Modeling of microtrenching and bowing effects in nanoscale Si inductively coupled plasma etching process

Abstract

Plasma etching effects, such as microtrenching and bowing, negatively impact device performance. Modeling of these effects at nanoscale is challenging, and theoretical and experimental investigations are highly desired to gain insights into mechanisms. In this paper, we propose a new plasma etching model based on Monte Carlo simulations with a cellular method. This model considers reactions and ion-enhanced etching and consists of a novel particle reflection algorithm, which is a key factor impacting the etch profile. This model reproduces the adjustable microtrenching and bowing effects in periodic dense trenches with tens of nanometer dimensions. We conduct experiments of Si etching by Cl2 and validate the model by comparing the simulated profile with cross-sectional scanning electron microscope images. This work enables a potential physical model driven process emulation tool toward design technology co-optimization.