Differentiable Edge-based OPC

TL;DR

DiffOPC is a novel differentiable edge-based OPC framework that combines the accuracy of pixel-based methods with industrial practicality, reducing wafer error and manufacturing costs.

Contribution

It introduces a gradient-based optimization approach for edge-based OPC that effectively minimizes wafer error and lowers manufacturing costs, bridging the gap with pixel-based OPC.

Findings

Achieves lower edge placement error compared to existing methods.

Reduces manufacturing cost by half.

Bridges the gap between accuracy and practicality in OPC.

Abstract

Optical proximity correction (OPC) is crucial for pushing the boundaries of semiconductor manufacturing and enabling the continued scaling of integrated circuits. While pixel-based OPC, termed as inverse lithography technology (ILT), has gained research interest due to its flexibility and precision. Its complexity and intricate features can lead to challenges in mask writing, increased defects, and higher costs, hence hindering widespread industrial adoption. In this paper, we propose DiffOPC, a differentiable OPC framework that enjoys the virtue of both edge-based OPC and ILT. By employing a mask rule-aware gradient-based optimization approach, DiffOPC efficiently guides mask edge segment movement during mask optimization, minimizing wafer error by propagating true gradients from the cost function back to the mask edges. Our approach achieves lower edge placement error while reducing manufacturing cost by half compared to state-of-the-art OPC techniques, bridging the gap between the high accuracy of pixel-based OPC and the practicality required for industrial adoption, thus offering a promising solution for advanced semiconductor manufacturing.