Impact Of Oxygen Diffusion On The Performance Of HfO2/GaAs Metal-oxide-semiconductor Field-effect-transistors

¹Centre for Research in Nanoscience and Nanotechnology (CRNN), University of Calcutta, JD2 Sector-III, Saltlake, Kolkata 700098, India

²Department of Electronic Science, 92 APC Road, University of Calcutta, Kolkata 700009, India

³Institute of Materials Research and Engineering, A*STAR, (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602, Singapore

Adv. Mater. Lett., 2016, 7 (2), pp 123-129

DOI: 10.5185/amlett.2016.6277

Publication Date (Web): Jan 04, 2016

Copyright © IAAM-VBRI Press

E-mail: scelc@caluniv.ac.in

Abstract

In the current work, electrical performance of n-channel GaAs MOSFETs with HfO₂ gate dielectrics has been investigated by considering the impact of oxygen diffusion from gate dielectric layer. Initially, the HfO₂/GaAs MOS capacitors are fabricated and its relevant process recipe has been simulated. The key parameters are extracted from both the experimental and simulated results to calibrate the simulator. The extracted parameters are subsequently fed into the simulator to investigate electrical performance of n-channel GaAs MOSFETs with varying gate lengths. The elemental diffusion of oxygen at HfO₂/GaAs interface has also been incorporated since oxygen naturally diffuses into the GaAs layer during deposition and annealing steps and thereby alters the effective doping concentration in the channel. The diffused oxygen has been observed to improve electrical performance parameters such as transconductance and threshold voltage, however, degrades DIBL of the HfO₂/GaAs MOSFET devices.

Keywords

GaAs, HfO₂, MOSFET, threshold voltage, transconductance.