CN111258177B - OPC graph generation method - Google Patents
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- CN111258177B CN111258177B CN202010159531.0A CN202010159531A CN111258177B CN 111258177 B CN111258177 B CN 111258177B CN 202010159531 A CN202010159531 A CN 202010159531A CN 111258177 B CN111258177 B CN 111258177B
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- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
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Abstract
The application discloses an OPC pattern generation method, and relates to the technical field of semiconductor lithography. The method comprises the steps of generating a basic graph generating library, wherein the basic graph generating library is used for generating a basic graph, and the shape of the basic graph comprises a line type and a hole type; calling a basic graph generating library, generating a basic graph according to a preset design graph, and combining the basic graph to generate an initial OPC graph; determining the size of the head graph to be added by using a weighting function and the line end position in the initial OPC graph, wherein the weighting function is used for calculating the weight of the line end; adding a corresponding head graph to the line end in the initial OPC graph according to the size of the head graph to be added to obtain a target OPC graph; the problem that the conventional OPC graphics are low in efficiency and easy to make mistakes is solved; the method achieves the effects of automatically generating the OPC graphics, optimizing the simulation result of the OPC graphics and improving the generation speed and accuracy of the OPC graphics.
Description
Technical Field
The application relates to the technical field of semiconductor lithography, in particular to an OPC pattern generation method.
Background
In semiconductor manufacturing, as the design dimensions continue to shrink, the diffraction effects of light become more and more pronounced, resulting in the actual pattern formed by photolithography on a silicon wafer becoming different from the design pattern. In order to correct this phenomenon, OPC (optical proximity correction ) is generated, and the pattern after lithography is brought close to the design pattern.
During the modeling and testing process, the OPC test patterns and the photolithography patterns need to be continuously measured and modified. The current process of generating OPC test patterns is basically a manual flow, needs to consume a large amount of time, is easy to make mistakes, and is difficult to meet the requirement of generating a large amount of OPC test patterns in a short time.
Disclosure of Invention
In order to solve the problems in the related art, the present application provides an OPC pattern generation method. The technical scheme is as follows:
in one aspect, an embodiment of the present application provides a method for generating an OPC pattern, where the method includes:
generating a basic graph generating library, wherein the basic graph generating library is used for generating a basic graph, and the shape of the basic graph comprises a line type and a hole type;
calling a basic graph generating library, generating a basic graph according to a preset design graph, and combining the basic graph to generate an initial OPC graph;
determining the size of the head graph to be added by using a weighting function and the line end position in the initial OPC graph, wherein the weighting function is used for calculating the weight of the line end;
and adding a corresponding head graph to the line end in the initial OPC graph according to the size of the head graph to be added, so as to obtain the target OPC graph.
Optionally, determining the size of the header pattern to be added to the initial OPC pattern using the weighting function and the line end position includes:
acquiring coordinates of a line end in an initial OPC graph;
calculating the weight of the line end according to the weighting function and the coordinates of the line end;
taking the product of the weight of the line end and the unilateral maximum width of the head graph as the width of the head graph to be added, and knowing the length of the head graph to be added.
Optionally, calculating the weight of the line end according to the weighting function and the coordinates of the line end includes:
and (5) bringing the coordinates of the line end into a weighting function, and calculating to obtain the weight of the line end.
Optionally, the weighting function is a gaussian function.
Optionally, adding a corresponding header pattern to a line end in the initial OPC pattern according to a size of the header pattern to be added to obtain a target OPC pattern, including:
generating a head graph according to the size of the head graph to be added corresponding to each line end aiming at each line end in the initial OPC graph, wherein the size of the head graph comprises the width and the length of the head graph;
and adding a corresponding head graph to each line end to obtain a target OPC graph.
Optionally, calling a base graphic generation library to generate a base graphic according to a predetermined design graphic, including:
determining the shape and the size of a basic pattern to be generated according to a preset design pattern;
and calling a basic graph generation library, and generating the basic graph according to the shape and the size of the basic graph to be generated.
Optionally, combining the base patterns generates an initial OPC pattern, including:
determining a combination rule and a position relation of the generated basic patterns according to the preset design patterns, wherein the position relation at least comprises the distance between the basic patterns;
and combining the generated basic graph according to the combination rule and the position relation to obtain the initial OPC graph.
Optionally, the dimensions of the linear base pattern include line length, line width.
