Effects of Hydrogen Incorporation on Mg Diffusion in GaN‐Doped with Mg Ions via Ultra‐High‐Pressure Annealing

Abstract

Magnesium (Mg) diffusion in gallium nitride (GaN) is assessed using various Mg dosages and annealing durations at 1300 °C under nitrogen at 500 MPa. Low Mg dosages of 3 × 1013 cm−2 result in diffusion based on Fick's law and a diffusion coefficient of 1.36 × 10−14 cm2 s−1. Ambient hydrogen atoms are also introduced into the specimens during annealing. Hydrogen has a larger diffusion coefficient than Mg but the hydrogen concentration is limited by the surface Mg concentration. After hydrogen atoms reach the Mg diffusion front, they enhance Mg diffusion by forming the Mg–hydrogen complexes. The more rapid Mg diffusion at higher Mg dosages above 1014 cm−2 can be explained by diffusive species involving vacancies and hydrogen.