Epitaxy Grow And Structure Characterristic Of LCMO Colossal Magnetoresistance Film And Fabrication Of LCMO FET

Since 1950, Jonker Van and Santen first found ferromagnetism in LaMnO₃ after the La substituted by Ca,Sr,Ba. then in 1989, Wolla and Koehler discovered Colossal magnetoresistance effect (CMR) in this series of film .The colossal magnetoresistance effect gives manganate great and potential application value in magnetic recording and magnetic detection and sensor field,which excitated people to research. In perovskite manganate people found complicated electromagnetism characteristic and structure phase graphes as well as interesting physical phenomena induced by various effects and their competition,involving many basic questions of condensed matter physics.Metal-Oxide-Semiconductor field effect transistors (MOSFETs) is the core and leading part in great size integrate circuit for example microprocessor and semicon-memorizer. To optimize the MOSFETs'performance will drive the micro-electronics field. At present,the function of micro-electronics apparatus that people ask for is far beyond Boolean calculation and being electron elements. People hope to fabricate new-style MOSFETs by finding new functional material in order to satisfy various needs in perplexing situation.So by far,MOSFETs with various channel material and various configuration have been empoldered.But finished-products of CMR MOSFETs havn`t gone to market. Along with the research for CMR materials goes deep,we think it is feasible to fabricate MOSFETs modulated simultaneitily by electric field and magnetic field when use CMR as its channel material.So the first task is to choose perovskite manganate as the channel materiall and PZT as the isolated-gate and LSCO as the electric-gate to design reasonable configuration and parameter for CMR MOSFET.Because of the microstructure of CMR thin film and the configuration of CMR MOSFETs are very important for the success to fabricate CMR MOSFETs and its well performance.So the second task is to research detailedly the grow of epitaxial LCMO film and structure characteristic and the relation between structure and characteristic . In this article,a series La_1-xCa_xMnO₃(x=0,0.2,0.8) polycrystal powder samples and epitaxial film samples were fabricated by three techniques:the early conventional solid-state powder process and the sol-gel spin-on process that is comparatively new and in common use .â‘ In order to research the microstructure of epitaxial LCMO film on Si substrate ,a series of samples of LCMO thin films are prepared with the saline solution of La,Ca and Mn by the sol-gel method,which is easily applied,convenient and efficient in the controlling of composites and possibled to form a large film.The films formed on the 100 oriented Si substrate.And then the samples are annealed at different temperatures .â‘¡materials of LCMO channel and isolated-gate and electric-gate are fabricated by Laser Ablation.The obtained samples were characterized by Atom force microscope,optic microscope and X-ray powder diffraction for their structure and appearance ,and finally we finded favorable technique and technological conditions to obtain good sample .The third task is to design technics route of colossal magnetoresistance film (CMR) Field-Effect-Transistors (FET), and successfully fabricate electricfield-modulative CMR MOSFETs combining technics principle of semiconductor integrate circuit and the results of structure and appearance characteristic analysis, We studied the magnetoresistance at different temperature and in different frequency ,the resistance-temperature characteristic modulated by...