Fabrication and Characterization of Reactively Sputtered AlInGaN Films with a Cermet Target Containing 5% Al and 7.5% In

AlInGaN films were deposited at a substrate temperature in the range of 100–400°C and a radio frequency (RF) output power in the range of 90–150 W on Si (100) by reactive sputtering in an (Ar + N 2 ) atmosphere. A (Ga + GaN) cermet target for sputtering, containing 5 at.% aluminum and 7.5 at.% indium powders, was made by hot pressing the mixed metal powders and ceramic GaN. The effects of substrate temperature and sputtering output power on the formation of AlInGaN films and their electrical and optical properties were investigated. X-ray diffraction results showed that AlInGaN films grew with a preferential m -( 10 1 ¯ 0 ) growth plane and had a wurtzite crystal structure. The film roughness was influenced by the sputtering power and the film composition. The AlInGaN films deposited at 400°C and 150 W had the best crystallinity, and an electron concentration of 4.5 × 10 17 cm −3 , a Hall mobility of 497 cm 2 V −1 s −1 , and an optical bandgap ( E g ) of 2.71 eV.