High Curie Temperature Ferromagnetism and High Hole Mobility in Tensile Strained Mn‐Doped SiGe Thin Films
High Curie Temperature Ferromagnetism and High Hole Mobility in Tensile Strained Mn‐Doped SiGe Thin Films
复制标题
DOI：
10.1002/adfm.202002513
复制
发表时间：
2020-04
影响因子：
19
通讯作者：
Huan-Hua Wang;Sen Sun;Jiating Lu;Jiayi Xu;X. Lv;Yong Peng;Xi Zhang;Yuan-Tin Wang;G. Xiang
中科院分区：
文献类型：
--
作者：
Huan-Hua Wang;Sen Sun;Jiating Lu;Jiayi Xu;X. Lv;Yong Peng;Xi Zhang;Yuan-Tin Wang;G. Xiang
基于IV族材料的稀释磁性半导体是与当前硅技术兼容的自旋电子器件的理想选择。在这项工作中，首先通过射频磁控溅射在Ge衬底上制备了非晶掺杂Mn的SiGe薄膜，然后通过快速热退火（RTA）结晶。经RTA处理后，样品成为铁磁性半导体，其居里温度随Mn掺杂浓度的增加而升高，当Mn掺杂浓度为5%时居里温度达到280 K。结果表明，SiGe晶体的铁磁性来自空穴介导过程，并通过拉伸应变增强。同时，为了消除异常霍尔效应的影响，在33 T下进行了霍尔效应测量，结果表明，由于拉伸应变引起的能带结构调制，退火样品的空穴迁移率大大提高，最大值为≈1000 cm2 V−1 s−1。具有高居里温度铁磁性和高空穴迁移率的Mn掺杂SiGe薄膜可能为半导体自旋电子学提供一个有前途的平台。
Diluted magnetic semiconductors based on group‐IV materials are desirable for spintronic devices compatible with current silicon technology. In this work, amorphous Mn‐doped SiGe thin films are first fabricated on Ge substrates by radio frequency magnetron sputtering and then crystallized by rapid thermal annealing (RTA). After the RTA, the samples become ferromagnetic semiconductors, in which the Curie temperature increases with increasing Mn doping concentration and reaches 280 K with 5% Mn concentration. The data suggest that the ferromagnetism comes from the hole‐mediated process and is enhanced by the tensile strain in the SiGe crystals. Meanwhile, the Hall effect measurement up to 33 T to eliminate the influence of anomalous Hall effect reveals that the hole mobility of the annealed samples is greatly enhanced and the maximal value is ≈1000 cm2 V−1 s−1, owing to the tensile strain‐induced band structure modulation. The Mn‐doped SiGe thin films with high Curie temperature ferromagnetism and high hole mobility may provide a promising platform for semiconductor spintronics.