{"title":"Atomic Layer Deposition of TiOx/Al2O3 Bilayer Structures for Resistive Switching Memory Applications†","authors":"Hehe Zhang, Nabeel Aslam, Marcel Reiners, Rainer Waser, Susanne Hoffmann-Eifert","doi":"10.1002/cvde.201407123","DOIUrl":null,"url":null,"abstract":"<div>\n \n <section>\n \n <p>The resistive switching (RS) properties of a thin Al<sub>2</sub>O<sub>3</sub> layer and TiO<sub><i>x</i></sub>/Al<sub>2</sub>O<sub>3</sub> bilayers integrated into TiN/metal oxide/Pt crossbar devices are investigated for future memristive device (ReRAM) applications. The oxide bilayer stack is realized in consecutive atomic layer deposition (ALD) processes at 300 °C without any post-annealing step. Stoichiometric Al<sub>2</sub>O<sub>3</sub> and oxygen-deficient TiO<sub><i>x</i></sub> thin films are grown from dimethylaluminum isopropoxide [DMAI: (CH<sub>3</sub>)<sub>2</sub>AlOCH(CH<sub>3</sub>)<sub>2</sub>] and tetrakis-dimethlyamido-titanium [TDMAT: Ti(N(CH<sub>3</sub>)<sub>2</sub>)<sub>4</sub>], respectively, as the metal sources, and water as the oxygen source. High insulating characteristics are confirmed for as-grown amorphous Al<sub>2</sub>O<sub>3</sub> films with a dielectric permittivity of 8.0 and disruptive field strength of about 7 MV cm<sup>−1</sup>, whereas the oxygen-deficient TiO<sub><i>x</i></sub> shows semiconducting behavior. The bipolar-type RS characteristics of TiN/TiO<sub><i>x</i></sub>/Al<sub>2</sub>O<sub>3</sub>/Pt cells show a strong dependence on both oxide layer thicknesses. A stable OFF/ON state resistance ratio of about 10<sup>5</sup> is obtained for the bilayer structure of 5 nm TiO<sub><i>x</i></sub> and 3.7 nm Al<sub>2</sub>O<sub>3</sub>.</p>\n </section>\n </div>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"20 7-8-9","pages":"282-290"},"PeriodicalIF":0.0000,"publicationDate":"2014-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201407123","citationCount":"12","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Vapor Deposition","FirstCategoryId":"1085","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/cvde.201407123","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 12
Abstract
The resistive switching (RS) properties of a thin Al2O3 layer and TiOx/Al2O3 bilayers integrated into TiN/metal oxide/Pt crossbar devices are investigated for future memristive device (ReRAM) applications. The oxide bilayer stack is realized in consecutive atomic layer deposition (ALD) processes at 300 °C without any post-annealing step. Stoichiometric Al2O3 and oxygen-deficient TiOx thin films are grown from dimethylaluminum isopropoxide [DMAI: (CH3)2AlOCH(CH3)2] and tetrakis-dimethlyamido-titanium [TDMAT: Ti(N(CH3)2)4], respectively, as the metal sources, and water as the oxygen source. High insulating characteristics are confirmed for as-grown amorphous Al2O3 films with a dielectric permittivity of 8.0 and disruptive field strength of about 7 MV cm−1, whereas the oxygen-deficient TiOx shows semiconducting behavior. The bipolar-type RS characteristics of TiN/TiOx/Al2O3/Pt cells show a strong dependence on both oxide layer thicknesses. A stable OFF/ON state resistance ratio of about 105 is obtained for the bilayer structure of 5 nm TiOx and 3.7 nm Al2O3.
期刊介绍:
Chemical Vapor Deposition (CVD) publishes Reviews, Short Communications, and Full Papers on all aspects of chemical vapor deposition and related technologies, along with other articles presenting opinion, news, conference information, and book reviews. All papers are peer-reviewed. The journal provides a unified forum for chemists, physicists, and engineers whose publications on chemical vapor deposition have in the past been spread over journals covering inorganic chemistry, materials chemistry, organometallics, applied physics and semiconductor technology, thin films, and ceramic processing.