Development of a low-temperature GaN chemical vapor deposition process based on a single molecular source H2GaN3

Abstract

We report the development of a simple and highly efficient chemical approach to growing GaN thin films between 150 and 700 °C using a single molecular source, H2GaN3. Uncommonly low-temperature growth of nanocrystalline GaN films with a wurtzite structure is readily achieved at 150–200 °C from the thermodynamically driven decomposition of the precursor via complete elimination of the stable and relatively benign H2 and N2 by-products. Highly oriented columnar growth of crystalline material is obtained on Si at 350–700 °C and heteroepitaxial growth on sapphire at 650 °C. Crucial advantages of this precursor include: significant vapor pressure which permits rapid mass transport at 22 °C; and the facile decomposition pathway of stoichiometric elimination of H2 and N2 over a wide temperature and pressure range which allows film growth at very low temperatures and pressures (10−4–10−8 Torr) with growth rates up to 80 nm per minute.