EP0719978B1 - Procédé pour distribuer des gaz à ultra haute pureté avec corrosion minimisée - Google Patents
Procédé pour distribuer des gaz à ultra haute pureté avec corrosion minimisée Download PDFInfo
- Publication number
- EP0719978B1 EP0719978B1 EP95402914A EP95402914A EP0719978B1 EP 0719978 B1 EP0719978 B1 EP 0719978B1 EP 95402914 A EP95402914 A EP 95402914A EP 95402914 A EP95402914 A EP 95402914A EP 0719978 B1 EP0719978 B1 EP 0719978B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- gas
- distribution network
- process according
- high purity
- wet cleaning
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000007789 gas Substances 0.000 title claims description 136
- 238000000034 method Methods 0.000 title claims description 56
- 230000008569 process Effects 0.000 title claims description 44
- 238000005260 corrosion Methods 0.000 title claims description 38
- 230000007797 corrosion Effects 0.000 title claims description 38
- 239000007788 liquid Substances 0.000 claims description 97
- 238000009826 distribution Methods 0.000 claims description 70
- 238000004140 cleaning Methods 0.000 claims description 58
- 238000001035 drying Methods 0.000 claims description 43
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 36
- 238000010926 purge Methods 0.000 claims description 34
- 229910001868 water Inorganic materials 0.000 claims description 27
- 239000003570 air Substances 0.000 claims description 18
- 239000002274 desiccant Substances 0.000 claims description 18
- 239000012535 impurity Substances 0.000 claims description 18
- 239000012459 cleaning agent Substances 0.000 claims description 15
- ATWLRNODAYAMQS-UHFFFAOYSA-N 1,1-dibromopropane Chemical compound CCC(Br)Br ATWLRNODAYAMQS-UHFFFAOYSA-N 0.000 claims description 11
- 230000002829 reductive effect Effects 0.000 claims description 11
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 10
- 239000011261 inert gas Substances 0.000 claims description 9
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- HEWZVZIVELJPQZ-UHFFFAOYSA-N 2,2-dimethoxypropane Chemical compound COC(C)(C)OC HEWZVZIVELJPQZ-UHFFFAOYSA-N 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 6
- 229910052786 argon Inorganic materials 0.000 claims description 4
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 239000002245 particle Substances 0.000 claims description 4
- KNKRKFALVUDBJE-UHFFFAOYSA-N 1,2-dichloropropane Chemical compound CC(Cl)CCl KNKRKFALVUDBJE-UHFFFAOYSA-N 0.000 claims description 3
- 239000012080 ambient air Substances 0.000 claims description 3
- 239000011236 particulate material Substances 0.000 claims description 3
- 239000012298 atmosphere Substances 0.000 claims description 2
- 239000001307 helium Substances 0.000 claims description 2
- 229910052734 helium Inorganic materials 0.000 claims description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 2
- 239000001257 hydrogen Substances 0.000 claims description 2
- 229910052739 hydrogen Inorganic materials 0.000 claims description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims 1
- 239000008367 deionised water Substances 0.000 claims 1
- 229910021641 deionized water Inorganic materials 0.000 claims 1
- 229910052751 metal Inorganic materials 0.000 description 14
- 239000002184 metal Substances 0.000 description 13
- 238000006243 chemical reaction Methods 0.000 description 12
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- 239000007787 solid Substances 0.000 description 6
- 238000003795 desorption Methods 0.000 description 5
- MROCJMGDEKINLD-UHFFFAOYSA-N dichlorosilane Chemical compound Cl[SiH2]Cl MROCJMGDEKINLD-UHFFFAOYSA-N 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
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- 239000003795 chemical substances by application Substances 0.000 description 3
- 238000002386 leaching Methods 0.000 description 3
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- 150000001298 alcohols Chemical class 0.000 description 2
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- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
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- 239000000463 material Substances 0.000 description 2
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- 150000002739 metals Chemical class 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
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- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 238000006557 surface reaction Methods 0.000 description 2
- ARITXYXYCOZKMU-UHFFFAOYSA-N 2,2-dibromopropane Chemical compound CC(C)(Br)Br ARITXYXYCOZKMU-UHFFFAOYSA-N 0.000 description 1
