CN1980859A - Method for the preparation of a gas or mixture of gases containing molecular fluorine - Google Patents
Method for the preparation of a gas or mixture of gases containing molecular fluorine Download PDFInfo
- Publication number
- CN1980859A CN1980859A CN 200580022253 CN200580022253A CN1980859A CN 1980859 A CN1980859 A CN 1980859A CN 200580022253 CN200580022253 CN 200580022253 CN 200580022253 A CN200580022253 A CN 200580022253A CN 1980859 A CN1980859 A CN 1980859A
- Authority
- CN
- China
- Prior art keywords
- gas
- fluorine
- mixture
- gaseous mixture
- plasma
- 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.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B7/00—Halogens; Halogen acids
- C01B7/19—Fluorine; Hydrogen fluoride
- C01B7/20—Fluorine
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Drying Of Semiconductors (AREA)
Abstract
Preparation of a gas or gas mixture (containing molecular fluorine) from a gas or gas mixture derived from fluorine, comprises: decomposing gas or fluoride gas mixture (preferably nitrogen trifluoride (NF3)), by cracking the fluoride gas molecules, to give an atomic fluorine mixture and other resultant species; and optionally cooling the mixture. - Preparation of a gas or gas mixture (containing molecular fluorine) from a gas or gas mixture derived from fluorine, comprises: decomposing gas or fluoride gas mixture (preferably nitrogen trifluoride (NF3)), by cracking the fluoride gas molecules, to give an atomic fluorine mixture and other resultant species; and optionally cooling (lower than 500 deg. C) the mixture to give molecular fluorine for at least 50% of formed atomic fluorine, minimize the recombination of the fluorine atoms with other cracking products, and to reform the gas or fluorinated gas mixture (containing the recovered fluorine).
Description
The present invention relates to the method that a kind of preparation contains the gas or the gaseous mixture of molecular fluorine.
Be used to prepare the device of semi-conductor and particularly film or the clean of etching deposit chamber and just becoming more and more difficult.Therefore, use fluorine gas F gradually more
2As sanitising agent.Because the physicals of fluorine gas, cause that the storage of fluorine in cylinder is stubborn problem on the semiconductor production position.The quantity that can be stored in the compression cylinder is low excessively for these clean aequums.In addition, for tangible security reason, be difficult at present imagine that this product is stored on the semiconductor production position with body or a large amount of mode.Here it is why now fluorine still seldom for cleaning purpose and be used for the semiconductor production unit.
US5788775 or US5812403 have instructed use nitrogen trifluoride NF
3Clean one wafer process chamber, it has outside plasma generator, for example is used for various CVD technologies, as CVD-SiO
2, SiN-CVD, SiC-CVD, SiOC-CVD and W-CVD.In this method, under the pressure of about 1～5 torr, by microwave argon gas+NF
3The plasma body of (+He) forms F base (atomic fluorine).Plasma generator is placed as far as possible near this chamber, make thus the F base once more in conjunction with minimizing.Approaching under the temperature of room temperature, reacting by the settling on F base and the chamber walls and realize clean, producing volatile matter such as SiF
4, WF
6And CF
4This method has been used NF
3Or F
2Source as the fluorine F base that is used to clean Processing Room.
Also can be with reference to following article: G.J.Stuebar etc., " Production offluorine-containg molecular species in plasma-generated Atomic F.Flows ", be published in Journal de Phys.Chem.A. (2002,107,7775-7782).
But this technology is difficult to be incorporated into simultaneously in the wafer stove that comprises a plurality of wafers in stove.For these wafer stoves, preferred thermal cleaning method.In addition, this method has been used fluorine gas F equally
2With nitrogen trifluoride NF
3
Suggestion recently uses fluorine (pure or form of mixtures) to be used for the thermal cleaning gas of polycrystalline sheet stove as original position.In the method, fluorine gas F
2Molecule is thermal decomposited.
But, owing to the peak pressure F that allows in partial safety requirements, the cylinder
2, transport law etc., cause F
2Become very stubborn problem in the locational storage of semiconductor production.
Therefore, attempted to develop and be used to replace original position and use F
2Other method.Technical, realized the KF-HF fusion electrolysis solution (about the more detailed content of this technical scheme, can referenced patent application ...).Though simple in theory, the defective that in fact this method exists is, because the required F of cleaning
2Flow velocity is much higher than the electrolyzer of reasonable size, is stored in demand in the surge tank so can produce the fluorine that will generate.In addition, the complicacy of this system has hindered the industrial application of this method (this system has comprised automatic feeding liquid HF and from F
2Separate HF gas in the gas).
