Temperature Dependence of Raman Scattering in 4H-SiC Films under Different Growth Conditions
WANG Hong-Chao1, HE Yi-Ting2, SUN Hua-Yang2, QIU Zhi-Ren2**, XIE Deng1, MEI Ting3**, Tin C. C.4, FENG Zhe-Chuan5
1Institute of Optoelectronic Material and Technology, South China Normal University, Guangzhou 510631 2State Key Laboratory of Optoelectronic Materials and Technologies and School of Physics and Engineering, Sun YatSen University, Guangzhou 510275 3The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an 710072 4Department of Mechanical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia 5College of Physics Science and Technology, and GXU-NAOC Center for Astrophysics and Space Science, Guangxi University, Nanning 530004
Abstract：The microRaman scattering of 4H-SiC films, fabricated by low pressure chemical vapor deposition under different growth conditions, is investigated at temperatures ranging from 80 K to 550 K. The effects of growth conditions on E2(TO), E1(TO) and A1(LO) phonon mode frequencies are negligible. The temperature dependences of phonon linewidth and lifetime of E2(TO) modes are analyzed in terms of an anharmonic damping effect induced by thermal and growth conditions. The results show that the lifetime of E2(TO) mode increases when the quality of the sample improves. Unlike other phone modes, Raman shift of A1 (longitudinal optical plasma coupling (LOPC)) mode does not decrease monotonously when the temperature increases, but tends to blueshift at low temperatures and to redshift at relatively high temperatures. Theoretical analyses are given for the abnormal phenomena of A1(LOPC) mode in 4H-SiC.
. [J]. 中国物理快报, 2015, 32(4): 47801-047801.
WANG Hong-Chao, HE Yi-Ting, SUN Hua-Yang, QIU Zhi-Ren, XIE Deng, MEI Ting, Tin C. C., FENG Zhe-Chuan. Temperature Dependence of Raman Scattering in 4H-SiC Films under Different Growth Conditions. Chin. Phys. Lett., 2015, 32(4): 47801-047801.
2015, Vol. 32 