- 206010003830 Automatism Diseases 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- -1 Diflon Substances 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
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- 239000007767 bonding agent Substances 0.000 description 1
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- 230000008859 change Effects 0.000 description 1
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- 239000012776 electronic material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- JOFNEGXELTXFTH-UHFFFAOYSA-L iron(2+);dibromide;hydrate Chemical class O.[Fe+2].[Br-].[Br-] JOFNEGXELTXFTH-UHFFFAOYSA-L 0.000 description 1
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Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto
- B08B9/02—Cleaning pipes or tubes or systems of pipes or tubes
- B08B9/027—Cleaning the internal surfaces; Removal of blockages
- B08B9/032—Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto
- B08B9/02—Cleaning pipes or tubes or systems of pipes or tubes
- B08B9/027—Cleaning the internal surfaces; Removal of blockages
- B08B9/032—Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing
- B08B9/0321—Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing using pressurised, pulsating or purging fluid
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto
- B08B9/02—Cleaning pipes or tubes or systems of pipes or tubes
- B08B9/027—Cleaning the internal surfaces; Removal of blockages
- B08B9/032—Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing
- B08B9/0321—Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing using pressurised, pulsating or purging fluid
- B08B9/0323—Arrangements specially designed for simultaneous and parallel cleaning of a plurality of conduits
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C9/00—Methods or apparatus for discharging liquefied or solidified gases from vessels not under pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2205/00—Vessel construction, in particular mounting arrangements, attachments or identifications means
- F17C2205/03—Fluid connections, filters, valves, closure means or other attachments
- F17C2205/0302—Fittings, valves, filters, or components in connection with the gas storage device
- F17C2205/0323—Valves
- F17C2205/0326—Valves electrically actuated
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2205/00—Vessel construction, in particular mounting arrangements, attachments or identifications means
- F17C2205/03—Fluid connections, filters, valves, closure means or other attachments
- F17C2205/0302—Fittings, valves, filters, or components in connection with the gas storage device
- F17C2205/0323—Valves
- F17C2205/0335—Check-valves or non-return valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2205/00—Vessel construction, in particular mounting arrangements, attachments or identifications means
- F17C2205/03—Fluid connections, filters, valves, closure means or other attachments
- F17C2205/0302—Fittings, valves, filters, or components in connection with the gas storage device
- F17C2205/0341—Filters
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2221/00—Handled fluid, in particular type of fluid
- F17C2221/05—Ultrapure fluid
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2227/00—Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
- F17C2227/01—Propulsion of the fluid
- F17C2227/0128—Propulsion of the fluid with pumps or compressors
- F17C2227/0135—Pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2227/00—Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
- F17C2227/04—Methods for emptying or filling
- F17C2227/044—Methods for emptying or filling by purging
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2250/00—Accessories; Control means; Indicating, measuring or monitoring of parameters
- F17C2250/04—Indicating or measuring of parameters as input values
- F17C2250/0404—Parameters indicated or measured
- F17C2250/043—Pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2260/00—Purposes of gas storage and gas handling
- F17C2260/05—Improving chemical properties
- F17C2260/053—Reducing corrosion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2265/00—Effects achieved by gas storage or gas handling
- F17C2265/01—Purifying the fluid
- F17C2265/012—Purifying the fluid by filtering
Definitions
- the present invention relates to the distribution of ultra high purity electronic specialty gases. More particularly, the present invention relates to the minimization of corrosion in the distribution of ultra high purity gases.
