CN111399334A

CN111399334A - Mask manufacturing method and mask

Info

Publication number: CN111399334A
Application number: CN201910003405.3A
Authority: CN
Inventors: 陈洁; 王谨恒; 朱斌; 张斌; 张剑
Original assignee: CSMC Technologies Fab2 Co Ltd
Current assignee: CSMC Technologies Fab2 Co Ltd; CSMC Technologies Corp
Priority date: 2019-01-03
Filing date: 2019-01-03
Publication date: 2020-07-10
Anticipated expiration: 2039-01-03
Also published as: CN111399334B; WO2020140718A1

Abstract

The invention relates to a mask manufacturing method and a mask, wherein the mask manufacturing method comprises the following steps: establishing an OPC program; providing a design graph, and preprocessing a corner graph in the design graph; performing OPC operation on a design graph containing the corner graph after pretreatment according to an OPC program; the mask is manufactured according to the graph after OPC operation, so that the intermediate CD can be guaranteed to meet the actual requirement, the corner CD can be guaranteed to meet the actual requirement, and the problem that the corner caused by the intermediate CD is too rounded to meet the user requirement by sacrificing the corner CD is effectively solved.

Description

Mask manufacturing method and mask

Technical Field

The invention relates to the technical field of semiconductors, in particular to a mask manufacturing method and a mask.

Background

With the rapid development of very large scale integrated circuits, the integrated circuit fabrication process becomes more and more complex and elaborate. In the key layers of 0.13um and the following technical nodes, the CD (critical dimension) of the key layers such as TO (active area layer), GT (gate oxide layer), An (metal connecting wire layer) and the like is smaller and smaller, and the CD of some key layers is close TO or even smaller than the wavelength 248nm of the light wave used in the photoetching process, so that certain deformation and deviation exist between the photoetching pattern and the mask pattern obtained on the actual product wafer in the exposure process in the photoetching due TO the interference and diffraction phenomena of light, and the circuit performance and the production yield are directly influenced by the error in the photoetching.

However, the existing OPC method meets the requirement of middle CD by sacrificing corner CD, which causes that the corner rounding cannot meet some special requirements of users, for example, when a special cell (cell) of 0.11umU LL (ultra-low leakage) is corrected by the existing OPC method, the TO corner rounding is larger, so that the following requirements cannot be met, namely, 1) FG (floating gate) covers TO, the size difference between the middle CD and the edge CD is smaller, and 2) the included angle formed by the TO corner and the FG cannot be too small.

Disclosure of Invention

Therefore, a mask manufacturing method and a mask are needed to be provided for solving the problem that the requirements of users cannot be met after the corner is rounded.

A mask manufacturing method comprises the following steps:

establishing an OPC program;

providing a design graph, and preprocessing a corner graph in the design graph;

performing OPC operation on a design graph containing the corner graph after pretreatment according to an OPC program;

and manufacturing a mask plate according to the graph after the OPC operation.

In one embodiment, the preprocessing of the corner pattern in the design pattern includes:

carrying out size decomposition on the corner graph;

determining size data of the decomposed corner graph;

performing OPC simulation according to the size data of the corner graph to obtain a corner simulation graph;

judging whether the difference value between the key size of the corner simulation graph and the key size of the target corner is within a first preset range;

and if not, adjusting the size data of the corner graph, and performing OPC simulation according to the adjusted size data of the corner graph until the difference value between the key size of the corner simulation graph obtained after simulation and the key size of the target corner is within a first preset range, wherein the adjusted corner graph is used as the preprocessed corner graph.

In one embodiment, before the mask is fabricated according to the pattern after the OPC operation, the method further includes:

verifying whether the difference value between the critical dimension of the graph after OPC operation and the target critical dimension is within a second preset range;

if so, manufacturing a mask plate according to the graph after OPC operation;

and if not, carrying out OPC operation on the design graph containing the corner graph after the pretreatment again according to the OPC program.

