AVS 46th International Symposium
    Plasma Science and Technology Division Monday Sessions
       Session PS-MoP

Paper PS-MoP9
Estimation of Surface Kinetic Parameters and 2D Simulation of InP Pattern Features during CH@sub 4@-H@sub 2@ Plasma Etching

Monday, October 25, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: A. Rhallabi, University of Nantes, France
Authors: A. Rhallabi, University of Nantes, France
L. Houlet, University of Nantes, France
G. Turban, University of Nantes, France
Correspondent: Click to Email
Dry etching pattern-transfer of III-V materials from resist mask is an essential process stage in the fabrication of optical devices because anisotropy and reproducibility are more ensured than that in wet etching as feature dimensions decrease. In this study, 2D model of InP etched surface profile under CH@sub 4@-H@sub 2@ plasma is developed. In order to move the InP etched surface, an improved string algorithm is applied. The surface is approximated by a series of nodes joined by straight line segments which define the surface elements or string. During the displacement of the etched surface, time step is controlled automatically to ensure a good stability of the surface profile. Langmuir adsorption and re-remission of radicals, spontaneous chemical etching and ion sputtering on both adsorbed and not adsorbed surface fraction are considered. The main difficulty to predict the etched surface features is the lack of the kinetic surface parameters. In this study, the etching kinetic parameters (sticking coefficient, etch coefficients on both adsorbed and no adsorbed surface fractions) of the InP surface are proposed by comparing the experimental and simulated etching rate curves as a function of the incident CH@sub 3@ flux. Least square optimization method is applied to deduce such estimated surface parameters. The simulation results show the effect of the plasma and surface kinetic parameters on the topography of the microscopic etched profiles.