Infrared impurity absorption in n‐type silicon carbide

Abstract

AbstractThe light absorption in the range 2 to 65 μm has been measured in 6H, 15R, and 27R SiC polytypes at 80 and 300 °K. It is shown that at 80 °K there is a broad absorption band in the infrared spectra of each polytype which is associated with electron transitions from the donor level to the conduction band. From the energy position of these bands values of the activation energy were estimated as follows: ΔE = 0.1 eV (6H SiC), ΔE = 0.05eV (27R SiC), and ΔE = 0.04 eV (15R SiC). From the analysis of the fine structure of the absorption in GH SiC at liquid nitrogen temperature three ground levels of the donor impurity in 6H SiC were obtained: two nearly coinciding with the activation energy of about 0.1 eV and one with the activation energy 0.15 eV.