Dislocation reduction in GaN thin films via lateral overgrowth from trenches

A technology to reduce the dislocation density in GaN thin films by lateral overgrowth from trenches (LOFT) is reported. In LOFT, a GaN thin film was grown on sapphire substrate first, then trenches were formed into the thin film by etching. GaN material was regrown laterally from the trench sidewalls to form a continuous thin film. The average surface density of threading dislocations is reduced from $8×109/cm2$ in the first GaN thin film to $6×107/cm2$ in the regrown GaN thin film.