Matrix optical process correction
View Patent ↗A method for performing a matrix-based verification technique such as optical process correction (OPC) that analyzes interactions between movement of a fragment on a mask and one or more edges to be created on a wafer. In one embodiment, each edge to be created is analyzed and one or more fragments of a mask are moved in accordance with a gradient matrix that defines how changes in position of a fragment affect one or more edges on the mask. Fragments are moved having a significant effect on an edge in question. Simulations are performed and fragments are moved in an iterative fashion until each edge has a objective within a prescribed tolerance. In another embodiment, each edge has two or more objectives to be optimized. A objective is selected in accordance with a cost function and fragments are moved in a mask layout until each edge has acceptable specification for each objective.
1. A method of preparing data for the creation of one or more photolithographic masks, comprising:
reading layout data that represents a target layout design defining a number of objects to be created on a semiconductor wafer, wherein the objects have edges that are printed on the wafer with at least two printing objectives having defined tolerances;
fragmenting the layout data by adding fragmentation endpoints to define a number of edge fragments, some of which correspond to edges to be printed on a wafer;
analyzing the printing objectives of an edge to be printed on a wafer by:
defining at least two matrix relationships that relate a change in position of two or more edge fragments that correspond to edges within an optical radius of the edge being analyzed to changes in the printing objectives of the edge;
selecting entries in the matrices having an effect on the printing objectives of the edge being analyzed that is greater than a predetermined value; and
moving a position of the edge fragment corresponding to one or more of the selected entries until the printing objectives of the edge being analyzed are within the tolerances.
2. The method of claim 1 , wherein the printing objectives include edge placement error (EPE).
3. The method of claim 1 , wherein the printing objectives include a contrast of the edge.
4. The method of claim 1 , wherein the printing objectives includes a maximum image intensity on a cutline passing through the edge.
5. The method of claim 1 , wherein the printing objectives includes a minimum image intensity on a cutline passing through the edge.
6. The method of claim 1 , wherein the printing objectives includes an image intensity curvature at a target edge position of the edge.
7. The method of claim 1 , wherein the matrix relationships are defined by gradient matrices.
8. A computer storage media including a number of instructions that are executed by a computer system to perform the method of any of claims 1 – 7 .