Electron Spin Transport in a Metal-Oxide-Semiconductor Si Two-Dimensional Inversion Channel: Effect of Hydrogen Annealing on Spin-Scattering Mechanism and Spin Lifetime

Abstract

Electron spin transport in a two-dimensional Si inversion channel was experimentally and theoretically studied in terms of the electron distribution in the subbands, electron momentum scattering processes, electron momentum lifetime, and spin lifetime. The electrical properties, electron charge transport, and spin transport were investigated by measuring a Si-based spin metal-oxide-semiconductor field-effect transistor with a 10 µm channel length under various bias and temperature conditions (4, 77, 150, and 295 K). In particular, in our unique procedure, the same device was measured before and after annealing to quantitatively clarify the change in the spin transport with lower and higher electron mobilities, by excluding device-to-device variability.Even when the distribution of electrons in the subbands, electron mobility, and temperature were significantly changed, the spin flip probability, which is defined as the ratio of electron momentum lifetime to spin lifetime, is nearly constant at ~1/25000 probably due to the Elliot-Yafet mechanism. The inferred spin conservation lengths at various temperatures were increased 2-50 times with the increase in both the electron mobility and spin drif. With a high electron