In one embodiment, verifying whether the difference between the critical dimension of the graph after the OPC operation and the target critical dimension is within a second preset range includes:

performing OPC simulation on the graph after OPC operation to obtain the key size of the graph after OPC operation;

comparing the critical dimension of the graph after OPC operation with the target critical dimension to obtain a difference value between the critical dimension and the target critical dimension;

and judging whether the difference value is within a second preset range.

carrying out size decomposition on the corner graph;

determining at least one group of size data of the decomposed corner graph to obtain at least one corner graph;

and performing OPC operation on the design graph containing the corner graph after the pretreatment, wherein the OPC operation comprises the following steps:

carrying out OPC operation on design graphs containing different corner graphs respectively to obtain at least one first graph;

manufacturing a mask plate according to the graph after OPC operation, comprising the following steps of:

and manufacturing the mask plate according to at least one first graph according to the position data information in the preset identification layer, wherein the preset identification layer comprises the position data information.

A reticle, comprising:

a body;

the body is provided with a mask pattern, the mask pattern is formed into an axisymmetric pattern and is provided with a symmetry axis, the mask pattern comprises a first pattern, a second pattern, a third pattern and a fourth pattern which are sequentially communicated, the width of the second pattern in the direction vertical to the symmetry axis is larger than or equal to the width of the first pattern in the direction vertical to the symmetry axis, the width of the third pattern in the direction vertical to the symmetry axis is smaller than or equal to the width of the second pattern in the direction vertical to the symmetry axis, and the width of the fourth pattern in the direction vertical to the symmetry axis is larger than or equal to the width of the second pattern in the direction vertical to the symmetry axis.

In one embodiment, the first pattern and the third pattern are formed as rectangles extending along the symmetry axis.

In one embodiment, the second pattern is formed in a substantially trapezoidal shape extending along the symmetry axis, and the width of the second pattern in a direction perpendicular to the symmetry axis increases stepwise in a direction from the first pattern toward the fourth pattern.

In one embodiment, the fourth pattern is formed in a shape of a "concave" and the height of the protruding portion of the "concave" shape in the direction along the symmetry axis is smaller than the height of the third pattern in the direction along the symmetry axis.

In one embodiment, the mask pattern includes a plurality.

According to the mask manufacturing method and the mask, the corner graph in the provided design graph can be preprocessed, then the OPC operation is carried out on the design graph containing the preprocessed corner graph according to the OPC program, and the mask is manufactured according to the graph after the OPC operation, so that the intermediate CD can be ensured to meet the actual requirement, the corner CD can be ensured to meet the actual requirement, and the problem that the requirement of a user cannot be met due to the fact that the corner is too arc caused by the fact that the intermediate CD is met by sacrificing the corner CD is effectively avoided.

Drawings

FIG. 1 is a layout of when the TO is covered by FG;

FIG. 2 is a schematic diagram of a TO mask obtained by using a conventional OPC method;

FIG. 3 is a photo-etched pattern obtained by photo-etching through the TO mask shown in FIG. 2;

FIG. 4 is a diagram of a pattern obtained by FG lithography on the basis of the pattern shown in FIG. 3;

FIG. 5 is a schematic diagram of the presence of Poly residue in the lithographic pattern shown in FIG. 4;

FIG. 6 is a flow diagram of a reticle fabrication method in one embodiment;

FIG. 7 is a flow diagram of preprocessing a corner pattern in one embodiment;

FIG. 8 is a diagram illustrating a dimensional breakdown of a corner pattern according to one embodiment;

FIG. 9 is a schematic view of a reticle in one embodiment;

FIG. 10 is a flow diagram of verification of a graph after an OPC operation in one embodiment;

FIG. 11 is a flowchart illustrating an embodiment of verifying whether a difference between a CD of the graph after the OPC operation and a target CD is within a second predetermined range;

FIG. 12 is a flow chart of a reticle fabrication method in another embodiment;

FIG. 13 is a schematic diagram of three simulated corner patterns obtained via OPC simulation in one embodiment;

FIG. 14 is a schematic view of a reticle structure according to the first embodiment;

FIG. 15 is a schematic view of a reticle structure according to a second embodiment.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

As described in the background section, in order TO eliminate the distortion and deviation between the lithography pattern and the mask pattern obtained on the actual product wafer, the OPC method can be used TO correct the design drawing TO some extent, however, the existing OPC method meets the requirement of the middle CD by sacrificing the corner CD (critical dimension), which results in that the corner can not meet some special requirements of users after being rounded, for example, when the existing OPC method is used TO correct the special unit of 0.11um U LL (ultra-low leakage), because the TO (active area level) corner is rounded more greatly, the following requirements can not be met, 1) the FG (floating gate) covers the TO, the difference between the sizes of the middle CD and the edge CD is better, and 2) the included angle formed by the TO corner and the FG can not be too small.

