HIGH PRESSURE VAPOR TRANSPORT OF ZnGeP2: II. THREE-DIMENSIONAL SIMULATION OF GASDYNAMICS UNDER MICROGRAVITY CONDITIONS

The uid dynamics in a vertical reactor for high pressure vapor transport (HPVT) of compound semiconductors is modeled. The modeling is for the growth of II-IV-V 2 chalcopyrite ZnGeP 2 and addresses the ow of dense phosphorus gas at 3:4210 5 Pascals pressure. EEects of density variations on p-polarized reeectance spectroscopy are also examined. The mathematical model for transport processes is described by the full gasdynamic equations (Navier Stokes equations coupled with an equation for energy). In addition, buoyancy eeects are included in the model through the gravitational term in the momentum equation. Numerical results of a 3-D steady ow are presented using a nite element discretization with non-uniform, quadrilateral elements. The numerical simulations were performed to study the eeects of gravitational-induced buoyancy-driven convection ows in HPVT crystal growth. Introduction Non-linear optical interactions in birefringent materials nd applications in phase-matched harmonic generation and frequency mixing. In particular, ZnGeP 2 , which has a high non-linear susceptibility coeecient, has been used for manu