AFM imaging of natural optical structures

The research in this field is focused to the investigation of biological structures with superior optical features. The study presents atomic force microscopy of biological optical structures on butterfly wings. The bright blue and dark black color scales exhibit the different topography. These scales were compared to the visually the same color scales of other two species of butterflies. The histograms of heights distribution are presented and show similar results for the scales of one color for different species

AFM study of structure influence on butterfly wings coloration

This study describes the structural coloration of the butterfly Vanessa Atalanta wings and shows how the atomic force microscopy (AFM) can be applied to the study of wings morphology and wings surface behavior under the temperature. The role of the wings morphology in colors was investigated. Different colors of wings have different topology and can be identified by them. AFM in semi-contact mode was used to study the wings surface. The wing surface area, which is close to the butterfly body, has shiny brown color and the peak of surface roughness is about 600 nm. The changing of morphology at different temperatures is shown

Substrate Preparation for Manufacturing of Aluminum Nitride Layers

Aluminum nitrides layers prepared on sapphire substrates are examined. The substrate surface was treated by dry plasma etching. The morphology of aluminum nitride thin films was studied by atomic force microscopy. Lateral force atomic force microscopy was used to study the morphology heterogeneity. The dependence of films morphology on the formation conditions has been defined. The objective of the study contributes to the improvement of technological process of dry etching and film deposition

Theoretical and experimental investigation of SiC thin films surface

This study describes morphology and structure of SiC thin films which are grown up by sublimation epitaxy in vacuum on the 6H-SiC substrates with thickness from tens of nanometers up to units of micrometers. Fashioned films are quite uniform in surface and volume. The crystal properties of the wafers and epitaxial layers are studied by electron diffraction investigation, X-ray techniques, and scanning probe microscopy. X-ray rocking curves show that structural perfection of SiC films is comparable with the structural perfection of monocrystalline 6H-SiC substrates. Calculated lattice parameters of epilayer by X-ray diffractometry also match with known values for 6H-SiC. Electron-diffraction measurement gives the confirmation of the crystallinity of the obtained layers and it is also proved by scanning probe microscopy. This technology allows making of defect treatment of the wafer in dependence on epitaxial conditions. Fundamental analysis in this field allows optimize conditions of thin films formation with prescribed properties and hence the using of them in the technology for elements of electronic engineering and by this reason the surface of monocrystalline SiC was analyzed

Optimization of gas injection conditions during deposition of AlN layers by novel reactive GIMS method

In 2011, we proposed a novel magnetron sputtering method. It involved the use of pulsed injection of working gas for the initiation and control of gas discharge during reactive sputtering of an AlN layer (Gas Injection Magnetron Sputtering – GIMS). Unfortunately, the presence of Al–Al bonds was found in XPS spectra of the AlN layers deposited by GIMS onto Si substrate. Our studies reported in this paper proved that the synchronization of time duration of the pulses of both gas injection and applied voltage, resulted in the elimination of Al–Al bonds in the AlN layer material, which was confirmed by the XPS studies. In our opinion the most probable reason of Al–Al bonds in the AlN layers deposited by the GIMS was the self-sputtering of the Al target in the final stage of the pulsed discharge

Microscopic optoelectronic defectoscopy of solar cells

Scanning probe microscopes are powerful tool for micro- or nanoscale diagnostics of defects in crystalline silicon solar cells. Solar cell is a large p-n junction semiconductor device. Its quality is strongly damaged by the presence of defects. If the cell works under low reverse-biased voltage, defects emit a light in visible range. The suggested method combines three different measurements: electric noise measurement, local topography and near-field optical beam induced current and thus provides more complex information. To prove its feasibility, we have selected one defect (truncated pyramid) in the sample, which emitted light under low reverse-biased voltage