Modulation of the high mobility two-dimensional electrons in Si/SiGe using atomic-layer-deposited gate dielectric

Abstract

Metal-oxide-semiconductor field-effect transistors (MOSFET's) using atomic-layer-deposited (ALD) Al${}_2$O${}_3$ as the gate dielectric are fabricated on the Si/Si${}_{1-x}$Ge${}_x$ heterostructures. The low-temperature carrier density of a two-dimensional electron system (2DES) in the strained Si quantum well can be controllably tuned from 2.5$\times 10^{11}$cm${}^{-2}$ to 4.5$\times 10^{11}$cm${}^{-2}$, virtually without any gate leakage current. Magnetotransport data show the homogeneous depletion of 2DES under gate biases. The characteristic of vertical modulation using ALD dielectric is shown to be better than that using Schottky barrier or the SiO${}_2$ dielectric formed by plasma-enhanced chemical-vapor-deposition(PECVD).

3 pages Revtex4, 4 figures

References in corpus (3)

• The Two-flux Composite Fermion Series of Fractional Quantum Hall States in Strained Si
• Two-dimensional metal-insulator transition and in-plane magnetoresistance in a high mobility strained Si quantum well
• Conductivity of a 2DEG in Si/SiGe heterostructure near metal- insulator transition: role of the short and long range scattering potential

Cited by in corpus (1)

• Silicon Quantum Electronics