The Japanese patent application JP04-323377 of Hitachi Electronics Eng.Co. has described a kind of cold air atmosphere discharge system (corona steam or dielectric intercept discharge), wherein NF
3Decompose and generate atomic fluorine F.But because the low electron density in this discharge, what this system produced several approximately per-cents hangs down rate of decomposition, and experimental result has obtained to contain the mixture of the atomic fluorine that is not more than 5 volume %, and it must be immediately contacts with wall to be cleaned.
US-A-4213102 has also instructed NF
3Thermolysis generates atomic fluorine F and molecular fluorine F
2But experiment shows, NF
3The thermolysis of molecule is very halfway, and is less than 50% NF
3Molecule is decomposed.And, found during this mixture of cooling, to form NF in fact
3Molecule causes like this generating and mainly contains NF
3Mixture.
The present invention does not have the shortcoming of such scheme, and its enforcement is much simple.It is characterized in that fluorine-containing gas or gaseous mixture, particularly nitrogen trifluoride NF
3Logical superheated high electron density plasma and decomposing, plasma body generates at normal atmosphere or near under the normal atmosphere, obtains top temperature T thus in plasma body
MaxThe heavier substances (except that electronics) that is higher than 2000K; Mixture with the various materials that exist in the plasma is cooled to temperature T subsequently
h, subsequently at T
hAnd T
bBetween fast the cooling, T
hAnd T
bBe respectively according to fluorine-containing gas or two temperature of gaseous mixture measuring, T
hFor fluorine-containing gas or or the molecule of the gaseous mixture temperature when beginning to be combined into once more gas molecule in the initial injected plasma, and T
bFor surpass in the plasma body of fluoro-gas or gaseous mixture 90% the fluorine atom that generates by division once more in conjunction with the time temperature, obtain to contain the molecular fluorine F of 50 volume % thus
2Gaseous mixture.
Preferably, the inventive method is characterised in that the top temperature that discharge generates heavier substances in the plasma body is 3000K～10000K.In addition preferably, plasma electron density is greater than 10
12Electronics/cm
3, be preferably 10
12～10
15Electronics/cm
3
According to replacement embodiment of the present invention, the inventive method is characterised in that, T
hAnd T
bBetween quick cooling time less than 5 * 10
-2Second, with a large amount of reformulations and the promotion fluorine molecule F that prevents parent material
2Formation.Preferably, quick cooling time is less than 10
-2Second, preferably less than 5 * 10
-3Second.
According to the present invention, preferred fluorine-containing gas is nitrogen trifluoride NF
3, T
hBe about 1200K and T
bBe about 800K.
According to another feature of the present invention, preferably, this plasma body is the plasma body that approaches thermodynamic(al)equilibrium, and the plasma body that is particularly generated by rf wave or microwave.
Atmospheric herein implication is near normal atmosphere, 10
14～10
16The pressure that changes between the pascal.
For example, can use be stored in the pressure cylinder and before it enters plasma slab or among expansible NF
3Also can use " eddy current " type injection system that fluorine-containing gas or gaseous mixture are injected, as described in the french patent application No.045127 (it is incorporated herein by reference) that submits to the applicant's name.Especially, when generation was used to clean the fluorine of gas-phase deposition reactor, wherein this class injection system with the component velocity injecting gas that is not parallel to axis was useful, and particularly (but and not exclusively) is at NF
3During the low flow velocity of class gas.Like this, the flow velocity of fluoro-gas (single or mixture) can be reduced to 2～60 liters/minute of numerical value (for example for NF
3Be up to 2L/ minute).Have in the system of " eddy current " in this class, fluorine-containing gas can be usually up to about 7 * 10
5Pascal's's (7 crust) pressure injects down.When this technology of use, preferably carrying out one or many fluoro-gas " downward " (with respect to the plasma body that generates in the vertical tube) injects, because the plasma that obtains is centrally located on around the tubular axis line, make it possible to keep the distance between plasma and the tube wall, avoid the local superheating (on point of contact) of described pipe thus.
According to the present invention, found after the molecule of division fluoro-gas,, can generate atomic fluorine usually if temperature is enough high, importantly, at about 1200K (T
h)～800K (T
b) between in the specific gas temperature range of (perhaps its part) at least, cooling is from the substance mixture of plasma generation fast.
Herein, implication is T fast
hAnd T
bBetween cooling time be not more than 5 * 10
-2Second, with a large amount of reformulations of preventing parent material with promote fluorine molecule F thus
2Formation.This time length is preferably less than 10
-2Second, be more preferably less than 5 * 10
-3Second.
