Growth of epitaxial CoSi2 on (100)Si

Abstract

A bilayer CoSi₂/TiN has been grown on (100)Si, starting from a (100) p‐type Si wafer deposited with thin layers of Ti followed by Co metal, through a two‐stage annealing in a nitrogen environment and an intervening etch. In this process, Co and Ti switch places to form CoSi₂ covered with TiN on Si. Cross‐section transmission electron microscopy, and Rutherford backscattering/channeling spectrometry were used to characterize the bilayer sample. The CoSi₂ was found to be single crystal, fully coherent, and epitaxial with (100)Si, whereas the TiN at the top of CoSi₂ was polycrystalline. The stress in the CoSi₂/TiN layer was found to be 1.9×10¹⁰ dynes/cm². The planar (100) CoSi₂/Si interface was interrupted with {111} ledges which are believed to be structural ledges present to maintain the coherency at the interface.