A comparative study of plasma parameters and gas phase compositions in Cl2 and HCl direct current glow discharges

This research work deals with the comparative study of C6F12O + Ar and CF4 + Ar gas chemistries in respect to Si and SiO2 reactive-ion etching processes in a low power regime. Despite uncertain applicability of C6F12O as the fluorine-containing etchant gas, it is interesting because of the liquid (at room temperature) nature and weaker environmental impact (lower global warming potential). The combination of several experimental techniques (double Langmuir probe, optical emission spectroscopy, X-ray photoelectron spectroscopy) allowed one (a) to compare performances of given gas systems in respect to the reactive-ion etching of Si and SiO2; and (b) to associate the features of corresponding etching kinetics with those for gas-phase plasma parameters. It was found that both gas systems exhibit (a) similar changes in ion energy flux and F atom flux with variations on input RF power and gas pressure; (b) quite close polymerization abilities; and (c) identical behaviors of Si and SiO2 etching rates, as determined by the neutral-flux-limited regime of ion-assisted chemical reaction. Principal features of C6F12O + Ar plasma are only lower absolute etching rates (mainly due to the lower density and flux of F atoms) as well as some limitations in SiO2/Si etching selectivity.

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Comparative study of heterogeneous photocatalytic decomposition of tetrachloroethene and trichloroethene in the gas phase

Applied Catalysis A General ◽

10.1016/j.apcata.2004.02.057 ◽

2004 ◽

Vol 271 (1-2) ◽

pp. 177-184 ◽

Cited By ~ 16

Author(s):

Márta Hegedüs ◽

András Dombi

Keyword(s):

Comparative Study ◽

Gas Phase ◽

Photocatalytic Decomposition

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Comparative Study of Mono- and Dinuclear Complexes of Late 3d-Metal Chlorides withN,N-Dimethylformamide in the Gas phase†

Inorganic Chemistry ◽

10.1021/ic100759h ◽

2011 ◽

Vol 50 (3) ◽

pp. 771-782 ◽

Cited By ~ 24

Author(s):

Lucie Ducháčková ◽

Jana Roithová ◽

Petr Milko ◽

Jan Žabka ◽

Nikos Tsierkezos ◽

...

Keyword(s):

Comparative Study ◽

Gas Phase ◽

Dinuclear Complexes ◽

Metal Chlorides

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Comparative Study of GaN Growth Process by MOVPE

MRS Proceedings ◽

10.1557/proc-572-463 ◽

1999 ◽

Vol 572 ◽

Author(s):

Jingxi Sun ◽

J. M. Redwing ◽

T. F. Kuech

Keyword(s):

High Temperature ◽

Comparative Study ◽

Gas Phase ◽

Residence Time ◽

Gas Flow ◽

Flow Sheet ◽

Flow Zone ◽

High Quality ◽

Phase Temperature ◽

High Temperature Gas

ABSTRACTA comparative study of two different MOVPE reactors used for GaN growth is presented. Computational fluid dynamics (CFD) was used to determine common gas phase and fluid flow behaviors within these reactors. This paper focuses on the common thermal fluid features of these two MOVPE reactors with different geometries and operating pressures that can grow device-quality GaN-based materials. Our study clearly shows that several growth conditions must be achieved in order to grow high quality GaN materials. The high-temperature gas flow zone must be limited to a very thin flow sheet above the susceptor, while the bulk gas phase temperature must be very low to prevent extensive pre-deposition reactions. These conditions lead to higher growth rates and improved material quality. A certain range of gas flow velocity inside the high-temperature gas flow zone is also required in order to minimize the residence time and improve the growth uniformity. These conditions can be achieved by the use of either a novel reactor structure such as a two-flow approach or by specific flow conditions. The quantitative ranges of flow velocities, gas phase temperature, and residence time required in these reactors to achieve high quality material and uniform growth are given.

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