Regular Nanopattern Fabricated By Colloidal Lithography And A Preliminary Study About Its Material Function

To get a simple and cheap nanostructure fabricating method, we combined colloidal lithography with magnetron sputtering technology and prepared nanomesh patterns on Si and T1O2surface with good quality. The preparation process has been optimized and analyzed and the material functions of this nanopattern have been investigated preliminarily.Firstly, in this thesis, close-packed monolayer colloidal crystal mask has been produced both in dropping and floating self-assembly method. The quality of the colloidal mask was studied by using scanning electron microscopy (SEM). The results showed that the two methods could both acquire qualified colloidal crystal on the plane samples with defect-free area more than100μm, but the results also showed that the dropping method was more sensitive to environmental temperature and surface morphology of the samples, the floating method was more extensive in contrast, so we chose the floating method to prepare the colloidal mask for next pattern transfer process.Secondly, pattern transfer process to obtain nanostructures with magnetron sputtering technology has been done in this step. We used profilometer to obtain the deposition rate and used sem、edx to study the pattern quality. The patterning capabilities and deposition strategies were analyzed too. The quality of the nanopattern obtained by dc magnetron sputtering on a variety of samples was not satisfactory, because the deposition rate of dc magnetron sputtering was too fast, resulting in the high temperature of the substrate and the damage of the colloidal particles, the function of the mask would lost in this situation. Then we used the high power pulsed magnetron sputtering (HiPPMS) prepared ti and cu nano patterns on the surface of the Si and TiO2samples. The SEM images showed that the regular nanomesh pattern was fabricated and the quality of pattern was meeting the requirements. Through the experiment, we found that the substrate temperature raised by thermal radiation from the target and the bombardment with sputtering particles were the most critical elements that affect the quality of nanostructures. Controlling the deposition rate and deposition time became the basic strategies to obtain good nanopattern. Increasing the target-substrate distance could both reduce the thermal radiation from the target and deposition rate, so it should be the first choice in process adjustment.Finally, we used the contact angle, photo catalysis, platelet adhesion and smooth muscle cells culture experiments to give a preliminary exploration of the material functions about the composite structure of the Cu nanopatterns on the surface of TiO2. The results showed that photo-induced hydrophilic phenomenon of TiO2still existed, and the photo-catalytic activity of TiO2even been enhanced with cu deposition. The platelet adhesion test showed that the Cu nanomesh pattern could inhibit the platelet adhesion, but induce the platelet activation to a certain extent. Smooth muscle cells culture experiments showed that Cu pattern could inhibit the adhesion and proliferation of SMCs; these results revealed the application prospects of this technology in biological material fields.