Development of Particle-in-Cell Simulation in a Two Dimensional Trench Geometry

TL;DR

This paper presents a 2D electrostatic Particle-in-Cell simulation to study ion anisotropy in trench geometries during plasma etching, revealing how trench width and charge buildup affect anisotropy.

Contribution

It introduces a novel 2D simulation code for trench plasma etching and analyzes how trench dimensions and charge effects influence ion anisotropy.

Findings

Anisotropy is maintained when trench width is smaller than Debye length.

Potential development across the trench can reduce ion anisotropy.

Charge buildup on trench bottom degrades ion anisotropy.

Abstract

A two dimensional electrostatic Particle-in-Cell simulation code is developed to investigate anisotropy of ions in a trench geometry for plasma etching. The numerical simulation results suggest that if the trench width is larger than Debye length scale, anisotropy can be lost due to potential development across the trench. Furthermore, the effects of ion charge build up on the trench bottom is investigated, which can degrade the anisotropy.