The mechanism of boron-enhanced diffusion from a thin boron layer deposited on the surface in the case of silicon crystal doping is proposed and investigated. It was supposed that lattice contraction occurs in the vicinity of the surface due to the difference between the atomic radii of boron and silicon. This lattice contraction provides a stress-mediated diffusion of silicon self-interstitials from the near-surface region to the bulk of a semiconductor. Due to the stress-mediated diffusion, the near-surface region is depleted of silicon self-interstitials, and simultaneous oversaturation of this species occurs in the bulk. In this way, a strong nonuniform distribution of silicon self-interstitials in the vicinity of the surface is formed without regard to the large migration length of this species. The oversaturation of the bulk of a semiconductor with nonequilibrium self-interstitials allows one to explain the boron-enhanced diffusion of impurity atoms. The strong nonuniform distribution of these point defects also results in a specific form of boron concentration profile in the vicinity of the surface. Good agreement of the calculated boron profile with the experimental data for the entire doped region was obtained within the limit of the proposed model.

中文翻译：

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硅基板近表面区域的硼扩散模拟

提出并研究了在硅晶体掺杂情况下沉积在表面上的薄硼层的硼增强扩散机制。据推测，由于硼和硅的原子半径不同，晶格收缩发生在表面附近。这种晶格收缩提供了硅自填隙从近表面区域到半导体主体的应力介导的扩散。由于应力介导的扩散，近表面区域耗尽了硅自填隙，并且该物质同时在体中发生过饱和。以这种方式，在表面附近形成强烈的非均匀分布的硅自填隙，而不考虑该物种的大迁移长度。具有非平衡自填隙的半导体本体的过饱和使得人们可以解释杂质原子的硼增强扩散。这些点缺陷的强烈不均匀分布也导致表面附近的特定形式的硼浓度分布。在所提出的模型的范围内，获得了计算的硼分布与整个掺杂区域的实验数据的良好一致性。