Diffusion of implanted Ge and Sn in β-Ga2O3.

The n-type dopants, Ge and Sn, were implanted into bulk (−201) β-Ga₂O₃ at multiple energies (60, 100, 200 keV) and total doses of ∼10¹⁴ cm⁻² and annealed at 1100 °C for 10–120 s under either O₂ or N₂ 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 °C anneals. Fitting of secondary ion mass spectrometry profiles was used to obtain the diffusivity of both Ge and Sn, with values at 1100 °C of 1.05 × 10⁻¹¹ cm s⁻¹ for Ge and 2.7 × 10⁻¹³ cm s⁻¹ for Sn for annealing under O₂ ambients. Some of the dopant is lost to the surface during these anneals, with a surface outgas rate of 1–3 × 10⁻⁷ s⁻¹. By sharp contrast, the redistribution of both dopants was almost completely suppressed during annealing in N₂ ambients under the same conditions, showing the strong influence of point defects on dopant diffusivity of these implanted dopants in β-Ga₂O_3. [ABSTRACT FROM AUTHOR]