Growth and Characterizations of Low Temperature GaN Epilayers Using Two-Heater MOCVD Reactor

• Main Author: 陳永翔
• Other Authors: 陳衛國
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/94735309950732283879

碩士 === 國立交通大學 === 電子物理系所 === 100 === In this theses, we use the home-made two-heater MOCVD reactor to grow low-growth temperature(850 ℃) GaN (LT-GaN) thin films. The electrical and optical properties of these samples were investigated by Hall, X-ray diffraction and photoluminescence measurements. Hall measurement results indicate that the optimized V/III ratio of LT-GaN thin films grown by two-heater MOCVD reactor is 10000. The carrier concentration and carrier mobility of LT-GaN thin films is 3.9x1018 cm-3 and 146 cm2/Vs. The LT-photoluminescence (19 K) result shows that the emission is dominated by near band emission. The X-ray diffraction and temperature dependent Hall measurement (TD-Hall measurement) are employed to confirm the scattering mechanism. The X-ray diffraction spectra show that the dislocation density does not change significantly with the various V/III ratios, implying that the dislocations scattering is insignificant in V/III series of GaN films. The TD-Hall measurements indicate that the native defects scattering is the dominated scattering mechanism.