He 离子注入的 6H-SiC 单晶中缺陷与磁性关联的正电子谱学研究
Correlation between defects and magnetic properties in He-implanted 6H-SiC investigated by positron annihilation spectroscopy
叶润 1徐菊萍 2刘建党 3叶邦角3
作者信息
- 1. 盐城师范学院物理与电子工程学院，盐城 224007
- 2. 散裂中子源科学中心，东莞 523803;中国科学院高能物理研究所，北京 100049
- 3. 中国科学技术大学近代物理系，合肥 230026
- 折叠
摘要
在 He 离子注入的 6H-SiC 单晶SiC:He2E16（剂量为 2 × 1016 cm-2）和 SiC:He1E17 剂量为 1 × 1017 cm-2）中观察到了室温铁磁性。SiC:He2E16 的饱和磁化强度（MS）为 1.23 emu/cm3，而 SiC:He1E17 的MS值减小到0.18 emu/cm3。湮没辐射多普勒展宽谱结果表明， He 注入后S 参数升高，正电子扩散长度发生明显变化，说明 He 注入产生了空位型缺陷并改变了正电子的缺陷俘获行为。两种 He 注量样品的 𝑆–𝑊 曲线斜率基本一致，表明其主导正电子湮没中心具有相似的局域电子环境，在本实验注量范围内未观察到明显的主导缺陷类型变化。值得注意的是， SiC:He1E17 具有较高的 𝑆 参数，但其 𝑀S 值明显低于 SiC:He2E16，表明 6H-SiC 的磁性响应与空位型缺陷的正电子湮没特征并非简单对应，可能还受到缺陷局域电子状态及缺陷间磁相互作用等因素的影响。研究结果表明， He 离子注入能够有效改变 6H-SiC 中的空位相关缺陷及磁性响应，为理解 SiC 中空位型缺陷与缺陷诱导磁性之间的关联提供了实验依据。
Abstract
Room-temperature ferromagnetism was observed in He-implanted 6H-SiC single crystals SiC:He2E16 (dose of 2 1016 cm2) and SiC:He1E17 (dose of 1 1017 cm2). The saturation magnetization (S) of SiC:He2E16 is 1.23 emu/cm3, whilst that of SiC:He1E17 decreased to 0.18 emu/cm3. Results from Doppler broadening annihilation radiation spectroscopy indicates that the -parameter increased following He implantation, and the positron diffusion length underwent a marked change, suggesting that He implantation generated vacancy-type defects and altered the defect capture behaviour of positrons. The slopes of the curves for the two samples with different He doping levels were essentially identical, indicating that their dominant positron annihilation centres possess similar local electronic environments; no significant change in the dominant defect type was observed within the doping range used in this experiment. It is worth noting that SiC:HeE exhibits a higher -parameter, yet the S value is significantly lower than that of SiC:He2E16. This suggests that the magnetic response of 6H-SiC does not correspond simply to the positron annihilation characteristics of vacancy-type defects, but may also be influenced by factors such as the local electronic states of the defects and magnetic interactions between defects. The results indicate that He-implantation can effectively alter vacancy-related defects and the magnetic response in 6H-SiC, providing experimental evidence for understanding the relationship between vacancy-type defects and defect-induced magnetism in SiC.关键词
正电子湮没谱学/缺陷/离子注入/半导体/铁磁性Key words
positron annihilation spectroscopy/defect/ion implantation/semiconductor/ferromagnetism引用本文复制引用
叶润,徐菊萍,刘建党,叶邦角.He 离子注入的 6H-SiC 单晶中缺陷与磁性关联的正电子谱学研究[EB/OL].(2026-09-11)[2026-09-16].https://chinaxiv.org/abs/202609.00113.学科分类
半导体技术
