Epitaxial growth of CoSi2 on hydrogen-terminated Si(001)

We demonstrate that ${\mathrm{CoSi}}_2$ grows epitaxially on H-terminated Si(001) and present the growth mechanism. It was found that direct reaction of Co with Si is suppressed on H-terminated Si below 400 °C. Thus, the hydrogen at the Co/Si interface hinders the formation of ${\mathrm{Co}}_2\mathrm{Si}$ and CoSi. Upon thermal desorption of hydrogen at around 400–550 °C, ${\mathrm{CoSi}}_2,$ which is closely lattice-matched to Si(001), grows on Si(001) and thus, thin epitaxial ${\mathrm{CoSi}}_2$ films are formed on Si(001). The {111}-faceting was completely suppressed in the epitaxial ${\mathrm{CoSi}}_2/\mathrm{Si}\text{(001),}$ leading to the atomically flat interface.