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

In this paper, we have investigated 4H-SiC p-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) with deposited SiO₂ followed by N₂O annealing. In addition to deposited oxides, dry-O₂-grown oxides and N₂O-grown oxides were also adopted as the gate oxides of SiC p-channel MOSFETs. The MOSFETs have been fabricated on the 4H-SiC (0001), (0001macr), (033macr8), and (112macr0) faces. The (0001) MOSFETs with deposited oxides exhibited a relatively high channel mobility of 10 cm²/V ldr s, although a mobility of 7 cm²/V ldr s was obtained in the (0001) MOSFETs with N₂O-grown oxides. The channel mobility was also increased by utilizing the deposited SiO₂ in the MOSFETs fabricated on nonbasal faces, although the MOSFETs on (0001macr) were not operational. Compared with the thermally grown oxides, the deposited oxides annealed in N₂O are effective in improving the performance of 4H-SiC p-channel MOSFETs.