scholarly journals Impact of Methanol Concentration on Properties of Ultra-Nanocrystalline Diamond Films Grown by Hot-Filament Chemical Vapour Deposition

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 5
Author(s):  
Lidia Mosińska ◽  
Robert Szczęsny ◽  
Marek Trzcinski ◽  
Mieczysław Karol Naparty
Keyword(s):  
Chemical Vapour Deposition ◽  
Photoelectron Spectroscopy ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Methanol Concentration ◽  
X Ray ◽  
Atomic Force ◽  
Wide Range ◽  
Innovative Material ◽  
Hot Filament

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.

Article

1998 ◽  
Vol 76 (11) ◽  
pp. 1559-1563
Author(s):  
J Hugh Horton ◽  
Johann Rasmusson ◽  
Joseph G Shapter ◽  
Peter R Norton
Keyword(s):  
Chemical Vapour Deposition ◽  
Photoelectron Spectroscopy ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organometallic Compounds ◽  
Vapour Phase ◽  
Scanning Tunnelling Microscopy ◽  
X Ray ◽  
Scanning Tunnelling ◽  
Tunnelling Microscopy

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.

Growth of Boron Carbide Nanostructures on Silicon Using Hot Filament Chemical Vapour Deposition

2018 ◽  
Vol 42 (2) ◽  
pp. 73-76 ◽  
Author(s):  
Azadeh Jafari ◽  
Mohammad Mosavat ◽  
Alireza Meidanchi ◽  
H. Hossienkhani
Keyword(s):  
Boron Carbide ◽  
Grain Boundaries ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Boron Concentration ◽  
Chemical Vapour ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Hot Filament

Boron carbide nanostructures were grown on Si wafers through introduction of a mixture of B2O3 dissolved in methanol using hot filament chemical vapour deposition. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), Raman spectroscopy and the four-point probe technique were applied to characterise the properties of the boron carbide nanostructures. The XRD results showed that two kinds of boron carbide chemical compounds (B4C and B2C2) were deposited and the effect of boron concentration was significant. The FESEM images showed that the boron carbide nanostructures are made of crystal clusters with a cauliflower-like shape, in which the grain boundaries appear more clearly with increasing boron concentration. In addition, the AFM results showed that the surface roughness of the boron carbide films decreased with increasing boron concentration due to grain boundary diffusivity. The Raman spectrum results confirmed the presence of a B4C network and G and D bands. The results of the four-point probe method indicated that samples with higher boron incorporation showed the lowest sheet resistance (0.06 ω sq−1), which may be because of the decrease in inter-grain boundaries caused by the larger cluster size. This study suggests that higher boron incorporation in boron carbide nanostructures results in larger crystal clusters, higher thickness and lower film resistivity.

Study on Deposition of NCD on AFM Probe

2010 ◽  
Vol 431-432 ◽  
pp. 499-502
Author(s):  
Ming Min Huang ◽  
Dun Wen Zuo ◽  
Wen Zhuang Lu ◽  
Feng Xu ◽  
Min Wang
Keyword(s):  
Atomic Force Microscope ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Nanocrystalline Diamond ◽  
Optimum Parameters ◽  
Atomic Force ◽  
Afm Probe ◽  
Hot Filament

The performance of Atomic Force Microscope (AFM) is greatly determined by the quality of its probe. Nowadays, probes of diamond tips have become more and more popular than silicon ones, and have been widely used in industries. In this paper, research about the fabricating of nanocrystalline diamond (NCD) coated AFM probe has been done using Hot-Filament Chemical Vapour Deposition (HFCVD) technique. The results showed that NCD films have been grown on the probe. Problems about the growth of NCD on the tips have been discussed. The optimum parameters have also been proposed. This research can provide reference for the further experiments on the fabrication of NCD coated tips.

Reduction of carbon impurities in aluminium nitride from time-resolved chemical vapour deposition using trimethylaluminum

2020 ◽  
Author(s):  
Polla Rouf ◽  
Pitsiri Sukkaew ◽  
Lars Ojamäe ◽  
Henrik Pedersen
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Aluminium Nitride ◽  
Methyl Groups ◽  
Time Resolved ◽  
Thermally Induced ◽  
Light Emitting ◽  
Carbon Impurities ◽  
Wide Range

<p>Aluminium nitride (AlN) is a semiconductor with a wide range of applications from light emitting diodes to high frequency transistors. Electronic grade AlN is routinely deposited at 1000 °C by chemical vapour deposition (CVD) using trimethylaluminium (TMA) and NH<sub>3</sub> while low temperature CVD routes to high quality AlN are scarce and suffer from high levels of carbon impurities in the film. We report on an ALD-like CVD approach with time-resolved precursor supply where thermally induced desorption of methyl groups from the AlN surface is enhanced by the addition of an extra pulse, H<sub>2</sub>, N<sub>2</sub> or Ar between the TMA and NH<sub>3</sub> pulses. The enhanced desorption allowed deposition of AlN films with carbon content of 1 at. % at 480 °C. Kinetic- and quantum chemical modelling suggest that the extra pulse between TMA and NH<sub>3</sub> prevents re-adsorption of desorbing methyl groups terminating the AlN surface after the TMA pulse. </p>

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