The technical scheme of the application at least comprises the following advantages:
the method comprises the steps of generating a basic graph generating library, calling the basic graph generating library, generating a basic graph according to a preset design graph, combining the basic graph to generate an initial OPC graph, determining the size of a head graph to be added by utilizing a weighting function and the line end position of the initial OPC graph, and adding a corresponding head graph to the line end in the initial OPC graph according to the size of the head graph to be added to obtain a target OPC graph; the problem that the conventional OPC graphics are low in efficiency and easy to make mistakes is solved; the method achieves the effects of automatically generating the OPC graphics, optimizing the simulation result of the OPC graphics and improving the generation speed and accuracy of the OPC graphics.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of an OPC pattern;
FIG. 2 is a schematic diagram of an OPC pattern with a head pattern added thereto;
FIG. 3 is a flowchart of an OPC pattern generation method provided in an embodiment of the present application;
FIG. 4 is a flowchart of another OPC pattern generation method provided in an embodiment of the present application;
FIG. 5 is a partial schematic view of an initial OPC pattern provided in an embodiment of the application;
FIG. 6 is a partial schematic diagram of a target OPC pattern provided in an embodiment of the application.
Detailed Description
The following description of the embodiments of the present application will be made apparent and complete in conjunction with the accompanying drawings, in which embodiments described are some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.
In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of description of the present application and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; the two components can be directly connected or indirectly connected through an intermediate medium, or can be communicated inside the two components, or can be connected wirelessly or in a wired way. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.
In addition, the technical features described below in the different embodiments of the present application may be combined with each other as long as they do not collide with each other.
The OPC pattern is generally formed by combining basic patterns with a plurality of sizes, the basic patterns can be divided into linear basic patterns and hole-type basic patterns according to the shapes of the basic patterns, when the sizes of the linear basic patterns are smaller than a preset value, the end structures, namely the line ends, of the linear basic patterns are particularly sensitive to optical effect reaction, the effect obtained by simulating the OPC pattern is not ideal, and as shown in fig. 1, the simulation result obtained after simulating the OPC pattern 11 is pattern 12; after adding the head pattern (head) 13 to the line end of the OPC pattern 11, the simulation result is optimized as shown in fig. 2.
When adding the head graph to the end of the OPC graph, the size of the added head graph needs to be determined according to the actual situation, and the process of generating the OPC graph in the prior art is basically a manual flow, so that the efficiency is low and the error rate is high.
As shown in fig. 3, which is a flowchart illustrating an OPC pattern generation method provided in an embodiment of the present application, the method may be executed by a computer program to automatically generate an OPC pattern, and the OPC pattern generation method may include the steps of:
in step 301, a base graphic generation library is generated.
The basic pattern generation library is used for generating basic patterns, and the shapes of the basic patterns comprise line patterns and hole patterns.
Optionally, the base pattern generation library includes at least a program for generating a line base pattern and a program for generating a hole-type base pattern. In the basic graph generation library, the size of the basic graph is a variable; when the base graph generation library is called, the size of the base graph to be generated can be customized.
Alternatively, the initial OPC is composed of at least a line-type base pattern and a hole-type base pattern, or the initial OPC is composed of at least a line-type base pattern, or the initial OPC is composed of at least a hole-type base pattern. When it is desired to add a header pattern to a line end position in an OPC pattern, the initial OPC pattern includes a line-type base pattern.
The predetermined design pattern is predetermined; the size of the predetermined design pattern, the shape and size of each base pattern constituting the predetermined design pattern, and the positional relationship between the base patterns are known.
Optionally, the positional relationship between the base patterns at least includes a base pattern pitch of any two base patterns.
When the base pattern is a linear base pattern, the dimensions include line length and line width; the distance between any two linear basic patterns is the line spacing, and the distance between the line ends of any two linear basic patterns is the line end spacing; when the base pattern is a hole-type base pattern, the dimensions include the hole diameter.
And calling a basic graph generating library, generating a basic graph according to the preset design graph, and combining the generated basic graph to obtain the initial OPC graph.
The generated OPC pattern is consistent with the predetermined design pattern.
The weighting function is used to calculate the weights of the line ends.
And determining the line end position of each line end in the initial OPC graph, and calculating the weight of each line end by using the weighting function and the line end position.
The head graph has a reference size, the reference size is a preset size, and the reference size can be determined according to actual conditions; and calculating the size of the head graph to be added corresponding to the line end according to the weight of the line end and the reference size of the head graph.
And determining the size of the head graph to be added corresponding to each line end according to the weight of each line end and the reference size of the head graph.
Optionally, the line end position of each line end is represented by coordinates.
Because the line end positions of each line end are different, the calculated line ends have different weights, and the sizes of the head patterns determined according to the weights of the line ends and the reference sizes are also different.
And step 304, adding a corresponding head graph to the line end in the initial OPC graph according to the size of the head graph to be added, and obtaining the target OPC graph.
