X-ray photoelectron spectroscopy and Raman spectroscopy investigations of amorphous SixC1x(H) coatings obtained by chemical vapour deposition from thermally labile organosilicon compounds

1983 ◽  
Vol 101 (1) ◽  
pp. 83-96 ◽  
Author(s):  
J.P. Gerault ◽  
R. Morancho ◽  
G. Constant ◽  
P. Mazerolles ◽  
J.J. Ehrhardt ◽  
...  
1998 ◽  
Vol 76 (11) ◽  
pp. 1559-1563
Author(s):  
J Hugh Horton ◽  
Johann Rasmusson ◽  
Joseph G Shapter ◽  
Peter R Norton

The adsorption of the organometallic compounds bis(hexafluoroacetylacetonato)zinc(II) (Zn(hfac)2) and bis(hexafluoroacetylacetonato)nickel(II) (Ni(hfac)2) on the surface of Si(111)-7×7 were studied by a combination of scanning tunnelling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). These compounds are analogues of the compound bis(hexafluoroacetylacetonato)copper(II), which is an important precursor for the chemical vapour deposition of copper that we have previously studied. Both XPS and STM results indicate that the Zn(hfac)2 is adsorbed intact on the surface, and remains intact on the surface at temperatures up to 300 K. The XPS shows a transition from a physisorbed state to a chemisorbed state at temperatures between 160 and 300 K. At higher temperatures Zn(hfac)2 decomposed to form Zn and fluorocarbon fragments. The metal component diffused into the substrate. The Ni(hfac)2 complex could not be successfully adsorbed on the Si surface: it was shown that this was due to decomposition of the molecule in the vapour phase, probably due to the higher temperatures needed to evaporate this relatively involatile compound.Key words: scanning tunnelling microscopy, chemical vapour deposition, zinc, copper.


2019 ◽  
Vol 70 (4) ◽  
pp. 329-331
Author(s):  
Petr Machac

Abstract Graphene preparation by the method of chemical vapour deposition on SiC substrates is described. Despite very low growth temperature (1080 °C) and with use of methane atmosphere, carbon layers in the form of multi-layer graphene were prepared. Graphene quality was verified by means of available analytical methods: Raman spectroscopy, X-ray photoelectron spectroscopy, Van der Paw method.


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 5
Author(s):  
Lidia Mosińska ◽  
Robert Szczęsny ◽  
Marek Trzcinski ◽  
Mieczysław Karol Naparty

Diamond is a very interesting material with a wide range of properties, making it highly applicable, for example, in power electronics, chemo- and biosensors, tools’ coatings, and heaters. Due to the high demand for this innovative material based on the properties it is already expected to have, it is important to obtain homogeneous diamond layers for specific applications. Doping is often chosen to modify the properties of layers. However, there is an alternative way to achieve this goal and it is shown in this publication. The presented research results reveal that the change in methanol content during the Hot Filament Chemical Vapour Deposition (HF CVD) process is a sufficient factor to tune the properties of deposited layers. This was confirmed by analysing the properties of the obtained layers, which were determined using Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and an atomic force microscope (AFM), and the results were correlated with those of X-ray photoelectron spectroscopy (XPS). The results showed that the increasing of the concentration of methanol resulted in a slight decrease in the sp3 phase content. At the same time, the concentration of the -H, -OH, and =O groups increased with the increasing of the methanol concentration. This affirmed that by changing the content of methanol, it is possible to obtain layers with different properties.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 459
Author(s):  
Zdeněk Krtouš ◽  
Lenka Hanyková ◽  
Ivan Krakovský ◽  
Daniil Nikitin ◽  
Pavel Pleskunov ◽  
...  

Plasma polymer films typically consist of very short fragments of the precursor molecules. That rather limits the applicability of most plasma polymerisation/plasma-enhanced chemical vapour deposition (PECVD) processes in cases where retention of longer molecular structures is desirable. Plasma-assisted vapour thermal deposition (PAVTD) circumvents this limitation by using a classical bulk polymer as a high molecular weight “precursor”. As a model polymer in this study, polylactic acid (PLA) has been used. The resulting PLA-like films were characterised mostly by X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance (NMR) spectroscopy. The molecular structure of the films was found to be tunable in a broad range: from the structures very similar to bulk PLA polymer to structures that are more typical for films prepared using PECVD. In all cases, PLA-like groups are at least partially preserved. A simplified model of the PAVTD process chemistry was proposed and found to describe well the observed composition of the films. The structure of the PLA-like films demonstrates the ability of plasma-assisted vapour thermal deposition to bridge the typical gap between the classical and plasma polymers.


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