Ultra-wide bandgap AlGaN metal oxide semiconductor heterostructure field effect transistors with high-k ALD ZrO2 dielectric. (25th October 2019)

• Record Type: Journal Article
• Authors: Mollah, Shahab; Gaevski, Mikhail; Chandrashekhar, MVS; Hu, Xuhong; Wheeler, Virginia; Hussain, Kamal; Mamun, Abdullah; Floyd, Richard; Ahmad, Iftikhar; Simin, Grigory; Eddy, Charles; Khan, Asif
• Is Part Of: Semiconductor science and technology. Volume 34:Number 12(2019)
• Publication Date: 2019-10-25
• Subjects: AlGaN HFET -- AlGaN MOSHFET -- high Al composition -- insulating gate -- atomic layer deposition -- threshold voltage -- fixed interface charges; Semiconductors -- Periodicals; 621.38152
• DOI: 10.1088/1361-6641/ab4781
• Languages: English
• ISSNs: 0268-1242

Abstract

Abstract: We report on Al0.65 Ga0.35 N/Al0.4 Ga0.6 N metal oxide semiconductor heterojunction field-effect transistor (MOSHFET) with high- k ZrO2 gate-dielectric deposited using atomic layer deposition process. As extracted from frequency dependent capacitance–voltage ( CV ) characteristics, the oxide gates resulted in an interfacial state trap density of ∼2 × 10 12 cm −2 . A comparative study, on the same material, shows the gate-leakage current of the ZrO2 MOSHFETs to be lower by five orders; their ON/OFF current ratio (∼10 7 ) to be higher by about four orders and their threshold voltage to decrease (less negative) by 3.5 V with respect to the Schottky gate devices.