- an equipment network also referred to as a gas distribution network
- a gas distribution network can include large lengths of tubing and many components for the control of pressure and flow rate (e.g. pressure reducers, valves, mass-flow controllers, filters, purifiers, etc.) which have to be interposed in a wafer fabrication between the source (e.g. gas cylinders) and the point of use (e.g. the process reactor) as well as other components well known to those of ordinary skill in the art.
- the current objective in purity of ultra clean electronic specialty gases to be delivered at point of use is in the range of 1 to 100 ppb (parts per billion) for any volatile impurity, particulate density lower that 1 particulate per cubic foot (under normal condition) and metal concentrations of less than 100 ppt (parts per trillion) for any metallic element present.
- a major mechanism of microcontamination in the above considered purity range arises from the difficulty of completely removing adsorbed molecules from the surface of the materials exposed to the electronics specialty gases, and in particular of moisture, which is widespread in the environment and presents a particularly strong adsorption energy to surfaces.
- the usual procedure carried out to clean such a gas distribution network is to flow ultra high purity inert gas (e.g. nitrogen or argon of purity better than 1 ppb) in order to purge all impurities present in the volume or at the communication surfaces of the gas distribution network.
- This procedure is nevertheless unsatisfactory for strongly adsorbed molecules, e.g. H 2 O molecules adsorbed on solid surfaces.
- Others have attempted to improve this purge procedure and reduce its duration by using successive pressure-vacuum cycles of the inert gas and also by heating the surface in order to induce thermal desorption of the strongly adsorbed molecular species.
- these vacuum-pressure purge cycles prove inefficient in locations representing deep deadspaces because of the inefficiency of pumping through minute orifices.
- Still others have attempted thermal baking at 120°C during the purge of metallic surfaces. Such a procedure is known to significantly reduce the time to reach the background level of the purge gas. For example, one can obtain 1 ppb purity in a few hours when flowing ultra high purity ( ⁇ 1 ppb impurity) nitrogen or argon at 0.1-10 standard liter per minute through a gas distribution network free of microleaks of a length between about 10 and about 200 meters, approximately.
- the thermal desorption of H 2 O on an electropolished stainless steel surface occurs in several steps, the last one being at temperature of the order of 400°-450°C. Such a temperature is difficult to apply in practice.
- lower baking temperatures are applied, e.g. frequently 120°C for practical reasons, the metal surface is not entirely free of adsorbed moisture.
- thermal baking cannot be applied in practice under some circumstances for safety, regulation or material stability reasons.
- the wet cleaning removes molecular species soluble in these liquids or removes by dilution or liquid mechanical friction molecular species and particulates which may reside on the surfaces before the below described wet drying.
- wet cleaning of the gas communicating surfaces of the various components of the gas distribution network removes surface impurities (molecules or particulates).
- FIG. 1a and 1b illustrate two different apparatus for carrying out the process of the present invention.
- Figure 2 is a graph that depicts particulates emitted from a gas cylinder through a cylinder valve.
- Figure 3 is a graph that depicts particulates emitted from a gas cylinder through a cylinder valve which has been liquid dried according to the present invention.
- Figure 4 is a comparative graph that depicts total metals leached on DI water of the HBr cylinder valve before and after the liquid drying of the present invention.
- Figure 5 is a comparative graph that depicts total metals leached on DI water rinsing of the DCS cylinder valve before and after the liquid drying of the present invention.
- the process of the present invention includes:
- the present invention provides for the corrosion reduced distribution of ultra high purity gases based on the improved removal of moisture adsorbed on metal surfaces and other surfaces comprised.
- the process of the present invention is particularly well suited for the problem of corrosion originating from a cylinder valve since thermal desorption of the species adsorbed in the cylinder valve is prevented by safety and regulation considerations.
- the present invention includes wet cleaning at least a portion of a gas distribution network which is the most corrosion sensitive (such as valves), liquid drying of at least said portions of the gas communicating surfaces of the gas distribution network through exposure to an H 2 O desorbing liquid drying agent which reacts with adsorbed moisture and preferably leaves neither substantial particulate residues nor substantial volatile molecules adherent to the metal surface.
