Bevel Correction for Layout Pattern Optical Proximity
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Solution Overview
Problem
In semiconductor manufacturing, deviations in the transfer of layout patterns from photomasks to semiconductor wafers due to optical proximity effects and process parameters compromise the accuracy and performance of integrated circuits, necessitating effective correction methods.
Innovation Solution
A method involving optical proximity correction with bevel correction is applied to layout patterns, where bevels are formed at corners of rectangular sub-patterns and moved towards interactions with neighboring segments under distance limitations to extend the patterns fully, ensuring accurate alignment and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If bevel correction is performed by chopping corners of rectangular sub patterns, then manufacturing precision of layout patterns is improved, but device complexity increases due to additional correction steps and parameters
Solution Approach 1:
The bevel correction is performed in advance during the optical proximity correction stage, before photomask fabrication. By pre-chopping the corners of rectangular sub patterns and calculating optimal bevel positions considering interactions with neighboring segments, the method eliminates the need for post-fabrication adjustments and ensures manufacturing precision is achieved at the design stage.
Solution Approach 2:
The correction method applies local bevel modifications only at specific corner regions where optical proximity effects are most pronounced, rather than uniformly correcting entire patterns. The bevel formation and movement are selectively applied based on local pattern characteristics and distance to neighboring segments, optimizing precision where needed while minimizing unnecessary complexity.
2Manufacturing precision
If bevels are moved toward interactions of neighboring segments to fully extend rectangular sub patterns, then manufacturing precision is improved, but the distance constraint between adjacent sub patterns creates limitations in correction effectiveness
Solution Approach 1:
The method dynamically adjusts bevel position parameters based on the distance between adjacent rectangular sub patterns. When distance exceeds a minimum threshold, bevels are moved toward neighboring segment interactions to fully extend patterns. This parameter-based adaptation allows the correction method to flexibly respond to different pattern densities and spacing conditions, maintaining precision across varying design scenarios.
Data Source
AI summary
A method of correcting a layout pattern is provided in the present invention. The method includes the following steps. A layout pattern including at least two adjacent rectangular sub patterns is provided. The layout pattern is then input into a computer system. An optical proximity correction including a bevel correction is then performed. The bevel correction includes forming a bevel at a corner of at least one of the two adjacent rectangular sub patterns, wherein the bevel is formed by chopping the corner, and moving the bevel toward an interaction of two neighboring segments of the bevel if a distance between the bevel and the other rectangular sub pattern is larger than a minimum value. The angle between a surface of the bevel and a surface of the rectangular sub pattern is not rectangular. The layout pattern is output to a mask after the optical proximity correction.