Fabrication Of Large-area Hydrophobic Silicon Texture Based On Friction-induced Selective Etching

The rapid development of information technology, biotechnology, advanced manufacturing, new energy and other high-tech fields puts forward new challenges for traditional micro/nanofabrication methods. It is urgent to develop new micro/nanofabrication methods. In the previous studies, a certain height (depth) of the nanostructure can be produced on silicon surface based on the friction-induced selective etching. However, by using the traditional working mode of single-tip, the processing efficiency is low and the range of processing is small, which strongly limits the practical application of friction-induced selective etching.In this paper, through the modification of equipment and optimization of fabrication processes, different types of large-area hydrophobic surface texture were produced on single crystal silicon based on the friction-induced selective etching. The main conclusions are summarized as follows.(1) Two new methods for multi-tips fabrication were proposed, namely as invert-mold and flat-mold. It was found that the flat-mold could produce multi-tips with much higher flatness and better accuracy than the invert mold.(2) Based on the continuous processing property of equipment, two types of texture were designed, namely as line-array and#-array texture. Both the line space and the area of textures were optimized based on the experimental results.(3) The fabrication processing of the texture was studied. First, the load was selected through the theoretical analysis and and experiment results. Second, the ideal etching period was set after the relationship between fabrication height of nanostructure and etching period was carefully investigated.(4) The effect of texture shape and size on the hydrophobicity of silicon surface was investigated. The results indicated that the narrower the line space was, the larger the contact angle would be. Compared with the line array texture, the contact angle of#-array texture was larger. It was also found that the fabricated texture on silicon surface showed good stability.Based on the above studies,, a new method for multi-tips fabrication was proposed and the fabrication of large-area hydrophobic silicon texture was realized based on friction-induced selective etching.