Photoemission Spectroscopy on photoresist materials: A protocol for analysis of radiation sensitive materials

TL;DR

This paper presents a protocol using photoemission spectroscopy to analyze radiation-sensitive photoresist materials, crucial for understanding chemical changes induced by EUV lithography in advanced device manufacturing.

Contribution

It introduces a detailed protocol for applying photoemission spectroscopy to study chemical modifications in photoresists caused by EUV radiation, addressing measurement-induced sample modifications.

Findings

Photoemission spectroscopy effectively probes chemical bonds in photoresists.

The protocol accounts for sample modifications during high-energy photon exposure.

Insights into EUV-induced chemical changes aid in improving photoresist performance.

Abstract

Device architectures and dimensions are now at an unimaginable level not thought possible even 10 years ago. The continued downscaling, following the so-called Moore's law, has motivated the development and use of extreme ultraviolet (EUV) lithography scanners with specialized photoresists. Since the quality and precision of the transferred circuit pattern is determined by the EUV induced chemical changes in the photoresist, having a deep understanding of these chemical changes is of pivotal importance. For this purpose, several spectroscopic and material characterization techniques have already been employed so far. Among them, photoemission can be essential as it not only allows direct probing of chemical bonds in a quantitative way but also provides useful information regarding the generation and distribution of primary and secondary electrons. However, since high energy photons are being employed for characterization of a photosensitive material, modification of the sample during the measurement is possible and this must be considered when investigating the chemical changes in the photoresist before and after exposure to EUV light.