Growth of the GaN films on (0001) sapphire substrates

• Main Author: 王興燁
• Other Authors: 龔志榮
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/98321970208710196484

碩士 === 逢甲大學 === 材料科學研究所 === 86 === 　　GaN films were grown on (0001) sapphire substrates in a temperature range of 500~1000℃ by exposing the substrates to trimethylgallium (TMG) and NH3 one at a time. High quality GaN films were achieved at 800~1000℃ with a thin GaN buffer layer predeposited at 500℃. The linewidth of the (0004) double-crystal rocking curve x-ray diffraction (DCXRD) of a 2.0 μm thick GaN film is about 250~500 arcsec. Increment in growth temperature over a temperature range of 800 ~1000℃ is helpful to suppress the intensity of yellow luminescence and to enhance the luminescence intensity of the near band-to- band emission. Typically, the room temperature photoluminescence intensity ratio of the near band edge emission to the yellow luminescence for an as-grown high quality GaN film is more than one order of magnitude. Best GaN films with superior optical behavior were achieved were achieved at 900℃ with a V/Ⅲ ratio of 5000.9 K PL measurements of these GaN films show strong and sharp near band-to-band emission with almost no yellow luminescence.