- the liquid drying of the present invention can be completed very effectively at room temperature using a liquid chemical which preferentially removes adsorbed H 2 O and which will leave neither particulate residue nor volatile molecules presenting strong interaction energy to the surface. The latter are hence easily purged out under vacuum-pressure cycles after the liquid drying step.
- such liquid drying agents include DMP (Acetone Dimethyl Acetal), DCP (2-2-Dichloropropane) or DBP (DiBromopropane).
- DMP Acetone Dimethyl Acetal
- DCP 2-2-Dichloropropane
- DBP DiBromopropane
- other H 2 O desorbing liquid drying agents known to those of ordinary skill in the art can be used in accordance with the present invention. It is most preferred to use pure liquids, in order to combine the wet cleaning and drying properties of these molecules.
- purging of any residual by-product is accomplished, preferably by pressure-vacuum cycle purge using ultra high purity inert gas, preferably dry and preferably containing less than 1 ppm of any impurity.
- an evacuation step is preferably carried out at a pressure which is preferably lower than 5 x 10 4 Pascal. The above procedure is done before exposing said surfaces to the electronic specialty gas, particularly the corrosive ones like HBr, or the like, or ambient air.
- the wet-cleaning by a high purity liquid e.g. DI water, alcohols, acetone or others, removes molecular species soluble in these liquids. It also removes by dilution or liquid mechanical friction molecular species and particulates which may accidentally reside on the gas communicating surfaces before the above described wet drying.
- a high purity liquid e.g. DI water, alcohols, acetone or others
- This step is particularly useful when the gas distribution network or any part thereof is accidentally exposed to air, e.g. during cylinder connection or opening the network for repair or component exchange, moisture will be adsorbed on the surfaces.
- the presence of adsorbed H 2 O will promote corrosion reactions.
- the detrimental effect of such accidental corrosions can be effectively substantially suppressed by the above-described combination of the wet cleaning step prior to the liquid drying step (with or without purging with high purity inert gas or with or without vacuum pressure cycles between wet cleaning and liquid drying).
- the same wet cleaning and liquid drying procedure is preferably also applied just after purging the ESG from an exposed component and before exposing it, even very briefly, to air. This is done in order to suppress the unwanted corrosion which may arise by reaction between residual adsorbed ESG and H 2 O molecules, which will occur after air exposure. Indeed, such reactions between adsorbed species are again catalytically activated and promote surface reaction leading to corrosion, particulates and formation of unwanted surface molecules.
- the wet cleaning is accomplished with a high purity liquid such as DI water, alcohols, acetone or other similar cleaning agents known to those of skill in the art.
- the wet cleaning agents used in this step of the process according to the invention shall be high purity cleaning agents suitable for cleaning metallic surfaces, particularly stainless steel surfaces.
- high purity it is meant cleaning agents which, when they are used pure (or in admixture with other cleaning agents or solvents) do not leave substantial solid residues on the treated surface, i.e. comprising less than 1 mg. of solid residue per liter and preferably less than 10 -6 g of solid residue per liter.
- the injection of the wet cleaning (liquid) agent is made by any appropriate means such as disclosed hereafter with Figure 1a and 1b. This injection can be done either manually with a syringe or automatically with a pump through capillary tubes.
- the duration of this wet cleaning step is usually between about 1 min. to at most 1 hour. If the pipes and other components are new (i.e. have never been used before), it is usually not necessary to wet clean them. However, if it is believed that some particles or condensible molecules may have already adhered, wet cleaning during about 1 min. to about 2 min. is sufficient. If the pipe distribution network and/or other components of the network have already been used before, it is usually recommended to clean them between about 5 to about 30 min., preferably about 10 min.
- this cleaning is applicable to pipings, valves, mass flow controllers and the like.
- a new or existing gas distribution network it is advisable to provide the process according to the invention each time, as an internal surface of the network shall be in contact with air.
