Investigation of boron diffusion in 6H-SiC

Abstract

p -type doping of 6H-SiC was implemented by diffusion of boron at temperatures higher than 1900 °C. The doping profiles were clearly divided into steep (zone I) and long-tail (zone II) regions. The boron diffusions in both regions are well fitted by erfc functions but with different diffusion coefficients, which are an activation energy (EA) of 6.1 eV and a prefactor (D0) of 3.2 cm2/s for zone I and 4.6 eV and 0.1 cm2/s for zone II, respectively. Further, it has been confirmed that the boron acceptors in zone I are primarily located at shallow energy levels (∼300 meV) and the ones in zone II are located at deep energy levels (∼700 meV).