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US 6,315,965 B1Granted
Phosphine generator for producing phosphine-containing gas
AssigneeDegesch de Chile LTDA
InventorsFranziskus Horn Feja, Christoph Reichmuth
Life of this patent
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Abstract
A process and apparatus is disclosed for generating a mixture of phosphine and diluent gas(es). A hydrolysable metal phosphide, preferably magnesium phosphide, is released directly into liquid water under an atmosphere of gas inert to phosphine and in a free-flowing particulate form, composed of loose metal phosphide particles. The generated mixture of phosphine and inert carrier gas, e.g. CO2, is used as such or is diluted into a gas mixing chamber with air to a concentration below the ignitability limit before being used in fumigation. Using argon as a carrier gas the phosphine mixture is suitable for semiconductor doping.
Claims29
A phosphine generator suitable for carrying out a process for generating a mixture of phosphine gas and diluent gas or gases, which comprises:
- a phosphine generating chamber containing liquid water;
- an inlet for admitting a hydrolysable metal phosphide composition into the water in the generating chamber;
- a gas outlet positioned to discharge the phosphine from the generating chamber;
- and
- apparatus for feeding said metal phosphide through the inlet at a controlled rate in a free-flowing particulate form, composed of loose metal phosphide particles, said apparatus for feeding
- a) being supplied with a supply of said loose metal phosphide particles in a free-flowing particulate form and/or
- b) being designed to render the loose metal phosphide particles free-flowing,
- wherein the outlet of the phosphine generating chamber is connected to a gas mixing chamber having an air inlet connected to a source of air, the mixing chamber in turn having a discharge outlet for feeding a non-ignitable mixture of air, phosphine and gas inert to phosphine, produced in the mixing chamber, into a gas mixture supply duct and wherein the phosphine generating chamber has a water inlet connected to a supply of water and a water outlet discharging into a phosphine stripping vessel equipped with aerating means supplied with air from said source of air and having an air outlet leading into the mixing chamber.
5 more elements
A phosphine generator suitable for carrying out a process for generating a mixture of phosphine gas and diluent gas or gases, which comprises:
- a phosphine generating chamber containing liquid water;
- an inlet for admitting a hydrolysable metal phosphide composition into the water in the generating chamber;
- a gas outlet positioned to discharge the phosphine from the generating chamber;
- and
- apparatus for feeding said metal phosphide through the inlet at a controlled rate in a free-flowing particulate form, composed of loose metal phosphide particles, said apparatus for feeding
- a) being supplied with a supply of said loose metal phosphide particles in a free-flowing particulate form and/or
- b) being designed to render the loose metal phosphide particles free-flowing,
- wherein the outlet of the phosphine generating chamber is connected to a gas mixing chamber having an air inlet connected to a source of air, the mixing chamber in turn having a discharge outlet for feeding a non-ignitable mixture of air, phosphine and gas inert to phosphine, produced in the mixing chamber, into a gas mixture supply duct, wherein the mixing chamber includes temperature monitoring means and wherein the temperature monitoring means, is connected to automatically interrupt the supply of phosphine gas to the mixing chamber in the event of a predetermined temperature being exceeded in the mixing chamber.
5 more elements
A phosphine generator suitable for carrying out a process for generating a mixture of phosphine gas and diluent gas or gases, which comprises:
- a phosphine generating chamber containing liquid water;
- an inlet for admitting a hydrolysable metal phosphide composition into the water in the generating chamber;
- a gas outlet positioned to discharge the phosphine from the generating chamber;
- and
- apparatus for feeding said metal phosphide through the inlet at a controlled rate in a free-flowing particulate form, composed of loose metal phosphide particles, said apparatus for feeding
- a) being supplied with a supply of said loose metal phosphide particles in a free-flowing particulate form and/or
- b) being designed to render the loose metal phosphide particles free-flowing,
- wherein the apparatus for feeding includes a pneumatic entrainment device for the particulate composition operated with the moisture-free diluent gas, serving as a carrier and propellant gas and wherein the said feed means includes:
- (i) a gas tight closed supply vessel for holding a supply of the free-flowing particulate metal phosphide;
- (ii) inside the supply vessel a riser tube, the bottom end of which is open near the bottom of the supply vessel and faces a venturi nozzle connected or adapted to be connected to a propellant gas supply inert to the metal phosphide;
- (iii) a bend remote from the inlet end of the riser tube, leading by way of a duct outside the supply vessel;
- (iv) an aperture at the beginning of and through the outer periphery of the bend inside the supply vessel and in axial alignment with the riser tube.
9 more elements
A phosphine generator suitable for carrying out a process for generating a mixture of phosphine gas and diluent gas or gases, which comprises:
- a phosphine generating chamber containing liquid water;
- an inlet for admitting a hydrolysable metal phosphide composition into the water in the generating chamber;
- a gas outlet positioned to discharge the phosphine from the generating chamber;
- and
- apparatus for feeding said metal phosphide through the inlet at a controlled rate in a free-flowing particulate form, composed of loose metal phosphide particles, said apparatus for feeding
- a) being supplied with a supply of said loose metal phosphide particles in a free-flowing particulate form and/or
- b) being designed to render the loose metal phosphide particles free-flowing.
4 more elements
A phosphine generator suitable for carrying out a process for generating a mixture of phosphine gas and diluent gas or gases, which comprises:
- a phosphine generating chamber containing liquid water;
- an inlet for admitting a hydrolysable metal phosphide composition into the water in the generating chamber;
- a gas outlet positioned to discharge the phosphine from the generating chamber;
- and
- apparatus for feeding said metal phosphide through the inlet at a controlled rate in a free-flowing particulate form, composed of loose metal phosphide particles, said apparatus for feeding
- a) being supplied with a supply of said loose metal phosphide particles in a free-flowing particulate form and/or
- b) being designed to render the loose metal phosphide particles free-flowing and which includes
- (i) a phosphine hydrolysis chamber, wherein metal phosphide is hydrolysed under an atmosphere of gas inert to phosphine to result in a mixture containing a concentration of phosphine which is ignitable when brought into contact with air;
- (ii) a gas mixing chamber connected downstream of said phosphine hydrolysis chamber but otherwise separate therefrom and a so separate from the environment, having an air inlet connected to a source of air and an outlet connected or to be connected to a duct for feeding a gas mixture produced in the mixing chamber into a fumigation space;
- and
- (iii) regulating means connected to adjust the ratio of phosphine to air and not allowed further gas or gases in the gas mixing chamber (ii) to a value at which such mixture of gases produced in the mixing chamber is non-ignitable.
8 more elements
Dependencies are inferred from the claim text.