Byun, D Kim, HJ Hong, CH Park, CS Kim, G Koh, SK Choi, WK Kum, DW 2024-01-21T14:44:54Z 2024-01-21T14:44:54Z 2021-09-05 1999-11-16 0031-8965 https://pubs.kist.re.kr/handle/201004/141834 It has been confirmed that the reactive ion (N-2(+)) beam (RIB) pretreatment of the sapphire substrate at room temperature is an alternative pretreatment method. The chemical and physical status of RIB treated sapphire surface results in the etching of the surface and the formation of a very thin amorphous-like disordered AlON layer under the sapphire surface. The threading dislocation density of GaN on Al2O3(0001) with RIB pretreatment was decreased due to the partial crystallization of the RIB layer during high temperature main growth of GaN. The crystallized region may contribute to the preferential nucleation site for GaN, promoting the 2-D growth mode. In addition, the remaining amorphous layer may absorb lattice strain originating from the lattice misfit between sapphire and GaN film. The optical properties of GaN films have improved with RIB pretreatment. Current observation clearly shows that the RIB pretreatment of the sapphire surface can be used to improve the GaN films grown by metalorganic chemical vapor deposition (MOCVD). English WILEY-V C H VERLAG GMBH DISLOCATION DENSITY EPITAXY GROWTH LAYER New pretreatment method of sapphire for GaN deposition Article 10.1002/(SICI)1521-396X(199911)176:1<643::AID-PSSA643>3.0.CO;2-I 1 PHYSICA STATUS SOLIDI A-APPLIED RESEARCH, v.176, no.1, pp.643 - 648 PHYSICA STATUS SOLIDI A-APPLIED RESEARCH 176 1 643 648 scie scopus 000084032200121 2-s2.0-0033221288 Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Materials Science Physics Article; Proceedings Paper DISLOCATION DENSITY EPITAXY GROWTH LAYER RIB pretreatment