Error Detection And Trajectory Control Of Micro-nano Manipulation Platform Inside SEM

Since the beginning of the 21st century Nanotechnology has been rapidly developed and widely used.It is expected that while promoting the transformation and upgrading of traditional industries,nanotechnology can also improve the quality of life and living environment.Traditional semiconductor manufacturing technology is difficult to meet the requirement of stability and reliability in nano device manufacturing.The nanomanipulation system inside scanning electron microscope(SEM)is one of the solutions to this problem.Micro-nano manipulation platform is an important part of nanomanipulation system,which equipped with end-effector to complete nanooperation tasks.The micro-nano manipulation platform with three degrees of freedom can perform linear motion in the x-y-z direction.During the movement of the micro-nano manipulation platform,many factors such as the assembly problem of the platform will cause errors in the motion of the micro-nano manipulation platform,and thus affect the stability and success rate of the nanooperation.In this paper,the visual imaging based on SEM and image processing methods were used to detect the motion error of the micro-nano manipulation platform.The feedforward compensation strategy was used to compensate the linear motion of the X-axis and Y-axis of the micro-nano manipulation platform.Combined with the interpolation algorithm,the micro-nano manipulation platform moved stably along the trajectory,and finally realize the nanooperation task of transporting carbon nanotubes(CNT)along the trajectory based on the oppositely mounted micro-nano manipulation platform.The main research contents of this paper are as follows:(1)The micro-nano manipulation platform used in this project is a micro-nano motion platform model SLC-1720-S developed by SmarAct,Germany.The stick-slip motion mechanism and internal structure of the micro-nano manipulation platform were analyzed.The secondary electron image processing method was studied.For the problem of secondary electron image noise,the filtering method was used for smoothing.For the promble of brightness and contrast are not fixed,daptive threshold segmentation based on image histogramis was used,For the promble of secondary electron image drift caused by charge accumulation,drift detection and compensation of image were studied.(2)For the promble of linear motion error existing when the micro-nano manipulation platform moved along the X-axis and Y-axis directions,and the error cannot be detected by the sensor.Combined with the visual imaging of SEM,the image processing method of tip detection of edge contour was used to locate and track the tip position of the CNT,which picked up by the end effector,and describe the motion trajectory and the motion error when the micro-nano manipulation platforms moved along the X-axis and Y-axis directions under different speed.Combined with the stick-slip motion mechanism and mechanical structure composition of micro-nano manipulation platform,the influence factors of motion trajectory and motion error were analyzed..(3)In order to meet the requirement of stable movement of micro-nano manipulation platform.Combining the causes of motion errors and the motion trajectory data table,the motion trajectory of micro-nano manipulation platform was modeled by fitting,and the feed-forward control function of displacement output was obtained.The motion control software was developed based on VC++,the linear motion error was compensated by the micro-nano manipulation platform with vertical axis(X-Y).The experimental results showed that the average compensation efficiency of linear motion error was 86%.Based on the realization of stable linear motion,combined with the linear interpolation algorithm and the circular interpolation algorithm,the stable motion of the micro-nano manipulation platform along the trajectory was realized.Two platforms installed opposite each other were controlled to complete the nanooperation task of transporting CNT along the trajectory,and the IV curve of the CNT after transport was measured.The experimental results showed that the motion error of the micro-nano manipulation platform was reduced the stability was improved.