Surfaces, Interfaces and Films

Reactive etching of SiC by energetic CF₃: molecular dynamics simulation

F. Gou^a1a2, Z. Chen^a2 and C. Zhiqian^a1

School of Material Engineering, Southwest university, Chongquing, 400715 P.R. China

School of Electronic Science and Information Technology, Guizhou University (HuaXi), 550025, Guizhou Province, P.R. China

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.

(Received August 21 2006)

(Revised October 29 2006)

(Accepted February 2 2007)

(Online publication March 21 2007)

PACS:

• 52.65.Yy – Molecular dynamics methods;
• 81.65.Cf – Surface cleaning, etching, patterning;
• 52.77.Dq – Plasma-based ion implantation and deposition

g.fujun@gzu.edu.cn