Method for evaluation of reticle image using aerial image simulator
First Claim
1. A method of analyzing a mask manufacturing process, the method comprising:
- imaging at least a portion of a mask to be used in a wafer structure formation process;
simulating lithographic processing using data received from or derived from the imaging of the portion of the mask, thereby obtaining a first simulated wafer structure;
simulating lithographic processing using mask design data corresponding to the imaged portion of the mask as an input, thereby obtaining a second simulated wafer structure;
comparing the first simulated wafer structure to the second simulated wafer structure;
comparing the first and second simulated wafer structures to an ideal wafer structure representing the desired structure on a fabricated wafer to be transferred by the mask; and
based on the comparing steps, evaluating critical dimension variations across the wafer structure.
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Abstract
A method of evaluating a wafer structure formation process includes extracting the outline of an actual mask pattern, and simulating a lithographic process using the actual mask pattern to obtain a simulated wafer structure. The extracting the outline of the actual mask pattern may include, for example, imaging the actual mask using a scanning electron microscope (SEM). A second simulated wafer structure may also be obtained, by simulating the lithographic process using the ideal mask pattern design that was used in producing the actual mask pattern. Thus the relative contribution of mask pattern effects to overall wafer proximity effects may be evaluated by comparing the two simulated wafer structures, either with each other or against a benchmark such as a desired, ideal structure. This information may then be used to generate optical proximity correction (OPC) mask designs which compensate for mask patterning errors and give better wafer performance. The simulated wafer structures may be overlaid upon one another to allow for a direct comparison and full analysis of CD variations.
64 Citations
19 Claims
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1. A method of analyzing a mask manufacturing process, the method comprising:
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imaging at least a portion of a mask to be used in a wafer structure formation process; simulating lithographic processing using data received from or derived from the imaging of the portion of the mask, thereby obtaining a first simulated wafer structure; simulating lithographic processing using mask design data corresponding to the imaged portion of the mask as an input, thereby obtaining a second simulated wafer structure; comparing the first simulated wafer structure to the second simulated wafer structure; comparing the first and second simulated wafer structures to an ideal wafer structure representing the desired structure on a fabricated wafer to be transferred by the mask; and based on the comparing steps, evaluating critical dimension variations across the wafer structure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification