Electron effective mass enhancement in ultrathin gate-oxide Si-MOSFETs

Dragosavac, M., Paul, D.J. , Pepper, M., Fowler, A.B. and Buchanan, D.A. (2005) Electron effective mass enhancement in ultrathin gate-oxide Si-MOSFETs. In: 27th International Conference on the Physics of Semiconductors - ICPS-27, Flagstaff, AZ, USA, 26-30 Jul 2004, pp. 495-496. (doi: 10.1063/1.1994200)

Abstract

The effective mass (m*) of two‐dimensional electrons in Si‐MOSFETs, obtained from measurements of the thermal damping of Shubnikov‐de Haas oscillations, has been studied as a function of electron density for samples with physical gate‐oxide thicknesses of 4.7 nm and 3.1 nm. The electron‐electron interaction‐driven enhancement of m* in both thin‐oxide samples is well described by m*/mb = 0.96 + γrs, where mb is the bare band mass within the plane of confinement, and γ is a constant. Although the results from both sets of samples are in good quantitative agreement with previous experiments on thicker‐oxide MOSFETs, a small but significant difference in γ between the thin‐oxide samples was observed. We speculate that the experiments could provide evidence of a reduction in the mass enhancement due to the screening effect of the gate. The response of m* to changes in the confining potential for the two‐dimensional electron system is also investigated.

• Item Type: Conference Proceedings
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Paul, Professor Douglas
• Authors: Dragosavac, M., Paul, D.J., Pepper, M., Fowler, A.B., and Buchanan, D.A.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Research Group: Semiconductor Devices