skip to main content

Title: Screening of remote charge scattering sites from the oxide/silicon interface of strained Si two-dimensional electron gases by an intermediate tunable shielding electron layer

We report the strong screening of the remote charge scattering sites from the oxide/semiconductor interface of buried enhancement-mode undoped Si two-dimensional electron gases (2DEGs), by introducing a tunable shielding electron layer between the 2DEG and the scattering sites. When a high density of electrons in the buried silicon quantum well exists, the tunneling of electrons from the buried layer to the surface quantum well can lead to the formation of a nearly immobile surface electron layer. The screening of the remote charges at the interface by this newly formed surface electron layer results in an increase in the mobility of the buried 2DEG. Furthermore, a significant decrease in the minimum mobile electron density of the 2DEG occurs as well. Together, these effects can reduce the increased detrimental effect of interface charges as the setback distance for the 2DEG to the surface is reduced for improved lateral confinement by top gates.
Authors:
; ; ;  [1]
  1. Department of Electrical Engineering, Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544 (United States)
Publication Date:
OSTI Identifier:
22299931
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ELECTRON DENSITY; ELECTRONS; INTERFACES; LAYERS; MOBILITY; QUANTUM WELLS; SCATTERING; SEMICONDUCTOR MATERIALS; SHIELDING; SILICON; SILICON OXIDES; STRAINS; SURFACES; TUNNEL EFFECT; TWO-DIMENSIONAL CALCULATIONS