Diffusion of dopants and impurities in β-Ga2O3

The understanding and availability of quantitative measurements of the diffusion of dopants and impurities in Ga2O3 are currently at an early stage. In this work, we summarize what is known about the diffusivity of the common donor dopants, Sn, Ge, and Si, as well as some of the deep acceptors, N, Fe, and Mg, and donors, Ir. Two commonly encountered interstitial impurities are H and F, the former through growth and processing ambients and the latter through its use in plasmas used for stripping dielectrics from Ga2O3. Both are found to have high diffusion coefficients and an effect on electrical conductivity, and H shows anisotropy in its diffusion behavior. Si, Ge, and Sn implanted into bulk beta-Ga2O3 at total doses from 2 x 10(13) to 2 x 10(15) cm(-2) and annealed at 1100 & DEG;C for 10-120 s in either O-2 or N-2 ambients showed a significant effect of the annealing ambient on the donor's diffusivity. In the case of O-2 annealing, there was extensive redistribution of the Si, Sn, and Ge across the entire dose range, while, in sharp contrast, the use of N-2 annealing suppressed this diffusion. The N-2 ambient also suppressed loss of dopants to the surface, with > 90% of the initial dose retained after annealing at 1100 & DEG;C for 120 s, compared to 66%-77% with O-2 anneals under the same conditions.& nbsp;& nbsp;

Automated summary

The understanding of dopant and impurity diffusion in gallium oxide is still in its early stages, with high diffusion coefficients of impurities like H and F impacting electrical conductivity. Nitrogen annealing suppresses diffusion and loss of dopants, retaining a higher initial dose compared to oxygen annealing.