Recently, geometry-induced quantum effects in periodic nanostructures were introduced and observed. Nanograting has been shown to dramatically improve thermoelectric and electron emission properties, and originate a geometry induced doping or G-doping. Here, we concentrate on experimental investigation of G-doping. We fabricate nanograting (NG) layers and measure their electron transport properties. The grating was fabricated on the surface of a silicon on insulator (SOI) wafer device layer using laser interference lithography followed by reactive ion etching. Next, large square islands were shaped in the device layer.The characteristics of NG and plain islands were compared to investigate G-doping. Resistivity temperature dependences were recorded in the range of 4-300 K. For all 21 samples, the NG layers show a 2-3 order of magnitude reduction in resistivity with respect to the plain layer. Hall coefficient and thermopower measurements demonstrate that the NG layers are n-type. Obtained G-doping level corresponded to an "effective impurity" concentration of 10 18 cm À3 . The dependence of the resistivity and Hall coefficient on temperature and magnetic field were recorded in the ranges of 2-300 K and 0-3 T, respectively.

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Boron doped Si/SiO2/substrate (Si:B) structure with subwavelength grating on the top Si:B layer was studied by spectroscopic ellipsometry and photoluminescence spectroscopy at room temperature. A clear modification of the dielectric function was observed after reactive ion etching of the top Si:B layer subjected to laser lithography to make a subwavelength grating with high precision. A striking feature of the dielectric function of the grated surface layer is a sharp and intense peak at the energy of 2.968 eV in the interband density of states. Emission band with a remarkable peak structure that emerges in the photoluminescence spectrum of the grated multilayer structure at and below the last energy is absent on pure or boron doped Si. The obtained results are discussed in terms of the G-doping effect in the considered surface grated multilayer structure.

Recently, geometry-induced quantum effects were observed in periodic nanostructures. Nanograting (NG) geometry significantly affects the electronic, magnetic, and optical properties of semiconductor layers. Silicon NG layers exhibit geometry-induced doping. In this study, G-doped junctions were fabricated and characterized and the Fermi-level tuning of the G-doped layers by changing the NG depth was investigated. Samples with various indent depths were fabricated using laser interference lithography and a consecutive series of reactive ion etching. Four adjacent areas with NG depths of 10, 20, 30, and 40 nm were prepared on the same chip. A Kelvin probe was used to map the work function and determine the Fermi level of the samples. The G-doping-induced Fermi-level increase was recorded for eight sample sets cut separately from p-, n-, p+-, and n+-type silicon substrates. The maximum increase in the Fermi level was observed at a10 nm depth, and this decreased with increasing indent depth in the p- and n-type substrates. Particularly, this reduction was more pronounced in the p-type substrates. However, the Fermi-level increase in the n+- and p+-type substrates was negligible. The obtained results are explained using the G-doping theory and G-doped layer formation mechanism introduced in previous works.