- the process as disclosed in this specification particularly steps (a) and (b).
- Purging with inert gas between the wet cleaning step (a) and the liquid drying step (b) is usually optional.
- the wet cleaning step (a) is then followed by a step comprising a liquid drying of the gas communicating surfaces of the gas distribution network through exposure to chemicals which react with adsorbed moisture and leave neither particulate residues nor volatile molecules adherent to the metal or other surface.
- This wet-drying step is intended to prevent any catalytic reaction of decomposition by water of the electronic specialty gases which flow through the distribution network.
- Liquid drying according to the present invention can be effectively completed at room temperature using a liquid chemical which preferably removes adsorbed H 2 O and which will leave neither particulate residue nor volatile residue (liquid/vapor) but being chemically active with adsorbed moisture. (No particulate residues means that the liquid contains usually less than 1 mg and preferably less than 10 -6 /g of particulate material per liter). These liquid chemicals are hence easily purged out under vacuum-pressure cycles after the liquid drying.
- the duration of this liquid drying step is preferably between about 1 min. to about 20 minutes.
- the device or piping distribution network is new and the roughness of the internal surface of the same is less than 5 x 10 -6 m (Ra ⁇ 5 x 10 -6 m)
- about 1 to about 2 minutes are usually enough.
- the device, piping or network are not new and/or if the roughness of the surface Ra is greater than 5 x 10 -6 m, then it is usually recommended to treat with the drying agent during about 10 minutes or more.
- purging of any residual by-product is accomplished preferably by pressure-vacuum cycle purge using ultra high purity inert gas, comprising preferably less than 1 ppm of any purity.
- the gas distribution network is purged with an inert gas such as nitrogen, argon, helium or with a reductive gas such as hydrogen, after the wet cleaning and liquid drying steps have been completed and before the delivery of the ESG.
- the duration of purging may vary between about 1 minute to about 10 minutes, preferably between 2 to 5 minutes.
- the gas used for such purging has to be of course extremely pure, i.e. less than bout 100 ppb of volatile impurities and less than one particle per liter in normal conditions of temperature and pressure. (This purging with the above gases is usually carried out with alternate vacuum).
- an ESG is introduced into the gas distribution network.
- an ESG means a corrosive gas or an electronic specialty gas which may have some corrosive properties or suspected corrosive properties.
- gas distribution network, or parts thereof which are essentially treated as disclosed hereabove, whether used to flow corrosive gas or any other gas (such as N 2 ).
- the present process essentially comprises the various treatment steps to reduce corrosion, whether or not a corrosive gas is further flown in the gas distribution network.
- the wet cleaning and the liquid drying steps (a) and (b) of the present invention are additionally performed just after purging the ESG from the distribution network and before exposing the network, even very briefly, to air. This reduces the occurrence of unwanted chemical reaction between residual adsorbed ESG and H 2 O molecules, which will occur after air exposure. Indeed, such reactions between adsorbed species are again catalytically activated and promote surface reaction leading to corrosion.
- two cycles or more of wet cleaning e.g. the first using e.g. Di water--less volatile--the second using e.g. acetone or alcohol--more volatile
- This sequence is particularly effective both before and after any exposure of a gas communicating surface of the gas distribution network to an ESG, particularly when the surface has been exposed to air.
- the process of the present invention is intended for use before (a) any exposure (even for a minimal time) to air and (b) before flowing the ESG through the gas distribution system or any part thereof.
- the above process can be applied to a total gas distribution network.
- the most critical parts are those involving deep deadspaces such as found in a valve construction or other components such as mass flow controllers, pressure regulators, etc. Accordingly, the present invention is specially directed to such components in the gas distribution network.
- a gas distribution network capable of carrying out the wet cleaning and/or liquid drying step of the present invention is rather intricate because of the deadspaces involved in a valve construction. Accordingly, the present invention is also directed to a gas distribution network capable of carrying out the process of the present invention with minimal deadspace.
