Si(111) 기판 위에 MOCVD 법으로 성장시킨 GaN의 성장 특성에 관한 TEM 분석

• Published in: Biuletyn Uniejowski Vol. 36; no. 2; pp. 135 - 140
• Main Authors: 신희연(Hui-Youn Shin), 정성훈(S.H. Jung), 유지범(J.B. Yoo), 서수정(S.J. Suh), 양철웅(C.W. Yang)
• Format: Journal Article
• Language: Korean
• Published: 한국표면공학회 2003
• Subjects: 기계공학; Metalorganic chemical vapor deposition (MOCVD); Semiconductor; Aluminum nitride (AlN); Transmission electron microscopy (TEM); Gallium nitride (GaN)
• ISSN: 1225-8024; 2299-8403; 2288-8403

The difference in lattice parameter and thermal expansion coefficient between GaN and Si which results in many defects into the grown GaN is larger than that between GaN and sapphire. In order to obtain high quality GaN films on Si substrate, it is essential to understand growth characteristics of GaN. In this study, GaN layers were grown on Si(111) substrates by MOCVD at three different GaN growth temperatures ($900^{\circ}C$, $1,000^{\circ}C$ and $1,100^{\circ}C$), using AlN and LT-GaN buffer layers. Using TEM, we carried out the comparative investigation of growth characteristics of GaN by characterizing lattice coherency, crystallinity, orientation relationship and defects formed (transition region, stacking fault, dislocation, etc). The localized region with high defect density was formed due to the lattice mismatch between AlN buffer layer and GaN. As the growth temperature of GaN increases, the defect density and surface roughness of GaN are decreased. In the case of GaN grown at $1,100^{\circ}$, growth thickness is decreased, and columns with out-plane misorientation are formed.