Specifically, referring TO FIG. 1, FG is overlaid on TO TO form a small cell (bit), and a plurality of repeated small cell forming cells (cells) are overlaid on TO, TO is square on a design pattern (L ayout). when the TO in FIG. 1 is corrected by using the existing OPC method, the CD of the obtained mask is shown in FIG. 2, and correspondingly, the photoetching pattern obtained on the product wafer is shown in FIG. 3. As can be seen from FIG. 3, when the TO in FIG. 1 is corrected by using the existing OPC method, the CD of corners is sacrificed, such as the size at positions ① - ④, namely, the corners are rounded, and the size at positions ⑤ - ⑥ is ensured by the corner rounding, so that the size at positions ⑤ - ⑥ meets the design size, namely, the requirement of the middle CD is met by sacrificing the corner CD.

Because of the presence of the arc at the position ① - ④ on the TO, when the FG covers the TO, as shown in fig. 4, the middle CD (CD 1 in the figure) of the FG is significantly larger than the edge CD (CD 2 in the figure), and at the same time, as shown in fig. 5, the corner of the TO is too small after being rounded off, and the included angle formed with the FG is too small, so that Poly residues are generated.

Fig. 6 is a flowchart of a reticle fabrication method in an embodiment, and as shown in fig. 6, the reticle fabrication method includes:

step 602, an OPC procedure is established.

Specifically, when the OPC program is established, the photolithography process condition may be determined, the OPC data corresponding to the photolithography process condition may be collected, the OPC model may be created according to the OPC data, and the OPC program may be established according to the OPC model.

And step 604, providing a design graph, and preprocessing the corner graph in the design graph.

Specifically, the corner pattern in the design pattern may be preprocessed, so that the preprocessed corner pattern meets the preset requirement. Taking TO as an example, a designer can firstly design the overall graphics of the TO according TO requirements TO obtain a design graphics of the TO, wherein the design graphics comprise an intermediate graphics and a corner graphics, and in order TO effectively avoid that an intermediate CD caused by performing OPC correction on the design graphics by adopting an existing OPC method meets requirements, and a CD with a corner rounded has a large difference with a target corner CD, the corner graphics can be firstly preprocessed TO ensure that the corner CD also meets requirements.

In one embodiment, as shown in fig. 7, the preprocessing of the corner pattern in the design pattern includes:

and step 702, carrying out size decomposition on the corner angle graph.

In one embodiment, the corner pattern is dimensionally decomposed, comprising: and carrying out size decomposition on the corner graph by taking the vertex of the corner graph as an end point. For example, before performing OPC correction on the design pattern, the design of the corner positions may be decomposed into different sizes with reference to fig. 8, that is, the corner patterns are labeled with different sizes, and each label has a corresponding label (e.g., A, B, C, …) for differentiation.

And step 704, determining size data of the decomposed corner graph.

Specifically, when providing the design pattern, the designer typically provides corresponding pattern data, and performs dimension data labeling on the decomposed corner pattern based on the pattern data, that is, performs assignment on each dimension, for example, table 1 exemplarily provides dimension data of a corner pattern:

TABLE 1

And step 706, performing OPC simulation according to the size data of the corner graph to obtain the corner simulation graph. The OPC simulation can be implemented by using the prior art, and details are not described here.

Step 708, determining whether a difference between the key dimension of the corner simulation graph and the key dimension of the target corner is within a first preset range, wherein the first preset range can be calibrated according to an actual situation.

And 710, if not, adjusting the size data of the corner graph, and performing OPC simulation according to the adjusted size data of the corner graph until the difference value between the key size of the corner simulation graph obtained after simulation and the key size of the target corner is within a first preset range, wherein the adjusted corner graph is used as the preprocessed corner graph.