Containing fluorine molecule, particularly NF
3The decomposition cycle during, the temperature of usually raise the apace gas or the gaseous mixture that contain this fluoro-gas divides the molecule of fluoro-gas thus and reaches plasma temperature T up to 10000K
Max, and it is preferably usually above T
h(wherein, T
hFor NF
3Be the temperature of about 1200K, and can determine experimentally) for other material.Subsequently, seldom to influence F usually
2Or NF
3The speed of the formation of perhaps initial fluoro-gas, with gaseous mixture from T
MaxBe cooled to T
hOne reaches this temperature T
h(medial temperature of the mixture that from plasma body, produces), and, just mixture is cooled fast to T at least earlier than this time
bPerhaps be lower than T
bTemperature (about usually 800K), promptly for example cool off the mixture that produces in the plasma body by the heat exchange between mixture and the quench region (for example cooling stave, cooling gas or alternate manner arbitrarily).
The present invention also relates to a kind of fluoro-gas producer that the gas that contains molecular fluorine is provided, it is characterized in that it comprises: fluoro-gas such as nitrogen trifluoride NF
3The source; Be used to generate the device of hot high electron density plasma, it is used to decompose fluorine-containing gas molecule and is equaling 2000K or higher heavier substances top temperature T
MaxUnder generate plasma body; The device of the gaseous mixture that is used to cool off this decomposition and generates; Be cooled to be lower than T with being used for
bTemperature after reclaim and to contain fluorine molecule F
2The device of gaseous mixture.
The producer that is used to implement the inventive method also can comprise and being used for before decomposing by the cracking fluoro-gas, among and/or the device of diluent gas afterwards, and the recovery gas that contains fluorine can be contacted with surface or volume; This surface or volume are made by metal or polymkeric substance; Gas or gaseous mixture derived from fluorine can mix (before the cracking step) with first gas, preferred rare gas element in advance; During the cracking mixture or afterwards, can be with this mixture of second gas, particularly inert gas dilution; The temperature of second gas for example makes it be used for carrying out at least in part quick cooling step, and it may be necessary for the formation that promotes molecular fluorine; After the cooling, gaseous mixture can be mixed with the 3rd gas, preferred rare gas element; First, second or the 3rd gas are selected from nitrogen, argon gas, helium, krypton gas, xenon, CO
2, CO, NO, hydrogen, pure gas or its mixture; Gaseous mixture comprises the molecular fluorine F of 75mol%～1ppm
2When cooling off by oil heat exchanger by the mixture that produces in plasma body, use not can with the cooling oil of fluorine reaction.
Plasma body for example can connect and be bordering on thermodynamic(al)equilibrium, makes hot benefit play main in the decomposition of fluoro-gas (for example nitrogen trifluoride) but is not whole effects, as for example being microwave plasma or inductively coupled plasma (ICP).
Preferably cool off fast apace very much, preferably plasma body is cooled to equal 800K or lower temperature simultaneously with the quenching form.For example, this quenching can be avoided various safety problems, even two kinds of products are not in contact with one another in principle each other thus by for example with not coming the refrigerative heat exchanger to carry out with the oil of fluorine reaction.
Before carrying out the cracking step, can be with gas or gaseous mixture (preferred NF derived from fluorine
3) mix with rare gas element such as nitrogen and/or particularly argon gas.
Between quick cooling step, mixture is diluted with gas, particularly rare gas element such as nitrogen and/or argon gas.
Cooling step can adopt gas to carry out fast, and preferably, the cold air of injection contacts with mixture, carries out the quenching of gases of described mixture thus.
In a kind of substitute mode, the gaseous mixture after the cooling is mixed with rare gas element, particularly nitrogen and/or argon gas, and be sent in the pending container.
Preferably adopt aforesaid way to come the fluorine-containing gaseous mixture of cracking, make atomic fluorine thus.
Especially, fluorine-containing gaseous mixture carries out cracking by the plasma body that is kept by the discharge that obtains in the electromagnetic field, and this plasma body is definition known in those skilled in the art " heat " plasma.
With reference to the accompanying drawing of this paper, by the following illustrative embodiments that provides as non-limiting example, will understand the present invention better, wherein:
Fig. 1 has shown the synoptic diagram of apparatus of the present invention and method, wherein has pressure-controlling;
Fig. 2 has shown the substitute mode of Fig. 1, is in the fluorine flow pattern;
Fig. 3 has shown the substitute mode of Fig. 2, wherein simultaneously fluorine is supplied with multiple arrangement;
Fig. 4 has shown the substitute mode of Fig. 1, wherein flows by proofreading and correct mouthful control;
Fig. 5 has shown the substitute mode of Fig. 4, has wherein set forth to be transformed into fluorine generation position;
Fig. 6 has shown the substitute mode of Fig. 4, has wherein set forth the operation of supplying with during the fluorine;
Fig. 7 has shown the substitute mode of Fig. 4, wherein proofreaies and correct mouth and has replaced with mass flow controller.
