Konsol kiriş yapılı metalik mikro çınlaçlar: Üretim ve mekanik özellik ölçümleri

The objective of this work is to improve the performance of a micro-cantilever resonator by modifying its fabrication flow and by measuring actual mechanical properties of its structural constituents. The latter is important for the quantification of biological measurements as resonators are intended to be used in biological sensing applications. Electro-plating, one of the critical steps in the proposed fabrication method of the biosensor chip is studied. The effect of changing current density and time to deposited nickel thickness and surface roughness is illustrated. For 1000 nm nickel thickness, a surface roughness range between 10-20 nm is obtained. By using a new photolithography layout, same fabrication procedure is carried out both on silicon and silicon-on-insulator (SOI) wafers, and obtained results on these substrates are compared. The surface roughness for the etched gap underneath the micro-cantilevers is decreased from 15-30 nm to 0.5-5 nm when switched from silicon wafer to SOI wafer. It is seen that better surface properties are obtained with SOI samples which is also more suitable for the optical resonance frequency measurement setup.In continuation of this thesis, modulus of elasticity values for materials used in the fabrication of micro-cantilever resonators are determined by using resonance technique. Theoretical formulations and optical measurement setups used in this method are demonstrated. At the end, 165.5 GPa is obtained for the modulus of elasticity of electro-plated nickel (800 nm-thick) with a standard deviation of 10.5 GPa; 53.75 GPa is obtained for the modulus of elasticity of RF sputtered gold (100 nm-thick) with a standard deviation of 39.37 GPa; 67 GPa is obtained for the modulus of elasticity of RF sputtered chromium (20 nm-thick) with a standard deviation of 16 GPa. Obtained modulus values for thin nickel, gold and chromium films are in good agreement with what was found in the literature before. Finally, the change in the resonance frequency and the reliability of double-layered double-clamped micro cantilevers are studied over a 10-month period. The reliability study did not allow us to reach a conclusion about the factors affecting the resonance frequency of these devices.