second auxiliary graphic 22 . By changing the size and shape of the first protruding portion 41 and the second protruding portion 42, the shape of the target pattern can be changed to obtain a pattern with an ideal length ratio between the etching in the X direction and the Y direction.

The above are only the preferred embodiments of the present application. It should be pointed out that those skilled in the art can make some improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the present invention. protection scope of the invention.

Claims (16)

1. A photomask, comprising:

a plurality of first stripe patterns extending and arranged along a first direction and a plurality of first auxiliary patterns spaced and arranged along the first direction;

the first bar patterns and the first auxiliary patterns are overlapped and arranged along the first direction, the first auxiliary patterns and the first bar patterns are provided with overlapping areas, and at the edges of the overlapping areas, the first auxiliary patterns are provided with protruding parts which are not covered by the first bar patterns.

2. The mask of claim 1 wherein the protrusion comprises at least two protrusion sub-portions arranged on different sides of the overlap region.

3. The mask of claim 2 wherein said protruding subparts are disposed on opposite sides of said overlap region.

4. The mask of claim 1 wherein the protrusions are polygonal.

5. The mask of claim 2 wherein the length of the shortest side of the protruding sub-portion ranges from 5 to 10nm and the angle of the longest side of the protruding sub-portion to the edge of the overlap region ranges from 10 to 20 °.

6. A photomask set, comprising:

the first photomask is provided with a plurality of first strip-shaped patterns extending and arranged along a first direction and a plurality of first auxiliary patterns spaced and arranged along the first direction;

the first strip-shaped patterns and the first auxiliary patterns are overlapped and arranged along the first direction, the first auxiliary patterns and the first strip-shaped patterns are provided with a first overlapped area, and the first auxiliary patterns are provided with first protruding parts which are not covered by the first strip-shaped patterns at the edge of the first overlapped area;

the second photomask is provided with a plurality of second strip-shaped patterns which are arranged in an extending mode along a second direction and a plurality of second auxiliary patterns which are arranged at intervals along the second direction;

the second bar patterns and the second auxiliary patterns are overlapped and arranged along the second direction, the second auxiliary patterns and the second bar patterns are provided with second overlapped areas, and the second auxiliary patterns are provided with second protruding parts which are not covered by the second bar patterns at the edges of the second overlapped areas;

when exposing, the first photomask and the second photomask are respectively placed along the first direction and the second direction, the first overlapping area and the second overlapping area are overlapped to form a target overlapping area, and the first protruding part, the second protruding part, the first overlapping area and the second overlapping area are overlapped to form a target pattern.

7. The mask set of claim 6, wherein the target pattern comprises a critical dimension in an X-direction and a critical dimension in a Y-direction, the critical dimension in the X-direction and the critical dimension in the Y-direction being perpendicular, a length of the critical dimension in the X-direction and a length of the critical dimension in the Y-direction being determined by a shape and a size of the first protrusion, the second protrusion, the first overlap region, and the second overlap region, and a ratio of the length of the critical dimension in the X-direction to the length of the critical dimension in the Y-direction being greater than 1.05.

8. The reticle set of claim 6, wherein the first protrusions and the second protrusions are centrally symmetrically distributed along the target overlap region.

9. The reticle set of claim 6, wherein the first protrusion and the second protrusion are polygonal.

10. The reticle set of claim 6, wherein the shortest sides of the first and second protrusions range in length from 5 to 10nm and the longest sides of the first and second protrusions range in angle from 10 to 20 ° from the edge of the target overlap region.

11. A method of patterning, comprising:

providing a mask set according to claim 6;

providing a substrate, and forming a mask layer on the substrate;

and exposing the mask layer by the photomask set, and forming the target pattern on the mask layer.

12. The patterning method of claim 11, wherein said mask layer includes a first sub-mask layer and a second sub-mask layer, exposing said mask layer with said set of reticles, and forming said target pattern on said mask layer includes:

forming a first sub-mask layer on the substrate, exposing the first sub-mask layer by using the first photomask, and forming a first target pattern in the first sub-mask layer;

forming a second sub-mask layer on the first sub-mask layer, exposing the second sub-mask layer by using the second photomask, and forming a second target pattern in the second sub-mask layer;

and transferring the second target pattern to the first sub-mask layer, and forming the target pattern in the first sub-mask layer.

13. The patterning process of claim 11, wherein the target pattern includes an X-direction critical dimension and a Y-direction critical dimension, the X-direction and Y-direction critical dimension being perpendicular, and wherein the ratio of the length of the X-direction critical dimension to the length of the Y-direction critical dimension is greater than 1.05 by adjusting the shape and size of the first protrusion, the second protrusion, the first overlap region, and the second overlap region to change the size and shape of the target pattern.

14. The patterning process of claim 11, wherein said first protrusions and said second protrusions are centrally symmetrically distributed along said target overlap region.

15. The patterning method of claim 11, wherein the first and second protrusions are polygonal.

16. The patterning process of claim 11, wherein said first and second protrusions have a length in the range of 5-10 nm and a longest edge of said first and second protrusions is at an angle in the range of 10-20 ° to an edge of said target overlap region.