Effect of substrate temperature and Ga source precursor on growth and material properties of GaN grown by hollow cathode plasma assisted atomic layer deposition

Abstract

-GaN thin films grown by hollow cathode plasmaassisted atomic layer deposition (HCPA-ALD) at two different substrate temperatures (250 and 450 °C) are compared. Effect of two different Ga source materials named as trimethylgallium (TMG) and triethylgallium (TEG) on GaN growth and film quality is also investigated and reviewed. Films were characterized by X-ray photoelectron spectroscopy, spectroscopic ellipsometery, and grazing incidence X-ray diffraction. GaN film deposited by TMG revealed better structural, chemical, and optical properties in comparison with GaN film grown with TEG precursor. When compared on basis of different substrate temperature, GaN films grown at higher substrate temperature revealed better structural and optical properties.

Atomic layer deposition: an enabling technology for the growth of functional nanoscale semiconductors

“…Deposited films on Si (100) were polycrystalline with hexagonal (002) preferred orientation, however, the same preferred orientation was not observed on c-plane sapphire substrates [131]. Use of HCPEALD was found to be quite effective in decreasing the oxygen impurity within GaN films by more than two orders of magnitude [131][132][133][134][135][136]. Motamedi et al reported PEALD of GaN with Ga(C 2 H 5 ) 3 and forming gas mixture (95% N 2 /5% H 2 ) plasma reactants at 275 °C.…”