Deposition of carbon-containing hole injection layers on p-type Al0.8Ga0.2N grown by metalorganic vapor phase epitaxy

Abstract

A carbon-containing amorphous film is deposited on metalorganic-vapor-phase-epitaxy-grown AlN or AlGaN templates by flowing propane, aluminum, and nitrogen gases at 1010 °C. The deposited ∼1-nm-thick layers show p-type conductivity with a sheet carrier density of ∼1 × 1013 cm-2. When the film is deposited on Mg-doped Al0.8Ga0.2N prior to metallization, it acts as a hole injection layer into p-type AlGaN and shows nearly a double increase in hole current. The transmittance of the deposited layer is ∼90% in the 200-400-nm wavelength range. Hence, the deposited layer is a promising hole injection layer into high-Al-content p-type AlGaN.