Numerical Simulation and Parametric Study of Carbon Deposition During Graphene Growth in PECVD System

Abstract

The aim of the present work is to understand the carbon deposition during graphene growth in plasma enhanced chemical vapor deposition system containing Ar/C2H2/H2 gas mixture and to optimize the process parameters for the enhanced growth of graphene. In this regard, many numerical simulations have been carried out using two-dimensional axis-symmetrical inductively coupled plasma module in COMSOL multi physics 5.2a simulation software. From the simulation outcomes, it is found that the electron density, electron energy density, electric potential, and collisional power losses decrease with an increase in temperature. The number densities of various dominant ions were found to decrease and number densities of dominant neutrals were found to increase with an increase in temperature. During the carbon deposition, the formation of non-uniform horizontal graphene layer has been observed along the substrate and vertically oriented graphene sheet has been observed at the edges of the substrate. It is found that the thickness of horizontal graphene along the substrate and height of vertical graphene at the edges of the substrate increases with an increase in gas temperature. Moreover, the reduction in the carbon deposition on the substrate (growth of parallel graphene) and enhanced growth of vertical graphene sheet have been observed on applying substrate biasing. Our numerical simulation results are in good agreement with existing experimental observations and confirms the adequacy of the computational and simulation approach.