Atomic scale study of InP etching by Cl₂-Ar ICP plasma discharge

Abstract

A gas phase kinetic model combined to a 3D atomic etching model have been developed to study the etching process of InP under Cl 2 -Ar ICP plasma discharge. A gas phase global kinetic model is used to calculate the reactive particle fluxes implied in the etching mechanisms. The 3D atomic InP etching model is based on the Monte-Carlo kinetic approach where the plasma surface interactions are described in the probability way. The coupling between the plasma chemistry model and the surface etching model is an interesting approach to predict the etched surface properties in term of the etch rate, the surface roughness and surface steochiometry as a function of the operating conditions.A satisfactory agreement is obtained by comparing the experimental and the simulation results concerning the evolution of the main plasma discharge parameters such as the electron density and temperature versus the ICP source power for surface recombination coefficient of atomic chlorine fixed at γ Cl =0.04. On the other hand, simulation results show the effect of the operating conditions on the etched surface roughness and the etch rate evolutions with time in the early stage. Moreover, the simulation results show the correlation between the decrease of the ion to chlorine flux ratio and the decrease of the RRMS as a function of the pressure.

(Invited) Challenges for Etch Technology and the Integration of New Channel Materials Beyond 7 nm

“…The work of Rhallabi and co-workers is a close analogue of the work of Jensen et al in that they combine continuum approaches with insights from classical molecular dynamics to describe an InP etch using a Cl 2 plasma. 33 Required are chemistry studies that can model much better versions of realistic surfaces. DFT model based simulations (e.g., VASP) of gas-surface chemistry of the type used for the description of atomic layer deposition processes or the generation of defects in electronic structures are an essential part of multi physics models for novel channel material etch owing to the complexity of these films.…”

Modeling of InP Etching Under ICP Cl2/Ar/N2 Plasma Mixture: Effect of N2 on the Etch Anisotropy Evolution

“…Their experimental and simulation results showed clearly that the increase of the Cl 2 flow rate and the substrate temperature allows the reduction of the faceting and the trenching in GaAs ridge structures. Rhallabi et al have developed an atomistic approach based on the Monte‐Carlo method connected to the 0D global kinetic model of Ar/Cl 2 to study the plasma surface interaction mechanisms for InP etching 23. Simulation results show the effect of the operating conditions on the etched surface roughness and the etch rate evolutions with time in the early stage.…”