Mohammadi Vahid, Nihtianov Stoyan, Fang Changming
Department of Microelectronics, Delft University of Technology, 2628 CD, Delft, The Netherlands.
Brunel Centre for Advanced Solidification Technology (BCAST), Brunel University London, Uxbridge, Middlesex, UB8 3PH, UK.
Sci Rep. 2017 Oct 16;7(1):13247. doi: 10.1038/s41598-017-13100-0.
The interest in nanostructures of silicon and its dopants has significantly increased. We report the creation of an ultimately-shallow junction at the surface of n-type silicon with excellent electrical and optical characteristics made by depositing an atomically thin boron layer at a relatively low temperature where no doping of silicon is expected. The presented experimental results and simulations of the ab initio quantum mechanics molecular dynamics prove that the structure of this new type of junction differs from all other known rectifying junctions at this time. An analysis of the junction formation has led to the conclusion that the chemical interaction between the surface atoms of crystalline silicon and the first atomic layer of the as-deposited amorphous boron is the dominant factor leading to the formation of a depletion zone in the crystalline silicon which originates from the surface. The simulation results show a very strong electric field across the c-Si/a-B interface systems where the charge transfer occurs mainly from the interface Si atoms to the neighboring B atoms. This electric field appears to be responsible for the creation of a depletion zone in the n-silicon resulting in a rectifying junction-formation between the n-silicon and the atomically thin boron layer.
对硅及其掺杂剂纳米结构的兴趣显著增加。我们报告了在n型硅表面创建了一个具有优异电学和光学特性的极浅结，该结是通过在相对较低温度下沉积原子级薄的硼层制成的，在此温度下预计不会对硅进行掺杂。所呈现的实验结果和从头算量子力学分子动力学模拟证明，这种新型结的结构与此时所有其他已知的整流结不同。对结形成的分析得出结论，晶体硅表面原子与沉积的非晶硼的第一原子层之间的化学相互作用是导致在晶体硅中形成源自表面的耗尽区的主要因素。模拟结果表明，在c-Si/a-B界面系统中存在非常强的电场，电荷转移主要从界面Si原子转移到相邻的B原子。这个电场似乎是在n型硅中形成耗尽区的原因，从而导致在n型硅和原子级薄的硼层之间形成整流结。
