The Impact of V/III Ratio on GaN Growth by HVPE

Abstract

Thick GaN films grown with different V/III ratio on sapphire by hydride vapour phase epitaxy have been investigated. The V/III ratio is changed from 240 to 30. All the GaN films, which are n type, show only (0002) oriented peak and have the band emission with no yellow luminescence bands. When V/III ratio is 30, the full width at half maximum of (0002) X-ray rocking curve is the smallest, line-width of the band edge emission is narrow, the surface morphology shows step-flow growth and the growth rate is the highest.