Reactive etching of SiC by energetic CF₃: molecular dynamics simulation

¹ School of Material Engineering, Southwest university, Chongquing, 400715 P.R. China
² School of Electronic Science and Information Technology, Guizhou University (HuaXi), 550025, Guizhou Province, P.R. China

Corresponding author: g.fujun@gzu.edu.cn

Received: 21 August 2006
Revised: 29 October 2006
Accepted: 2 February 2007
Published online: 21 March 2007

Abstract

Molecular dynamics simulations were performed to investigate CF₃ continuously bombarding SiC surfaces with energies of 10, 50 and 100 eV at normal incidence and room temperature. In the simulation, the deposition yield of C and F atoms from CF₃, the etching yield and rate of C and Si from the initial substrate, and the surface structure profile are discussed. Accompanying the saturation of F atoms from the incident CF₃ molecules deposited on the surface, a balance between C removal from the substrate and C deposition from CF₃ is established, while Si and C etching from the initial substrate reaches a steady state. The simulated results show that the etch rate of Si is more than that of C. A carbon-rich surface layer is observed which is in good agreement with experiments. In the F-containing reaction layer, SiF in SiF_x species is dominant.