Dimethylgallium Isopropoxide as a New Volatile Source for ALD and MOCVD of Ga2O3

Abstract

Dimethylgallium isopropoxide, Me2GaOiPr, is a gallium analogue of the volatile aluminum source dimethylaluminum isopropoxide, Me2AlOiPr, which was recently commercialized as a precursor for Al2O3. It is a liquid at room temperature and has a reasonably high vapor pressure, high enough for atomic layer deposition and/or metal organic chemical vapor deposition. We employed this precursor in the atomic layer deposition (ALD) and metalorganic chemical vapor deposition (MOCVD) of Ga2O3 thin films. Our ALD process, in which water was used as the oxygen source, showed an apparent ALD temperature window between 300 and 325ºC with a growth rate of ~1.5 Aå/cycle. The MOCVD was performed in the temperature range 450-625ºC with oxygen as the reacting gas. The Ga2O3 films deposited in both processes were found to be stoichiometric and amorphous.