Transport and quantum scattering time in field-effect transistors

A modulated magnetoresistance method was applied to measure the transport (tau(t)) and quantum (tau(q)) scattering times for electrons in Si metal-oxide-semiconductor field-effect transistors. Both tau(t) and tau(q) were determined by self-consistent fitting the derivative of the low-field magnetoresistance and the derivative of Shubnikov-de Haas oscillations. The ratio tau(t)/tau(q) allows to estimate a distance of the electron gas to the plane containing scattering centers to be equal to about 2 nm. This agrees with a mean distance of the electron density to the interface given by self-consistent calculations of the electrostatic potential. Application of the method for nanotransistors is discussed. (c) 2007 American Institute of Physics.