Normally‐off AlGaN/GaN MOS‐HEMT using ultra‐thin Al0.45Ga0.55N barrier layer. Issue 8 (15th May 2017)

• Record Type: Journal Article
• Authors: Chakroun, Ahmed; Jaouad, Abdelatif; Bouchilaoun, Meriem; Arenas, Osvaldo; Soltani, Ali; Maher, Hassan
• Is Part Of: Physica status solidi. Volume 214:Issue 8(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-05-15
• Subjects: AlGaN -- digital etching -- GaN -- high electron mobility transistors -- metal–oxide–semiconductor structures -- passivation; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201600836
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : In this work, we report on the fabrication of a normally‐off AlGaN/GaN Metal–Oxide–Semiconductor High Electron Mobility Transistor (MOS‐HEMT) using an ultra‐thin Al0.45 Ga0.55 N barrier layer. The AlGaN barrier was thinned down to 1 nm using a digital etching process (Oxidation/Etching) and was followed by a PECVD deposition technique of a 7 nm thick SiOx layer used as gate insulator. Thanks to the thin AlGaN barrier layer (4 nm), only a few digital etching cycles are required to shift the threshold voltage toward positive values. The fabricated normally‐off device exhibits a pinch‐off voltage of +1.1 V, a maximum I DS current of 460 mA mm −1 at V GS = +5 V, an On‐state resistance ( R ON ) of 7.8 Ω · mm and an I ON / I OFF ratio higher than 10 9 . Moreover, the pulsed I DS – V DS and capacitance–voltage ( C–V ) curves versus frequency confirm that there is no damage induced by the digital etching process.