Negative tone chemically amplified i-line resists possess several advantages compared to conventional DNQ-Novolak resist. 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 resist of logic applications is that the difference in CD for various features at a fixed dose is small relative to conventional positive resists, allowing the maximum potential for printing these features simultaneously. ULTRA- i 300/310 are negative acting i-line photoresist with excellent lithographic performance optimized for 90 degrees C PAB/110 degrees 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 which is expected to reduce across chip linewidth variation. 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.
This paper was published in SPIE Proceedings Vol. 3678
Advances in Resist Technology and Processing XVI, Will Conley, Editors, pp.751-765