Generating a head graph to be added according to the size of the head graph to be added, and adding the head graph corresponding to each line end in the initial OPC graph to obtain the target OPC graph.
In summary, according to the OPC pattern generation method provided by the embodiment of the present application, by generating the base pattern generation library, calling the base pattern generation library, generating the base pattern according to the predetermined design pattern, and combining the base pattern to generate the initial OPC pattern, determining the size of the head pattern to be added by using the weighting function and the line end position of the initial OPC pattern, and adding the corresponding head pattern to the line end in the initial OPC pattern according to the size of the head pattern to be added, thereby obtaining the target OPC pattern; the problem that the conventional OPC graphics are low in efficiency and easy to make mistakes is solved; the method achieves the effects of automatically generating the OPC graphics, optimizing the simulation result of the OPC graphics and improving the generation speed and accuracy of the OPC graphics.
As shown in fig. 4, which is a flowchart illustrating another OPC pattern generation method provided in an embodiment of the present application, the method may be executed by a computer program to automatically generate an OPC pattern, and the OPC pattern generation method may include the steps of:
in step 401, a base graphic generation library is generated.
The basic pattern generation library is used for generating basic patterns, and the shapes of the basic patterns comprise line patterns and hole patterns.
This step is described in step 301, and will not be described here again.
And determining the shapes and the sizes of the plurality of basic patterns to be generated according to the preset design patterns, wherein the plurality of basic patterns to be generated can be combined into the preset design patterns.
When the basic graph to be generated is a linear basic graph, calling a program for generating the linear basic graph in a basic graph generation library, and generating the linear basic graph according to the size of the basic graph to be generated; and when the basic pattern to be generated is a hole-type basic pattern, calling a program for generating the hole-type basic pattern in the basic pattern generation library, and generating the hole-type basic pattern according to the size of the basic pattern to be generated.
The dimensions of the line-type base pattern include line length and line width.
And step 404, determining the combination rule and the position relation of the generated basic graph according to the preset design graph.
The positional relationship includes at least a base pattern pitch.
Optionally, the positional relationship between the base patterns is determined according to coordinates.
It should be noted that the same predetermined design pattern may have a plurality of combination rules, and each combination rule corresponds to a different basic pattern; when the combination rule and the position relation are determined, the combination rule and the position relation corresponding to the preset design graph are determined according to the generated basic graph.
And 405, combining the generated basic graph according to the combination rule and the position relation to obtain an initial OPC graph.
The initial OPC pattern is the same as the preset design pattern, and the actual pattern on the silicon wafer is different from the preset design pattern after photoetching according to the initial OPC pattern, and the head pattern is added at the line end of the initial OPC pattern to correct the pattern.
When the base pattern pitch, the positional relationship between the base patterns is known, the line end position in the initial OPC pattern can be represented by coordinates.
In one example, as shown in fig. 5, the line ends of the line-type basic pattern 51, the line-type basic pattern 52, and the line-type basic pattern 53 in the initial OPC pattern need to be added with a header pattern, if the coordinates of the line end of the line-type basic pattern 52 are known as (a, a); line widths of the line-type basic pattern 51, the line-type basic pattern 52 and the line-type basic pattern 53 are equal, and the line width is width; the distance between any two adjacent linear basic patterns is equal, and the distance is space; the coordinates of the line end of the line-type base pattern 51 are (a- (width + space), a), and the coordinates of the line end of the line-type base pattern 53 are (a+ (width + space), a).
The weighting function is used to calculate the weights of the line ends. The weighting function is a predetermined known function when calculating the weights of the line ends.
And (5) bringing the coordinates of the line end into a weighting function, and calculating to obtain the weight of the line end.
Optionally, the weighting function is a gaussian function, and the formula for calculating the weight of the line end is as follows:
in one example, the coordinates of the line end (a- (width+space), a), the line end coordinates (a+ (width+space), a), and the line end coordinates (a, a) are respectively taken in
The weights obtained are G (a- (width+space), a), G (a+ (width+space), a), G (a, a), respectively; it can be seen that the weights corresponding to the different line ends are different.
Optionally, the weighting function is a normal distribution function; and the coordinates of the line ends are brought into a weighting function, and the weight of the line ends can be calculated.
In step 408, the product of the weight of the line end and the single-side maximum width of the head pattern is used as the width of the head pattern to be added, and the length of the head pattern to be added is known.
And calculating the product of the weight of the line end and the unilateral maximum width of the head graph for each line end to obtain the width of the head graph to be added corresponding to each line end.
