This study examined the insertion effect of an interfacial, 7-nm-thick SiNx and SiOF layer on the performance of p-channel tin monoxide (SnO) field-effect transistors (FETs). The control SnO FETs, which had a thermal SiO2 gate dielectric, exhibited a mobility, gate swing, threshold voltage (VTH) and ION/OFF ratio of 2.8 cm2 V−1s−1, 6.9 V decade−1, 19.0 V, and 1.8 × 103, respectively. The SiNx-inserted SnO FETs showed a loss in drain current modulation due to the creation of interfacial trap states. In contrast, the gate swing and VTH values were improved substantially to 5.4 V decade−1 and 2.0 V for the SiOF-inserted SnO FETs, respectively, whereas the comparable mobility and ION/OFF ratio were preserved. The rationale of the improvement is discussed with respect to Fermi-energy pinning based on the valence band spectra.
- field-effect transistors
- p-type semiconductors