Computational study on silicon oxide plasma enhanced chemical vapor deposition (PECVD) process using tetraethoxysilane/oxygen/argon/ helium

摘要

Plasma enhanced chemical vapor deposition (PECVD) of silicon oxide (SiO2) using tetraethoxysilane (TEOS) was investigated theoretically by developing an unprecedented plasma chemistry model in TEOS/O-2/Ar/He gas mixture. In the gas phase reactions, a TEOS molecule is decomposed by the electron impact reaction and/or chemically oxidative reaction, forming intermediate TEOS fragments, i.e., silicon complexes. In this study, we assume that SiO is the main precursor that contributes to SiO2 film growth under a particular process or simulation condition. The surface reaction was also investigated using quantum mechanic& simulations with density functional theory. Based on the gas and surface reaction models, we constructed a computational plasma model for SiO2 film deposition in a PECVD process. The simulation results using CHEMKIN pro and CFD-ACE + have shown that the neutral atomic O and SiO as well as the charged O-2 + are the dominant species to obtain a high deposition rate and uniformity. The spatial distributions of various species in the TEOS/O-2/Ar/He gas mixture plasma were shown in the study. The uniformity of deposited film due to the change in the plasma bulk property was also discussed. (C) 2019 The Japan Society of Applied Physics