For high speed high mobility devices, the conventional notion of the electron mobility determining the device speed no longer applies. The ballistic transport plays the dominant role. The electron response becomes faster with the mobility increase in a limited range of relatively low mobility values. With a further increase in the electron mobility, first the plasmonic ringing determines the characteristic response time and then the viscous transport becomes dominant for small feature sizes. The minimum response time and the maximum device modulation frequency correspond to the subpicosecond and terahertz ranges, respectively. The recent experiments of the FET switching using femtosecond optical laser pulses are in good agreement with the predicted sub picosecond switching times and demonstrate a larger sensitivity enhancement due to the constructive interference of the impinging THz pulse and the optical pulse field rectified by the device nonlinearity.

Date Published: 18 May 2017
PDF: 5 pages
Proc. SPIE 10194, Micro- and Nanotechnology Sensors, Systems, and Applications IX, 101942M (18 May 2017); doi: 10.1117/12.2261105

Published in SPIE Proceedings Vol. 10194:
Micro- and Nanotechnology Sensors, Systems, and Applications IX
Thomas George; Achyut K. Dutta; M. Saif Islam, Editor(s)