Programmable lithography engine (ProLE) grid-type supercomputer and its applications

Abstract

There are many variables that can affect lithographic dependent device yield. Because of this, it is not enough to make optical proximity corrections (OPC) based on the mask type, wavelength, lens, illumination-type and coherence. Resist chemistry and physics along with substrate, exposure, and all post-exposure processing must be considered too. Only a holistic approach to finding imaging solutions will accelerate yield and maximize performance. Since experiments are too costly in both time and money, accomplishing this takes massive amounts of accurate simulation capability. Our solution is to create a workbench that has a set of advanced user applications that utilize best-in-class simulator engines for solving litho-related DFM problems using distributive computing. Our product, ProLE™ (Programmable Lithography Engine), is an integrated system that combines Petersen Advanced Lithography Inc.'s (PAL's) proprietary applications and cluster management software wrapped around commercial software engines, along with optional commercial hardware and software. It uses the most rigorous lithography simulation engines to solve deep sub-wavelength imaging problems accurately and at speeds that are several orders of magnitude faster than current methods. Specifically, ProLE uses full vector thin-mask aerial image models or when needed, full across source 3D electromagnetic field simulation to make accurate aerial image predictions along with calibrated resist models;. The ProLE workstation from Petersen Advanced Lithography, Inc., is the first commercial product that makes it possible to do these intensive calculations at a fraction of a time previously available thus significantly reducing time to market for advance technology devices.In this work, ProLE is introduced, through model comparison to show why vector imaging and rigorous resist models work better than other less rigorous models, then some applications of that use our distributive computing solution are shown. Topics covered describe why ProLE solutions are needed from an economic and technical aspect, a high level discussion of how the distributive system works, speed benchmarking, and finally, a brief survey of applications including advanced aberrations for lens sensitivity and flare studies, opticalproximity-correction for a bitcell and an application that will allow evaluation of the potential of a design to have systematic failures during fabrication.Keywords: lithography, simulation, EDA, TCAD, RET, yield, systematic failure, DFM, PSM, GRID computing IntroductionThe ability of IC designers to simply send a completed layout to a fab and expect high production yields ended with the advent of the sub-wavelength era. As designs reached 130nm feature size and below, design and manufacturing complexity dramatically increased: the addition of non-printing features such as optical proximity correction (OPC) and phase shifters required new levels of simulation to insure functionality and yields. The gap between circuit layout and actual results on sil...

Resist requirements in the era of resolution enhancement techniques

“…Ultimately this means we need to use simulation, lots of it, 1 if we are to succeed. And, excluding the exposure tools for the moment, means that the physical chemistry and material science of resist materials must be well understood and their behavior must be something we can accurately model so that we can find imaging problems or litho related systematic failures a priori, and solve them before they occur in the fab.…”