Nucleation and growth of polycrystalline SiC

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

Kaiser, M.^1 ; Schimmel, S.^1 ; Jokubavicius, V.^2 ; Linnarsson, M.K.^3 ; Ou, H.^4 ; Syväjärvi, M.^2 ; Wellmann, P.^1

Materials Department 6, University of Erlangen, Martensstrasse 7, D-91058 Erlangen, Germany^1

Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping, Sweden^2

School of Information and Communication Technology, KTH Royal Institute of Technology, SE-16440 Kista, Sweden^3

Department of Photonics Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark^4

关键词: Diffusion limited;    Hexagonal platelets;    Lateral expansion;    Nucleation and growth;    Polycrystalline SiC;    Pyrolytic graphite;    Solid-gas interface;    Thermal equilibrium condition;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/56/1/012001/pdf
DOI  :  10.1088/1757-899X/56/1/012001

来源: IOP

【 摘 要 】

The nucleation and bulk growth of polycrystalline SiC in a 2 inch PVT setup using isostatic and pyrolytic graphite as substrates was studied. Textured nucleation occurs under near-thermal equilibrium conditions at the initial growth stage with hexagonal platelet shaped crystallites of 4H, 6H and 15R polytypes. It is found that pyrolytic graphite results in enhanced texturing of the nucleating gas species. Reducing the pressure leads to growth of the crystallites until a closed polycrystalline SiC layer containing voids with a rough surface is developed. Bulk growth was conducted at 35 mbar Ar pressure at 2250°C in diffusion limited mass transport regime generating a convex shaped growth form of the solid-gas interface leading to lateral expansion of virtually [001] oriented crystallites. Growth at 2350°C led to the stabilization of 6H polytypic grains. The micropipe density in the bulk strongly depends on the substrate used.