Optimal 3D phase-shifting masks in partially coherent illumination.

PSM design for inverse lithography with partially coherent illumination.

Phase-shifting masks (PSM) are resolution enhancement techniques (RET) used extensively in the semiconductor industry to improve the resolution and pattern fidelity of optical lithography. Recently, a set of gradient-based PSM optimization methods have been developed to solve for the inverse lithography problem under coherent illumination. Most practical lithography systems, however, use partia...

Binary and Phase Shifting Mask Design for Optical Lithography

We propose a number of pre-distorted mask design techniques for binary and phase-shifting masks. Our approach is based on modeling the imaging mechanism of a stepper by the Hopkins equations and taking advantage of the contrastenhancement characteristics of photoresist. Optimization techniques such as the branch and bound algorithm and simulated annealing algorithm are used to systematically de...

Characterizing Polarized Illumination in High Numerical Aperture Optical Lithography with Phase Shifting Masks

Towards a Unified Treatment of 3 D Display using Partially Coherent Light

This thesis develops a novel method of decomposing a 3D phase space description of light into multiple partially coherent modes, and applies this decomposition to the creation of a more flexible 3D display format. Any type of light, whether it is completely coherent, partially coherent or incoherent, can be modeled either as a sum of coherent waves or as rays. A set of functions, known as phase...

Simplified Models for Edge Transitions in Rigorous Mask Modeling

A new method is described for very accurate and rapid 3D simulation of alternating phase-shifting masks. This method for arbitrary 2D mask patterns is based on scalar imaging theory and is therefore much faster (200X or more) than rigorous 3D electromagnetic simulation. It is shown that an alternating phase-shifting mask can be decomposed into single openings and, subsequently, accurate scalar ...