In one example, the single-sided maximum width of the header graph is b, b is known, and G (a- (width+space), a), G (a+ (width+space), a), G (a, a) of the weight of each line end is known, and then the widths of the header graph to be added corresponding to each line end are G (a- (width+space), a) ×b, G (a+ (width+space), a) ×b, G (a, a) ×b, respectively.
The header pattern may be generated according to the width of the header pattern and the length of the header pattern.
And generating the head graphics according to the width and the length of each head graphics to be added.
In one example, in the initial OPC pattern shown in fig. 5, the line ends of the line-type base pattern 51, the line-type base pattern 52, and the line-type base pattern 53 are each added with the corresponding header pattern 60, as shown in fig. 6.
In summary, in the OPC pattern generation method provided in the embodiment of the present application, by generating a base pattern generation library, calling the base pattern generation library, generating a base pattern according to a predetermined design pattern, and combining the base patterns to generate an initial OPC pattern, obtaining coordinates of line ends in the initial OPC pattern, calculating weights of the line ends according to a weighting function and the coordinates of the line ends, taking a product of the weights of the line ends and a single-side maximum width of a head pattern as a width of the head pattern to be added, generating a head pattern according to a size of the head pattern to be added corresponding to each line end for each line end in the initial OPC pattern, and adding a corresponding head pattern to each line end to obtain a target OPC pattern; the problem that the conventional OPC graphics are low in efficiency and easy to make mistakes is solved; the method achieves the effects of automatically generating the OPC graphics, optimizing the simulation result of the OPC graphics and improving the generation speed and accuracy of the OPC graphics.
From the above, it is obvious that, in different OPC patterns, the pitch of the base patterns is different, the size of the base patterns is different, and the positions of the line ends are different, if the sizes of the head patterns are all the same, it is unreasonable, because the sizes of the head patterns are affected by the pitch of the line ends and the sizes of the base patterns, determining the sizes of the head patterns by weighted average is more reasonable, calculating the weights of the line ends in the initial OPC patterns by using a weighted function, and then automatically determining the sizes of the head patterns to be added corresponding to the line ends according to the weights of the line ends.
It should be noted that, when OPC patterns with different sizes need to be generated, only the predetermined design pattern needs to be changed, and the steps 301 to 304 or the steps 401 to 410 are executed by using a computer program, so that the target OPC patterns with different sizes can be generated conveniently and rapidly.
It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While nevertheless, obvious variations or modifications may be made to the embodiments described herein without departing from the scope of the invention.
Claims (7)
1. A method of generating OPC graphics, the method comprising:
generating a basic graph generating library, wherein the basic graph generating library is used for generating a basic graph, and the shape of the basic graph comprises a line type and a hole type;
calling the basic graph generation library, generating a basic graph according to a preset design graph, and combining the basic graph to generate an initial OPC graph;
determining the size of the head graph to be added by using a weighting function and the line end position in the initial OPC graph;
adding a corresponding head graph to the line end in the initial OPC graph according to the size of the head graph to be added to obtain a target OPC graph;
wherein the determining the size of the head pattern to be added to the initial OPC pattern using the weighting function and the line end position includes:
acquiring coordinates of a line end in the initial OPC graph;
calculating the weight of the line end according to the weighting function and the coordinates of the line end;
taking the product of the weight of the line end and the unilateral maximum width of the head graph as the width of the head graph to be added, wherein the length of the head graph to be added is known.
2. The method of claim 1, wherein said calculating the weight of the line end from the weighting function and the coordinates of the line end comprises:
and carrying the coordinates of the line end into the weighting function, and calculating to obtain the weight of the line end.
3. A method according to any one of claims 1 to 2, wherein the weighting function is a gaussian function.
4. The method according to claim 1, wherein adding a corresponding header pattern to a line end in the initial OPC pattern according to the size of the header pattern to be added, to obtain a target OPC pattern, includes:
generating a head graph according to the size of the head graph to be added corresponding to each line end in the initial OPC graph, wherein the size of the head graph comprises the width and the length of the head graph;
and adding a corresponding head graph to each line end to obtain the target OPC graph.
5. The method of claim 1, wherein invoking the base graphic generation library to generate a base graphic from a predetermined design graphic comprises:
determining the shape and the size of a basic pattern to be generated according to the preset design pattern;
and calling the basic graph generation library, and generating the basic graph according to the shape and the size of the basic graph to be generated.
6. The method of claim 1, wherein the combining the base graphic to generate an initial OPC graphic comprises:
determining the combination rule and the position relation of the generated basic graph according to the preset design graph, wherein the position relation at least comprises basic graph spacing;
and combining the generated basic graph according to the combination rule and the position relation to obtain an initial OPC graph.
7. The method of claim 5, wherein the dimensions of the linear base pattern include line length, line width.
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