Optical proximity correction (OPC) methods and methods of manufacturing masks using the OPC methods
View Patent ↗An optical proximity correction method includes extracting edges of a layout of a pattern on a mask, including at least one edge of the layout that is a curvilinear edge, and generating an optical image of the pattern by applying an edge filter, which includes an any-angle filter corresponding to an angle of the curvilinear edge, to the extracted edges of the layout. The any-angle filter may be generated using source sector rotation to correspond to the angle of the curvilinear edge.
1. An optical proximity correction (OPC) method, comprising:
extracting edges of a layout of a pattern on a mask, including at least one edge of the layout that is a curvilinear edge; and
generating an optical image of the pattern by applying an edge filter, which includes an any-angle filter corresponding to an angle of the curvilinear edge, to the extracted edges of the layout.
2. The OPC method of claim 1 , wherein the any-angle filter is generated using source sector rotation to correspond to the angle of the curvilinear edge.
3. The OPC method of claim 1 , wherein the edge filter comprises a vertical filter and a horizontal filter, which are applied to an orthogonal edge; and wherein the any-angle filter is expressed by applying a weight to the vertical filter and the horizontal filter, according to the following relationship:
AA -filter= w*V -filter+(1− w )* H -filter,
where “AA-filter” designates the any-angle filter, “V-filter” designates the vertical filter, “H-filter” designates the horizontal filter, and “w” designates the weight.
4. The OPC method of claim 3 , wherein w is equivalent to sin 2 θ, where θ designates an average slope with respect to a horizontal line within a set range of the curvilinear edge.
5. The OPC method of claim 1 , wherein the any-angle filter has characteristics that vary as a function of a type of light source used during said generating an optical image.
6. The OPC method of claim 5 , wherein the any-angle filter is generated using source sector rotation in a reflective light source.
7. The OPC method of claim 5 , wherein the any-angle filter is generated using source sector rotation and polarization decomposition in a transmissive light source.
8. The OPC method of claim 7 , wherein polarization decomposition is a method of forming an X, Y, XY, TE, or TM polarization by combining an X polarization and a Y polarization according to positions of a source sector.
9. The OPC method of claim 8 , wherein a polarization of the any-angle filter is expressed as a linear sum of an X polarization and a Y polarization of a vertical filter and a horizontal filter by applying the polarization decomposition and a weight.
10. The OPC method of claim 9 , wherein the polarization of the any-angle filter is equivalent to:
Δ D x x ( r )= w×V x x ( r )+(1− w )×Δ H x x ( r )(2),
where Δ(r) is a signal value of an edge filter value of an edge viewed from a distance r, D x x is an x polarization of the any-angle filter, V x x is an x polarization of the vertical filter, H x x is an x polarization of the horizontal filter, and “w” designates a weight, which is equivalent to sin 2 θ, where θ is the angle of the curvilinear edge.
11. The OPC method of claim 1 , wherein the optical image is a near-field image comprising a first optical image generated using a thin mask approximation and a second optical image generated using the edge filter.
12. The OPC method of claim 1 , wherein said generating the optical image is followed by:
generating an OPC model based on the optical image; and
obtaining design data about the mask by performing a simulation using the OPC model.
13. An optical proximity correction (OPC) method, comprising:
designing a layout of a pattern on a mask;
extracting edges of the layout, including at least a curvilinear edge;
generating a first optical image of the pattern using a thin mask approximation;
generating a second optical image of the pattern by applying an edge filter to the edges of the layout, said edge filter comprising an any-angle filter, which corresponds to an angle of the curvilinear edge.
14. The OPC method of claim 13 , wherein the edge filter comprises a vertical filter and a horizontal filter, which are to be applied to an orthogonal edge; and wherein the any-angle filter is obtained by applying a weight to the vertical filter and the horizontal filter, which corresponds to the angle of the curvilinear edge.
15. The OPC method of claim 13 , wherein the any-angle filter is generated using source sector rotation in a reflective light source; and wherein the any-angle filter is generated using source sector generation and polarization decomposition in a transmissive light source.
16. The OPC method of claim 15 , wherein the polarization decomposition is a method of forming an X, Y, XY, TE, or TM polarization by combining an X polarization and a Y polarization according to positions of a source sector; and wherein a polarization of the any-angle filter is expressed as a linear sum of an X polarization and a Y polarization of a vertical filter and a horizontal filter by applying the polarization decomposition and a weight.
17. The OPC method of claim 13 , wherein generating of the final optical image is followed by:
generating an OPC model based on the final optical image; and
obtaining design data about the mask by performing a simulation using the OPC model.
18. A method of manufacturing a mask, the method comprising:
extracting edges of a layout of a pattern on a mask, including at least a curvilinear edge;
generating an optical image of the pattern by applying an edge filter, which includes an any-angle filter corresponding to an angle of the curvilinear edge, to the edges;
generating an optical proximity correction (OPC) model based on the optical image;
obtaining design data about the mask by performing a simulation using the OPC model;
transmitting the design data as mask tape-out (MTO) design data;
preparing mask data based on the MTO design data; and
performing an exposure process on a substrate for the mask, based on the mask data.
19. The method of claim 18 , wherein the edge filter comprises a vertical filter and a horizontal filter to be applied to an orthogonal edge; and wherein the any-angle filter is generated by applying a weight to the vertical filter and the horizontal filter, which corresponds to the angle of the curvilinear edge.
20. The method of claim 19 , wherein the any-angle filter is expressed by applying a weight to the vertical filter and the horizontal filter, according to the following relationship:
AA -filter= w*V -filter+(1− w )* H -filter,
where “AA-filter” designates the any-angle filter, “V-filter” designates the vertical filter, “H-filter” designates the horizontal filter, and “w” designates the weight; and wherein w is equivalent to sin 2 θ, where θ designates an angle of the curvilinear edge.