High-mobility thin InSb films grown by molecular beam epitaxy

The problem of preparing high-mobility thin InSb films is revisited for magnetoresistive and spintronic sensor applications. We introduce a growth process that significantly improves the electrical properties of thin unintentionally doped InSb layers (60–300 nm) epitaxially grown on GaAs(100) substrates by reducing the density of dislocations within the interfacial layer. The epilayer properties are well described by a differential two-layer model. This model confirms that the contribution of the interface can only be donor-like. Moreover, the electrical properties of the InSb layers change continuously away from the interface up to sample thickness of the order of 1 μm.