Growth of Multiple Metal/Semiconductor Nanoheterostructures through Point and Line Contact Reactions

Abstract

Forming functional circuit components in future nanotechnology requires systematic studies of solid-state chemical reactions in the nanoscale Here, we report efficient and unique methods, point and line contact reactions on Si nanowtres, fabricating high quality and quantity of multiple nanoheterostructures of NiSi/Si and investigation of NiSi formation in nanoscale By using the point contact reaction between several Ni nanodots and a Si nanowire carried out in situ in an ultrahigh vacuum transmission electron microscopy, multiple sections of single-crystal NISI and Si with very sharp interfaces were produced in a Si nanowire Owing to the supply limited point contact reaction, we propose that the nucleation and growth of the sugar cane-type NISI grains start at the middle of the point contacts between two Ni nanodots and a Si nanowire The reaction happens by the dissolution of Ni into the Si nanowire at the point contacts and by interstitial diffusion of Ni acorns within a Si nanowire. The growth of NISI stops as the amount of Ni in the Ni nanodots is consumed Additionally, without lithography, utilizing the line contact reaction between PS nanosphere-mediated Ni nanopatterns and a nanowire of Si. we have fabricated periodic multi-NiSi/Si/NiSi heterostructure nanonowires that may enhance the development of circuit elements in nanoscale electronic devices Unlike the point contact reaction, suicide growth starts at the contact area in the line contact reaction, the different silicide formation modes resulting from point and line contact reactions are compared and analyzed A mechanism on the basis of flux divergence is proposed for controlling the growth of the nanomultiheterostructures