According to first kind of substitute mode of the present invention, be used for decomposing (cracking) NF
3The device of molecule is made of plasma generator, wherein with nitrogen trifluoride NF
3With pure compound or to inject with the form of mixtures of one or more preferred inertia and preferred plasma-generating gas (as nitrogen, argon gas, helium, neon, krypton gas and/or xenon).CO
2And/or NO goes for some situation.
Plasma generator of the present invention is characterised in that by cracking NF
3Generate molecular fluorine F
2, be this situation basically when the pressure of plasma body approaches normal atmosphere.Being used to implement optimum plasma body of the present invention is high electron density plasma such as microwave plasma, particularly surface wave plasma, inductively coupled plasma (ICP) and arc plasma, and preferred corona and dielectric intercept discharge (DBD) plasma body.This is because must there be the active substance of sufficient amount in plasma body, with cracking high density NF
3
It is too far away that maintenance high intensity discharge does not under atmospheric pressure depart from thermodynamic(al)equilibrium.This point means that the temperature of heavier substances (neutral and ionic) is not less than 1/10th of electronic temp usually.Therefore the gas in the discharge may be very warm, up to 7000 ℃.Therefore, heat exchange mechanism plays very important effect in the chemical conversion mechanism of nitrogen trifluoride.The effect of very high temperature is to make very apace the final state that this system is transformed to be provided by thermodynamics in the discharge.Thermoelectron outside the balance self has been strengthened this effect.Gas temperature can for example be measured by optical emitting spectral measurement method.Discovery (sees table) NF in plasma body
3Exist by cracking and with the atomic fluorine form fully.
Cooling gas (chemical quenching) can prevent reversed reaction and NF very apace
3Reformulation.Therefore, the progress of this system is very highly irreversible, that is, gas is always away from thermodynamic equilibrium state in fact.Preferably, must be shorter than NF greatly typical cooling time
3The reversed time of the kinetic coefficient of the reversed reaction that culminates in the reformulation.
The at room temperature also non-stable material of atomic fluorine.Between cold snap,,, the combination once more of atomic fluorine takes place so interacting by volume basically because main pressure is normal atmosphere.Subsequently, generate two substance reactions of molecular fluorine than regeneration NF
3The reaction possibility bigger.
Therefore, for implementation basis the present invention by NF
3Generate F
2Effective ways, should preferably the gaseous mixture that generates in the plasma body be delivered in the highly efficient cooling device as far as possible apace, this device can drop to gas temperature very apace and be lower than NF
3Can with the temperature spot of its degradation production coexistence.Prevented like this because degradation production is reformulated nitrogen trifluoride.In order to carry out this quick cooling, preferred use heat exchanger (sometimes, for low-temperature plasma, be used for these devices of cooling gas mixture and can be simply form) by (normally cold) wall of the container that receives this mixture that generates from plasma body.The feature of heat exchanger (size, heat exchange structure) must make feature significantly be shorter than cooling time to cause NF
3The reversed time of the kinetic coefficient of the reversed reaction of reformulating.Refrigerating unit can for example be made up of liquid suction heat exchanger, it is using water coolant from the loop of using semi-conductor generation equipment, for example have coil pipe or Pipe bundle structure (these manage preferred parallel or substantially parallel), make the heat exchange area maximization thus.This heat exchanger is installed, is made its inlet mouth be positioned at downstream boundary as far as possible near plasma slab.
The high density plasma of any type can be used for implementing the present invention, preferably approach normal atmosphere (perhaps more high pressure) operation down, and particularly by the application's design and be described in atmospheric pressure microwave plasma source in patent EP-A-0820801 and EP-A-1332511 and US5961786 and 6290918 especially.Usually, preferably approach the plasma body of (perhaps departing from not far) thermodynamic(al)equilibrium.
May also can form by suitable device by the plasma source that is described among US-A5418430 or the WO03/0411111.
