Formation of ultra-thin NiGe film with single crystalline phase and smooth surface


 Formation of an ultra-thin nickel-germanide (Ni-germanide) film on a SiO2 film has been tried with stacking structures of Ni with various thicknesses formed on Ge films with thicknesses of 4 nm or 20 nm and annealing in an N2 ambient condition. Physical analyses revealed that the ultra-thin Ni-germanide films with smooth surfaces were able to be formed on the SiO2 film after annealing at 400℃ without depending on the Ni thickness on the 4-nm-thick Ge films. In the formation, reductive and oxidative reactions occurred in the films, which are quite important for determining a composition of the Ni-germanide.