Automatic Location Technology Of The Atomic Force Microscope's Probe Based On Visual Inspection

In recent years,with the development of the semiconductor industry,chip integration is higher and higher,the size of the key unit has reached tens of nanometers.The current industrial detection means put forward new demands and challenges.Currently optical detection techniques and electron microscopic detection technology has been widely used in the detection is difficult to meet the needs of key units feature sizes of highly integrated IC.AFM is a high-precision equipment with sub-nanometer resolution and environmental adaptability.Currently,AFM has been widely used in biology,materials,chemistry,and other fields.However,because current AFM are usually used in the lab environment,the approaching between the probe and the sample,the approximation toward to the target and the replacement of the probe are carried out manually.This can not meet the automation requirement for industrial applications.So there are still a lot of technical problems to acheve.the industrial and automation of the AFM.The study is based on the AFM platform developed by the laboratory,the paper focus on solving a number of technical problems existing in the process of industrialization AFM.On the basis of a detailed analysis of industry needs,this paper focus its work as following:1 Research on AFM automatic approaching method.Conventional science-based AFM probe are completed manually,continuous detection can not be achieved in industrial applications.Therefore,an AFM automatic approaching method based on machine vision and accurate force feedback control is proposed in this paper.This method combine the rough positioning and fine positioning to achieve an AFM tip can approach to a sample surface automatically.At the same time,the paper make some improvements of autofocus algorithm in computer vision which improve the focusing accuracy and universality of the algorithm.2 Study of the method of Automatic Approximation to target location.During the process of AFM scan imaging process,it is difficult to achieve to the position of the sample and the probe.This paper based on Machine Vision presents a scanning probe tip blind positioning technology.The specific sample is put under a scanning probe tip by using two-dimensional coordinate visual,three-dimensional coordinates,andthree-dimensional motion platform coordinate transformation,so as to realize a specific position of the sample is scanned.3 Research on automatic replacement method of AFM probe.To achieve the scanning process can work continuity,AFM probe must implement the automatic replacement.This paper designed a new AFM probes automatic changer,combine the electromagnetic force and a f permanent magnetic force,so that the holder can crawling and automatic release AFM probe,and then complete the scanning probe replacement.Scanning probe cantilever end and automatic alignment of the laser spot and the use of machine vision methods to achieve after the replacement.4 The set up of AFM control system.Based on the above three aspects of the work,a set up of the entire AFM system is built.And transplants Automatic Approaching,Automatic Approximation and automatic replacement method of AFM probe.Experimental results show that the proposed method using vison algorithms,AFM probe can completed the position task on several levels,it is possible to automate the operation of the AFM.Above work provide an effective technology solutions to a number of technical problems arised during the development of industrial-type AFM.It has an important significance in the study of the localization of industrial-type AFM.