LOW-TEMPERATURE GROWTH OF GAN FILMS ON GAAS(100) SUBSTRATES BY HOT PLASMA CHEMICAL-VAPOR-DEPOSITION

This work presents low-temperature growth of GaN films on GaAs (100) s ubstrates by radio frequency nitrogen hot plasma with power up to 5 kW . This nitrogen hot plasma provides abundant nitrogen atoms as nitroge n source for growth of GaN films which results in a growth rate as hig h as 4 mu m/h. In addition, for the first time, GaN films can be grown at room temperature by using only triethylgallium as Ga source, in wh ich triethylgallium is effectively dissociated by the strong vacuum ul traviolet emissions from the hot plasma. Low-temperature photoluminesc ence (18 K) of the sample grown at room temperature shows strong blue emission with broad region from 3.5 to 2.1 eV and main emission peak a t 2.997 eV. X-ray diffraction and transmission electron microscopy res ults show that GaN films grown at low-temperature have a mixed structu re of cubic, hexagonal and amorphous phases; however, GaN films grown at 600 degrees C have mainly a cubic structure.