Deposition-Free Process on Reactor Sidewalls during Si Deposition in Vertical Rotating Disk Reactors

Abstract

An effective deposition-free process that can suppress extraneous deposition on reactor sidewalls during Si deposition from a SiHCl3-H2 gas mixture in a vertical rotating disk (VRD) reactor is proposed. The experimental results indicated that etching (or cleaning) could remove deposition on and around a susceptor, whereas the deposition remained on the sidewalls because the temperature of the sidewalls was estimated to be lower than that of the susceptor. In addition, the Si deposition rate decreased when hydrogen chloride (HCl) gas was added to the inlet carrier hydrogen (H2) gas, and became zero when the inlet concentrations of SiHCl3 and HCl gases were 3 and 7% in the H2 carrier gas, respectively. Based on these experimental results, a numerical analysis was conducted to evaluate a suitable way to provide HCl gas into the VRD reactor for the purpose of suppressing extraneous deposition on the sidewalls. It was numerically predicted that providing HCl gas along the side wall was effective and controllable by adjustment of the concentration and flow rate of additive HCl gas. An experiment was conducted to verify the proposed measure in a commercial VRD reactor and the results showed that it enabled suppression of extraneous deposition during the Si deposition process in a VRD reactor.