Investigation On The Characterization Methods And System Of Thin Film Mechanical Properties Based On Microscopic Interferometry And AFM

In recent years,the film/substrate structure are widely usded in the field of microelectronics,biology,aerospace and so on,which realized the miniaturization and informatization of the system effectively.However,the failure forms including buckling,fracture,debonding and so on,will generate on the film/substrate structure under the external load,which will have a serious impact on the devices and the performance of the system.So it is great important to do some research on the mechanical and interface properties of the film/substrate structure.The micro force loading of cantilever probe of the atomic force microscope and the measurement of microscopic interferometer are combined in this paper.The buckling morphology,mechanical properties and interface performance of the the film/substrate structure were studied using the combined system.The main work include the following:1.Design and built a micro-nano mechanic test system based on AFM,which mainly includes an AFM force loading module and a microscopic interference module.Realize the loading of micro-nano force and measurement of three-dimensional topography of the surface microstructure synchronously.2.Two kinds of superhard micro cantilever probes have been calibrated by the balance and the optical lever based on the Hook's Law.It improved the accuracy of the subsequent research on the mechanical properties of thin film.3.Based on the system and working principle of the Linnik microscopic interference,the phase of microstructure object were calculated and the phase inconstancies were recovered by programming using the theory and algorithms of phase-stepping interferometry.This method has been applied to the buckling 3D measurement and height acquisition of thin film.4.Different thickness copper films were deposited on PMMA by the means of direct current magnetron sputtering.And the observation of straight-sided buckling initiation and the conversion to bubbles has been carried in the process of the film/substrate structure under uniaxial loading and unloading.Under the combination of the micro cantilever force load and microscopic interference 3D measurement,the morphology and the mechanical property of thin film have been studied.5.Based on the theoretical model of interface energy release rate of film/substrates,nano-indentation is performed on delaminated region and perfect region by atomic force microscope.The different indentation load of the two regions is adopted to characterize interface release rate.