Transport mechanisms at Ni-Si Schottky barriers for spin injection

摘要

Spin injection from a magnetic metal into a semiconductor requires spin conservation during the transport of electrons. It is particularly interesting because it allows the integration of magnetic devices with microelectronics. The conductivity mismatch problem has been shown to prevent ohmic contacts from being used for spin injection [1]. Instead, Schottky barriers and Ferromagnet/Insulator/Semiconductor contacts have been proposed. It has been shown that electrodeposition is a promising technique for Ni-Si Schottky barriers [2]. In this digest, the transport mechanisms in electrodeposited Ni-Si Schottky barriers are studied. Moderately doped Si shows a high quality Schottky barrier with ultra low reverse leakage and domination of thermionic emission. Tunneling takes over for highly doped Si, giving leakage-free thermionic field emission in reverse bias.