Effect of atomic-hydrogen irradiation on reduction of residual carrier concentration in β-FeSi_2 films grown on Si substrates by atomic-hydrogen-assisted molecular beam epitaxy

摘要

β-FeSi_2 films were epitaxially grown by atomic-hydrogen-assisted molecular beam epitaxy (MBE) on high-resistive n-type floating-zone (FZ) Si(l 1 1) (p > 1000 Ω cm). They showed n-type conduction with a reduced electron concentration of an order of 10~(16) cm~(-3) at room temperature (RT). In contrast, β-FeSi_2 films prepared without atomic hydrogen or prepared with molecular hydrogen showed p-type conduction with a large hole density of over 10~(18) cm~(-3). These results show that the atomic-hydrogen irradiation is an effective means to reduce the residual carrier concentration in undoped β-FeSi_2 films.