Raman Scattering and Carrier Diffusion Study in Heavily Co-doped 6H-SiC Layers

EMRS 2013 Spring Meeting, Symposium G: Alternative approaches of SiC and related wide bandgap materials in light emitting and solar cell applications

Gulbinas, K.^1 ; Šcajev, P.^1 ; Bikbajavas, V.^1 ; Grivickas, V.^1 ; Korolik, O.V.^2 ; Mazanik, A.V.^2 ; Fedotov, A.K.^2 ; Jokubaviius, V.^3 ; Linnarsson, M.K.^4 ; Syväjärvi, M.^3 ; Kamiyama, S.^5

Institute of Applied Research, Vilnius University, Vilnius, Lithuania^1

Department of Energy Physics, Belarusian State University, Minsk, Belarus^2

Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden^3

School of Information and Communication Technology, Royal Institute of Technology, Kista, Sweden^4

Faculty of Science and Technology, Meijo University, Nagoya, Japan^5

关键词: Ambipolar diffusion coefficients;    Boron concentrations;    Carrier diffusions;    Compensation ratio;    Donor-acceptor pairs;    High injection;    Sublimation methods;    Transient grating technique;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/56/1/012005/pdf
DOI  :  10.1088/1757-899X/56/1/012005

来源: IOP

【 摘 要 】

Thick 6H-SiC epilayers were grown using the fast sublimation method on low-off-axis substrates. They were co-doped with N and B impurities of ≈1019cm-3and (4·1016- 5·1018) cm-3concentration, respectively. The epilayers exhibited donor-acceptor pair (DAP) photoluminescence. The micro-Raman spectroscopic study exposed a compensated n-6H-SiC epilayer of common quality with some 3C-SiC inclusions. The compensation ratio of B through 200 μm thick epilayer varied in 20-30% range. The free carrier diffusivity was studied by transient grating technique at high injection level. The determined ambipolar diffusion coefficient at RT was found to decrease from 1.15 cm2/s to virtually 0 cm2/s with boron concentration increasing by two orders.