Fabrication, Test And Application Of Nano-Beams Structure

This paper presents the fabrication, test and application of nano-beams structure that is the fundamental structure in Nanoelectromechanical Systems(NEMS). So the study of fabrication using various kinds of method, test of mechanical and electrical character and applications in integrated circuit and sensor field of nano-beams are important.Using the methods of Tetramethylammonium Hydroxide (TMAH) etching , standand process of silicon on glass and sidewall process, the nano-beams made of silicon nitride (Si3N4) ,silicon oxide(SiO2) and aluminum (Al) material are fabricated. By designing the process flow and mask pattern of nano-beams, different shapes of the nanobeams can be fabricated.Stand-alone nano mechanical testing system (TriboIndenter) is used to test the mechanical character of nano-beams with silicon block. The test accuracy of this equipment is reach to nano meter in displacement and nano newton in force. By analyzing the pull in voltage method, the dopple velocity and position finder method, and electromagnetic drive method, we make a helpful attempt to using those test methods. After studied the theoretical and experimental results recently, a new model based on non-continuity assumption is constructed. This new model is used to simulate some experimental results, and the experimental data were reproduced by using this model. So the rationality of this new model is proved. That provides a coherent interpretation about the Young's modulus in nano-scale.Based on the test result of Stand-alone nano mechanical testing system (TriboIndenter), a new model reproduce some experimental data is constructed. Using this model, young's modulus is can be extracted from experimental data. To offset the drawback of this new model, a experiential model is given.This paper tests the electrical character of the Al nano-beams with tensile stress. The test results show that the electric resistance of Al nano-beams with tensile stress is instability. The scan electric current decrease the tensile stress in the nano-beams, so the electric resistance increase with the scan electric current times.The sidewall stress is tested by nano-cantilever method in this paper. This method can be used to test the sidewall stress in strained silicon transistor and the stress in Shallow-trench isolation (STI). The nano-beams with silicon block can be seen as accelerometer is proved. This new nano-accelerometer has ultrasensitive sensors and high measurement range to 4000 gravitational acceleration.