Study On The Measurement And Characterization Of Nanobeam Resonator

According to the detailed investigation on NEMS testing techniques, research work is finally focused on NEMS mechanical and dynamic testing techniques based on atomic force microscope and micro-laser Doppler vibration measurement system, taking an important NEMS device of nanobeam resonator as testing object. Testing results will be used to estimate the specific NEMS process and the performance of NEMS devices. The research work of the dissertation mainly includes the following aspects:1. The importance and general situation of NEMS mechanical and dynamic testing techniques and the corresponding estimation of NEMS process is roundly investigated and analyzed, including the classification of techniques, application field, current status and development trend.2. To solve the limitation of the approximation and destructive effect existing in the nano thickness measurement method using SEM, a precise method of nanobeam thickness measurement based on AFM bending test is presented. Nano indenter is used for the comparison test.3. Bending model of Young's modulus and residual stress of fixed-fixed beam is set up. Aimed at a fixed-fixed beam array with uniform residual stress under a single process, an experimental strategy of combining Raman shift test and AFM bending test is brought forward. Stress strengthen theory is applied in the geometry-nonlinear finite element model so as to estimate the theoretical errors of bending model.4,Process related electrical model, mechanical model and pull-off voltage model are set up, and rounded analysis of the dynamic response of fixed-fixed beam is done, both of which is the theoretical basis of the dynamic property testing of fixed-fixed beam under electrostatic actuation.5,The resonance frequency model of fixed-fixed beam with residual stress is set up. The amplitude frequency response characteristics of tungsten- silicon carbide double-layer fixed-fixed beam are measurement using micro-laser Doppler vibration measurement system. For the evaluation of the corresponding process, the distribution of residual stress of test structures is calculated using the experimental date processing strategy of combing numerical iteration method and finite element modal analysis.6,The physical model of AFM tapping force and the AFM out-of-plane vibration measurement system of tapping mode and tapping force curve mode are established, based on which the feasibility and bandwidth of AFM vibration measurement method is discussed. The amplitude frequency response characteristics of tungsten-silicon carbide double-layer fixed-fixed beam are measurement using AFM vibration measurement system. The measurement errors of AFM out-of-plane vibration measurement techniques under tapping force and tapping force curve mode are evaluated combining the comparison test results and the calculation results of AFM vibration measurement system modal.