摘要
Grain coalescence has been applied in many areas of nanofabrication technology, including modification of thinfilm properties, nanowelding, and self-assembly of nanostructures. However, very few systematic studies of selfassembly using the grain coalescence, especially for threedimensional(3D) nanostructures, exist at present. Here, we investigate the mechanism of plasma triggered grain coalescence to achieve the precise control of nanoscale phase and morphology of the grain coalescence induced by exothermic energy. Exothermic energy is generated through etching a silicon substrate via application of plasma. By tuning the plasma power and the flow rates of reactive gases, different etching rates and profiles can be achieved, resulting in various morphologies of grain coalescence. Balancing the isotropic/anisotropic substrate etching profile and the etching rate makes it possible to simultaneously release 2D nanostructures from the substrate and induce enough surface tension force,generated by grain coalescence, to form 3D nanostructures.Diverse morphologies of 3D nanostructures have been obtained by the grain coalescence, and a strategy to achieve self-assembly, resulting in desired 3D nanostructures, has been proposed and demonstrated.
Grain coalescence has been applied in many areas of nanofabrication technology, including modification of thinfilm properties, nanowelding, and self-assembly of nanostructures. However, very few systematic studies of selfassembly using the grain coalescence, especially for threedimensional(3D) nanostructures, exist at present. Here, we investigate the mechanism of plasma triggered grain coalescence to achieve the precise control of nanoscale phase and morphology of the grain coalescence induced by exothermic energy. Exothermic energy is generated through etching a silicon substrate via application of plasma. By tuning the plasma power and the flow rates of reactive gases, different etching rates and profiles can be achieved, resulting in various morphologies of grain coalescence. Balancing the isotropic/anisotropic substrate etching profile and the etching rate makes it possible to simultaneously release 2D nanostructures from the substrate and induce enough surface tension force,generated by grain coalescence, to form 3D nanostructures.Diverse morphologies of 3D nanostructures have been obtained by the grain coalescence, and a strategy to achieve self-assembly, resulting in desired 3D nanostructures, has been proposed and demonstrated.
基金
supported by an NSF CAREER Award(CMMI-1454293)
a Grant-In-Aid(GIA)program/a start-up fund at the University of Minnesota,Twin Cities
Parts of this work were carried out in the Characterization Facility,University of Minnesota,a member of the NSF-funded Materials Research Facilities Network(www.mrfn.org)via the MRSEC program
A portion of this work was also carried out in the Minnesota Nano Center which receives partial support from the NSF through the NNCI program
the 3M Science and Technology Fellowship
