Role of electron and ion irradiation in a reliable lift-off process with e-beam evaporation and a bilayer PMMA resist system

TL;DR

This study investigates how electron and ion irradiation affect the reliability of a lift-off process using electron beam evaporation and bilayer PMMA resist, demonstrating a modified setup that eliminates resist damage.

Contribution

It introduces a passive component-based modification to the evaporation chamber that prevents resist shrinkage and blistering, improving lift-off quality.

Findings

Elimination of resist shrinkage and blistering.

Near-perfect deposition results across various materials.

Effective use of passive components in evaporation setup.

Abstract

This paper addresses issues related to cracking and blisters in deposited films encountered in a lift-off process with electron beam evaporation and a bilayer PMMA resist system. The impact of charged particles, i.e. electrons and ions, is investigated using an electron beam evaporation chamber equipped with ring-magnets and a plate electrode placed in front of the sample. By replacing the plate electrode with a hollow cylinder, the modified evaporation setup utilizing passive components allows a complete elimination of resist shrinkage and blistering yielding near perfect deposition results for a large variety of different materials.