Effects of non-equilibrium Sn diffusion into β-Ga2O3 films
摘要
β-Ga2O3 is a potential super wide bandgap semiconductor material. The N-type conductive behavior of β-Ga2O3 may be greatly improved by doping Sn cation or other tetravalent cations. However, the diffusion of Sn cations into β-Ga2O3 under non-equilibrium environment is not clear yet, which may limit the application of β-Ga2O3. In this study, an electron beam evaporation method coupled with post-annealing processing was employed to successfully prepare Sn-doped β-Ga2O3 thin films with different Sn ratios from 3 to 12 at%. The effects of Sn on the structural, electrical, and light emission properties of the films were investigated. Especially, with the addition of 10-at% Sn in the film, the film morphology turns to be uniform, and the film’s electrical properties surpassed the other samples with its resistivity of 503 Ω·cm, the carrier content of 1.3 × 1015 cm−3, and the carrier mobility of 9.654 cm2V−1 s−1. The light emission property was greatly degraded due to the absorption of incidence light by more free carriers. The corresponding electrical compensation mechanism was discussed.