Density functional theory study on the impact of heavy doping on Si intrinsic point defect properties and implications for single crystal growth from a melt
Density functional theory study on the impact of heavy doping on Si intrinsic point defect properties and implications for single crystal growth from a melt
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DOI：
10.1063/1.4825222
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发表时间：
2013-10
影响因子：
3.2
通讯作者：
K. Sueoka;E. Kamiyama;J. Vanhellemont
中科院分区：
文献类型：
--
作者：
K. Sueoka;E. Kamiyama;J. Vanhellemont
用密度泛函理论（DFT）计算得到了Si晶体中掺杂原子周围一个球体内所有位置的空位V和自间隙I的形成能，V和I的半径分别为6 a和5 a。替代P型（B和Ga）、中性（C、Ge和Sn）和n型（P、As、Sb和Bi）掺杂剂被考虑。结果表明，掺杂原子周围V和I的形成能随掺杂类型和尺寸的不同而变化，即取决于掺杂原子周围的电态和局域应变。得到了熔点缺陷的总热平衡浓度（掺杂剂周围的自由V或I和V或I的总和）与每种掺杂剂的类型和浓度的关系。进一步的DFT计算表明，熔体中大部分合并点缺陷都有助于对复合。从熔体中生长的重掺杂单晶Si点缺陷行为的合适模型。
Density functional theory (DFT) calculations are performed to obtain the formation energies of the vacancy V and the self-interstitial I at all sites within a sphere around the dopant atom with 6 A radius for V and 5 A radius for I in Si crystals. Substitutional p-type (B and Ga), neutral (C, Ge, and Sn), and n-type (P, As, Sb, and Bi) dopants were considered. The results show that the formation energies of V and I around dopant atoms change depending on the types and sizes of the dopants, i.e., depending on the electrical state and the local strain around the dopants. The dependence of the total thermal equilibrium concentrations of point defects (sum of free V or I and V or I around the dopants) at melting temperature on the type and concentration of each dopant is obtained. Further DFT calculations reveal that most of the total incorporated point defects from the melt contribute to pair recombination. An appropriate model of point defect behavior in heavily doped single crystal Si growing from a melt i...