Interface Properties of 4H-SiC ( ) and ( ) MOS Structures Annealed in NO

Interface properties of 4H-SiC (112̅0) and (11̅00) walls, the absence of junction FET resistance, and the higher metal-oxide-semiconductor (MOS) structures annealed in nitric oxide are characterized by conductance, high-low, and C-ψ_s methods. Compared with 4H-SiC (0001) MOS structures, generation of very fast interface states by nitridation is much smaller in 4H-SiC (112̅0) and (11̅00). The effective mobility of planar MOSFETs fabricated on Al+-implanted p-body doped to 1×10¹⁷ cm^-3 is 10³ cm²/Vs on (11̅00), 92 cm²/Vs on (112̅0), and 20 cm²/Vs on (0001). The mobility-limiting factors are discussed on the basis of experimental results. The high channel mobilities for (112̅0) and (11̅00) MOSFETs can be correlated with the lower density of fast interface states generated by nitridation.