High-resolution negative-tone chemically amplified i-line resists

Abstract

Negative tone chemically amplified i-line resists possess several advantages compared to conventional DNQ-Novolak resists. These advantages include excellent lithographic performance at a fast, tunable photospeed, high transparency, high thermal flow stability and improved etch resistance. An additional advantage of using negative resists for logic applications is that the difference in CD for various features (US, Iso L, CH, Trenches, Posts) at a fixed dose is small relative to conventional positive resists1, allowing the maximum potential for printing these features simultaneously.ULTRA_iTM 300/310 are negative acting i-line photoresists with excellent lithographic performance optimized for 90°C PAB/l 10°C PEB processing. These materials offer extremely high resolution capability without microbridging, fast photospeed, and a robust post exposure delay process window with minimal film loss over a period of hours. These resists exhibit extremely low PEB temperature sensitivity (2-3 nm/°C) which is expected to reduce across chip linewidth variation (ACLW). Low optical density permits thick film applications producing high aspect ratio relief images with vertical profiles. Furthermore, addition of appropriate dyes permits resists to be designed for lift-off applications with controlled retrograde profiles.