Electron power loss in the (100) n channel of a Si metal-oxide-semiconductor field-effect transistor. I. Intrasubband phonon scattering

Abstract

The electron energy relaxation is studied as a function of the ‘‘electron temperature’’ T_e in the n channel of a (100) surface silicon MOSFET (metal‐oxide‐semiconductor field‐effect transistor) device by inspecting the phenomenological energy relaxation time τ_ε(T_e) at 4.2 °K, 77 °K, and 300 °K lattice temperatures. τ_ε is theoretically calculated in order to determine the relative contributions of shear horizontal (SH), pressure‐shear vertical (P‐SV), shear vertical‐pressure (SV‐P), total reflection shear vertical pressure (TR), and Rayleigh (R) surface acoustic phonon modes to the electron energy relaxation at the interface. Two‐dimensional electron transport is assumed and the effects of subbanding near the interface are included. Only electron scatter events within subbands are studied (intrasubband). This exhaustive study finds that surface modes do not dominate the electron energy relaxation at the Si–SiO₂ interface at T_L =4.2 °K. Some other mechanism(s) must predominate at T_L =4.2 °K.