Apparatus and Method for Optical Proximity Correction under Process Variations

Physical Sciences : Electrical

Available for non-exclusive licensing


  • Zhigang Pan, Ph.D. , Electrical and Computer Engineering
  • Peng Yu, M.S. , Electrical and Computer Engineering

Background/unmet need

Optical proximity correction (OPC) is a key step between the design and manufacturing of integrated circuits (ICs) in nanometer scales.

Invention Description

This invention discloses a new method and apparatus to perform process variation-aware optical proximity correction (PV-OPC). The PV-OPC herein is enabled by variational lithography modeling and calibration which can explicitly and efficiently consider process variations (such as focus and dosage) during the evaluation of silicon images. This invention can be used for Mask Data Preparation (MDP), or mask synthesis, to get a higher yield for IC manufacturing.


  • Can result in better semiconductor manufacturing robustness with respect to the manufacturing process variations
  • Better robustness of post-OPC silicon images under process variations, for both geometrical and electrical characteristics
  • Different from previous OPC technology, which only considers process variation or process window through excessive process sampling (which can be incomplete or too expensive), this invention explicitly considers the entire process variations.


  • Uses a new concept of variational edge placement error (V-EPE).
  • Closed-form formulae or the like may be obtained to speed up the evaluation of V-EPE during OPC operations.
  • Proposes a hue process variation-aware OPC which explicitly considers process variations through more compact models than present OPC technology
  • Uses compact modeling and quick metric evaluation

Market potential/applications

IC design and manufacturing companies