Specifically, after the corner pattern corresponding to table 1 is simulated by OPC, the corner simulation pattern and the CD of the corner simulation pattern may be obtained, and then compared with the target corner CD to calculate a difference therebetween, and determine whether the difference is within a first preset range. If so, the corner CD of the photoetching pattern finally obtained based on the corner pattern corresponding to the current table 1 can meet the user requirement, and the corner pattern corresponding to the table 1 is taken as the final corner pattern; if not, it is indicated that the corner CD of the lithographic pattern finally obtained based on the corner pattern corresponding to table 1 cannot meet the user requirement, for example, the corner rounding is too large or too small, at this time, the size data of the corner pattern may be adjusted, for example, when the rounding effect is not good, the difference at the corresponding position may be relatively large, at this time, the size data of the corner pattern corresponding to the position with the relatively large difference may be adjusted, the adjustment amount may be determined according to the difference, and it is assumed that the size data of the adjusted corner pattern is shown in table 2:

TABLE 2

Then, performing OPC simulation on the corner graph corresponding to the table 2, comparing the CD of the corner simulation graph with a target corner CD to judge whether the difference value of the two is within a first preset range, and if so, taking the corner graph corresponding to the table 2 as a final corner graph; if not, continuously adjusting the size data of the corner graph until the difference value between the CD of the corner simulation graph obtained after simulation and the target corner CD is within a first preset range so as to obtain the corner graph meeting the preset requirement. Therefore, the CD needed to be adjusted by the corner part can be manually adjusted according to the requirements of users, so that the corner part can meet the actual requirements.

And 606, performing OPC operation on the design graph containing the preprocessed corner graph according to an OPC program.

Specifically, after the corner graphics are preprocessed, OPC operation is carried out on the whole design graphics, the corner graphics in the design graphics are the preprocessed corner graphics, and the preprocessed corner graphics can meet preset requirements.

And step 608, manufacturing a mask according to the graph after the OPC operation. For example, fig. 9 shows a schematic view of a corner portion in a reticle obtained from the pattern data after OPC operation.

In the embodiment, the corner graph in the design graph is preprocessed, so that the preprocessed corner graph meets the user requirement, and then OPC correction is performed on the basis of the design graph containing the preprocessed corner graph to manufacture the mask, so that not only can the intermediate CD meet the actual requirement, but also the corner CD can meet the actual requirement, so that the whole mask meets the user requirement, and the problem that the user requirement cannot be met due to the fact that the corner caused by the intermediate CD is excessively rounded by sacrificing the corner CD is effectively avoided.

In one embodiment, as shown in fig. 10, before the reticle is fabricated according to the post-OPC pattern, the method further includes:

step 1002, verifying whether a difference value between the critical dimension of the graph after the OPC operation and the target critical dimension is within a second preset range, wherein the second preset range can be calibrated according to an actual situation.

In one embodiment, as shown in fig. 11, verifying whether the difference between the critical dimension of the graph after the OPC operation and the target critical dimension is within a second preset range includes:

step 1102, performing OPC simulation on the graph after OPC operation to obtain the critical dimension of the graph after OPC operation.

And 1104, comparing the critical dimension of the graph after the OPC operation with the target critical dimension to obtain a difference value between the critical dimension and the target critical dimension.

In step 1106, it is determined whether the difference is within a second predetermined range.

Specifically, when verifying whether the difference between the CD of the graph after OPC operation and the target CD is within the second preset range, OPC simulation may be performed on the graph after OPC operation to obtain the CD of the graph after OPC operation, then the difference between the CD of the graph after OPC operation and the target CD is calculated, and finally, whether the difference is within the second preset range is determined.

And 1004, if so, manufacturing a mask plate according to the graph after the OPC operation.

And step 1006, if not, performing OPC operation on the design graph containing the preprocessed corner graph again according to the OPC program.

Specifically, after performing OPC operation on the design pattern including the corner pattern after preprocessing according to the OPC program, verifying the pattern after OPC operation, for example, comparing the difference between the CD of the pattern after OPC operation and the target CD, and repeating the OPC operation on the design pattern including the corner pattern after preprocessing according to the OPC program until the CD of the finally obtained pattern after OPC operation satisfies the target CD if the target CD is not satisfied, and repeating the loop and performing mask making according to the final pattern after OPC operation.

