Hall measurements as a function of temperature on monocrystalline SiC thin films

Hall measurements were conducted at temperatures up to 1000 K on unintentionally doped n-type β(3C)- and α(6H)-SiC thin films epitaxially grown on both on-axis and vicinal Si (100) and α(6H)-SiC (0001) by chemical vapor deposition. The carrier concentration versus temperature data were analyzed using a compensation model. The β-SiC films grown on Si were highly compensated (N_A/N_D=0.73-0.98). The compensation ratio was not as large in the SiC films grown on α-SiC (N_A/N_D=0.36, for β-SiC on α-SiC, and 0.02, for α-SiC on α-SiC). The donor ionization energy for β-SiC on Si was calculated to be 14-21 meV. Analogous values for β- and α-SiC films on α-SiC were 33 and 84 meV, respectively. These values are smaller than those for N determined from photoluminescence studies.