- An apparatus for carrying out the process of the present invention includes a means for wet cleaning the gas distribution network and a means for liquid drying the gas distribution network with an H 2 O desorbing liquid agent.
- the wet cleaning and/or liquid drying agent can be introduced to the gas distribution network manually using a syringe type introduction system as represented on Figure 1a and 1b.
- the circulation of the wet cleaning and/or liquid drying agents is achieved by the use of capillary tubing and includes the use of a circulation pump as a preferred method of operation as depicted in Figure 1a.
- the apparatus of Figure 1a provides a mechanically activated liquid circulation system designed to reach deep deadspaces within the components of the gas distribution network in implementing the process of the present invention.
- the system is based on a pump to provide liquid flow, capillary inlet and outlet lines to provide minute deadspaces and an assembly allowing clean fluid handling and minimal air exposure on connection and disconnection.
- the apparatus of Figure 1a is further described below.
- the cylinder valve head assembly of Figure 1a includes a cylinder valve 1, diaphragm 2, spring 3, spindle 4, polymeric sealing material such as Diflon, Teflon or others 5, cylinder valve port 6, gas flow from cylinder 7 (for example HBr), outlet of cylinder valve 8, polymeric packing 9 and fitting and connector 10.
- a cylinder valve 1 diaphragm 2, spring 3, spindle 4, polymeric sealing material such as Diflon, Teflon or others 5, cylinder valve port 6, gas flow from cylinder 7 (for example HBr), outlet of cylinder valve 8, polymeric packing 9 and fitting and connector 10.
- the cylinder valve head assembly is in fluid communication with a length of capillary tubing 11 and a first end of a "T" type male connector 12.
- a first end of a three-way diaphragm valve for wet cleaning and/or liquid drying inlet 20 is in fluid communication with a second end of the "T" type male connector 12.
- Ceramic cement as a vacuum-tight, non-reactive and non-outgasing metal-metal bonding agent.
- a liquid pump 24 is in fluid communication with a second end of the three-way diaphragm valve for wet cleaning and/or liquid drying inlet 20. Liquid pump 24 is further in fluid communication with a 0.1 ⁇ m filter 26 and wet cleaning agent or liquid drying agent 25.
- a third end of the three-way diaphragm valve for wet cleaning and/or liquid drying inlet 20 is in fluid communication with diaphragm valve 21 which is in further communication with 0.1 ⁇ m filter 22 and dry gas inlet 23.
- Dry gas inlet 23 is used for the introduction of purge gases (inert or reductive, usually used between the cleaning step and the drying step).
- a third end of the "T" type male connector 12 is in fluid communication sequentially with a three-way diaphragm valve for evacuation 14 by oil free vacuum pump 19, a three-way diaphragm valve 15 for moisture monitor by hygrometer 18, a diaphragm valve 16 and a vent line 17 for wet cleaning and/or liquid drying which is connected to recovering means (not shown in the drawing) to recover those products after being used.
- valve and connector parts which are exposed to air under conventional operation conditions of a gas cylinder are evacuated using an oil-free pump.
- the liquid cleaning agent and liquid drying agent respectively are introduced as a jet driven by the difference of the pressures surrounding the liquids (atmospheric pressure) and the one residing inside the valve and its connector parts.
- HBr from a gas cylinder through a cylinder valve was analyzed.