In the embodiment, the corner graph in the provided design graph is preprocessed to enable the preprocessed corner graph to meet the preset requirement, then, according to an OPC program, OPC operation is performed on the design graph containing the preprocessed corner graph, and the mask is manufactured according to the graph after the OPC operation, so that the requirement of an intermediate CD can be met, the requirement of the corner CD can be met, the problem that the corner caused by the intermediate CD is too rounded to meet the requirement of a user due to the fact that the corner is met by sacrificing the corner CD is effectively avoided, and the defect risk possibly existing in the data processing flow of the unit area is eliminated. In addition, the whole process can realize complete programmed processing, the program portability is strong, and the effect is higher compared with the traditional manual OPC mode.

In one embodiment, as shown in fig. 12, the corner pattern in the design pattern is preprocessed, which includes:

and step 1202, carrying out size decomposition on the corner graph.

In one embodiment, the corner pattern is dimensionally decomposed, comprising: and carrying out size decomposition on the corner graph by taking the vertex of the corner graph as an end point. For example, the design of the corner position can be decomposed into different sizes with reference to fig. 8, i.e., the corner pattern is labeled with different sizes, and each label has a corresponding label (e.g., A, B, C, …) for differentiation.

At step 1204, at least one set of size data of the decomposed corner pattern is determined to obtain at least one corner pattern.

Specifically, at the beginning of development, sometimes the developer does not know which CD better meets the requirements of the own factory, for example, which corner rounding better meets the requirements of the own factory, so in order to provide valuable parameter data to the developer, the designer may first provide multiple sets of dimension data of the corner pattern, for example, three sets of dimension data of the corner pattern, as shown in table 3, and then fabricate a reticle based on the corner patterns corresponding to the three sets of dimension data, so as to obtain multiple patterns on the same reticle for analysis by the developer.

TABLE 3

Further, the OPC operation on the design graph containing the corner graph after the pretreatment comprises the following steps: in step 1206, OPC operations are performed on the design patterns including different corner patterns, respectively, to obtain at least one first pattern.

Specifically, the corner pattern corresponding to the first set of size data in table 3 may be subjected to OPC operation according to the created OPC procedure to obtain the first set of pattern data, the corner pattern corresponding to the second set of size data in table 3 may be subjected to OPC operation according to the created OPC procedure to obtain the second set of pattern data, and the corner pattern corresponding to the third set of size data in table 3 may be subjected to OPC operation according to the created OPC procedure to obtain the third set of pattern data, as shown in fig. 13.

Still further, according to the graph after OPC operation, making a mask plate, comprising: and 1208, manufacturing the mask according to at least one first graph according to the position data information in the preset identification layer, wherein the preset identification layer comprises the position data information.

Specifically, after obtaining three group of graphic data, make three figure on same mask according to three group's graphic data respectively, then carry out the photoetching through this mask, can obtain three photoetching figure to same corner figure on same wafer like this, thereby make research and development personnel can once only collect the data that multiunit is different on same wafer and carry out the analysis, in order to determine which kind of CD accords with the demand of oneself mill more, for example, which kind of corner arc ization accords with the demand of oneself mill more, so not only can reduce the cost of mask, and can effectively reduce the follow-up analysis problem because of the difference that comes from different wafers causes.

In practical application, an identification layer can be set for each group of size data of the corner pattern, the identification layer comprises position data information and is used for determining the position of the pattern obtained through OPC operation on a mask, and the problem that multiple plate making is carried out on the same position based on different patterns is solved, so that the purpose of simultaneously obtaining multiple patterns on the same mask is facilitated.

In the embodiment, the corner graph is subjected to size decomposition, multiple groups of size data are given to the same corner graph according to user requirements, multiple different graph data can be obtained simultaneously through the same OPC program, multiple different graphs can be obtained on the same mask according to the multiple different graph data, photoetching is carried out according to the mask with the multiple different graphs, multiple photoetching graphs can be obtained on the same wafer, and therefore research and development personnel can collect different data corresponding to the same corner graph on the same wafer at one time for analysis, the cost of the multiple masks can be reduced, and the problem of follow-up analysis caused by differences from different wafers can be effectively reduced.

