AVS 51st International Symposium
    Surface Science Thursday Sessions
       Session SS3-ThM

Paper SS3-ThM4
Chemically Assisted Ion Beam Etching of GaAs by Argon and Chlorine Gases: Experimental and Simulation Investigations

Thursday, November 18, 2004, 9:20 am, Room 213B

Session: Halogen and Oxygen Surface Reactions and Etching
Presenter: A. Rhallabi, University of Nantes, France
Authors: A. Rhallabi, University of Nantes, France
M. Gaillard, Veeco, France
L. Elmonser, IMN-LPCM, France
G. Marcos, LPCM-IMN, France
A. Talneau, LPN-CNRS, France
F. Pommereau, OPTO+, France
P. Pagnod, University of Nantes, France
J.P. Landesman, LPCM-IMN, France
N. Bouadma, France Telecom
Correspondent: Click to Email
It is now evident that the improvement of the optical and electrical performances of the III-V components depends on the optimization of the critical process steps such as the dry etch processes especially for the submicron and nanometer devices. The Chemically Assisted Ion Beam Etching (CAIBE) is one of dry etch processes where etching rate and etched surface profile are controlled by the synergy between the reactive neutral species and ion bombardment. This technique uses inert ion bombardment in a reactive gas environment to achieve a separate control between sputtering and chemical etching components. A direct injection of a reactive gas close to the surface avoids the development of chemical reactions in gas phase and allows to have a better control of the transfer of the slopes in the case of mesa structure etching and the anisotropy in the case of trench etching. Experimental investigations of the chlorine and argon CAIBE process for the fabrication of vertical, ultrahigh quality facets in GaAs are reported. The effects of CAIBE process parameters as ion current and energy, chlorine flow rate and substrate temperature on the etching rate and etched GaAs topography evolution have been analyzed. To complete the experimental study, two types of 2D CAIBE model have been developed to predict the etching rate evolution and the etching GaAs profiles through the mask. The first one is an analytical model based on the concept of adsorbed surface fraction by chlorine and the second is based on the Monte-Carlo technique to study the etched surface kinetic. For both models, the simulation and the experiment results agree well with the experiment. Finally, in order to assess the compliance of Cl2/Ar+ CAIBE etching with device applications, 980 nm Ridge lasers have been processed and their electro-optic characteristics have been compared to regular wet-chemical etched ridge stripe.