Study On Some Critical Technique In NEMS Testing

Nanobeams are significant NEMS devices with very good application prospects in RF and sensing areas. Mechanical characterization and motion characteristic testing of nanobeam resonators are common key testing techniques in NEMS testing. Taking nanobeam resonators as testing objects, mechanical characterization and motion characteristic testing of nanobeam resonators are proceeded. Through the experimental results, the processing technic and working performances of nanobeam resonators are evaluated and characterized. Key points are classified as following.1. Nanoindentation test is conducted on silicon nitride film with the thickness of 110nm on AFM based on nanoindentation testing technology. Hardness value of silicon nitride film is characterized. The residual indentation area is usually calculated using area function. A method of residual indentation area calculation using is developed. The corresponding data processing software is written. This method effectively avoids the unreliability of the residual indentation area calculation at lower indentation depth using area function.2. The mechanical characteristic of fixed-fixed silicon nitride and silicon nanobeams is measured on AFM based on bending test. The Young's modulus of fixed-fixed nanobeam is measured. The testing data have good consistency. It verifies the feasibility of the experimental method. In the Young's modulus measuring test, an experimental method of measuring the thickness of the nano beam with nano gaps is put forward, and the implementation details are given. Finally, the influence of the load force position in bending testing is simulated using ANSYS finite element analysis software. In bending test, the spring constant of AFM micro cantilever is corrected through the calibration of its effective length.3. The vibration properties of nanobeam resonators are completed based on micro laser Doppler micrometer. The processing technic and working performances of nanobeam resonators are evaluated and characterized. The electrical model and mechanical model of nanobeam resonators actuated by electrostatic, and the relationship of the electrostatic force and the exciting voltage are analyzed. Through the analysis of the experimental results, the vibration curves of the resonator are anostomotic with the theoretical analysis.