Abstract
Abstract Two fantastic nanotemplate were produced in this thesis, the self-assemble diblock copolymer and polystyrene nanospheres. These two masks provide low cost, high throughput, large scale and fundamentally simple means to create periodic nanostructure below photolithographic resolution. First, we demonstrate a large-area fabrication of hexagonally ordered nanopore arrays with an area density of 1011/cm2. We can produce mostly distributed 18 nm Pt nano dots with a 36 nm period by using sputtering technique via block copolymer nanolithography with total molecular weight of 67000g/cm3 and the PS volume fraction of 0.7, inspire of the existence of the wetting layer between the periodic mask and the silicon substrate. Further improvement on this experiment mainly depends on the dry etching such as reactive ion etching in order to penetrate the periodic nanopore through the wetting layer without attacking the original hexagonally close packed structure. The second part, the nanosphere lithography (NSL), was used to fabricate large periodic arrays of Pt nanodots and nickel disilicide. A single layer of self-assemble polystyrene spheres was first uniformly deposited on a silicon wafer as a mask, and then electron beam vaporization or sputter coating technique were used to deposit a metal layer through the mask. Some DL masks and nanostructures were also found somewhere on the substrate. On one hand, in the sputtered Pt case, the size of and inter-particle spacing between the Pt dots are tunable simply by varying deposition thickness t the diameter of the polystyrene spheres D. The relationship between the dot size after annealing d and as-deposited film thickness t is shown as follows: On the other hand, we both evaporate and sputter 30nm Ni nanoparticle arrays via this self-assemble nanosphere lithography (NSL). The as-deposited morphology between these two techniques can be easily explained on the perspectives of incident angle and energy. Furthermore, the nickel pattern after annealing at 900oC shows clearly two-directional facet bar in the SEM analysis, which gives us an indirection hint that the bar represents the nickel disilicide phase. As a result, this provides a lattice-modulated substrate and opens a broad way in further research and applications.