Dry etching of a device quality high-k GaxGdyOz gate oxide in CH4/H2-O2 chemistry for the fabrication of III-V MOSFETs

• Published in: Microelectronic engineering Vol. 84; no. 5-8; pp. 1124 - 1127
• Main Authors: LI, X, ZHOU, H, HILL, R. J. W, WILKINSON, C. D. W, THAYNE, I. G
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier Science 01.05.2007
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Microelectronic fabrication (materials and surfaces technology); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transistors; MOSFET; Dry etching; Compound semiconductor; Channel structure; Transistor gate; Multiple layer; III-V compound; Microelectronic fabrication; Reactive ion etching; Gate oxide; Molecular beam epitaxy; High k dielectric; GaxGdj,Oz; Ga2O3(Gd2O3) RIE; III-V MOSFET
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2007.01.045

This paper investigates the reactive ion etching of GaxGdyOz, a device quality high-k gate oxide for the fabrication of III-V metal-oxide-semiconductor field-effect-transistors (MOSFETs) based on high mobility channel device layer structures. The etching of GaxGdyOz (GGO) was performed in an SRS System ET340 with a CH4/H2/O2 based chemistry The GGO high-k gate stacks for GaAs MOSFETs were grown by molecular beam epitaxy in a dual-chamber system. Etching profile was characterised by SEM using a wet chemical HCl/HF/H2O decoration etch to assist layer identification. The effects of etching gas, RF power, and duration of CH4/H2 and O2 gas cycles on etch process were investigated.