Epitaxial growth of NiSi_2 on (001 )Si inside nanoscale contact holes prepared by atomic force microscope tip-induced local oxidation of the thin Si_3N_4 layer

摘要

Epitaxial NiSi_2 has been grown on (001)Si inside 50-200 nm Si_3N_4 openings prepared by atomic force microscope tip-induced local oxidation. The morphology of epitaxial NiSi_2 was found to be significantly influenced by the opening size. For specific annealing conditions, there exists a transitional opening size below which a pyramidal faceted structure of epitaxial NiSi_2 is preferred. The opening size effect is attributed to a limited supply of Ni atoms, the increased interface/volume ratio of silicides with decreasing size of openings, and the considerable stress level inside miniature openings.