Room-temperature detection of spin accumulation in silicon across Schottky tunnel barriers using a metal-oxide-semiconductor field effect transistor structure (invited)

摘要

Using a metal-oxide-semiconductor field effect transistor structure with a high-quality CoFe~+-Si contact, we systematically study spin injection and spin accumulation in a nondegenerated Si channel with a doping density of ～4.5 × 10~(15) cm~(-3) at room temperature. By applying the gate voltage (V_G) to the channel, we obtain sufficient bias currents (I_(Bias)) for creating spin accumulation in the channel and observe clear spin-accumulation signals even at room temperature. Whereas the magnitude of the spin signals is enhanced by increasing I_(Bias) it is reduced by increasing V_G interestingly. These features can be understood within the framework of the conventional spin diffusion model. As a result, a room-temperature spin injection technique for the nondegenerated Si channel without using insulating tunnel barriers is established, which indicates a technological progress for Si-based spintronic applications with gate electrodes.