Research On The Automatic AFM Electric Field Processing Method

AFM as a probe into nanometer world of sophisticated equipment,at the beginning of the invention is used to scan imaging,along with the continuous efforts of scientific research personnel and its ability as a nanomanipulation got development,AFM can be used in a variety of high precision,including nano mechanical force operation such as cutting,score,push-pull.In needlepoint to join voltage and can be used in the oxidation,evaporation,etc.Due to its piezoelectric ceramic actuator is driven,its precision can be Dana level meters,its significant advantages make it has wide application background.Field evaporation is the use of metal atoms in strong voltage,under the action of ionization,sputtering in the electric field gradient direction to the substrate,can be used in welding,and can be applied to the processing of nano device,provides the nano device processing and an easy solution based on AFM.A single processing cost and expensive,as is known to all,nano device large-scale automation is the path to the road of commercialization.Based on commercial AFM,connection necessary equipment,built a set of automated nano electric deposition processing equipment,in the face of all aspects of the program control automatic processing,this paper mainly studied the following content:AFM as a probe into nanometer world of sophisticated equipment,at the beginning of the invention is used to scan imaging,along with the continuous efforts of scientific research personnel and its ability as a nanomanipulation got development,AFM can be used in a variety of high precision,including nano mechanical force operation such as cutting,score,push-pull.In needlepoint to join voltage and can be used in the oxidation,evaporation,etc.Due to its piezoelectric ceramic actuator is driven,its precision can be Dana level meters,its significant advantages make it has wide application background.Field evaporation is the use of metal atoms in strong voltage,under the action of ionization,sputtering in the electric field gradient direction to the substrate,can be used in welding,and can be applied to the processing of nano device,provides the nano device processing and an easy solution based on AFM.A single processing cost and expensive,as is known to all,nano device large-scale automation is the path to the road of commercialization.This article is based on commercial AFM,connection necessary equipment,built a set of automated nano electric deposition processing equipment,in the face of all aspects of the program control automatic processing,this paper mainly studied the following contents:(1)The AFM electric field processing theory and simulation analysisThis paper introduces the principle of field evaporation deposition,field evaporation process was deduced from the Angle of molecular dynamics,and several metal evaporation field intensity is calculated,which provides theoretical guidance for the field evaporation deposition operation.In addition,through the finite element simulation method,calculated the AFM tip electric field distribution in three-dimensional space,and discusses the parameters such as voltage,tip-samples from the influence of electric field distribution.Metal atoms obtained molecular dynamics calculation evaporation need field intensity,electric field simulation and the relation between the voltage and electric field intensity,the combination can be set for the voltage needed to field evaporation deposition.(2)The AFM conducting probe coating processing parameter analysisGiven the commercial conductive metal coating parameters of the probe is fixed,is not conducive to study the effect of coating on the evaporation deposition process,therefore conducted using ion sputtering apparatus processing probe research of metal coating.Through experiment,the relation between the sputtering time and needle tip coating thickness and coating thickness were analyzed its influence on deposit.Through experiments it is concluded that the most suitable for coating thickness of sedimentary process.(3)Tip-sample distance and tip-sample loop current control methodControl for AFM tip-basal distance is difficult,because the tip is a flexible cantilever beam,susceptible to interference environment,this chapter introduces the use of the capillary force of water film and can change the voltage and current constant offset distance,the method of effective deposition voltage field control and deposition process of sediment control,which is based on program control automatic/semi-automatic large-scale electric field sedimentary AFM provides the most basic implementation conditions.(4)The AFM automation electric deposition experiment resultsThis chapter mainly introduces the process control automation of nano electric deposition process of hardware equipment,system process,pinpoint scanning PID algorithm,deposition processing closed-loop control algorithm,the experiment obtained good results,the processing of nano point good homogeneity,proved the possibility of AFM electric deposition process automation,processing and provides the basis for future possible nano device.The significance of this thesis is to explore a kind of automatic program control,repeatable nano deposition machining method has high precision,can be used in the main CNT nano welding processing,and also for the future large-scale nano device provides a method based on AFM.