Influence of sputtering parameters on the crystallinity and crystal orientation of AlN layers deposited by RF sputtering using the AlN target

Aluminum nitride (AlN) layers were grown on c-sapphire by radio frequency (RF) sputtering in plasma containing a mixture of argon and nitrogen gas using an AlN target. The influence of nitrogen gas fraction, RF power, and sputtering pressure on crystalline quality and growth rate as well as surface morphology were investigated. Crystalline quality improves as nitrogen gas fraction and RF power increase. The growth rate increases as the RF power increases and decreases as the sputtering pressure increases.