Characteristics of InxGa1 − xN/GaN grown by LPMOVPE with the variation of growth temperature

Abstract

Abstract We have studied the growth of In x Ga 1 − x N/GaN on (0 0 0 1) sapphire substrates. The films were grown in a horizontal MOVPE reactor at the reduced pressure of 100 Torr. In composition, x in In x Ga 1 − x N/GaN grown at 810°C determined by the DCXRD is 0.08 and 0.13 for 770°C. The FWHMs of the DCXRD for (0 0 0 2) diffraction from the In 0.08 Ga 0.92 N and In 0.13 Ga 0.87 N are 11 arcmin and 9 arcmin, respectively, whose difference is considered to be resulted from In dissociation. In addition, we confirmed that the thermal pit density of In 0.08 Ga 0.92 N was higher than that of In 0.13 Ga 0.87 N with the SEM observation. The carrier concentration and mobility of In 0.08 Ga 0.92 N are 3 × 10 18 /cm 3 and 47 cm 2 /V s, and those of In 0.13 Ga 0.87 N are 9 × 10 18 /cm 3 and 70 cm 2 /V s, respectively. In spite of the lower carrier concentration, the mobility of In 0.08 Ga 0.92 N is lower than that of In 0.13 Ga 0.87 N, which is considered to be due to the higher defect density of In 0.08 Ga 0.92 N than that of In 0.13 Ga 0.87 N as can be seen from the result of DCXRD. The FWHMs of band-edge emission peak measured by PL at room temperature were 110 meV at 395 nm for In 0.08 Ga 0.92 N and 120 meV at 410 nm for In 0.13 Ga 0.87 N. The In composition in InGaN increased as the growth temperature decreased, and In was still dissociated at 770°C. Some high-quality InGaN films were grown on GaN films compared with the recent results of others.