Normally-Off GaN-on-Si MISFET Using PECVD SiON Gate Dielectric

• Published in: IEEE electron device letters Vol. 38; no. 8; pp. 1090 - 1093
• Main Authors: Kim, Hyun-Seop, Han, Sang-Woo, Jang, Won-Ho, Cho, Chun-Hyung, Seo, Kwang-Seok, Oh, Jungwoo, Cha, Ho-Young
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-08-2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Capacitance; Chemical vapor deposition; Current density; Dielectric breakdown; Dielectrics; Dynamic characteristics; Electric breakdown; Field effect transistors; Gallium nitride; Gallium nitride (GaN); Gallium nitrides; Hysteresis; Logic gates; MIS (semiconductors); MISFETs; normally-off; plasma enhanced chemical vapor deposition (PECVD); Semiconductor devices; Silicon; Silicon oxynitride; silicon oxynitride (SiON); Surface mount technology; Threshold voltage
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2017.2720719

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 12 MV/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 7.85 mQ · cm 2 , and a breakdown voltage of ~640 V at the OFF-state current density of 1 μA/mm. The extracted interface trap density was 1 × 10 12 cm -2 · eV -1 at E c - E t = 0.442 eV, which resulted in negligible hysteresis and excellent dynamic characteristics.