Impurity Conduction in Silicon Carbide
Impurity Conduction in Silicon Carbide
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碳化硅中的杂质传导
DOI：
10.4028/www.scientific.net/msf.556-557.367
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
L. Frey
中科院分区：
文献类型：
--
作者：
M. Krieger;K. Semmelroth;H. B. Weber;G. Pensl;M. Rambach;L. Frey
本文报道了低温下掺铝6H-SiC晶体的导纳光谱（AS）研究。在高掺杂样品（NA≥7.2×1017 cm-3）的肖特基触点上的导纳谱显示出两组电导峰，这导致了Arrhenius图的两个不同斜率。陡峭的斜率是由Al受体引起的，而较平坦的斜率是由最近邻跳变的活化能ε3引起的。我们提出了一个模型，该模型解释了低温电导峰的意外锐化和低受体浓度下这些峰的消失。通过仿真验证了模型的正确性，并与4H-和相同的6HSiC样品的电阻率测量结果进行了比较。
We report on admittance spectroscopy (AS) investigations taken on aluminum (Al)- doped 6H-SiC crystals at low temperatures. Admittance spectra taken on Schottky contacts of highly doped samples (NA ≥ 7.2×1017 cm-3) reveal two series of conductance peaks, which cause two different slopes of the Arrhenius plot. The steep slope is attributed to the Al acceptor, while the flatter one - obtained from the low temperature peaks - is attributed to the activation energy ε3 of nearest neighbor hopping. We propose a model, which explains the unexpected sharpness of the low temperature conductance peaks and the disappearance of these peaks for low acceptor concentrations. The model is verified by simulation, and the AS results are compared with corresponding results obtained from resistivity measurements taken on 4H- and the identical 6HSiC samples.