- DCS Dichlorosilane
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Cleaning By Liquid Or Steam (AREA)
- Cleaning Or Drying Semiconductors (AREA)
Claims (18)
- Procédé de réduction de la corrosion dans un réseau de distribution de gaz d'un gaz à pureté ultra élevée ou dans une partie quelconque dudit réseau de distribution, comprenant :(a) le nettoyage par voie humide du réseau de distribution de gaz ou d'au moins une partie de celui-ci à l'aide d'un agent de nettoyage par voie humide ;(b) le séchage à liquide dudit réseau de distribution de gaz ou d'au moins ladite partie de celui-ci à l'aide d'un agent de séchage à liquide désorbant H2O, choisi parmi le groupe se composant du diméthylacétal d'acétone DMP, du 2,2-dichloropropane DCP ou du 2,2-dibromopropane DBP, de mélanges de ces derniers ou d'un équivalent quelconque de ceux-ci ;(c) la purge dudit réseau de distribution de gaz ou de toute dite partie de celui-ci à l'aide d'un gaz sec à pureté élevée, comprenant moins de 1 ppm d'une impureté quelconque ;(d) l'évacuation dudit réseau de distribution de gaz ou d'une dite partie quelconque de celui-ci à une pression qui est inférieure à 5 x 104 Pascal ; et(e) l'exposition dudit réseau de distribution de gaz ou d'une dite partie quelconque de celui-ci à une atmosphère comprenant un gaz ou un air corrosif à pureté ultra élevée.
- Procédé selon la revendication 1, caractérisé en ce que l'étape de nettoyage par voie humide est effectuée pendant une durée allant d'environ 1 minute à environ 1 heure.
- Procédé selon la revendication 2, utilisant un réseau de distribution d'un gaz à pureté ultra élevée, comprenant pour l'essentiel des composants ou des pièces de celui-ci qui n'ont jamais été utilisés auparavant, caractérisé en ce que ladite étape de nettoyage par voie humide est effectuée pendant une durée d'environ 1 minute à environ 2 minutes.
- Procédé selon la revendication 2, utilisant un réseau de distribution d'un gaz à pureté ultra élevée, comprenant pour l'essentiel des composants ou des pièces de celui-ci qui n'ont jamais été utilisés auparavant, caractérisé en ce que ladite étape de nettoyage par voie humide est effectuée pendant une durée d'environ 5 à environ 30 minutes.
- Procédé selon la revendication 1, caractérisé en ce que l'étape (b) de séchage à liquide est effectuée pendant une durée d'environ 1 minute à environ 20 minutes.
- Procédé selon la revendication 5, utilisant un réseau de distribution d'un gaz à pureté ultra élevée, comprenant pour l'essentiel des composants ou des pièces de celui-ci qui n'ont jamais été utilisés auparavant, et ayant une rugosité de leur surface interne Ra qui est inférieure à 5 x 10-6 m, caractérisé en ce que ladite étape de séchage à liquide est effectuée pendant une durée d'environ 1 à environ 2 minutes.
- Procédé selon la revendication 5, utilisant un réseau de distribution d'un gaz à pureté ultra élevée, comprenant pour l'essentiel des composants ou des pièces de celui-ci qui ont été utilisés au moins une fois auparavant, caractérisé en ce que ladite étape de séchage à liquide est effectuée pendant une durée d'environ 10 minutes ou plus.
- Procédé selon la revendication 5, utilisant un réseau de distribution d'un gaz à pureté ultra élevée comprenant pour l'essentiel des composants ou des pièces de celui-ci, qui ont une rugosité de leur surface interne Ra qui est supérieure à 5 x 10-6 m, caractérisé en ce que ladite étape de séchage à liquide est effectuée pendant une durée d'environ 10 minutes ou plus.
- Procédé selon la revendication 1, caractérisé en ce que ledit agent de nettoyage par voie humide est un liquide comprenant moins de 1 mg par litre de matériau particulaire.
- Procédé selon la revendication 1, caractérisé en ce que ledit agent de nettoyage par voie humide est un liquide comprenant moins de 10-6 g par litre de matière particulaire.
- Procédé selon la revendication 1, caractérisé en ce que ledit agent de nettoyage par voie humide est choisi parmi le groupe comprenant l'eau déionisée, l'alcool isopropylique, l'acétone ou un mélange de ces derniers.