Quite big advantage of the present invention is, do not use usually that pure fluorine cleans, non-infiltration (impermeabilization) or other operation.Usually use with mixture with nitrogen.When carrying out like this, adopt nitrogen trifluoride NF
3The decomposition of plasma body (or heat) cause forming by cracking and start from two molecule NF
3Per molecule nitrogen three molecular fluorine F
2(particularly as whole NF
3Molecule is during by cracking): therefore, the mixture of Xing Chenging comprises the fluorine of maximum 75mol% and the nitrogen of 25mol% like this.According to the present invention with the type of the mixture that obtains, can be with this mixture with nitrogen and/or other gas dilution arbitrarily, make the gaseous mixture that contains 75mol% fluorine and 25mol% nitrogen thus, up to the pure nitrogen gas form that wherein contains several ppm or with other inert, reduction (H
2Deng) or oxidation (O, O
3Deng) mixture of gas blended fluorine.Before the cracking fluoro-gas molecule or after the cracking, before the mixture that quick cooling forms and/or afterwards, can add fluorine-containing other gas (SF
6Deng) or other not fluorine-containing gas, but also carry out this cooling or quenching fast (for this purpose, can inject cooling gas-nitrogen, argon gas, helium etc., up to-180 ℃, perhaps in addition adopt the convection current cooling liqs spraying of preferred gas to be cooled).
In microelectronic applications (for example, clean semiconductor generates the chamber), with the NF of " electronics " level
3Gas begins, and promptly purity equals semi-conductor generation desired degree of purity at least, can found in the annual route map of publishing by SEMI about this specification.
Other application can be by more low-grade NF usually
3Begin.
The molecular fluorine of preparation is usually at low temperature and preferably at room temperature supply with user's equipment.Therefore, the heat exchanger that is positioned at the plasma exit that is used for chemical quench gas also has the function that mixture is cooled to for example to be lower than 50 ℃ temperature, and this gaseous mixture can be stored in the surge tank or use as described below immediately subsequently.
(adopt for example mixing device, it receives the nitrogen/fluorine mixture that generates in plasma reactor and diluent gas such as nitrogen and/or other gas arbitrarily, contains with supply and is less than 75mol%F using more or less diluted mixture thing
2Gaseous mixture) afterwards; this mixture is reclaimed with the cleaning by product in the exit of user's equipment; mixture is delivered in decomposition/washing device; or wet method (for example by caustic soda or liquor kalii caustici) or dry method (the reactive absorption on soda-lime particle or other alkaline absorbent); perhaps on aforesaid plasma decomposes device; the source (oxygen, ozone, steam etc.) of oxygenant wherein is provided, and the mixture by fluorine after the plasma body and oxygenant generates one or more HF, COF
2, type such as NOF compound, himself destroys by above-mentioned dry method or wet method decomposition/washing device.
In the substitute mode, gas can be stored in the surge tank after using.
Obviously, according to another substitute mode of the present invention, producer of the present invention can be coupled with another plasma body system, as mentioned above, and its online outlet that is connected in the device that uses fluoro-gas.This class plasma body system extensively is described in the document, and its design is used for destroying the molecule of PFC/HFC type and particularly fluorine F
2, in the presence of oxygenant, steam etc., form effluent thus, as HF or other, it is adsorbed in washing water or other system subsequently.
Now various substitute mode of the present invention will be described in conjunction with the accompanying drawings.
Several configurations are suitable for implementing this NF
3The cracking system, to provide fluorine to machining cell, for example cleaning unit or semiconductor production instrument, " CVD " type sediment chamber particularly, and the device of fluoridizing that for example is used for polymer plastic jar (PVC etc.), make the latter not be subjected to the influence of hydrocarbon vapour by their not porous like this to make by the fluorine-containing layer of formation on polymer surfaces.
Required instant and mean flow rate, unit number to be supplied with and required supply pressure are depended in used selection basically.
The simplelyst be configured as wherein instant F
2Demand is lower than instant NF
3The cracking capacity.
At this moment, the preferred forms plasma body that is to keep lighting is forever at N
2Flow down face (with low energy model), and pass through NF
3Add nitrogen gas stream or by using NF
3Thoroughly or partly replace nitrogen gas stream, be converted to load model (Fig. 2 and 3, or Fig. 4～6, or Fig. 7 are according to master mode) from this ready mode (Fig. 1).
Be used for being converted to the requirement that the condition of cracking pattern (Fig. 2 and 3) can produce by device or falling (owing to forming) by the pressure the distribution circuit and trigger by user's device using gas from ready mode (Fig. 1).In order to give bigger handiness aspect time of response of other pattern being used for being converted to from a kind of pattern, this distribution circuit can be equipped with surge tank.The distance between user's device and the producer is depended in the selection of triggering mode basically, when (circuit gas is enough to play pooling feature), preferably recommends the triggering based on line pressure when distribution system is arranged in away from this device.
