Requirements for the bottom layer of the trilevel resist system are examined with the aid of the SAMPLE simulator. Some conventional positive photoresists and our new bottom layer material RG-3900B are evaluated as a bottom layer. RG-3900B is a phenolic resin mixed with a novel azide compound. It is found that RG-3900B has the following excellent optical properties with relatively short baking time at about 200°C; it strongly absorbs the exposing light and is transparent at visible regions for alignment. Therefore, when applied as a bottom layer, it minimizes linewidth variations on highly reflective substrate topography without degradation of alignment accuracy. RG-3900B has been successfully applied to our various devices with multilevel metalization to obtain fine patterns.

Date Published: 9 July 1986
PDF: 7 pages
Proc. SPIE 0631, Advances in Resist Technology and Processing III, (9 July 1986); doi: 10.1117/12.963655

Published in SPIE Proceedings Vol. 0631:
Advances in Resist Technology and Processing III
C. Grant Willson, Editor(s)