A scanning tunnelling microscopy insight into the preparation of carbon molecular sieves by chemical vapour deposition

2003 ◽  
Vol 13 (7) ◽  
pp. 1513-1516 ◽  
Author(s):  
Juan I. Paredes ◽  
Silvia Villar-Rodil ◽  
Amelia Martínez-Alonso ◽  
Juan M. D. Tascón
Keyword(s):  
Chemical Vapour Deposition ◽  
Molecular Sieves ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Scanning Tunnelling Microscopy ◽  
Carbon Molecular Sieves ◽  
Scanning Tunnelling ◽  
Tunnelling Microscopy ◽  
Insight Into

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.

Scanning Tunnelling Microscopy Study of the Growth Mechanism for Hydrogenated Amorphous Silicon Produced by Plasma Enhanced Chemical Vapour Deposition

1998 ◽  
Vol 507 ◽  
Author(s):  
A.J. Flewitt ◽  
W.I. Milne ◽  
J. Robertson ◽  
A.W. Stephenson ◽  
M.E. Welland
Keyword(s):  
Amorphous Silicon ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapour ◽  
Dangling Bonds ◽  
Scanning Tunnelling Microscope ◽  
Hydrogen Atoms ◽  
Scanning Tunnelling ◽  
Hydrogenated Amorphous

ABSTRACTThin films of hydrogenated amorphous silicon (a-Si:H) have been deposited by plasma-enhanced chemical vapour deposition (PECVD), and the resulting topography measured in-situ on a nanometre scale using a scanning tunnelling microscope (STM). An island structure is observed on the surface of device quality a-Si:H, which can be quantitatively analysed using a one dimensional Fourier transform of the topography. Results suggest that deposition is limited by the creation of dangling bonds on the a-Si:H surface and not by the surface transport of SiH 3 radicals at the deposition temperature (598 K). Island nucleation takes place through the abstraction of hydrogen atoms from the a-Si:H surface by plasma etching and the subsequent attachment of an SiH 3 radicals to the available sites. A thermally activated hydrogen effusion process around the edge of each island, where the step edge causes a high local hydrogen concentration, then creates further dangling bonds which allow the islands to grow. A simulation has been constructed, which confirms this two stage mechanism.

Low-pressure chemical vapour deposition of mullite coatings in a cold-wall reactor

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-395-Pr8-402 ◽  
Author(s):  
B. Armas ◽  
M. de Icaza Herrera ◽  
C. Combescure ◽  
F. Sibieude ◽  
D. Thenegal
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Low Pressure ◽  
Cold Wall ◽  
Pressure Chemical ◽  
Mullite Coatings

Thermodynamical and experimental conditions of hafnium carbide chemical vapour deposition

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-373-Pr8-380 ◽  
Author(s):  
P. Sourdiaucourt ◽  
A. Derré ◽  
P. Delhaès ◽  
P. David
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Hafnium Carbide ◽  
Experimental Conditions

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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