Piezoresistance properties of silicon carbide ceramics doped with trivalenet element and nitrogen

Evaluation samples of p-type α-silicon carbide ceramics were first fabricated by glass capsule HIP method using powder mixture of silicon carbide with boron, aluminum, or gallium at various ratios. The resultant p-type silicon carbide ceramics were doped with nitrogen by changing the post-HIP nitrogen gas pressure. The lattice parameter decreased with nitrogen doping pressure indicating that the incorporated nitrogen were dissolved into silicon carbide. In the case of boron and aluminum doped samples, the piezoresistive coefficient decreased with the nitrogen doping pressure, while gallium doped one remained almost constant with doping pressure.