Diffusion of implanted Ge and Sn in β-Ga2O3

The n-type dopants, Ge and Sn, were implanted into bulk (-201) beta-Ga2O3 at multiple energies (60, 100, 200 keV) and total doses of similar to 10(14) cm(-2) and annealed at 1100 degrees C for 10-120 s under either O-2 or N-2 ambients. The Ge-implanted samples showed almost complete recovery of the initial damage band under these conditions, with the disordered region decreasing from 130 to 17 nm after 1100 degrees C anneals. Fitting of secondary ion mass spectrometry profiles was used to obtain the diffusivity of both Ge and Sn, with values at 1100 degrees C of 1.05 x 10(-11) cm s(-1) for Ge and 2.7 x 10(-13) cm s(-1) for Sn for annealing under O-2 ambients. Some of the dopant is lost to the surface during these anneals, with a surface outgas rate of 1-3 x 10(-7) s(-1). By sharp contrast, the redistribution of both dopants was almost completely suppressed during annealing in N-2 ambients under the same conditions, showing the strong influence of point defects on dopant diffusivity of these implanted dopants in beta-Ga2O3. Published by the AVS.