Hetero-Epitaxial Growth Of A Gan Film By The Combination Of Magnetron Sputtering With Ar/Cl-2 Gas Mixtures And A Separate Supply Of Nitrogen Precursors From A High Density Radical Source

Hetero-epitaxial growth of a gallium nitride (GaN) film on an AlN(0 0 0 1) buffer layer on a sapphire(0 0 0 1) substrate was demonstrated by supplying gallium precursors and nitrogen radicals separately from two individually operated plasma sources to control the V/III supplying ratio precisely. The sources were a reactive Ar-Cl-2-mixture plasma sputtering of a gallium target and a remote low inductance antenna (LIA) for N-2-H-2 inductively coupled-plasma. Lateral growth of the GaN film was observed in 0.5%-Cl-2-added Ar sputtering at a low growth temperature of 670 degrees C, whilst the growth mode coalesced at temperatures lower than 600 degrees C. With more than 2.0% of Cl-2, no film was deposited due to etching by the reactive chlorine whenever the temperature was at 500 degrees C. At the growth temperature of 670 degrees C, crystallinity with narrow a X-ray rocking curve GaN (0 0 0 2) was obtained at the condition of 0.5% Cl-2 and 27.4% N-2, even though the background pressure was 10(-4) Pa. (C) 2019 The Japan Society of Applied Physics