Abstract: Provided is a novel method of and system for recovering and recirculating a deuterium-containing gas. According to the inventive method, a deuterium-containing feed gas is introduced into a chamber. An exhaust gas containing deuterium is removed from the chamber. The deuterium concentration of the exhaust gas is adjusted to a predetermined value, thereby producing a concentration-adjusted gas stream. Finally, the concentration-adjusted gas stream is introduced into the chamber as the deuterium-containing feed gas. The invention makes the use of deuterium, for example, in the mass production of semiconductor devices, commercially feasible.

Abstract: Methods and systems of delivering ultra-high purity gas to a point of use are claimed and described. The methods include providing a source of ultra-high purity liquid (the source preferably at a pressure and temperature sufficient to maintain the liquid in substantially the liquid phase); transporting (preferably via pressure in the source alone) the ultra-high purity liquid from the source to one or more means to effect a phase change of the ultra-high purity liquid to an ultra-high purity gas; effecting a phase change (preferably at or near equilibrium vaporization conditions) of the ultra-high purity liquid to form an ultra-high purity gas in the one or more means to effect the phase change; and routing the ultra-high purity gas from the means to effect the phase change to a point of use (preferably with no intermediate, potentially impurity-generating media between the means to effect the phase change and the point of use other than ultra-clean conduit).

Abstract: A method of detecting a malfunction or failure of a pressure regulator in a corrosive or reactive gas distribution system while in use involves continuously measuring or monitoring the output pressure of the pressure regulator, both in the presence and the absence of gas flow. The onset of a malfunction of the pressure regulator can be predicted when the differential output pressure between flowing and non-flowing gas fluctuates highly and increases gradually. Failure of the pressure regulator or of the total system is detected when the differential output pressure in the presence and absence of flowing gas exceeds some experimentally determined value.

Abstract: A process for reducing corrosion in a gas distribution network of ultra high purity gas or any part of said distribution network, including:(a) Wet cleaning the gas distribution network or at least one part thereof with a wet cleaning agent,(b) Liquid drying the gas distribution network or the at least one part thereof with an H.sub.2 O desorbing liquid drying agent selected from the group consisting of acetone dimethylacetal DMP, 2.2 dichloropropane DCP or 2.2 dibromopropane DBP, mixtures thereof and any equivalent thereof,(c) purging said gas distribution network or any part thereof with a dry high purity gas comprising less than 1 ppm of any impurity, and(d) evacuating the gas distribution network or any part thereof at a pressure which is lower than 5.times.10.sup.4 Pascal(e) exposing the gas distribution network or any part thereof to an atmosphere including an ultra high purity corrosive gas or air.

Abstract: In accordance with the present invention, methods and systems are provided which afford solutions to the problems of gas distribution of ultra-high purity ESGs at high gas flow rates. A first aspect of the invention is a system comprising a compressed liquefied gas container; an internal heat exchanger within the compressed liquefied gas container; a gas supply conduit which takes feed from the container and delivers the ESG to a process; and an external heat exchanger positioned effectively near the conduit downstream of the container but upstream of the process.

Abstract: A process to avoid or limit corrosion at the junction of two piping comprising devices welded together, said piping comprising devices being adapted to flow corrosive gases through them, said process comprising the steps of:a) providing a first piping comprising device and connecting it to an inert gas source;b) purging it with an inert gas comprising substantially not more than 10 ppb of an oxidizing gas selected from the group consisting of oxygen, carbon dioxide, water vapor or mixtures thereof, said inert gas flowing from a first opening to a second opening of said piping comprising device;c) providing a second pipe comprising device in flow communication with the first one, while continuing to purge the first piping comprising device;d) welding the two piping comprising devices, said welding being carried out under an inert gas atmosphere; ande) repeating steps c and d if necessary.

Abstract: A process for welding stainless steel tubing in the presence of an inert gas comprising a silicon base gas, in particular silane SiH.sub.4. During the welding operation, a suitable quantity of silicon is deposited by chemical vapor deposition at the weld joint to significantly improve the corrosion resistance of the weld.

Abstract: A process for coating powders with ultrafine particles of silicon, silicon oxide, silicon nitride or alloys thereof, entailing:a) introducing a reactant gas into a bed of core powders, thereby uniformly suspending the core powders in the reactant gas,b) entraining the uniformly suspended core powders into a chemical vapor deposition (CVD) reactor,c) selectively forming ultrafine particles of silicon, silicon oxide, silicon nitride or alloys thereof in the gas phase by homogeneous deposition of the reactant gas, while minimizing core powder growth by CVD at surfaces of suspended core powders, andd) coating the core powders with the ultrafine particles of silicon, silicon oxide, silicon nitride or alloys thereof, by introducing hot inert gas into the uniformly suspended core powders in the reactant gas.

Abstract: A process for producing a deposit of an inorganic and amorphous protective coating on an organic polymer substrate, the coating comprising compounds in the form of an oxide, nitride, carbide, or alloys thereof, by photosensitized decomposition in the gas phase, which comprises decomposing a gas medium by photosensitized decomposition, including precursors of the elements constituting the deposit of the inorganic and amorphous protective coating to be produced by photonic excitation of an impurity which has been previously introduced into the medium, said decomposition being adapted for producing an indirect transfer of energy to the molecules of the medium, thereby causing the decomposition and subsequent deposition of the these elements onto the substrate.

Abstract: The invention relates to a method of forming a silicon diffusion and/or overlay coating on the surface of a metallic substrate comprising the steps of introducing the sample into a cold wall Low Pressure Chemical Vapor Deposition (LPCVD) enclosure, evacuating the enclosure up to a pressure P.sub.1 which is lower than 0.5 Torr, maintaining said pressure P.sub.1 while heating up said sample to a temperature which is comprised between about room temperature and about 300.degree. C., bringing under same pressure P1 the sample to the CVD temperature comprised between about 50.degree. C. and 1000.degree. C., introducing a gas or gas mixture comprising at least one silicon hydride gas, maintaining the pressure inside the enclosure between about 0.

Abstract: The present invention provides a method of forming a free standing shape made of a material containing refractory metal, which entails providing a mandrel in a CVD enclosure, injecting a refractory halide gas and a reducing gas in the enclosure, reacting the gases in the enclosure to generate a material containing refractory metal, growing a layer of the material containing refractory metal on the mandrel and removing the mandrel to obtain the free standing shape, wherein the reducing gases is a silicon hydride gas or a mixture thereof.

Abstract: The invention relates to a process of making a high purity silicide target comprising the steps of providing a substrate in a CVD enclosure, evacuating said enclosure up to a pressure P1 which is at least equal to or smaller than 5.times.10.sup.-5 Torr, heating the substrate at a temperature T1, which is at least equal to or greater than 20.degree. C., injecting in said enclosure a refractory metal halide MXm having a purity, as far as metallic impurities are concerned, greater than 5N (99,999%) and a silicon hydride having a purity, as far as metallic impurities are concerned, greater than 6N (99,9999%) setting the pressure in the enclosure between about 0.01 Torr and the atmospheric pressure while maintaining the temperature in the CVD enclosure between about 20.degree. C.