Sputter-deposition of NiMnSb magnetic thin films from a composite target onto Si substrates

Abstract

We have deposited ferromagnetic NiMnSb thin films by sputtering from a single composite target onto Si wafer substrates. Similarly to earlier results using glass substrates, we find that a combination of low radio frequency power, low argon pressure, and moderate substrate temperature is successful at directly obtaining stochiometric, single-phase polycrystalline films with the bulk C1_b crystal structure. The use of Si substrates, however, is compatible with standard electronic processing and integration into electronic device structures. The similarity of the films to bulk NiMnSb suggests that the predicted half-metallic (100% spin-polarized) electronic properties of NiMnSb can be reproduced in a magnetically active thin-film device structure.