P-Channel MOSFETs on 4H-SiC {0001} and Nonbasal Faces Fabricated by Oxide Deposition and $hbox{N}_{2}hbox{O}$ Annealing

摘要

In this paper, we have investigated 4H-SiC p-channel metal–oxide–semiconductor field-effect transistors (MOSFETs) with deposited $hbox{SiO}_{2}$ followed by $hbox{N}_{2}hbox{O}$ annealing. In addition to deposited oxides, dry-$hbox{O}_{2}$-grown oxides and $hbox{N}_{2}hbox{O}$-grown oxides were also adopted as the gate oxides of SiC p-channel MOSFETs. The MOSFETs have been fabricated on the 4H-SiC (0001), $(hbox{000}bar{hbox{1}})$, $(hbox{03}bar{hbox{3}}hbox{8})$, and $(hbox{11}bar{ hbox{2}}hbox{0})$ faces. The (0001) MOSFETs with deposited oxides exhibited a relatively high channel mobility of 10 $hbox{cm}^{2}/hbox{V}cdot hbox{s}$, although a mobility of 7 $hbox{cm}^{2}/hbox{V}cdothbox{s}$ was obtained in the (0001) MOSFETs with $hbox{N}_{2}hbox{O}$ -grown oxides. The channel mobility was also increased by utilizing the deposited $hbox{SiO}_{2}$ in the MOSFETs fabricated on nonbasal faces, although the MOSFETs on $(hbox{000}bar{hbox{1}})$ were not operational. Compared with the thermally grown oxides, the deposited oxides annealed in $hbox{N}_{2} hbox{O}$ are effecti-nve in improving the performance of 4H-SiC p-channel MOSFETs.