Energy relaxation of electrons in the (100) n-channel of a Si-MOSFET: II. Surface phonon treatment

Abstract

The electron energy relaxation is investigated as a function of the “electron temperature” T e in the n-channel of a (100) surface silicon MOSFET device by inspecting the phenomenological energy relaxation time τ ε( T e). τ ε is determined theoretically and compared to experimental results in order to identify the energy relaxation mechanism(s) present at the interface. Two dimensional electron transport is assumed. Single activation temperature (θ) Rayleigh wave scattering and acoustic Rayleigh wave scattering are studied as possible energy loss processes. The effects of electric subbanding near the surface are included. τ ε is calculated for T e ≲ 15 K in the electric quantum limit. We find that a single θ = 12.0 K Rayleigh phonon fits theory to experiment for a single electron inversion density ( N inv) case, but can not provide a fit simultaneously for more than one N inv value. Theory and experiment disagree when Rayleigh wave acoustic scattering is assumed.