Molecular weight tailoring in methacrylate 193 nm photoresists

Abstract

A survey of some of the interplays between molecular weight, thermal properties, dissolution behavior, and lithographic performance of methacrylate-based 193 nm polymers is presented. This includes the discontinuities in thermal properties surrounding the polymer critical entanglement molecular weight. Tg versus molecular weight curves for both platforms are in good agreement with predictions of the Gibbs-DiMarzio model and reveal that molecular weight is ca. 8,000 for these systems. Lithographic characterization at, below, and above this molecular weight reveals failure due to fraying and line collapse at low molecular weight, failure due to excessive bottom scumming at high molecular weight, and best performance or near molecular weight.