LOW-TEMPERATURE ELECTRON-PHONON INTERACTION IN SI MOSFETS

We investigate electron-phonon coupling in a silicon metal-oxide-semic onductor field-effect transistor by measuring heat flow. Earlier studi es of the electron-phonon interaction through similar measurements wer e complicated by electron diffusion, a competing cooling mechanism. We reduce the diffusion by using an unusually long sample, and account f or the remainder by comparing results from two segments of different l ength. We find that the power dissipation from electron-phonon scatter ing is proportional to T-5, with a magnitude smaller than theoreticall y predicted.