AlN/Al0.5Ga0.5N HEMTs with heavily Si-doped degenerate GaN contacts prepared via pulsed sputtering. (1st March 2022)

• Record Type: Journal Article
• Authors: Maeda, Ryota; Ueno, Kohei; Kobayashi, Atsushi; Fujioka, Hiroshi
• Is Part Of: Applied physics express. Volume 15:Number 3(2022)
• Publication Date: 2022-03-01
• Subjects: AlN -- AlGaN -- sputtering -- transistor -- HEMT; Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.35848/1882-0786/ac4fcf
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: This paper reports AlN barrier Al0.5 Ga0.5 N high electron mobility transistors (HEMTs) with heavily Si-doped degenerate GaN contacts prepared by pulsed sputtering deposition. Selectively regrown n-type GaN contacts exhibit typical degenerate properties with the electron concentration and mobility of 2.6 × 10 20 cm −3 and 115 cm 2 V −1 s −1, respectively, resulting in a record low contact resistance R C of 0.43 Ω mm for the AlN/Al0.5 Ga0.5 N HEMTs. The AlN/Al0.5 Ga0.5 N HEMTs displayed a remarkable DC output characteristic with a maximum drain current density of 250 mA mm −1, a transconductance of 32 mS mm −1, and an On/Off ratio >10 6 . The present results show potential overcoming challenges in ohmic contact formation for high-power and high-frequency AlGaN electron devices with high Al composition.