Numerical Simulation of Gas Phase Reaction for Epitaxial Chemical Vapor Deposition of Silicon Carbide by Methyltrichlorosilane in Horizontal Hot-Wall Reactor.

Botao Song,Bing Gao,Pengfei Han,Yue Yu,Xia Tang

doi:10.3390/ma14247532

Abstract

Methyltrichlorosilane (CH3SiCl3, MTS) has good performance in stoichiometric silicon carbide (SiC) deposition and can be facilitated at relatively lower temperature. Simulations of the chemical vapor deposition in the two-dimensional horizontal hot-wall reactor for epitaxial processes of SiC, which were prepared from MTS-H2 gaseous system, were performed in this work by using the finite element method. The chemistry kinetic model of gas-phase reactions employed in this work was proposed by other researchers. The total gas flow rate, temperature, and ratio of MTS/H2 were the main process parameters in this work, and their effects on consumption rate of MTS, molar fraction of intermediate species and C/Si ratio inside the hot reaction chamber were analyzed in detail. The phenomena of our simulations are interesting. Both low total gas flow rate and high substrate temperature have obvious effectiveness on increasing the consumption rate of MTS. For all cases, the highest three C contained intermediates are CH4, C2H4 and C2H2, respectively, while the highest three Si/Cl contained intermediates are SiCl2, SiCl4 and HCl, respectively. Furthermore, low total gas flow results in a uniform C/Si ratio at different temperatures, and reducing the ratio of MTS/H2 is an interesting way to raise the C/Si ratio in the reactor.

Highlights

Since it has good performance on resistance to high temperature [1] and the ability to work under extremely harsh conditions with exceptional functionalities [2], silicon carbide (SiC) became an attractive material for power electronics and optoelectronics applications [1,3]
Computational fluid dynamics, and heat and mass transfer coupled in the models deliver great contributions in these simulations to calculate the temperature distribution, gas phase velocity distribution, and molar fractions of intermediate species formed inside the reactor for each case
Simulations of the MTS-H2 gaseous system occurring in a two-dimensional horizontal hot-wall chemical vapor deposition (CVD) reactor model were calculated by using finite element method

Summary

Introduction

Since it has good performance on resistance to high temperature [1] and the ability to work under extremely harsh conditions with exceptional functionalities [2], silicon carbide (SiC) became an attractive material for power electronics and optoelectronics applications [1,3]. Methyltrichlorosilane (CH3 SiCl3 , MTS) is one of the chlorides contained species and can be used as the precursor gas for hot-wall chemical vapor deposition of SiC [17,18,23]. The desired composition of gas phase species inside the reactor greatly affected by the MTS/H2 ratio, temperature and total flow rate [26]. The CVD model for the epitaxial growth process of SiC in a horizontal hot-wall reactor was simulated by using finite element method, which was widely employed in calculations for thermodynamic, computational fluid dynamics (CFD), and chemistry kinetic. MTS/H2 ratio and total flow rate were employed in this work, and their effects on the consumption rate of precursor, molar fractions of major intermediates, and. C/Si ratios based on important intermediates were analyzed in detail

Simulation Modeling

Results and Discussion

C Contained Species

Conclusions