Investigation of electrical properties of P-type 6H-SiC bulk crystal

6H-SiC single crystals with different aluminum doping concentrations were grown by physical vapor transport (PVT) method. Al<sub>2</sub>O<sub>3</sub> powder was used as Al source during the growth and was put into a small crucible to avoid the rapid depletion of aluminum source. The incorporation of Al atoms and electrical properties of p-type 6H-SiC were characterized by secondary ion mass spectroscopy (SIMS) and Hall measurements in Van-der-Pauw configuration, respectively. Results showed that the maximum hole concentration in aluminum concentration of 4×10<sup>18</sup> cm<sup>-3</sup> was 1.3×1017 cm<sup>-3</sup> with Hall mobility of 24.8 cm<sup>2</sup>/V·S and resistivity of 1.89 Ω·cm. The resistivities of samples were investigated in detail by a noncontact resistivity testing system and an innovative contactless resistivity measurement system at room temperature. Results showed that the minimum resistivity of 855 mΩ·cm was obtained at the center region of one wafer with the aluminum content of 4×10<sup>18</sup> cm<sup>-3</sup>. In addition, the resistivity distributions along the growth direction and the radial direction were discussed.

[1]  T. Bessho,et al.  Solution Growth of p-Type 4H-SiC Bulk Crystals with Low Resistivity , 2014 .

[2]  H. Tsuchida,et al.  Low Resistivity, Thick Heavily Al-Doped 4H-SiC Epilayers Grown by Hot-Wall Chemical Vapor Deposition , 2013 .

[3]  D. Queren,et al.  Vapor growth of SiC bulk crystals and its challenge of doping , 2006 .

[4]  P. Wellmann,et al.  High Al-Doping of SiC Using a Modified PVT (M-PVT) Growth Set-Up , 2005 .

[5]  A. Henry,et al.  Aluminum doping of epitaxial silicon carbide , 2003 .

[6]  A. Powell,et al.  High-purity semi-insulating 4H-SiC for microwave device applications , 2003 .

[7]  A. Winnacker,et al.  Aluminum p-type doping of silicon carbide crystals using a modified physical vapor transport growth method , 2002 .

[8]  A. Winnacker,et al.  Study of Boron Incorporation During PVT Growth of p-type SiC Crystals , 2001 .

[9]  A. Winnacker,et al.  Absorption Measurements and Doping Level Evaluation in n-Type and p-Type 4H-SiC and 6H-SiC , 2001 .

[10]  G. Pensl,et al.  Growth of Highly Aluminum-Doped p-type 6H-SiC Single Crystals by the Modified Lely Method , 2001 .

[11]  A. Winnacker,et al.  Investigation of a PVT SiC-Growth Set-up Modified by an Additional Gas Flow , 2001 .

[12]  M. Zafrani,et al.  Static and dynamic characterization of large-area high-current-density SiC Schottky diodes , 1998, 56th Annual Device Research Conference Digest (Cat. No.98TH8373).

[13]  Tsunenobu Kimoto,et al.  Step-controlled epitaxial growth of SiC: High quality homoepitaxy , 1997 .

[14]  R. Johnson,et al.  Status of silicon carbide (SiC) as a wide-bandgap semiconductor for high-temperature applications: A review , 1996 .