Fabrication and properties of A1N film on GaN substrate by using remote plasma atomic layer deposition method

Abstract

A1N films on n-type GaN (0001) were prepared using a remote-plasma atomic-layer-deposition (RPALD) technique with a trimethylaluminum(TMA) precursor and nitrogen/hydrogen, argon/hydrogen radicals ranging in temperature from room temperature (RT) to 500°C. The growth rate per cycle was varied with the substrate temperature from 2.3 Å/ cycle at R. T. to 0.9 Å/cycle at 500°C. X-ray diffraction results showed that the as-grown AlN films on GaN substrates had amorphous phase structures. The estimated interface trap density measured was about 2.4 × 10¹¹/cm²eV at 1.08 eV below the conduction band edge. The leakage current densities measured at room temperature was about 5 × 10⁻¹⁰ A/cm² under a field of 1 MV/cm.