Structural and Optical Characterization of GaN deposited on (111) Si using Er2O3/Gd2O3 buffer layer

• Main Authors: Ko-Ying Lo, 羅可瑩
• Other Authors: Jyh-Rong Gong
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/67795984819949776895

碩士 === 國立中興大學 === 物理學系所 === 102 === The structural and optical characteristics of GaN film deposited on Er2O3/Gd2O3-coated (111) Si were studied using double-crystal x-ray rocking curve (DCXRC), high resolution transmission electron microscopy (HRTEM) and photoluminescence (PL) spectroscopy in this thesis. By comparing the DCXRC signals of (11 ¯02)GaN and (12 ¯12)GaN asymmetric planes and (0002) GaN symmetric plane, respectively, it was found that, most of the TDs in GaN of the GaN/ Er2O3/Gd2O3/(111)Si sample are type a TDs in nature. Based on the results of DCXRC studies, it is believed that the FWHM of (11 ¯02)GaN and (12 ¯12)GaN asymmetric planes are primarily due to the contributions of the 1/3 <12 ¯10>GaN components of the Burgers vectors of type a and type c+a TDs on the interplanar spacing distortions of (11 ¯02)GaN and (12 ¯12)GaN planes in GaN of the GaN/ Er2O3/Gd2O3/(111)Si sample. Using invisibility criterion g ∙ b = 0, various types of dislocations in GaN film were further identify. HRTEM observations revealed the presence of extrinsic SFs and Frankel PDs in GaN near the GaN/ Er2O3/Gd2O3 hetero-interface. Strong PL emissions indicate that high quality GaN can be achieved by employing certain optimized Er2O3/Gd2O3 buffer layer structures.