Goroshko D L, Galkin N G, Fomin D V, Gouralnik A S, Vavanova S V
Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, Russia.
J Phys Condens Matter. 2009 Oct 28;21(43):435801. doi: 10.1088/0953-8984/21/43/435801. Epub 2009 Oct 5.
Electrical and optical properties of thin iron layers grown at room temperature on the epitaxial silicide Si(111)-(2 × 2)-Fe phase and on an Si(111)7 × 7 surface were investigated using in situ Hall effect registration, atomic force microscopy, and optical spectroscopy. It was established that Si(111)-(2 × 2)-Fe phase has semiconducting properties with a 0.99 eV effective band gap and acts as a diffusion barrier for the deposited iron atoms, preventing intermixing with the substrate at room temperature. Peculiarities in the optical spectra of a sample with a 2 nm iron film grown on the Si(111)-(2 × 2)-Fe phase typical for both metal and semiconducting natures prove a conservation of the phase under the iron layer. The process of iron growth on the Si(111)-(2 × 2)-Fe phase is accompanied by the development of high stress in the subsurface area resulting in band dispersion changes. Apparently the tension reaches a maximum at an iron layer thickness of 1.35 nm, and a high effective hole mobility equal to 820 cm(2) V(-1) s(-1) was registered.
利用原位霍尔效应记录、原子力显微镜和光谱学，研究了室温下在外延硅化物Si(111)-(2×2)-Fe相和Si(111)7×7表面上生长的薄铁层的电学和光学性质。结果表明，Si(111)-(2×2)-Fe相具有半导体性质，有效带隙为0.99 eV，并且作为沉积铁原子的扩散阻挡层，在室温下防止与衬底混合。在Si(111)-(2×2)-Fe相上生长的具有2 nm铁膜的样品的光谱特性，对于金属和半导体性质来说都很典型，这证明了铁层下该相的保留。在Si(111)-(2×2)-Fe相上生长铁的过程伴随着亚表面区域高应力的产生，导致能带色散变化。显然，在铁层厚度为1.35 nm时张力达到最大值，并且记录到了高达820 cm² V⁻¹ s⁻¹的高有效空穴迁移率。
