We have developed a silicon oxynitride (SiON) deposition process using a plasma-enhanced chemical vapor deposition system for the gate dielectric of GaN-on-Si metal-insulator-semiconductor field-effect transistors (MISFETs). The optimized SiON film had a relative dielectric constant of 5.3 and a breakdown field of 12MV/cm. A normally-off GaN-on-Si MISFET fabricated with a 33-nm SiON gate dielectric exhibited a threshold voltage of ∼2 V, an ON-resistance of 7.85Ω·cm2, and a breakdown voltage of 640 V at the OFF-state current density of 1 μA/mm. The extracted interface trap density was 1×1012 cm-2·eV-1 at Ec - Et = 0.442 eV, which resulted in negligible hysteresis and excellent dynamic characteristics.
Bibliographical noteFunding Information:
This work was supported by NRF of Korea under Grant 2015R1A6A1A03031833, Grant 2012M3A7B4035274, and Grant 2016R1D1A1B03935445.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering