Neural-Augmented Optical Correction: High-Fidelity Mask Optimization via Mixed Point Spread Function Learning and Sub-Resolution Assist Feature-Aware Richardson–Lucy Deconvolution
摘要
The proximity effect in optical lithography causes substantial pattern distortions due to diffraction, spherical aberration, and light scattering, severely affecting resolution and pattern fidelity in advanced semiconductor fabrication. This study introduces a hybrid correction methodology that integrates machine learning, deconvolution, and diffraction-aware layout enhancement. A convolutional neural network is trained to classify and quantify the contributions of Gaussian, sinc, and Airy disk point spread functions. A secondary U-shaped convolutional neural network predicts optimal placement of serif and hammerhead features to improve line-end integrity. In parallel, spherical aberration is explicitly modeled and incorporated into the process. The process includes size reduction, followed by Richardson–Lucy deconvolution, and the strategic insertion of sub-resolution assist features (SRAFs) to enhance aerial image contrast. The final corrected pattern achieves significant improvements: peak signal-to-noise ratio (PSNR) of 18.18, structural similarity index (SSIM) of 0.9445, edge normalized cross-correlation (ENCC) of 0.1304, and a deconvolution quality factor (DQF) of 0.9840, demonstrating high-resolution pattern transfer.