Fabrication of SiGe quantum devices by electron-beam induced damage

Ryan, J.M., Broers, A.N., Paul, D.J. , Pepper, M., Whall, T.E., Fernandez, J.M. and Joyce, B.A. (1997) Fabrication of SiGe quantum devices by electron-beam induced damage. Superlattices and Microstructures, 21(1), pp. 29-36. (doi: 10.1006/spmi.1996.0137)

Abstract

The effects of electron beam irradiation damage has been investigated in Si/SiGe heterostructures. The damage to SiGe two-dimensional hole gases (2DHGs) was measured as a function of accelerating voltage and electron dose. For 40 keV electrons at a dose of 2 Cm−2(typical PMMA resist values), the material properties were not significantly altered. For 100 keV and higher energy electrons, the irradiated material became more resistive at 300 K as the electron energies were increased. The material became highly resistive at low temperatures and froze out at between 20 and 30 K. The 2DHGs also became more resistive at 300 K when the irradiation dose was increased. A number of narrow channel devices were fabricated on high mobility SiGe two-dimensional electron gases (2DEGs) using the damage technique and gated using Schottky gates. Plateaux were observed in the conductance as a function of gate voltage. Random telegraph signals (RTSs) were observed from a 10μm-wide Hall bar irradiated with 300 keV electrons at a dose of105C m−2.

• Item Type: Articles (Letter)
• Additional Information: The work in this paper was supported by EPSRC. One of the authors (J.M.F.) wishes to acknowledge financial support through a European Union Human Capital and Mobility Fellowship.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Paul, Professor Douglas
• Authors: Ryan, J.M., Broers, A.N., Paul, D.J., Pepper, M., Whall, T.E., Fernandez, J.M., and Joyce, B.A.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Research Group: Semiconductor Devices
• Journal Name: Superlattices and Microstructures
• Publisher: Elsevier
• ISSN: 0749-6036
• ISSN (Online): 1096-3677