Storage and delivery system for gaseous compounds

Gas separation: apparatus – Solid sorbent apparatus – With means regenerating solid sorbent

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96108, 96147, 206 07, B01D 5304

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active

059353058

DESCRIPTION:

BRIEF SUMMARY
DESCRIPTION

1. Field of the Invention
This invention relates generally to storage and dispensing systems for the selective dispensing of gaseous reagents comprising hydride and halide gases, from a vessel or storage container in which the hydride and/or halide gas component(s) are held in sorptive relationship to a solid sorbent medium, and are desorptively released from the sorbent medium in the dispensing operation.
2. Description of the Related Art
In the manufacture of semiconductor materials and devices, and in various other industrial processes and applications, there is a need for a reliable source of hydridic and halidic gases. Many of such gases, including for example silane, germane, ammonia, phosphine, arsine, diborane, stibine, hydrogen sulfide, hydrogen selenide, hydrogen telluride, and corresponding and other halide (chlorine, bromine, iodine, and fluorine) compounds, as a result of toxicity and safety considerations, must be carefully stored and handled in the industrial process facility.
The gaseous hydrides arsine (AsH.sub.3) and phosphine (PH.sub.3) are commonly used as sources of arsenic (As) and phosphorous (P) in ion implantation. Due to their extreme toxicity and high vapor pressure, their use, transportation and storage raise significant safety concerns for the semiconductor industry. Ion implantation systems typically use dilute mixtures of AsH.sub.3 and PH.sub.3 at pressures as high as 1500 psig. A catastrophic release of these high pressure cylinders could pose a serious injury potential and even death to fab workers.
Based on these considerations, the ion implant user must choose between solid or gas sources for arsenic and phosphorous species. Switching from As to P on an implanter with solid sources can take as long as 90 minutes. The same species change requires only 15 minutes with gas sources. However, arsine (AsH.sub.3) and phosphine (PH.sub.3), the two most commonly used source gases, are highly toxic. Their use has recently been the focus of widespread attention due to the safety aspects of handling and processing these gases. Many ion implantation systems utilize hydride gas sources supplied as dilute mixtures (10-15%), in either 0.44 L or 2.3 L cylinders at pressures of 400-1800 psig. It is the concern over the pressure-driven release of the gases from cylinders that has prompted users to investigate safer alternatives.
U.S. Pat. No.4,744,221 issued May 17, 1988 to Karl O. Knollmueller discloses a method of storing and subsequently delivering arsine, by contacting arsine at a temperature of from about -30.degree. C. to about +30.degree. C. with a zeolite of pore size in the range of from about 5 to about 15 Angstroms to adsorb arsine on the zeolite, and then dispensing the arsine by heating the zeolite to an elevated temperature of up to about 175.degree. C. for sufficient time to release the arsine from the zeolite material.
The method disclosed in the Knollmueller patent is disadvantageous in that it requires the provision of heating means for the zeolite material, which must be constructed and arranged to heat the zeolite to sufficient temperature to desorb the previously sorbed arsine from the zeolite in the desired quantity.
The use of a heating jacket or other means exterior to the vessel holding the arsine-bearing zeolite is problematic in that the vessel typically has a significant heat capacity, and therefore introduces a significant lag time to the dispensing operation. Further, heating of arsine causes it to decompose, resulting in the formation of hydrogen gas, which introduces an explosive hazard into the process system. Additionally, such thermally-mediated decomposition of arsine effects substantial increase in gas pressure in the process system, which may be extremely disadvantageous from the standpoint of system life and operating efficiency.
The provision of interiorly disposed heating coil or other heating elements in the zeolite bed itself is problematic since it is difficult with such means to uniformly heat the zeolite bed to achieve the desired u

REFERENCES:
patent: 240423 (1881-04-01), James
patent: 1608155 (1926-11-01), Barnebey
patent: 1714245 (1929-05-01), Schaefer
patent: 2356334 (1944-08-01), Maude et al.
patent: 2450289 (1948-09-01), Marek
patent: 2663626 (1953-12-01), Spangler
patent: 2987139 (1961-06-01), Bush
patent: 2997371 (1961-08-01), Wadsworth et al.
patent: 3006153 (1961-10-01), Cook
patent: 3080307 (1963-03-01), Rinald
patent: 3093564 (1963-06-01), Weisman et al.
patent: 3116132 (1963-12-01), Haller et al.
patent: 3144200 (1964-08-01), Taylor et al.
patent: 3176444 (1965-04-01), Kiyonaga
patent: 3264803 (1966-08-01), Read
patent: 3287432 (1966-11-01), Sensel
patent: 3415069 (1968-12-01), Hauser
patent: 3469375 (1969-09-01), Barrington et al.
patent: 3675392 (1972-07-01), Reighter
patent: 3713273 (1973-01-01), Coffee
patent: 3719026 (1973-03-01), Sand
patent: 3788036 (1974-01-01), Lee et al.
patent: 4023701 (1977-05-01), Dockery
patent: 4168149 (1979-09-01), Armond et al.
patent: 4263018 (1981-04-01), McCombs et al.
patent: 4343770 (1982-08-01), Simons
patent: 4414005 (1983-11-01), DeBievre et al.
patent: 4477265 (1984-10-01), Kumar et al.
patent: 4552571 (1985-11-01), Dechene
patent: 4578256 (1986-03-01), Nishino et al.
patent: 4673415 (1987-06-01), Stanford
patent: 4723967 (1988-02-01), Tom
patent: 4738693 (1988-04-01), Tom
patent: 4738694 (1988-04-01), Godino et al.
patent: 4744221 (1988-05-01), Knollmueller
patent: 4749384 (1988-06-01), Nowobilski et al.
patent: 4761395 (1988-08-01), Tom et al.
patent: 4869733 (1989-09-01), Stanford
patent: 4881958 (1989-11-01), Eckardt et al.
patent: 5051117 (1991-09-01), Prigge et al.
patent: 5089244 (1992-02-01), Parent et al.
patent: 5114440 (1992-05-01), Reiss
patent: 5133787 (1992-07-01), Diot et al.
patent: 5151395 (1992-09-01), Tom
patent: 5202096 (1993-04-01), Jain
patent: 5224350 (1993-07-01), Mehra
patent: 5238469 (1993-08-01), Briesacher et al.
patent: 5385689 (1995-01-01), Tom et al.
patent: 5409526 (1995-04-01), Zheng et al.
patent: 5417742 (1995-05-01), Tamhankar et al.
patent: 5518528 (1996-05-01), Tom et al.
"Beaded Carbon UPS Solvent Recovery", Chemical Engineering, vol. 84, No. 18, pp. 39-40, Aug. 29, 1977.
McManus, J.V., Tom, G.M., and Kirk, R., "A Zeolite-Based Atmospheric Pressure Hydride Gas Source for Ion Implantation", paper presented at the X International Conference on Ion Implantation Technology, Catania, Italy, Jun. 13-17, 1994.

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