Technology related issues regarding fabrication of AlGaN/GaN-based MOSHFETs with GdScO3 as dielectric

• Published in: 2006 International Conference on Advanced Semiconductor Devices and Microsystems pp. 241 - 244
• Main Authors: Heidelberger, G., Roeckerath, M., Steins, R., Stefaniak, M., Fox, A., Schubert, J., Kaluza, N., Marso, M., Luth, H., Kordos, P.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-10-2006
• Subjects: Aluminum gallium nitride; Dielectrics and electrical insulation; Etching; Fabrication; Gallium nitride; HEMTs; Leakage current; MODFETs; MOSHFETs; Ohmic contacts
• DOI: 10.1109/ASDAM.2006.331198

Starting out from our well established process for AlGaN/GaN HFETs, the authors discuss ways to enrich the process in order to fabricate metal-oxide-semiconductor HFETs (MOSHFETs) with a gadolinium scandate (GdScO 3 ) insulation layer. In particular, adequate processing orders, various etching procedures and possible drawbacks of the GdScO 3 deposition process on ohmic contacts are discussed. Making use of the gained knowledge, the authors fabricated GdScO 3 -MOSHFETs for the first time. Compared to a conventional HFET the new device shows a higher saturation drain current and a lower gate leakage current. Nevertheless, the potential insulating properties of GdScO 3 are not fully exploited yet and further optimization of the deposition process is needed