Shock-Assisted Superficial Hexagonal-to-Cubic Phase Transition in GaN/Sapphire Interface Induced by Using Ultra-violet Laser Lift-Off Techniques
CHEN Wei-Hua1, HU Xiao-Dong1, SHAN Xu-Dong2, KANG Xiang-Ning1, ZHOU Xu-Rong1, ZHANG Xiao-Min1, YU Tong-Jun1, YANG Zhi-Jian1, YOU Li-Ping2, XU Ke1, ZHANG Guo-Yi1
1State Key Laboratory for Mesoscopic Physics and Department of Physics, School of Physics, Peking University, Beijing 1008712Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871
Shock-Assisted Superficial Hexagonal-to-Cubic Phase Transition in GaN/Sapphire Interface Induced by Using Ultra-violet Laser Lift-Off Techniques
CHEN Wei-Hua1, HU Xiao-Dong1, SHAN Xu-Dong2, KANG Xiang-Ning1, ZHOU Xu-Rong1, ZHANG Xiao-Min1, YU Tong-Jun1, YANG Zhi-Jian1, YOU Li-Ping2, XU Ke1, ZHANG Guo-Yi1
1State Key Laboratory for Mesoscopic Physics and Department of Physics, School of Physics, Peking University, Beijing 1008712Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871
Ultra-violet (KrF excimer laser,λ=248nm) laser lift-off (LLO) techniques have been operated to the GaN/sapphire structure to separate GaN from the sapphire substrate. Hexagonal to cubic phase transformation induced by the ultra-violet laser lift-off (UV-LLO) has been characterized by micro-Raman spectroscopy, micro-photoluminescence, along with high-resolution transmission electron microscopy (HRTEM). HRTEM indicates that UV-LLO induced phase transition takes place above the LLO interface, without phase transition under the LLO interface. The formed cubic GaN often exists as nanocrystal grains attaching on the bulk hexagonal GaN. The half-loop-cluster-like UV-LLO interface indicates that the LLO-induced shock waves has generated and played an assistant role in the decomposition of the hexagonal GaN and in the formation of cubic GaN grains at the LLO surface.
Ultra-violet (KrF excimer laser,λ=248nm) laser lift-off (LLO) techniques have been operated to the GaN/sapphire structure to separate GaN from the sapphire substrate. Hexagonal to cubic phase transformation induced by the ultra-violet laser lift-off (UV-LLO) has been characterized by micro-Raman spectroscopy, micro-photoluminescence, along with high-resolution transmission electron microscopy (HRTEM). HRTEM indicates that UV-LLO induced phase transition takes place above the LLO interface, without phase transition under the LLO interface. The formed cubic GaN often exists as nanocrystal grains attaching on the bulk hexagonal GaN. The half-loop-cluster-like UV-LLO interface indicates that the LLO-induced shock waves has generated and played an assistant role in the decomposition of the hexagonal GaN and in the formation of cubic GaN grains at the LLO surface.
[1] Nakamura S and Fasol G 1997 The Blue Laser Diode(Heidelberg: Springer) chap 2 p 21 [2] Kelly M K, Ambacher O, Dahlheimer B, Groos G, Dimitrov R,Angerer H and Stutzmann M 1996 Appl. Phys. Lett. 69 1749 [3] Wong W S, Sands T and Cheung N W 1998 Appl. Phys.Lett. 72 599 [4] Wong W S, Cho Y, Weber E R, Sands T, Yu K M, Kruger J,Wengrow A B and Cheung N W 1999 Appl. Phys. Lett. 751887 [5] Ho H P, Lo K C, Siu G G, Surya C, Li K F and Cheah K W2003 Mater. Chem. Phys. 81 99 [6] Kim J G, Frankel A C, Liu H and Park R M 1994 Appl.Phys. Lett. 65 91 [7] Mashimo T, Nakamura K, Tsumoto K, Zhang Y, Ando S andTonda H 2002 J. Phys.: Condens. Matter 14 10783 [8] Ichiyanagi K, Adachi S, Nozawa S, Hironaka Y and NakamuraK G 2007 Appl. Phys. Lett. 91 31918 [9] Kawai N, Nakamura K G and Kondo K 2004 J. Appl.Phys. 96 4126 [10] Kisielowski C, Kruger J, Ruvimov S, Suski T, Ager J W,Jones E, Liliental Z, Rubin M and Weber E R 1996 Phys. Rev. B 54 17745 [11] Perlin P, Jauberthie-Carillon C, Itie J P, Miguel A S,Grzegory I and Polian A 1992 Phys. Rev. B 45 83 [12] Siegle H, Eckey L, Hoffmann A, Thomsen C, Meyer B K,Schikora D, Hankeln M and Lischka K 1995 Solid State Commun. 96 943 [13] Tabata A, Enderlein R, Leite J R, Silva S W, Galzerani JC, Schikora D, Kloidt M and Lischka K 1996 J. Appl. Phys. 79 4137 [14] Cheng L, Zhou K, Zhang Z, Zhang G, Yang Z and Tong Y 1999 Appl. Phys. Lett. 74 661 [15] Chen W H, Kang X N, Hu X D, Lee R, Wang Y J, Yu T J, YangZ J, Zhang G Y, Shan L, Liu K X, Shan X D, You L P and Yu D P 2007 Appl. Phys. Lett. 91 121114 [16] Kim J H and Holloway P H 2004 Appl. Phys. Lett. 84 711
2009, Vol. 26 
