Structure of Velocity Distribution of Sheath-Accelerated Secondary Electrons in Asymmetric RF-DC Discharge

TL;DR

This paper investigates the velocity distribution of sheath-accelerated secondary electrons in asymmetric RF-DC discharges, combining detailed simulations with an analytic model to understand EVDF features.

Contribution

It introduces a new analytic model predicting EVDF structures and provides detailed simulation data on electron impact velocities in RF-DC discharges.

Findings

Ballistic electrons influence electron shading effects.

Peaked and step-like EVDF structures are predicted.

Simulation results confirm the analytic model's predictions.

Abstract

The ballistic population is thought to be responsible for alleviating the electron shading effect and the notching of the photoresist layer. We have performed test-particle simulations where the features in the EVDF of electrons impacting the RF electrode are fully resolved at all energies. An analytic model has been developed to predict existence of peaked and step-like structures in the EVDF.