The Preparation Of Amorphous HfO₂ Gate And Its Electrical Properties On The Surface Of Conductive SrTiO₃

The electronic information industry is developing rapidly,and the demand for electronic devices is constantly improving,especially the miniaturization and high sensitivity.In the process of the development of the device,the traditional gate oxide has exposed various defects,which makes people pay more attention on these problems.HfO₂ is one of the most promising materials for the next generation of gate oxides with the following characteristics:high dielectic constant,relatively small leakage current under the same conditions,good matching with substrate and good contact of the device.HfO₂ and SrTiO₃ are the main materials in this study,including preparation of HfO₂ thin films by pulsed laser deposition technology.The SrTiO₃surface morphology and electrical conductivity was tested by AFM and ampere meter,respectively.Research on the stability of SrTiO₃ surface conductive layer coated by HfO₂ thin film,and the gate field effect performance of HfO₂ on the SrTi O₃ surface conductive layer.The leakage mechanism was analyzed emphatically.The main contents are as follows:1.Single crystal SrTiO₃ was bombarded by Ar⁺to prepare surface conductive layer.The surface conducting layer is of metallic like.The resistance increases with the temperature increases.Further analysis of the conductive properties of the SrTiO₃surface conductive layer was studied,including the doping concentration Nd,rho-T,?-T and n-T.2.The stability in air of SrTiO₃ surface conductive layer was studied.It improved that the resistance of SrTiO₃ surface conductive layer increase linearly as the time increase,and is almost three times as the initial resistance after 4 days.So,SrTiO₃surface conductive layer is unstable.In order to solve the ability problem,based on the transmission length method?TLM?test and metal surface contact resistance of the conductice layer Rc and the change of the surface resistance?Rs?of conductive layer itself.Further analyzing was study on the changes of SrTiO₃ surface conductive layer.The result show that the contact resistance?Rc?and surface resistance of conductive layer?Rs?changed,and Rs plays an important role on the process.3.The HfO₂ films were deposited by pulsed laser deposition technique,and AFM was used to analyze the surface morphology and thickness of thin film.The properties of the SrTiO₃ surface conductive layer coated by HfO₂ was analyzed.The experiment results show that the stability was improved after coated by HfO₂ film.And the stable effect was different with different HfO₂ film.4.The field effect performance of mental/HfO₂/SrTiO₃ was confirmed and the I-V characteristic of mental/HfO₂/SrTiO₃ was researched at different temperature.The leakage mechanism of amorphous HfO₂ film was deeply analyzed.The results show that it is the Ohmic conduction at low voltage?<0.18 V?and it is P-F leakage mechanism at high voltage?>0.5 V?.The barrier height of amorphous HfO₂ is 0.48 eV.