170-nm gates fabricated by phase-shift mask and top antireflector process
- 8 August 1993
- proceedings article
- Published by SPIE-Intl Soc Optical Eng
- Vol. 1927, 182-189
- https://doi.org/10.1117/12.150423
Abstract
N-channel field effect transistors (FETs) with poly linewidths as small as 170 nm have been fabricated with phase shift mask (PSM) lithography using a 0.45 NA I-line stepper. Narrow poly lines were defined using the edge of a (pi) shifter rectangle with superimposed chrome lines of variable width to produce a range of linewidths. Using a chrome-less phase edge, resist linewidths of 240 nm were obtained at nominal exposure, while + 25% overexposure yielded linewidths of 190 nm. Excellent linewidth control was obtained on the device wafers with 3 (sigma) variation of roughly 20 nm for the resist lines. The use of a top anti-reflector (TAR) process improved linewidth control by approximately 35% relative to a normal single layer resist process. Linewidths were also measured after poly etch and, in the final devices, Leff was measured by electrical testing. Devices fabricated using PSM showed significant improvement in lithographic process latitude over control devices fabricated using conventional chrome masks.This publication has 0 references indexed in Scilit: