In this study, the effects of the doping concentration of n-type GaN on AI/HfO2/GaN metal-oxide-semiconductor capacitors that incorporated sputtered HfO2 gate dielectric were determined. Electron mobility decreased and conductivity increased as doping concentration increased. The FWHM of the X-ray rocking curves of GaN(0002) also increased with doping concentration. A positively shifted and stretched capacitor-voltage (C-V) curve relative to the ideal one was obtained. Accumulation capacitance increased slightly as doping concentration increased, increasing the dielectric constant and effective oxide thickness. A moderately doped sample (ND ∼ 2 × 1018) with the lowest flat-band voltage shift (∼1,6V) showed the least stretched C-V curve, and the lowest effective oxide charge (3.2 × 1012 em-3) and interface density (1.2 × 1012 cm-2) among the studied samples. Results of this study significantly contribute to the development of GaN-based metal-oxide-semiconductor field-effect transistors (MOSFETs) or metal-oxide-semiconductor heterojunction field-effect transistors (MOSHFETs).
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)