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arXiv 2007.03985cond-mat.mtrl-sci
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质子辐照n型4 H- SiC中一次缺陷的退火转化途径

Conversion pathways of primary defects by annealing in proton-irradiated n-type 4H-SiC

Robert Karsthof, Marianne Etzelmüller Bathen, Augustinas Galeckas, Lasse Vines

摘要:

利用深能级瞬态谱和光致发光谱研究了n型4 H-SiC在质子辐照和退火后的缺陷布居的发展。提出了一个全面的模型来描述在低于1000°C的退火过程中辐照诱导的点缺陷的演化和相互转换。该模型提出的EH 4和EH 5陷阱经常发现DLTS起源于(+/0)属于不同配置的碳反位碳空位(CAV)复合物的电荷跃迁水平。此外,我们表明,硅空位(VSi)和CAV之间的转换通道被有效地阻止在n型条件下,但变得可用在样品中的费米能级已移动到带隙的中心,由于辐射诱导的施主补偿。在高达400°C的温度下,VSi和碳空位(VC)的退火被示出为由与残余自激体的复合主导。到更高的温度,CAV对密度的衰减的报告,这是密切相关的VC浓度的重新增加。对这个过程的一个可以想象的解释是CAV对分解成单独的碳反型体和VC缺陷。最后,所提出的数据支持的索赔,即在辐照SiC中的自由载流子的去除是由于引入补偿缺陷,而不是钝化的浅氮施主。

英文摘要:

The development of defect populations after proton irradiation of n-type 4H-SiC and subsequent annealing experiments is studied by means of deep level transient (DLTS) and photoluminescence (PL) spectroscopy. A comprehensive model is suggested describing the evolution and interconversion of irradiation-induced point defects during annealing below 1000°C. The model proposes the EH4 and EH5 traps frequently found by DLTS to originate from the (+/0) charge transition level belonging to different configurations of the carbon antisite-carbon vacancy (CAV) complex. Furthermore, we show that the transformation channel between the silicon vacancy (VSi) and CAV is effectively blocked under n-type conditions, but becomes available in samples where the Fermi level has moved towards the center of the band gap due to irradiation-induced donor compensation. The annealing of VSi and the carbon vacancy (VC) is shown to be dominated by recombination with residual self-interstitials at temperatures of up to 400°C. Going to higher temperatures, a decay of the CAV pair density is reported which is closely correlated to a renewed increase of VC concentration. A conceivable explanation for this process is the dissociation of the CAV pair into separate carbon anitisites and VC defects. Lastly, the presented data supports the claim that the removal of free carriers in irradiated SiC is due to introduced compensating defects and not passivation of shallow nitrogen donors.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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