Electron cyclotron resonance plasma enhanced chemical vapour deposition of sioxny : optical properties and applications

D.Ing. (Electrical And Electronic Engineering )Please refer to full text to view abstrac

Protective coatings for front surface silver mirrors by atomic layer deposition

Silver is a metal which provides the highest reflectivity in the very broad wavelength range as well as the lowest polarization splitting. However, it is not very stable chemically and silver mirrors are easily damaged in a corrosive or oxidizing environment, leading first to the drastic drop in reflection followed by the complete disintegration of a silver layer. For this reason aluminum is much more in use. The problem of protection of silver layer is a very important one for number of applications, requiring the front side reflection, such as telescopes mirrors, reflective IR imaging optics, gratings, photovoltaic concentrator mirrors, etc. Atomic layer deposition (ALD) technique using trimethylaluminum (TMA) and water as precursors provides a very efficient way to protect a sensitive surface of silver from a corrosive and oxidizing environment, because ALD coatings can be deposited at rather low temperature. Moreover, ALD layer provides extremely high conformality (even when deposited over high aspect ratio features) and has high integrity, efficiently blocking foreign species diffusion to silver-overcoat interface. In our studies we tested the efficiency of the protection of silver mirrors by ALD-deposited Al2O3 layers against oxygen plasma exposure by correlating the ellipsometric measurements with the absolute reflection measurements and Glow-Discharge Optical Emission Spectroscopy (GD-OES) data. We have found that for optimal protection the thickness of ALD deposited layer should exceed at least 15 nm (about 150 ALD cycles at 150 oC), as thinner layers do not provide reliable protection of silver surface against oxygen plasma. We have also demonstrated that the deposition of 15 nm of a protective ALD-deposited Al2O3 layer does not affect the absolute reflectivity of a silver mirror in a spectral range 300 -2500 nm.Comment: 19 pages, 7 figures, 1 table, article is based on the regular talk given at The 8th International Conference on Spectroscopic Ellipsometry, May 26-31, 2019, Barcelon

Stable microcrystalline silicon thin-film transistors produced by the layer-by-layer technique

International audienceMicrocrystalline siliconthin films prepared by the layer-by-layer technique in a standard radio-frequency glow discharge reactor were used as the active layer of top-gate thin-film transistors(TFTs). Crystalline fractions above 90% were achieved for silicon films as thin as 40 nm and resulted in TFTs with smaller threshold voltages than amorphous siliconTFTs, but similar field effect mobilities of around 0.6 cm2/V s. The most striking property of these microcrystalline silicontransistors was their high electrical stability when submitted to bias-stress tests. We suggest that the excellent stability of these TFTs, prepared in a conventional plasma reactor, is due to the stability of the μc-Si:H films. These TFTs can be used in applications that require high stability for which a-Si:HTFTs cannot be used, such as multiplexed row and column drivers in flat-panel display applications, and active matrix addressing of polymer light-emitting diodes

Inverse problem of Mueller polarimetry for metrological applications

International audienceAbstract Inverse problem of Mueller polarimetry is defined as a determination of geometrical features of the metrological structures (i.e. 1D diffraction gratings) from its experimental Mueller polarimetric signature. This nonlinear problem was considered as an optimization problem in a multi-parametric space using the least square criterion and the Levenberg–Marquardt algorithm. We demonstrated that solving optimization problem with the experimental Mueller matrix spectra taken in conical diffraction configuration helps finding a global minimum and results in smaller variance values of reconstructed dimensions of the grating profile

An interfacial study of a a-C:H interlayer for the adhesion enhancement of plasma deposited silica thin films on polycarbonate

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Capillary jet injection of SiH4 in the high density plasma chemical vapor deposition of SiO2

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Plasma enhanced chemical vapour deposition of SiOxNy in an integrated distributed electron cyclotron resonance reactor

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Plasma treatment of polycarbonate for improved adhesion

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Deposition of SiO2 in integrated distributed electron cyclotron resonance microwave reactor

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