Fig. 1 has shown the exemplary embodiment of the invention with plasma source, as described in US-A-5965786 and the US-A-6290918.
In the figure, have identical reference number, perhaps be shown in the subsequent figure, and do not use reference number in mode identical among Fig. 1 with those components identical in the subsequent figure.
Plasma source of the present invention comprise be equipped with in the unit 1 of dielectric tube 22, the opening 4 by being positioned at the pipe top is with NF
3In gas (the pure or mixture) inlet tube 22, the plasma body starting electrode 3 near being connected in high pressure producer (also not shown in the drawings) forms spark thus in pipe.The unit 1 of dielectric tube 21 is by the waveguide 2 in its thinner centre portions 49, centre portions 49 opens at 48 and 47 every side places, end 47 is connected in the outlet of magnetron 21, magnetron 21 is formed at the height place of conduit 49 to form in the pipe 22 and produces the necessary microwave of plasma body, and hold 48 to be connected in mobile short-circuit plunger (not shown), it forms adjustable impedance matching box, to prevent the reflection of microwave energy to magnetron.Waveguide field applicator is used for concentrating the microwave energy than fine duct part 49 places, and launches gradual surface-duided wave, and this surface-duided wave is propagated on the either side of conduit along dielectric tube, gradually its energy is delivered plasma body, to keep the latter.
Heat exchanger 24 is positioned at the outlet of as close as possible discharge tube 23.Preferably, discharge tube is sufficiently long just in time, makes that the distance from the region of discharge downstream end to pipe outlet 23 is randomly minimum.This is that the cooling of gas normally is not enough to (except " cold " plasma body situation) and causes quenching at least, and a certain amount of NF because surpass described distance
3May reformulate, particularly in the minor diameter situation, wherein the surface once more the bonded relative proportion increase.Minimum value and value is subjected to preventing following the influence that needs that the surface-duided wave of plasma body reflects between region of discharge downstream end and the pipe outlet 23 on the common metal parts, and the fluid that this metal parts constitutes the discharge tube end connects.Otherwise, may cause the appearance of surface-duided wave equilibrium mode like this, it is disadvantageous owing to having strengthened crest place energy density and to reliability, and will be by giving the energy coupled characteristic that this system partial resonance characteristic has reduced plasma source.
This device comprises the source nitrogen 20 that is connected in valve 18, and the pressure warning unit at by-pass valve control 16 and valve 7 places, valve 7 are connected in the correction mouth 46 of logic controller 9 and valve 6 upstreams by control circuit 12.Valve 6 and 7 outlet are connected in the pipeline 5 that gaseous mixture (or scrubbed gas) is transported to outlet 4 and by-pass valve control 8 outlets (shown in the electronically controlled pipeline 11 that also is connected in logic controller 9), and its outlet is connected in pressure detector 13, by-pass valve control 15, self is positioned at NF
3The valve 17 of gas source 19 outlets.
The outlet 23 of vitrified pipe 22 is connected in the inlet of valve 5 and 33 by heat exchanger 24.Valve 25 is used for the gas that heat exchanger 24 produces is delivered to treatment loop 29, and by valve 28 and correction 45, perhaps by valve 26 and pump 27, its outlet is connected in the outlet of proofreading and correct mouth 45 30.
Pipeline 44 is used for gas is directly sent into pipeline 5 by calibration valve 32, when its overpressure exists, directly delivers to a little 30 and deliver to treatment unit 29 thus.
Explain various forms of operations in conjunction with Fig. 1～7 now, Fig. 1～7 have all shown identical device, randomly have some substitute modes, have the color indication that shows whether valve is closed or opened.In Fig. 1, apparatus of the present invention promptly in low-yield service voltage (1KW) electricity operation down, do not produce fluorine gas with the operation of " non-activity " pattern thus.For this purpose, valve 6,8,26 and 33 is (black) of closing, and other valve is (white) opened.Therefore, only nitrogen can flow by valve 7 (opening by controller 9), with by dielectric tube 22, keeps the plasma body under low-yield (1KW) thus, and plasma body only uses nitrogen, and the gas of processing is transferred to device 29 by 25,28 and 45.
Fig. 2 has shown device identical among Fig. 1, but when operating fully by NF
3Generate fluorine.For this purpose, valve 6 and 7 is (black) of closing, and valve 8 is opened.In order to use the gas of nitrogen dilution by plasma generation, when opening valve 8 (using controller 9), it enough avoids thoroughly cutting off nitrogen feed (valve 6,7).Therefore, nitrogen trifluoride is F by cracking
2+ N
2(has residual NF
3) mixture.Valve 25 is closed, and simultaneously valve 33 is opened, if when not indicating valve-off 40 by 38 electronic signals of receiving, surge tank 35 and feeding unit 42 are given in charging.
