Contour Calculation Method Of Micro-structure Sputtering Etching With Focused Ion Beam

Focused ion Beam(FIB)technology is a powerful technology for manufacturing high-quality micro-devices and high-precision micro-structure.This study focuses on the characteristics of FIB sputtering on silicon and the contour calculation method of micro-structures in manufacturing.Based on the experimental results of line structure,the influence regularity of different process parameters on micro-structure contour is obtained,and the beam distribution model with multiple process parameters is established.By comparing contour calculation results and experimental results of the rectangular structures and the re-deposition structures,the beam distribution model shows its accuracy and the contour calculation method is effective and feasible.And then,the research explores the design of the contour calculation process to obtain the micro-structure of specific contour.The research work is mainly as the following.Firstly,the relationship between the ion beam current,the dwell time and the depth of the line structure is analyzed.And the factors which influence the rectangle structure including dwell time and pixel overlap rate are analyzed simultaneously.The boundary effects of rectangular overlap are proposed.The threshold value of dwell time for dwell time for creating the redeposition structure is got by the experimental method.The profile accumulation effects in the redeposition are found by researching the interference experiments of redeposition structure.Based on the principal of the change of the line structure profile,a model of three bunches of Gaussian ion beam distribution was established for different electrical current and different dwell time.Comparing rectangular profile in calculating results and in the experimental results,in addition with the variation of average sputtering yield in the redeposition etching,where calculation method was introduced in the redeposition profiling,shows that the calculating model is feasible,which can be used to calculate the etching process with different parameters and designing processing technology.Finally,this paper firmly analyzed the fabricating parameters in calculating the special profile of the structure,especially the slope and the curve structure using depth stratified calculation and width correction to fabricate the profile structure.The feasibility of these method turned out to be right comparing with the experimental results.According to applying the processing of the rectangular structure with high pixel overlap rate to the periodic array of cylinder structure,an improved method was introduced in fabricating array structure.Based on the bulk deposition effect in the redeposition structure,the tetrahedral structure was fabricated which is difficult to obtain in the FIB sputtering etching.