三维层合纳米多铁异质结的原子层沉积法制备

In order to conquer the leakage current is too large to get a strong magnetoelectric coupling effect in early magnetoelectric nano-composites materials, and to break through the limitation of the existing multiferroic heterostructures still confined to planar structures and macroscopic sizes. A new method for preparing 3D nano-laminated multiferroic heterostructures are developed based on ALD technology. Take the advantage of ALD technology, such as, self-limiting monolayer by monolayer atomic growth, uniform and conformal films growth on 3D substrates, precise films thickness controllability et.al. The new multiferroic heterostructures with three-dimensional laminated nanostructures was constructed by breaking the bottleneck of traditional preparation techniques such as physical vapor deposition and chemical vapor deposition et.al. The strong chemical bond interaction formed by the ALD process on the interface of films, and the high interface rate of the 3D nano-laminated multiferroic heterostructures, which are expected to get strong mechanical coupling effects and Novelty physical phenomena. Systematic investigate the growth mechanism of the two kinds of oxides and the intrinsic mechanism of the strong magnetoelectric coupling effect. An appropriate mathematical prediction model will be established to explain the properties.The development of this new technology and the construction of new structures will lay an important technical and theoretical basis for multiferroic heterostructures to three-dimensional, miniaturization, integration, low power consumption and greatly improve the storage density. It is important for multiferroic heterostructures to integrate with existing mainstream microelectronic devices and circuits, and to obtain large-scale applications.

针对早期纳米复合磁电材料漏导过大，无法获得强磁电耦合效应的问题和突破现有多铁异质结受限于平面结构和宏观尺寸的现状，开发了基于原子层沉积（ALD）技术的多铁异质结制备新方法。利用ALD特有的单原子层逐层自限制(Self-limiting)生长、三维均匀性和膜厚精确可控等特点，突破物理气象沉积和化学气相沉积等传统制备技术的瓶颈，构建出具有三维层合纳米结构的新型多铁异质结。利用ALD在两相界面处通过化学键形成的牢固机械耦合效应、三维纳米结构特有的高界面比和纳米尺寸效应，有望获得强大的磁电耦合效应和新奇的物理现象。探索制备过程中两相氧化物的生长机理和实现强磁电耦合效应的内禀属性，建立相应的数学预测模型。这种新技术的开发和新结构的构建对多铁异质结走向三维化、微型化、集成化、低功耗和大幅提高存储密度奠定重要的技术和理论基础。为多铁异质结实现与现有主流微电子器件和电路相集成，走大规模的应用具有重要意义。

针对早期纳米复合磁电材料漏导过大，无法获得强磁电耦合效应的问题，开发了基于原子层沉积（ALD）技术的多铁异质结制备新方法。利用ALD特有的单原子层逐层自限制(Self-limiting)生长、三维均匀性和膜厚精确可控等特点，突破物理气象沉积和化学气相沉积等传统制备技术的瓶颈，成功构建出了PMN-PT/Fe3O4多铁异质结。并系统地研究了这种多铁异质结的磁电耦合性能，在PMN-PT/Fe3O4多铁异质结中获得了高达78 Oe cm/kV的磁电调控性能，这因为ALD所制备的薄膜和衬底之间具有化学键强相互作用，应力通过这种强相互作用在铁电和铁磁两相之间高效传递的结果。此外我们还利用惰性贵金属作为湿法腐蚀硬掩模，解决了光刻胶作为PMN-PT单晶基片湿法刻蚀掩膜无法长时间抗住强酸腐的问题，依次优化光刻和湿法刻蚀等微纳加工工艺参数，研究刻蚀沟槽深度随刻蚀时间的变化关系曲线，最后我们在PMN-PT单晶基片上面得制备出了不同深宽比的鳍式三维沟槽结构，所制备出的PMN-PT三维鳍式沟槽架构，周期均匀，深宽比可控。最后我们还构建出了Al2O3/ZnO/Al2O3和Fe3O4/ZnO三维纳米异质结和平面异质结，并研究了其磁学和光学等相关性能。