AVS 57th International Symposium & Exhibition
    Plasma Science and Technology Thursday Sessions
       Session PS1-ThA

Paper PS1-ThA2
Molecular Cross-Section Calculations Enabling Etch-Profile Simulations of a Microwave Source Silicon Etch using Ar/HBr/O2

Thursday, October 21, 2010, 2:20 pm, Room Aztec

Session: Plasma Modeling
Presenter: J. Munro, University College London, UK
Authors: J. Munro, University College London, UK
J. Tennyson, University College London, UK
S.-Y. Kang, Tokyo Electron Limited, Japan
D. Brown, Quantemol Ltd., UK
Correspondent: Click to Email
The introduction of new microwave plasma sources for Silicon and Silicon-Nitride etch processes has renewed interest in a more detailed understanding of the etch process in a microwave regime. The use of Ar/HBr/O2 for Silicon etching in this regime is common. In particular the inclusion of HBr has been found to reduce "microtrenching" [1]. The etching yields of high density HBr plasmas have been studied previously [2]. Here we study the additional effects of the etching products SiBr and SiBr2 near the wafer.

A set of quantum electron scattering calculations are performed on SiBr and SiBr2 using the electron-molecule code Quantemol-N [3]. The resulting cross-sections are used to complete a set of gas-phase reactions contributing to the etch process. Etch-profile simulations are then performed using the Monte Carlo Feature Profile Model code (MCFPM) [4]. Here we use incident species fluxes derived from simulations of Ar/HBr/O2 plasmas. Results are presented which include an analysis of the contribution of the etch products SiBr and SiBr2.

[1] J. M. Lane, F. P. Klemens, K. H. A. Bogart, M. V. Malyshev, and J. T. C. Lee, J. Vac. Sci. Technol. A 18, 188 (1999)

[2] S. A. Vitale, H. Chae, H. H. Sawin, J. Vac. Sci. Technol. A, 19, 2197 (2001)

[3] J. Tennyson, D. B. Brown , J. J. Munro , I. Rozum , H. N. Varambhia and N. Vinci, J. Phys.: Conf. Ser., 86, 012001 (2007)

[4] R. J. Hoekstra, M. J. Grapperhaus, and M. J. Kushner, J. Vac. Sci. Technol. A 15, 1913 (1997)