A 3-D fluid simulation of a dry-etching aluminium hexode reactor

The author presents 3-D numerical simulation of a hexode etching reactor for aluminum wafers based on chlorine based on fluid-dynamic equations. The results include the prediction of flow, pressure, temperature, concentration of different chemical species, etch rate, and uniformity for different processing conditions. It is difficult to establish the true stoichiometry of the aluminum-chlorine surface reaction because both molecular and atomic chlorine etch aluminum once the native oxide layer has been removed, and the surface is constantly bombarded with ions that sputter partially chlorinated compounds. In these circumstances, the reaction has been simplified to the solution of a three-species system, Cl/sub a/, AlCl/sub b/, and a carrier gas, where a and b represent average coefficients for reactant and by product and were fitted to experimental data. The average values obtained correspond to atomic chlorine (a approximately=1) and aluminum dichloride (b approximately=2). The simulation results agree with experimental results for different gas injector designs, flow rates, and loading conditions.<>