In one embodiment, there is provided a reticle, as shown in fig. 14, comprising: a body 1; the body 1 is provided with a mask pattern 11, the mask pattern 11 is formed into an axisymmetric pattern and has a symmetry axis, the mask pattern 11 comprises a first pattern 111, a second pattern 112, a third pattern 113 and a fourth pattern 114 which are sequentially communicated, the width d2 of the second pattern 112 in the direction vertical to the symmetry axis is greater than or equal to the width d1 of the first pattern 111 in the direction vertical to the symmetry axis, the width d3 of the third pattern d3 in the direction vertical to the symmetry axis is less than or equal to the width d2 of the second pattern 112 in the direction vertical to the symmetry axis, and the width d4 of the fourth pattern d4 in the direction vertical to the symmetry axis is greater than or equal to the width d2 of the second pattern 112 in the direction vertical to the symmetry axis.

That is, the mask pattern 11 may include four portions, respectively, a first pattern 111, a second pattern 112, a third pattern 113, and a fourth pattern 114, wherein the first pattern 111 corresponds to a portion of the photolithography pattern to be formed, the third pattern 113 and the fourth pattern 114 correspond to a corner portion of the photolithography pattern to be formed, and the second pattern 112 corresponds to a portion of the photolithography pattern to be formed and a connection portion of the corner portion. For example, when the pattern to be formed is rectangular and only one end of the rectangle needs to be ensured to satisfy the requirement for rounding, the first pattern 111 corresponds to the middle portion and the other end of the rectangle to be formed, the third pattern 113 and the fourth pattern 114 correspond to one end of the rectangle to be formed, and the second pattern 112 corresponds to the middle portion and the connecting portion of one end of the rectangle to be formed, so that the rectangle formed by the mask pattern 11 not only allows the middle portion to satisfy the requirement for rounding, but also allows one end of the rectangle to satisfy the requirement for rounding, and simultaneously ensures that the middle portion and the connecting portion of one end of the rectangle satisfy the requirement for rounding. It can be understood that, when it is required to ensure that the two rectangular end portions all meet the requirement for circular arc formation, the same patterns as the second pattern 112, the third pattern 113 and the fourth pattern 114 may be sequentially disposed at the end of the first pattern 111 far away from the second pattern 112, so as to ensure that not only the middle portion of the formed rectangle meets the actual requirement, but also the two rectangular end portions all meet the requirement for circular arc formation.

In one embodiment, as shown in fig. 14 or 15, the first pattern 111 and the third pattern 113 are formed in a rectangular shape extending along the symmetry axis. It should be noted that, in general, the width d3 of the third pattern 113 in the direction perpendicular to the symmetry axis is larger than the width in the direction along the symmetry axis, and the width d1 of the first pattern 111 in the direction perpendicular to the symmetry axis is smaller than the width in the direction along the symmetry axis, so that the third pattern 113 can be regarded as a rectangle in the lateral direction of the figure, and the first pattern 111 is a rectangle in the longitudinal direction of the figure.

In one embodiment, as shown in fig. 15, the second pattern 112 is formed in a substantially trapezoidal shape extending along the symmetry axis, and the width of the second pattern 112 in a direction perpendicular to the symmetry axis increases stepwise in a direction from the first pattern 111 toward the fourth pattern 114. That is, the second pattern 112 may be formed of a plurality of rectangles having different widths in a direction perpendicular to the symmetry axis, and the widths of the rectangles gradually increase in a direction from the first pattern 111 toward the fourth pattern 114, so that the connecting portion of the middle portion and the corner portion of the formed photolithography pattern does not have an inward recess, and the connecting portion meets the actual requirement.

In one embodiment, as shown in fig. 15, the fourth pattern 114 is formed in a shape of "concave", and the height of the protruding portion of the shape of "concave" in the direction along the symmetry axis is smaller than the height of the third pattern 113 in the direction along the symmetry axis. That is, the fourth pattern 114 may be formed of a rectangular shape having protruding portions at both ends, so that the rounding of the corner portions of the lithography pattern formed by the mask pattern 11 can be effectively reduced, thereby making the corner portions meet practical requirements.

