Diazonaphthoquinone Molecular Glass Photoresists: Patterning without Chemical Amplification

Abstract

Molecular glass photoresists have attracted increasing attention as next-generation replacements for traditional polymeric resists. Most of those reported so far have been based on a contrast generation mechanism known as chemical amplification, but increasing concerns as to the ultimate resolution obtainable by this process prompted us to investigate nonchemically amplified molecular glass resists. In this submission, we describe the synthesis of a p-tert-butyl calix[4]resorcinarene core functionalized with photoactive diazonapthoquinone groups (DNQ-CR). These materials are characterized using conventional wet chemistry techniques, such as NMR, and their amorphous nature was investigated via powder X-ray diffraction. Lithographic characterization using 405 nm radiation resulted in the formation of positive tone images, with both contrast and sensitivity increasing with the degree of functionalization. Exposure to electron-beam radiation resulted in the formation of negative tone images as small as 60 nm, and a probable cross-linking mechanism is discussed.