DIFFUSION MODELING OF ZINC IMPLANTED INTO GAAS

The diffusion of implanted zinc in GaAs is studied and modeled for ann ealing temperatures of 625 through 850 degrees C. Secondary ion mass s pectrometry data for the annealed profiles are presented. The substitu tional interstitial diffusion (SID) mechanism is used to explain how t he deviation of the local gallium interstitial concentration from its equilibrium value regulates the Zn diffusion. We are able to simulate both the box shaped profiles resulting from high temperature anneals a nd the kink-and-tail profiles resulting from lower temperature anneals . The simulation results have allowed us to determine Arrhenius relati ons for: the intrinsic diffusion coefficient for implanted Zn, D-Zn(in t) = 0.6075 exp(-3.21 eV/k(B)T) cm(2) s(-1); the equilibrium Ga inters titial concentration, C-lGa = 7.98x10(30) exp(-3.47 eV/k(B)T) cm(-3); and the Ga interstitial diffusion coefficient, D-lGa = 0.4384 exp(-2. 14 eV/k(B)T) cm(2) s(-1). (C) 1997 American Institute of Physics.