Swift chemical sputtering of covalently bonded materials

Numerous experiments have shown that low-energy H ions and neutrals can erode amorphous carbon at ion energies of 1-10 eV, where physical sputtering is impossible, but at erosion rates which are clearly higher than those caused by thermal ions. In this paper, we will first review our computer simulation work providing an atom-level mechanism for how this erosion occurs, and then present some new results for H and He bombardment of tungsten carbide and amorphous hydrogenated silicon (a-Si:H), which indicate the mechanism can be of importance in a wide range of covalently bonded materials. We also discuss how the presented mechanism relates to previously described abstraction and etching mechanisms.

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Physical and Chemical Sputtering at Very Low Ion Energy: the Importance of the Sputtering Threshold

MRS Proceedings ◽

10.1557/proc-129-477 ◽

1988 ◽

Vol 129 ◽

Cited By ~ 4

Author(s):

Christoph Steinbruchel

Keyword(s):

Threshold Energy ◽

Surface Binding ◽

Ion Energy ◽

Chemical Sputtering ◽

Surface Binding Energy ◽

Physical Sputtering ◽

Chemical Etch ◽

Ion Energies ◽

The Difference ◽

Physical And Chemical

ABSTRACTA variety of data for physical etching (i.e. sputtering) and for ion-enhanced chemical etching of Si and SiO2 is analyzed in the very-low-ion-energy regime. Bombardment by inert ions alone, by reactive ions, and by inert ions in the presence of reactiveneutrals is considered. In all cases the etch yield follows a square root dependence on the ion energy all the way down to the threshold energy for etching. At the same time, the threshold energy has a non-negligible effect on the etch yield even at intermediate ion energies. The difference between physical and ion-enhanced chemical etch yields can be accounted for by a reduction in the average surface binding energy of the etch products and a corresponding reduction in the threshold energy for etching. These results suggest that, in general, the selectivity for ion-enhanced etch processes relative to physical sputtering can be increased significantly at low ion energy.

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Amorphous Hydrogenated Silicon P-I-N Solar Cells Grown from Hydrogen-Diluted Silane

MRS Proceedings ◽

10.1557/proc-192-45 ◽

1990 ◽

Vol 192 ◽

Author(s):

Murray S Bennett ◽

Jacob C Tu

Keyword(s):

Solar Cells ◽

Deposition Pressure ◽

Hydrogenated Silicon ◽

Hydrogen Dilution ◽

Amorphous Hydrogenated Silicon ◽

Deposition Parameters ◽

Wide Range ◽

The Stability ◽

Made In ◽

Deposition Conditions

ABSTRACTWe investigated p-i-n solar cells in which the i-layer was grown from hydrogen-diluted silane. The deposition parameters which were varied include flow rates, deposition pressure and power, and the degree of hydrogen dilution. We found that high quality devices could be made in which the i-layer was grown under a wide range of deposition conditions but that over this range neither the initial performance nor the stability of the devices differed significantly from those of cells having the same structure, but in which the i-layer was deposited from SiH4 with no H2-dilution.

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Universal Energy Dependence of Sputtering Yields At Low Ion Energy

MRS Proceedings ◽

10.1557/proc-223-41 ◽

1991 ◽

Vol 223 ◽

Cited By ~ 2

Author(s):

J. Muri ◽

Ch. Steinbrüchel

Keyword(s):

Noble Gas ◽

Large Body ◽

Threshold Energy ◽

Ion Energy ◽

Chemical Sputtering ◽

Physical Sputtering ◽

Ion Energies ◽

Atom Interaction ◽

Physical And Chemical ◽

Sputtering Yields

ABSTRACTSputtering yields Y(E)at ion energies E keV are shown to be described by the equation Y(E) = A(En - ) where A, n, and the threshold energy Eth are constants characteristic for a particular projectile/target combination. Examination of a wide variety of systems reveals that n = 0.5 provides an excellent universal representation of a large body of data, including physical sputtering of metals by noble gas ions, selfsputtering of metals, as well as physical and chemical sputtering of Si and SiO2. The above value for n is consistent with a 1/r4 power law atom-atom interaction potential within Sigmund's theory of sputtering. Another conclusion is that the effect of Eth on Y(E) must be taken into account at ion energies as high as 1 keV, not just near the sputtering threshold.

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Control of Bonded SiH in Silicon Oxides Deposited by Remote Plasma Enhanced CVD

MRS Proceedings ◽

10.1557/proc-105-73 ◽

1987 ◽

Vol 105 ◽

Cited By ~ 2

Author(s):

D. V. Tsu ◽

G. N. Parsons ◽

G. Lucovsky ◽

M. W. Watkins

Keyword(s):

Silicon Oxide ◽

Chemical Vapor ◽

Optical Emission ◽

Plasma Region ◽

Remote Plasma ◽

Silicon Oxides ◽

Hydrogenated Silicon ◽

Plasma Enhanced Cvd ◽

Amorphous Hydrogenated Silicon ◽

Wide Range

AbstractThis paper describes Optical Emission Spectrocopy (OES) and Mass Spectrometry (MS) studies of the plasma region in the Remote Plasma Enhanced Chemical Vapor Deposition (PECVD) of amorphous hydrogenated silicon (a-Si:H) and silicon oxide thin films. In Remote PECVD, only the O2/He mixture is plasma excited, silane is introduced into the deposition chamber well below the plasma region. Deposition of films has been studied over a wide range of relative He and O2flows, between 100% He and 100% O2. The incorporation of SiH in the oxides derives from the same mechanism as the deposition of a-Si:H, i.e., a metastable He induced fragmentation of silane.

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