硅基p-n结半导体输运行为的磁场调控

Recently the giant magnetoresistance (MR) in the non-magnetic silicon material (MR >2000% at room temperature) has been one of the hottest issues. The aim in this project is to reveal the mechanism of the magnetic field-induced transport behavior changes in single and two-type doped silicon based semiconductors by the manipulation of the space charge distributions. Firstly, we plan to fabricate the samples with large MR ratio by adjusting the doped atom compositions, concentrations and distributions. The fabrication methods are based on the ion diffusion or ion implantation combined with the sputtering technology. Secondly, we plan to measure the electrical transport properties (MR and Hall effect) at different temperatures, and systematically analysis semiconductor properties such as the carrier concentrations, nobilities and the space-charge region distributions as a function of temperature. Thirdly, for the samples with different space-charge region distributions we plan to study their magnetic field-induced transport behaviors by varying the external magnetic filed amplitudes and orientations, and further get the relationships between the MR effects and space-charge region distributions. Finally, compared to the MR data for single and two-types doped silicon and combined with the simulation results for electric field and magnetic field distributions, we could analysis mechanism of the magnetic field-induced modification of transport behaviors in details. The study can not only obtain the single and two-types doped silicon devices with high MR ratio and sensitivity at room temperature, but also gives a new insight into the silicon based magneto-electronics.

最近硅基非磁性材料巨磁阻效应（室温磁阻率>2000%）的发现引起人们极大的关注。本项目以研究磁场调控硅基p-n结半导体输运机制为目的，以控制空间电荷分布为关键展开研究。拟用离子扩散或注入技术并结合磁控溅射方法制备具有巨磁阻效应的单、双掺杂硅基半导体,掌握不同掺杂离子成分、浓度及空间电荷分布的硅基半导体制备工艺。通过不同温度下硅基半导体输运性质（电阻和霍尔）的测量，分析载流子浓度、迁移率以及空间电荷分布随温度的变化特性。在此基础上，改变磁场大小和夹角变化，系统测量具有不同空间电荷分布的单、双掺杂硅基半导体输运行为的磁场调制规律及巨磁阻效应。最后对比单、双掺杂硅基半导体磁电阻数据，结合电磁场分布模拟计算，进一步理解非磁性硅基p-n结半导体巨磁阻效应的产生机制。该研究不仅可以获得室温下低磁场、高磁电阻率的单、双掺杂硅基半导体，而且为今后硅基磁电子器件的设计和应用提供实验和理论依据。

本项目通过调节硅基材料掺杂离子浓度和分布，系统研究了磁场对非均匀空间电荷区的调控，在室温下实现了磁电阻高达2000%的硅基磁电阻器件。我们用离子注入并结合溅射技术制备具有不同掺杂成分、浓度和和构型的硅基半导体器件。通过不同温度下硅基半导体输运性质（电阻和霍尔）的测量，分析载流子浓度、迁移率以及空间电荷分布随温度的变化特性。在此基础上，改变磁场大小和夹角变化，系统测量具有不同空间电荷分布的单、双掺杂硅基半导体输运行为的磁场调制规律及巨磁阻效应。按照从材料到器件的思路，我们逐步设计、制备、测试和研究了掺杂单层硅、PN结二极管、硅基耦合三极管和二维石墨烯/硅复合器件的磁输运特性和磁电阻机理。由于二极管、三极管是当今电子器件的基石，对二极管、三极管实现磁场调控不仅可以进一步理解硅基材料反常巨大磁电阻的内部机制，而且为今后硅基半导体磁电子器件的设计和应用提供实验和理论依据。目前在项目资助下发表已标注SCI论文21篇，其中以本人为第一（或通讯）作者发表论文9篇，发明专利1项，搭建了多功能磁输运测试平台1套。期间培养本科毕业生4名，毕业博士生1名，硕士研究生2名，在读研究生4名，参加2014-2017历年国内秋季会议，2015-2016年美国APS春季会议 （March meeting）并作口头报告，2016年IEEE国际纳米电子会议（成都）并作口头报告和 2017年新加坡国际材料大会（ICMAT2017）并作口头报告。