ZnO(0001)/Si(111)　interface　is　engineered　by　using　a　three-step　technique,　involving　low-temperature　Mg　deposition,　oxidation,　and　MgO　homoepitaxy.　The　double　heterostructure　of　MgO(111)/Mg(0001)/Si(111)　formed　at　-10　degrees　C　prevents　the　Si　surface　from　oxidation　and　serves　as　an　excellent　template　for　single-domain　ZnO　epitaxy,　which　is　confirmed　with　in　situ　reflection　high-energy　electron　diffraction　observation　and　ex　situ　characterization　by　transmission　electron　microscopy,　x-ray　diffraction,　and　photoluminescence.　The　low-temperature　interface　engineering　method　can　also　be　applied　to　control　other　reactive　metal/Si　interfaces　and　obtain　high-quality　oxide　templates　accordingly.　(c)　2007　American　Institute　of　Physics.