In one embodiment, the mask patterns 11 include a plurality of mask patterns 11, wherein the size of each mask pattern 11 may be different, for example, the size of each mask pattern 11 at reference K is different, or the size of each mask pattern 11 at reference J is partially different, so that a plurality of lithography patterns may be obtained on the same wafer through the plurality of mask patterns 11, thereby facilitating a developer to collect different data corresponding to the same design pattern on the same wafer at one time for analysis, thereby not only reducing the cost of multiple reticles, but also effectively reducing the subsequent analysis problem caused by the difference from different wafers.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A mask manufacturing method is characterized by comprising the following steps:

establishing an OPC program;

providing a design graph, and preprocessing a corner graph in the design graph;

performing OPC operation on the design graph containing the corner graph after pretreatment according to the OPC program;

and manufacturing a mask plate according to the graph after the OPC operation.

2. The method according to claim 1, wherein the preprocessing of the corner pattern in the design pattern comprises:

carrying out size decomposition on the corner graph;

determining size data of the decomposed corner graph;

and if not, adjusting the size data of the corner graph, and performing OPC simulation according to the adjusted size data of the corner graph until the difference value between the key size of the corner simulation graph obtained after simulation and the key size of the target corner is within the first preset range, wherein the adjusted corner graph is used as a preprocessed corner graph.

3. The method of claim 2, wherein prior to fabricating a reticle in accordance with the post-OPC pattern, the method further comprises:

verifying whether the difference value between the critical dimension of the graph after the OPC operation and the target critical dimension is within a second preset range;

if yes, manufacturing a mask plate according to the graph after the OPC operation;

and if not, carrying out OPC operation on the design graph containing the preprocessed corner graph again according to the OPC program.

4. The method according to claim 3, wherein the verifying whether the difference between the CD of the graph after the OPC operation and the target CD is within a second preset range comprises:

performing OPC simulation on the graph after the OPC operation to obtain the key size of the graph after the OPC operation;

comparing the critical dimension of the graph after the OPC operation with the target critical dimension to obtain a difference value between the critical dimension and the target critical dimension;

and judging whether the difference value is within the second preset range.

5. The method according to claim 1, wherein the preprocessing of the corner pattern in the design pattern comprises:

carrying out size decomposition on the corner graph;

the OPC operation is performed on the design graph containing the corner graph after the pretreatment, and comprises the following steps:

performing OPC operation on the design graphs containing different corner graphs respectively to obtain at least one first graph;

the manufacturing of the mask plate according to the graph after the OPC operation comprises the following steps:

and manufacturing a mask plate according to the at least one first graph according to position data information in a preset identification layer, wherein the preset identification layer comprises the position data information.

6. A reticle obtained according to the method of any one of claims 1 to 5, comprising:

a body;

the mask pattern is formed on the body, the mask pattern is formed into an axisymmetric pattern and is provided with a symmetry axis, the mask pattern comprises a first pattern, a second pattern, a third pattern and a fourth pattern which are sequentially communicated, the width of the second pattern in the direction perpendicular to the symmetry axis is larger than or equal to the width of the first pattern in the direction perpendicular to the symmetry axis, the width of the third pattern in the direction perpendicular to the symmetry axis is smaller than or equal to the width of the second pattern in the direction perpendicular to the symmetry axis, and the width of the fourth pattern in the direction perpendicular to the symmetry axis is larger than or equal to the width of the second pattern in the direction perpendicular to the symmetry axis.

7. The reticle of claim 6, wherein the first pattern and the third pattern are formed as rectangles extending along the axis of symmetry.

8. The reticle as claimed in claim 6 wherein the second pattern is formed in a generally trapezoidal shape extending along the axis of symmetry and the second pattern increases in width in a direction perpendicular to the axis of symmetry in a step-like manner in a direction from the first pattern toward the fourth pattern.

9. The reticle as claimed in claim 6 wherein the fourth pattern is formed in a shape of a "concave" and a height of a protruding portion of the "concave" shape in a direction along the axis of symmetry is smaller than a height of the third pattern in the direction along the axis of symmetry.

10. The reticle as claimed in any one of claims 6 to 9 wherein the mask pattern comprises a plurality.