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Researches On The In-situ Electrical Measurements In A TEM With Micro-chips

Posted on:2015-02-25Degree:DoctorType:Dissertation
Country:ChinaCandidate:C ZhangFull Text:PDF
GTID:1108330509960995Subject:Electronic Science and Technology
Abstract/Summary:PDF Full Text Request
Low-dimensional nanomaterials,such as nanowires, carbon nanotube and graphene,have attracted great interest because their potential as the building block for nanodevices and their excellent electrical properties.There are continuous and urgent need to develop novel nanoscale electrical property testing systems with superior resolution and accuracy. For this, we developed a method of in-situ electrical measurements based on microchips in a transmission electron microscope(TEM). Besides the ability of atomic-scale lithography, this platform provides the structure information and electrical properties simultaneously for individual nanomaterials. The main work and contributions of this thesis are as follows:Firstly, a method was developed that combined with the modern electron microscopy characterization and in-situ electrical measurements for low-dimentional nanomaterials. The contacts between nanomaterials and electrode are controllable which improves the electrical method in situ TEM electrical measurement accuracy.Secondly, a method was developed that non-contamination lithography with atomic-scale. By avoiding the temperature for contamination and maintaining the stability of the sample with the drift lower than 1nm/min, a variety of nanomaterials were lithographied with atomic-scale and no contamination were observed.Thirdly, based on an InAs nanowires nanodot, Coulomb blockade phenomenon was successfully observed at 77 K. Followed by heating to 300 K, Coulomb blockade was suppresses bu the large thermal fluctuation which verifies the temperature is one of the key factors in the observed Coulomb blockade phenomenon.Fourthly, unusually electrical breakdown process of single tapered InAs nanowire was directly observed by the method of in-situ elecrical measurements in a TEM. Using high-resolution microscopy, electron energy loss spectroscopy and X-ray energy dispersive spectroscopy in situ study of the evolution of InAs nanowires in electric fracture process microstructure, it reveals the electrical breakdown of InAs nanowire is caused by electric field and Joule heat.Fifthly, a new dark field aperture was fabricated for TEM image, which greatly improves the image quality for graphene as example of weak phase object material, and endocytic multivescilar body as example of unstained biological sample.
Keywords/Search Tags:In-situ TEM, InAs nanowires, graphene, Coulomb blockade, finely lithography, electrical breakdown mechanism, dark field aperture
PDF Full Text Request
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