Fabrication And Research Of 3D Functional Micro-nanostructure Based On FIB Processing Technology

At present,the three-dimensional micro-nano structure has attached more and more extensive attention because of the excellent performance in the field of optoelectronics,communications,detector and so on.There are many methods of processing three-dimensional micro-nanostructures,including focused ion beam / ion beam induced chemical vapor deposition method,electron beam / optical grayscale processing method and three-dimensional direct writing technology.FIB processing technology has become the primary preparation method of three-dimensional micro-nanostructures because of its high accuracy,high resolution and multi-dimensional adjustable characteristics.Based on FIB technique,this paper prepares microstructures including metal crimp films,symmetrical cantilever beams,micro-windows and nano-channels by using FIB surface / line scan mode and FIB assisted deposition technique.The three-dimensional structure of the three-dimensional micro-nano-curled structure is realized,and the three-dimensional filtering structure of the infrared band is obtained.The closed nanometer channel is constructed in situ.The specific contents are as follows.Firstly,a new method for the preparation of three-dimensional micro-nano-crimp is proposed,which is based on a planar two-dimensional suspended metal thin film and is fabricated by FIB irradiation surface scanning technique.Processing methods of sealed tubular structure,multi-layer tubular structure and folded tubular structure are studied in detail.The influence of the length and breadth dimension of nanostructures on the radius of curvature of micro-nano-crimp structures are investigated.And the formation mechanism of three-dimensional micro-nano-crimp structure is studied.Secondly,the effect of ion beam etching depth on the forming of folded structure is studied by FIB line scanning mode,and the preparation of positive and negative folded three-dimensional micro-nanostructures is realized by multiple etching processes.The structure of the three-dimensional micro-window metamaterials is simulated by FDTD simulationa and combining with the principle of excitation of surface plasmon and the relationship between electromagnetic response and folding angle in the structure is investigated in detail.The three-dimensional micro-window structure has a good response in the mid-infrared band.When the folding angle is small angle,the structure can realize response of high order diffraction mode;when in the case of large angle,the three-dimensional structure can achieve the frequency tunable filter characteristics.We have calculated and calibrated different electromagnetic response of the structure separately and verified feasibility of the structure by experimental means.Finally,this paper presents an in-situ nanometer channel preparation method based on FIB-CVD technology.The preparation of multi-material system channels including Ag,Au and Ni is realized by using metal nanowires as sacrificial template as well as preparation of simple nano-single channel,mesh nano-channel and other different morphology of the nano-channel structure.The formation mechanism of nanometer channel is studied in detail.Different techniques including ion beam / electron beam deposition and thermal annealing are discussed respectively and effects of W / Pt two different deposited films on the formation of nanotubes are discussed.