Si基薄膜中电控磁效应的研究

Silicon(Si) is not only abundant (its oxide is sand), but it also is the most widely used elemental semiconductor and has matured processing technology in modern electronics. Mn,Sb codoped Si films are fabricated by laser molecular beam epitaxy and magnetron co-sputtering techniques. By optimizing the experimental parameters and doping concentration, the homogeneous Mn,Sb codoped Si films with room temperature ferromagnetism and a very wide range of carrier densities are hoped to be obtained. On the base of this, the structure of Pt layer/insulator layer/Mn,Sb:Si layer with different kinds of insulators will be designed. The transport properties including resistance and carrier density, and magnetic properties such as saturation magnetization, Curie temperature are hoped to be adjusted by applying different bias voltages on Pt layer with Si layer in the structure of Pt layer/insulator layer/Mn,Sb:Si layer. Based on these experimental results, the mechanism of adjusting the magnetic and transport properties by bias voltage is also discussed. This work will pave the way towards the novel spintronics devices with low energy consumption, allowing a seamless integration with electronic circuits.

本项目拟以地壳中第二丰富且在半导体工业中居于核心位置的Si作为研究对象，采用激光分子束外延和磁控共溅射技术，通过优化实验条件和共掺浓度，制备出载流子浓度可调且具有室温铁磁性的Mn、Sb共掺的Si稀磁半导体薄膜；通过设计具有不同绝缘层的Pt层/绝缘层/Mn,Sb:Si层测试单元，在Pt层和Si层之间施加一定的偏压来调制体系的电阻、载流子浓度等电输运性质，进而对其铁磁性进行调控，从而在Si体系中实现电场方式对磁性和电输运性质的共同操控。在此基础上，进一步探究电控磁效应的机制。本项目的研究结果将为研制一种新颖的、能与半导体工业有良好兼容性的、具有低能耗的自旋电子学器件奠定一定的基础。

自旋电子学可以同时利用电子的电荷和自旋属性，有望实现磁、电一体化，具有潜在的应用价值，从而引起人们的广泛关注。本项目采用磁控溅射技术制备了Fe/Si薄膜，通过优化实验条件和过渡金属掺杂浓度，获得了兼具磁电阻效应和室温铁磁性的Fe/Si磁性半导体薄膜；设计并制备了以Au、Pt作为顶、底电极的Pt/SiO2-Co/Au和Pt/ZnO/ZnO-Co/Au器件，通过在底电极接地，顶电极加电压，实现了电致阻变效应，并有效调制了器件的饱和磁化强度和磁电阻效应，从而实现了电的方式对磁性和电输运性质的共同操控，并探究了其中的机制。本项目的研究结果将为研制一种新颖的、能与半导体工业有良好兼容性的、具有低能耗的自旋电子学器件提供一定的参考。