Influence of excited states of a deep substitutional dopant on majority-carrier concentration in semiconductors
Influence of excited states of a deep substitutional dopant on majority-carrier concentration in semiconductors
复制标题
深取代掺杂剂的激发态对半导体中多数载流子浓度的影响
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
Hideharu Matsuura
中科院分区：
文献类型：
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作者：
Hideharu Matsuura
在p型宽带隙半导体中的受主的密度NA和能级EA，SiC、GaN和金刚石通过电荷中性方程与空穴浓度p T的温度依赖性的最小二乘拟合来确定，所述最小二乘拟合使用不考虑受体的激发态的影响的受体的费米-狄拉克分布函数。然而，以这种方式获得的NA远高于通过二次离子质谱法确定的受体原子的浓度。由于Ea远离价带最大值EV，而费米能级位于Ea和EV之间，因此受主激发态对pT的影响不可忽略.一个分布函数，包括激发态的影响，这是来自微正则系综的观点，而不是巨正则系综，导致可靠的NA和EA。在n型Te掺杂的Al 0.6Ga 0.4Sb中的情况是相同的，因为对于大的Al摩尔分数，Te施主能级远离导带最小值。最后，发现具有深能级的替代掺杂剂的激发态增强掺杂剂的电离，即使它们被期望抑制电离，因为它们根据从巨正则系综的观点导出的分布函数充当陷阱。
The density NA and energy level EA of an acceptor in a p-type wide-band-gap semiconductor e.g., SiC, GaN, and diamond are determined by a least-squares fit of the charge neutrality equation to the temperature dependence of the hole concentration p T using the Fermi-Dirac distribution function for acceptors that does not consider the influence of the excited states of the acceptor. The NA obtained this way is, however, much higher than the concentration of acceptor atoms determined by secondary ion mass spectroscopy. Because EA is far from the valence-band maximum EV and the Fermi level is between EA and EV, the influence of the excited states of the acceptor on p T should not be ignored. A distribution function including the influence of excited states, which is derived from the viewpoint of the microcanonical ensemble, not the grand canonical ensemble, leads to reliable NA and EA. The situation in n-type Te-doped Al0.6Ga0.4Sb is the same, because the Te donor level is far from the conduction-band minimum for large Al mole fraction. Finally, the excited states of a substitutional dopant with a deep energy level are found to enhance the ionization of the dopant, even though they were expected to suppress the ionization because they acted as a trap according to the distribution function derived from the viewpoint of the grand canonical ensemble.