Be used for being converted to the requirement that the condition of cracking pattern can produce by device or falling (owing to forming) by the pressure the distribution circuit and trigger by " instrument " using gas from ready mode.In order to give bigger handiness aspect time of response of other pattern being used for being converted to from a kind of pattern, this distribution circuit can be equipped with surge tank.The machining cell that uses fluorine and the distance between the producer are depended in the selection of triggering mode basically, when (circuit gas is enough to play pooling feature), preferably recommend the triggering based on line pressure when distribution system is arranged in away from this processing unit (plant).
In the above-described embodiments, use pure NF
3, make it possible to 100% N in the ready mode
2Logistics is converted into 100% NF in the cracking pattern
3Make it possible to not use flow control to carry out like this, but the NF of pressure-controlling producer upstream only
3And N
2At generator exports, (by pump, the technology that does not show) is allowed and lighted the first time of plasma body to vacuum line herein, and blew down the initial F that generates before being transformed into the processing circuit
2).
Fig. 3 has shown the identical schematic operation (distribution fluoro-gas) of apparatus of the present invention, have three devices 50,51,52 that are parallel to by the VBM60 distribution system connection of pipeline 39 chargings, be connected in pipeline 64, it is distributed to device 52,51 and 50 by pressure reducer/valve unit 61,62 and 63 respectively with gas respectively.
Fig. 4 is the substitute mode of Fig. 1, and wherein correction limit 73 and 76 places the upstream of valve 7 and 8 respectively, and pressure detector 74 places the circuit 5 in valve 7 and 8 outlet downstreams, and detector 74 is sent to controller 9 by electronic circuit 75 with pressure survey.
Fig. 5 has shown the switch process between " non-activity " step (Fig. 4) and the fluorine supplying step (Fig. 6).In this step, with respect to Fig. 4, valve 8 is opened, makes to give pipe 22 charging NF
3+ N
2Mixture (and cuts off N subsequently if desired
2).
Fig. 5 has set forth stabilization charging surge tank (valve 25 is closed with valve 33 and opened) and conveying fluorine auto levelizer 42 afterwards.
Therefore, can and not control feed pressure based on the control flow velocity and generate N
2/ F
2Mixture.At this moment, charging fixed or variable nitrogen and NF in the producer
3Mixture.This mixture can be by use proofreading and correct mouthful or other flow obstacle such as needle-valve or kapillary (fixed NF arbitrarily
3/ N
2Ratio) or mass flow controller (variable ratio) or the combination of the two prepare.The servo-actuated control of the overall flow rate by producer can realize by variety of way, as described as follows, but is not limited only to this:
Use flow obstacle: in the ready mode, nitrogen line only is fed at the low-yield producer of operation down.When pressure reduced in production requirement or circuit/snubber, generator power increased and NF
3Circuit is opened the NF that has predetermined concentration with generation
3/ N
2Mixture.The initial gas that generates at first is transferred to vent line stablize flow velocity and concentration, and the gas of generation delivers to process piping subsequently, randomly passes through surge tank.When product demand stopped, perhaps when pressure reached threshold values in the surge tank line, the gas of generation was delivered to vent line once more, and this system reverts to ready mode and (closes NF
3Pipeline etc.).The advantage of this method is that cost is low, but it needs frequent pattern conversion and the pressure change in the formation producer, and this may hinder its operation.
A solution can be to generate with respect to the higher flow velocity of user's processing units desirable value, and it is excessive is often removed by vent line.At this moment, the upstream pressure controller is used for the pressure that keeps process piping enough.
Fig. 7 is the substitute mode (in the operation) of Fig. 6, and correction limit 73 and 76 is replaced with mass flow controller (being respectively 82 and 81), comes electronically controlled by pipeline 84 and 83 by controller 9.
Replace flow obstacle by the functional quality flow director, can servo-actuated control pipeline in respect to the overall flow rate of pressure (with constant N
2/ NF
3Ratio), keep constant compression force thus.At this moment, be the needed speed of device with the flow rate regulation that produces, avoid this device to use F thus
2Pattern conversion during this time.In the situation that the identical hierarchy of control can be applied to control by flow obstacle similarly.
