Stability of hydrogen in ScAlMgO4

Hydrogen as ²H was incorporated into ScAlMgO₄ by both ion implantation and by exposure to a plasma at 250°C. In the implanted material diffusion begins at 500°C and most of the hydrogen is lost by ≤ 750°C. This thermal stability for hydrogen retention is considerably lower than for other substrate materials for GaN epilayer growth, such as Al₂O₃ and SiC. There is minimal permeation of ²H from a plasma at 250°C (D_H ≤ 5 × 10^?16 cm² s^?1) in ScAlMgO₄, and thus unintentional hydrogen incorporation into GaN overlayers should be minimal at typical growth temperatures.