Thickness variations in photoresist caused by substrate topography, and normal variations in deposited thin films, arc unavoidable sources of linewidth variation in optical lithography. Thin film interference effects cause exposure to vary by large amounts. A new approach to controlling these effects is the use of a top antircficctor (TAR) film on top of the photoresist. In this paper, the performance of a process using a water soluble TAR material is described. Simulation and experimental results arc given which show the effectiveness in controlling wafer reflectivity, and exposure dose in the presence of varying insulator and resist films. The effect of the TAR process on focus and exposure latitude is examined and initial results from device manufacturing are presented.

Date Published: 1 June 1992
PDF: 9 pages
Proc. SPIE 1674, Optical/Laser Microlithography V, (1 June 1992); doi: 10.1117/12.130348

Published in SPIE Proceedings Vol. 1674:
Optical/Laser Microlithography V
John D. Cuthbert, Editor(s)