title: Direct growth of freestanding GaN on C-face SiC by HVPE.
abstract: In this work, high quality GaN crystal was successfully grown on C-face 6H-SiC by HVPE using a two steps growth process. Due to the small interaction stress between the GaN and the SiC substrate, the GaN was self-separated from the SiC substrate even with a small thickness of about 100 μm. Moreover, the SiC substrate was excellent without damage after the whole process so that it can be repeatedly used in the GaN growth. Hot phosphoric acid etching (at 240 °C for 30 min) was employed to identify the polarity of the GaN layer. According to the etching results, the obtained layer was Ga-polar GaN. High-resolution X-ray diffraction (HRXRD) and electron backscatter diffraction (EBSD) were done to characterize the quality of the freestanding GaN. The Raman measurements showed that the freestanding GaN film grown on the C-face 6H-SiC was stress-free. The optical properties of the freestanding GaN layer were determined by photoluminescence (PL) spectra.
authors.affiliation: State Key Lab of Crystal Materials, Shandong University, Jinan, 250100, P. R. China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.affiliation: State Key Lab of Crystal Materials, Shandong University, Jinan, 250100, P. R. China.
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Shao
authors.affiliation: State Key Lab of Crystal Materials, Shandong University, Jinan, 250100, P. R. China.
authors.forename: Yongzhong
authors.initials: Y
authors.lastname: Wu
authors.affiliation: State Key Lab of Crystal Materials, Shandong University, Jinan, 250100, P. R. China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Hao
authors.affiliation: State Key Lab of Crystal Materials, Shandong University, Jinan, 250100, P. R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Lab of Crystal Materials, Shandong University, Jinan, 250100, P. R. China.
authors.forename: Yuanbin
authors.initials: Y
authors.lastname: Dai
authors.affiliation: State Key Lab of Crystal Materials, Shandong University, Jinan, 250100, P. R. China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Huo