Effect of barrier recess on transport and electrostatic interface properties of GaN-based normally-off and normally-on metal oxide semiconductor heterostructure field effect transistors. (November 2016)

• Record Type: Journal Article
• Authors: Capriotti, M.; Bahat Treidel, E.; Fleury, C.; Bethge, O.; Ostermaier, C.; Rigato, M.; Lancaster, S.L.C.; Brunner, F.; Detz, H.; Hilt, O.; Würfl, J.; Pogany, D.; Strasser, G.
• Is Part Of: Solid-state electronics. Volume 125(2016)
• Page Start: 118
• Page End: 124
• Publication Date: 2016-11
• Subjects: Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2016.07.009
• Languages: English
• ISSNs: 0038-1101

Abstract

Abstract: We perform a comprehensive electrical transport and physical characterization of metal oxide semiconductor heterostructure field effect transistors with ZrO2 gate dielectrics, having partially (referred here as MOS-HFET) and fully (here called true-MOS-FET) recessed GaN/AlGaN/GaN barrier, giving normally-on and normally-off behavior, respectively. The mobility of the MOS-HFETs decreases with the proximity of the Coulomb scattering centers, situated at the ZrO2 /AlGaN interface. The effect of the etching procedure and ZrO2 deposition on the formation of the interfacial charges, N int, is evaluated by X-ray Photoelectron Spectroscopy and by fitting the threshold voltage values to numerical model. For the both device types, the extracted value of N int lies within 15% around 2.8 × 10 13 cm −2, which is of the order of polarization charge, showing that our low-damage three step etching procedure does not introduce extra interface states.