Comparative study on unpassivated and passivated AlGaN/GaN HFETs and MOSHFETs

• Published in: Physica status solidi. A, Applications and materials science Vol. 203; no. 7; pp. 1876 - 1881
• Main Authors: Heidelberger, G., Bernát, J., Fox, A., Marso, M., Lüth, H., Gregušová, D., Kordoš, P.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.05.2006; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: 73.40.Qv; 90.60.Jv; Applied sciences; Electronics; Exact sciences and technology; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transistors; Aluminium nitride; Empirical method; MIS structure; Output signal; Gallium nitride; Coated material; Inorganic compound; Field effect transistor; Silicon carbide; Thick film; Silicon oxides; Manufacturing; Performance; Voltage capacity curve; Passivation
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.200565249

In this comparative study we investigate AlGaN/GaN‐based unpassivated and passivated HFETs and MOSHFETs with regards to DC‐, RF‐, and power‐performance. For optimal comparability, all devices emanate from the same wafer consisting of a SiC‐substrate, a 3 µm GaN‐ and a 30 nm Al0.28Ga0.72N‐layer. Devices are processed simultaneously to a large extend. Passivated devices are coated with a 10 nm thick SiO2‐layer between the electrodes, MOSHFETs contain a 10 nm thick SiO2‐layer serving as gate‐insulator underneath the gate and as conventional passivation‐layer between the electrodes. Unpassivated devices serve as reference. We present empirical evidence that MOSHFETs outperform both the conventional and the passivated HFETs with respect to DC‐, RF‐, and power‐performance, and we point out the different mechanisms responsible for the behaviour of the devices. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)