Nitrogen diffusion in the Si growth on GaN by low-pressure chemical vapor deposition

Abstract

Si film has been grown on a wurtzite gallium nitride layer on sapphire by low-pressure chemical vapor deposition. Uniform nitrogen incorporation was found in the Si film at the concentration of 5%, indicating an incorporation-limited process through interstitial diffusion from GaN layer to Si layer. The nitrogen occupied the substitutional sites in the Si film, leading this Si layer to be n-type doping with the carrier concentration of 1.42 × 10¹⁸/cm³ and the hall mobility of 158 cm²/(V s). This is consistent with other calculated and experimental results, which suggest that only 5% nitrogen can occupy the substitutional sites in the nitrogen-doped Si materials.