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• Main Authors: Shan-chun Yang, 楊善淳
• Other Authors: 鄭紹良
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/ps74ue

碩士 === 國立中央大學 === 化學工程與材料工程學系 === 102 === In this study, we demonstrated that large-area arrays of vertically aligned Si nanowires were successfully fabricated on (001)Si and (111)Si substrates by using the PS nanosphere lithography combined with the Au-assisted selective chemical etching process. The diameter and length of these silicon nanowires are adjustable through O2 plasma treatment and wet etching time. The morphology of the silicon nanowires can be converted from flat top to sharp top by metal catalyzed electroless deposition etching method through the reduction of silver. In this research, we noticed that thin kind of etching process is due to the hydrophobic etching on the top and the side wall of the silicon nanowires. Through tilting angle deposition of 90nm Ni and 500oc, 700oC 2hr N2 annealing, we can obtain half silicidation and fully silicidation in the silicon nanowires. Through TEM observation and the SAED analysis, we noticed that the triangle facets are (111) planes of the Nickel disilicide phase (NiSi2). These facet will be perpendicular to the side wall of the [111] silicon nanowires due to the difference of the orientation. We also demonstrated the research of the field emission property of the silicide wire. According to the changeless morphology, the beta enhancement factor is supposed to be unchanged. So we can tell that, through silicidation, the turn on field was reduced from 5.56Vum-1 to 1.2Vum-1 ,and the effective work function was reduced from 5.0eV to about 2.0eV. Another interesting issue in this research is about utilizing the shadow generated from the tilting angle process as the mask to fabricate the horizontally aligned metal wires. Through the deposition of proper thickness of SiO2 and lift off technique, we can obtain 20nm height of Ni wire horizontally aligned on the silicon wafer.