Silicon (Si) is an efficient n-type dopant in gallium oxide (Ga2O3) - an ultra-wide bandgap semiconductor promising in a number of applications. However, in spite of the technological importance for device fabrication, the activation energy for Si diffusion in Ga2O3 is missing in the literature. In the present work, we do such measurements in ion implanted monoclinic β-Ga2O3 samples employing anneals in air ambient, also admitting the influence of potential ion beam induced phase modifications on diffusion. Importantly, we show that Si diffusion in β-Ga2O3 fits with the concentration dependent diffusion model, involving neutral and single negatively charged point defects to mediate the process; so that we assumed gallium vacancies in the corresponding charge states to assist Si diffusion in β-Ga2O3 with activation energies of 3.2 ± 0.3 and 5.4 ± 0.4 eV, respectively. Moreover, we also found that a preexisting phase modified surface layer efficiently suppressed Si diffusion in β-Ga2O3 for temperatures up to 1000 °C.
Bibliographical noteFunding Information:
This work was performed within the Research Centre for Sustainable Solar Cell Technology (FME SuSolTech, Project No. 257639) and co-sponsored by the Research Council of Norway and industry partners. The Research Council of Norway is acknowledged for the support at the Norwegian Micro-and Nano-Fabrication Facility, NorFab, Project No. 295864. The INTPART Programs at the Research Council of Norway, Project Nos. 261574 and 322382, enabled the international collaboration.
© 2021 Author(s).
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)