Quantum Interference Effects in Degenerately Doped Silicon Nanowire Junction-less Transistors

Schupp, F. J., Mirza, M. M.A. , Mol, J.A., MacLaren, D. , Briggs, G.A.D. and Paul, D. (2017) Quantum Interference Effects in Degenerately Doped Silicon Nanowire Junction-less Transistors. Silicon Quantum Information Processing (SiQIP), Lancaster, UK, 11 Sep 2017.

Abstract

We demonstrate quasi-ballistic transport in degenerately-doped silicon nanowire junction-less transistors with 8 ± 0.5 nm channel diameters. Previously we established that a combination of low damage dry etch processes [1] and a high quality surface passivation [2][3] are key to produce high performance devices, where neutral impurity scattering is the dominant scattering mechanism [2]. 1D electron behaviour can be observed even at room temperature [4]. Here we present dc measurements at 13 mK from nanowire transistors doped at 2 x 1020 cm-3 which demonstrate Coulomb blockade with over 500 Coulomb peaks in a single island along the entire nanowire. For Si nanowires doped at a lower 4x1019 cm–3, quantum interference effects including universal conduction fluctuations dominate the transport up to 30 K and allow a phase coherence length of 63 ± 7 nm to be extracted. Further analysis of the fluctuations at mK temperatures allows a mean free path of 10 ± 2 nm to be extracted, significantly higher than the dopant spacing of 2.9 nm. The scattering lengths indicate 1D quasi-ballistic transport in the nanowires with either Coulombic or neutral impurity scattering rather than surface roughness scattering limiting the mobility. Coulomb gap behaviour also indicates strong many body interactions in the nanowires. 1. M.M. Mirza, et al., JVST-B, 30, 06FF02 (2012). 2. M.M. Mirza, et al., Nano Letters 14, 6056 (2014). 3. C. Busche, et. al., Nature 515, 545 (2014). 4. M.M. Mirza, et al., Scientific Reports, 7, 3004 (2017).

• Item Type: Conference or Workshop Item
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Mirza, Dr Muhammad M A and Paul, Professor Douglas and MacLaren, Professor Donald
• Authors: Schupp, F. J., Mirza, M. M.A., Mol, J.A., MacLaren, D., Briggs, G.A.D., and Paul, D.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering; College of Science and Engineering > School of Physics and Astronomy

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