Occurrence of Polytype Transformation during Nitrogen Doping of SiC Bulk Wafer
The polytype structural variations of a set of SiC bulk wafers with different Nitrogen (N) doping levels, prepared by Physical Vapore Deposition (PVD), are studied. The initial growth conditions were used to produce 6H-polytype SiC, which has been approved for the undoped and lightly doped materials. However, when extreme high N-dopants were applied, the obtained wafer was found with 4H- and 15R-polytype features. Our experimental results of HR-TEM and Raman scattering have revealed clearly the polytype transformation, indicating that the inducement of N in the reactor leads to the polytype transformation of the resulted SiC crystal.
Akira Suzuki, Hajime Okumura, Tsunenobu Kimoto, Takashi Fuyuki, Kenji Fukuda and Shin-ichi Nishizawa
J. Chen et al., "Occurrence of Polytype Transformation during Nitrogen Doping of SiC Bulk Wafer", Materials Science Forum, Vols. 600-603, pp. 39-42, 2009