Gamma-Gate MOS-HEMTs by Methods of Ozone Water Oxidation and Shifted Exposure

• Published in: IEEE electron device letters Vol. 32; no. 2; pp. 152 - 154
• Main Authors: LEE, Ching-Sung, YANG, Sheng-Han, LIN, Ming-Yuan
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2011; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Breakdown; Devices; Electron devices; Electronics; Epitaxy; Exact sciences and technology; Fabrication; Field plate; Gallium arsenide; Gamma -gate; Gates; Insulation; Logic gates; metal-oxide-semiconductor high-electron-mobility transistor (MOS-HEMT); Oscillations; Oxidation; Ozone; ozone water oxidation; Passivation; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transistors; Oscillation frequency; Transistor gate; Ozone; Γ-gate; Cut off frequency; High electron mobility transistor; Gate oxide; metal-oxide-semiconductor high-electron-mobility transistor (MOS-HEMT); Oxidation; ozone water oxidation; Gain; Field plate; Damaging; Passivation
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2010.2093501

This letter reports, for the first time, a Γ-gate metal-oxide-semiconductor high-electron-mobility transistor (MOS-HEMT), which can achieve gate-length reduction, improved gate insulation, and formations of a field plate and a full surface passivation within the drain-source region at the same time by using the ozone water oxidation and shifted exposure techniques. The present Γ-gate MOS-HEMT has demonstrated significant improvements of 523% in the two-terminal gate-drain breakdown, 137% in the on -state drain-source breakdown, and 28%/39.3% in the unity-gain cutoff frequency/maximum oscillation frequency (f T /f max ), as compared to a conventional Schottky-gate device fabricated upon the same epitaxial structure by using an identical optical mask.