- Procédé selon la revendication 1, comprenant en outre la répétition des étapes (a) et (b) avant l'exécution de l'étape (c).
- Procédé selon la revendication 1, comprenant en outre la purge, entre les étapes (d) et (e), du réseau de distribution de gaz ou d'une partie quelconque de ce dernier, à l'aide d'un gaz inerte ou réducteur.
- Procédé selon la revendication 13, caractérisé en ce que ledit gaz inerte ou réducteur est choisi parmi le groupe comprenant l'azote, l'argon, l'hélium ou l'hydrogène.
- Procédé selon la revendication 13 ou la revendication 14, caractérisé en ce que ledit gaz inerte ou réducteur comprend moins de 100 ppb d'impuretés volatiles et moins de 1 particule par litre dans les conditions standard de température et de pression.
- Procédé de distribution des gaz à pureté ultra élevée de la revendication 1, caractérisé en ce que ledit réseau de distribution de gaz comprend au moins une vanne de cylindre.
- Procédé selon la revendication 16, caractérisé en ce que ladite vanne de cylindre est soumise au moins à l'étape (a) et à l'étape (b), avant et après chaque contact de sa surface interne avec l'air ambiant.
- Procédé selon la revendication 1, comprenant en outre, pendant l'étape (e), la purge du réseau de distribution de gaz ou d'une partie quelconque de ce dernier à l'aide d'un gaz inerte à pureté élevée avant l'exposition à l'air ambiant dudit réseau de distribution de gaz ou d'une partie quelconque de ce dernier.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/366,468 US5591273A (en) | 1994-12-30 | 1994-12-30 | Process for distributing ultra high purity gases with minimized contamination and particulates |
| US366468 | 1994-12-30 | ||
| US08/506,867 US5676762A (en) | 1994-12-30 | 1995-07-25 | Process for distributing ultra high purity gases with minimized corrosion |
| US506867 | 1995-07-25 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP0719978A2 EP0719978A2 (fr) | 1996-07-03 |
| EP0719978A3 EP0719978A3 (fr) | 1997-05-02 |
| EP0719978B1 true EP0719978B1 (fr) | 2001-10-24 |
Family
ID=27003371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP95402914A Expired - Lifetime EP0719978B1 (fr) | 1994-12-30 | 1995-12-22 | Procédé pour distribuer des gaz à ultra haute pureté avec corrosion minimisée |
Country Status (2)
| Country | Link |
|---|---|
| EP (1) | EP0719978B1 (fr) |
| DE (1) | DE69523428T2 (fr) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999064780A1 (fr) * | 1998-06-08 | 1999-12-16 | Advanced Delivery & Chemical Systems, Ltd. | Systeme d'apport chimique avec dispositif d'evacuation utilisant diverses techniques de purge |
| DE10393621D2 (de) * | 2002-08-16 | 2005-07-07 | Water System Cleaning Ag | Verfahren und dazugehörige Einrichtungen zur Entfernung von Inkrustationen und Biofilmen in Fluidsystemen |
| DE602009001159D1 (de) | 2008-08-13 | 2011-06-09 | Mitsubishi Materials Corp | Aufbewahrungsbehälter für flüssiges Chlorsilan und Schließdeckel dafür |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4723363A (en) * | 1986-12-29 | 1988-02-09 | Motorola Inc. | Process for removal of water |
| IT1229187B (it) * | 1989-04-11 | 1991-07-23 | Metra Metall Trafilati Allumin | Sistema di profilati,particolarmente studiati per la realizzazione di porte interne |
-
1995
- 1995-12-22 EP EP95402914A patent/EP0719978B1/fr not_active Expired - Lifetime
- 1995-12-22 DE DE69523428T patent/DE69523428T2/de not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| EP0719978A3 (fr) | 1997-05-02 |
| DE69523428T2 (de) | 2002-07-11 |
| EP0719978A2 (fr) | 1996-07-03 |
| DE69523428D1 (de) | 2001-11-29 |
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