The Mechanical Properties Of Silicon Nanowires Based On Mems Technology And Manufacturing Methods

In this dissertation, the mechanical properties and the fabrication of a Micro Electro Mechanical System (MEMS) technology based Silicon Nanowires (SiNWs) are intensively studied. The model of SiNWs is setup and the molecular dynamics is used to simulate the mechanical elastic modulus. The size, the temperature, the surface state and geometric shape of SiNWs are analyzed as effects of the elastic modulus, as a result, the size effect, temperature effect and surface state effect of SiNWs are found. In the following, the fabrication of SiNWs based on MEMS technology is presented. The SiNWs are fabricated successfully through observation and control of etch process.Main features of this paper are as follows:1. The model and simulation method of SiNWs by molecular dynamics is setup, including selection of potential, construct of cell, build of SiNWs, the atomic structure of surface reconstruction and calculation of mechanical elastic modulus.2. The effect of size, temperature and surface state to mechanical properties of SiNWs are analyzed by molecular dynamics. The characteristics of silicon wires and structures on nano scale are studied.3. A simple process utilizing anisotropic etch of silicon is presented to fabricate SiNWs, that avoid using the expensive and time-consuming top-down method. The proposed fabrication method lowers the cost on fabrication, improves the efficiency.4. Observe the etch process of special structures, which incline some degree with [100] crystal direction, to control the time of anisotropic etch of silicon. This method improve the operation of etch and the reproduction of SiNWs.The simulation result of mechanical properties of SiNWs is promising to be used in the design of Nano Electro Mechanical System (NEMS) resonators. The fabricationmethod proposed in this dissertation may be used in the research and development of nano electronics devices, nano optics devices and nano sensonrs.