Threshold voltage control with high-temperature gate-oxide annealing in ultrawide bandgap AlGaN-channel MOSHFETs. (1st October 2022)

• Record Type: Journal Article
• Authors: Mollah, Shahab; Hussain, Kamal; Mamun, Abdullah; Alam, Md Didarul; Chandrashekhar, MVS; Simin, Grigory; Khan, Asif
• Is Part Of: Applied physics express. Volume 15:Number 10(2022)
• Publication Date: 2022-10-01
• Subjects: AlGaN MOSHFET -- bulk oxide charge -- interface charge -- threshold shift; Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.35848/1882-0786/ac8bc4
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: We report threshold voltage ( V TH ) control in ultrawide bandgap Al0.4 Ga0.6 N-channel metal oxide semiconductor heterostructure field-effect transistors using a high-temperature (300 °C) anneal of the high- k ZrO2 gate-insulator. Annealing switched the polarity of the fixed charges at the ZrO2 /AlGaN interface from +5.5 × 10 13 cm −2 to −4.2 × 10 13 cm −2, pinning V TH at ∼ (−12 V), reducing gate leakage by ∼10 3, and improving subthreshold swing 2× (116 mV decade −1 ). It also enabled the gate to repeatedly withstand voltages from −40 to +18 V, allowing the channel to be overdriven doubling the peak currents to ∼0.5 A mm −1 .