Yüzey karakterizasyonunda nanotel elektromekanik anahtarın kullanımı

The benefits of downscaling electromechanical systems have been demonstrated in the form of NEMS with high performance and low power consumption. Silicon nanowires (Si NWs) are one of the leading devices with a remarkable potential in the field of sensing and actuation. While improvements in Q-factor and resonance frequency have been obtained through miniaturization enabling further capabilities, the change in their physical properties is a direct outcome of size reduction. In this aspect size dependence of the mechanical behavior is mainly attributed to the significant contribution of surface area. Various attempts have been carried out to study the scale effect on the mechanical behavior of Si NWs. However, existing Modelling methods still fail to reproduce experimental findings. Moreover, fabrication of Si NWs with extreme dimensions imposes a significant challenge to study the scale effect on the mechanical properties of Si NWs. Utilizing the recently introduced field-emission scanning probe lithography (FE-SPL) in combination with cryogenic etching this study aims to generate Si NW switches. Secondary electrons emitted with Low energy are used in FE-SPL lithography, in contrast to previous methods, to minimize the proximity effects for high-resolution patterning at ambient temperatures and room conditions. The fabrication process is utilized to pattern a wide range of dimensions with lengths from 2 µm to 4 µm, widths from 40 nm to 100 nm and an average gap of 50 nm between each NW and electrodes. The fabrication process is developed on a silicon-on-insulator (SOI) substrate with a 14-nm-thick device layer. These switches are then utilized for the purpose of surface characterization, as pull-in voltage -as a straightforward parameter to characterize - depends heavily on surface elasticity and surface stress. Both comprite the leading properties of surfaces, which are very challenging to quantify. For this purpose, a multiphysics modeling technique is developed based on finite element analysis. NW deflection is estimated based on the modified Young-Laplace equation. Pull-in voltage is calculated for fixed-fixed and fixed-free boundary conditions. Remarkable size and boundary condition effects are obtained for Si NWs with high aspect ratios. These effects have been analyzed and a model to describe them is suggested. In the current project, we are aiming to address controversies observed in the surface contribution to the mechanical properties of Silicon through pull-in voltage measurements in silicon nanowire switches. Nanowires with high aspect ratios are being fabricated and a numerical model has been developed to model the electromechanical behavior of a silicon nanowire switch. Moreover, a methodology and measurement procedure is designed to extract the surface elasticity and surface stress parameters by utilizing the experimental and numerical results.