Design And Fabrication Of A Micro Mirror Based On Filed Induced Phase Transition Of Anti-ferroelectric Thick Film

The transmission and processing of a large amount of information through laser communication has broad prospects in the field of space communication.The driving principle of space laser communication can be divided into mechanical mode and non mechanical mode.At present,the main way to realize the deflection of the light beam in the spatial light communication is to control the reflector by means of the mechanical mode.This paper introduced a bridge structural micro mirror based on anti-ferroelectric thick film by applying the effect of field induced phase transition,and by using the silicon manufacturing technology combined with anti-ferroelectric materials.Aiming at the shortcoming of the current mechanical deflection system,such as instability,slow response,high precision,Large weigth and volume.In this paper,we firstly study the fabrication of anti-ferroelectric thick materials on the Pt/Ti/SiO2/Si substrate.Study on the influence of microstructure and properties of PLZT anti-ferroelectric thick film by adding excessive Pb and the introducing of seed thickness.The obtained Pb in excess 10%,and introduced of 1 layer of seeds the PLZT film has the most excellent performance.And the phase transition effect of PLZT anti-ferroelectric thick film under the action of external field is studied.Secondly,use COMSOL 5.0 to study the relationship between the strain,the driving displacement,the frequency response and the beam deflection angle of the anti ferroelectric micro mirror structure under the action of electric field is revealed,the following processing process is design.Finally,use sol-gel and multi-step annealing method,on the 4inch Pt/Ti/SiO2/Si substrate the anti-ferroelectric thick films are integrated,and also the fabrication of micro mirror device.Micro mirror device was made by MEMS micro machining technology,including photolithography,wet etching,dry etching,thin film deposition and Stripping Technology,the combination of the anti-ferroelectric material and the silicon based MEMS processing technology is realized.Set up the test platform,and the deflection of the device is tested.The maximum deflection angle of the micro bridge structure is 745.8μrad,and the requirement of the deflection of the beam deflection device is obtained.