Gallium nitride-based semiconductor stacked structure, method for fabrication thereof, gallium nitride-based semiconductor device and lamp using the device

摘要

A gallium nitride-based semiconductor stacked structure includes a single crystal substrate, a low-temperature buffer layer grown at a low temperature in a region contiguous to the single crystal substrate and a gallium nitride-based semiconductor layer overlying the low-temperature buffer layer. The low-temperature buffer layer possesses therein a single crystal layer formed of a hexagonal Al_XGa_γN-based Group III nitride material containing gallium predominantly over aluminum, wherein 0.5γ≦1 and X+γ=1. The single crystal layer has crystal defects at a smaller density on a (10-10) crystal face than on a (11-20) crystal face. A method for production of the gallium nitride-based semiconductor stacked structure is also disclosed.