In using the scheme of plasma body, producer of the present invention can be equipped with the system that can under atmospheric pressure produce high density plasma arbitrarily usually, promptly in fact plasma body about 10
4Pascal～10
6Operation down between pascal's (or higher), and electron density is 10
12～10
15Cm
-3, for example 10
13～10
14Cm
-3
In fact, find on the other hand, be used to obtain good NF
3In decomposition kinetics and the high efficiency high density plasma, when under low pressure operating, about 10
12Pascal and for example as described in the US5812403, at first mainly generate atomic fluorine, if and be not be used for like this chemical attack deposition solid film and thus cleaning remain on the unitary locular wall of CVD under the vacuum, on the cleaning solid surface once more in conjunction with and on volume than low degree copy molecular fluorine.Therefore, do not have favourable part to be, by a plurality of complex steps of this successive, these steps require the vacuum supportive device, realize the identical result shown in the present invention thus, promptly under atmospheric pressure supply with molecular fluorine.
In addition, other type discharge operation under atmospheric pressure such as corona vapor electric discharge or DBD are not suitable for implementing the present invention.The physicals of these discharges and those difference of considering above are bigger.They have the stream of electrons zone of heterogeneous texture usually, and wherein electron density can be about 10
11Electronics cm
-3, the density in the residual volume is no more than several 10
9Electronics cm
-3And these discharges remain pulse mode usually, make also to exist when medium does not contain high-energy electron for a long time.This just means that these discharges are for the high per-cent NF that dissociates
3To arrive the high density of being considered (for example about 1～10 volume %) is poor efficiency.In addition, in the zone between stream of electrons and the idle period of time between the excitation pulse will greatly NF may take place
3Reformulation because gas is at normal atmosphere and substantially at room temperature simultaneously.Therefore, the atmosphere pressure discharging that is called " cold " discharge in order to use is implemented the present invention, plasma source must general size more greater than the high density source of the partially or completely local thermodynamic equilibrium that is used for identical performance.
In user's device, use after the fluorine, may still contain fluorine waste gas must by wet method or dry method absorption system (wet cleaner or dry scrubber) or even in advance in plasma body (for example as mentioned above under atmospheric pressure) destroy, before the gas that leaves plasma body is handled in the wet scrubbing system, with gas preferably in water vapour or oxidizing gas injected plasma.
Illustrative embodiments:
Embodiment 1
With NF
3And the nitrogen (NF that comprises 1.3 volume %～18.0 volume %
3) mixture deliver to device described in EP-A-0820801 (the gas overall flow rate with rise/minute (SLM) be expressed as 20, the dielectric tube diameter is 8mm) in.The power of magnetron can change between 2500～4000W.About NF
3Decompose and F
2Generating the result who is obtained provides below.FT-IR measures and obtains remaining NF
3Concentration, and, obtain F by relatively
2Concentration, UV is measured as this F
2The true of concentration directly measured.Term DRE represents:
DRE%=100[1-(NF
3)
Go out/ (NF
3)
Go into]
Wherein, (NF
3)
Go intoThe NF of=introducing
3Concentration, (NF
3)
Go out=effusive NF
3Concentration.
Below in the table 1 term " inflow " described the flow velocity that enters the mouth in the plasma body (L/ minute-slm) and NF
3Volumetric concentration (at NF
3In the mixture of nitrogen).
| Inflow | 2500W | 3000W | 3500W | 4000W | Magnetron power | |||||||||||||
| Overall flow rate | NF 3 (％) | FT-IR | UV | FT-IR | UV | FT-IR | UV | FT-IR | UV | Canonical analysis | ||||||||
| DRE | F2 | DRE | F2 | DRE | F2 | DRE | F2 | Production concentration | ||||||||||
| (％) | SLM | ％ | (％) | SLM | ％ | (％) | SLM | (％) | SLM | ％ | ||||||||
| 20 | 1.3 | 92 | 0.4 | 1.8 | 1.9 | 97 | 0.4 | 1.9 | 1.9 | 98 | 0.4 | 1.9 | 1.9 | |||||
| 4.3 | 78 | 1.0 | 4.9 | 4.9 | 87 | 1.2 | 5.4 | 5.5 | 97 | 1.3 | 6.0 | 6.1 | ||||||
| 8.9 | 68 | 1.8 | 8.6 | 9.5 | 72 | 2.0 | 9.1 | 11.2 | 85 | 2.3 | 10.7 | 13.7 | 92 | 2.5 | 11.3 | 14.8 | ||
| 18.5 | 65 | 3.5 | 15.0 | 12.6 | 73 | 3.9 | 16.4 | 13.4 | 79 | 4.3 | 17.8 | 16.2 | 87 | 4.7 | 19.4 | 19.0 | ||
Example II: in this example II, only changed the diameter (4mm replaces 8mm) of dielectric tube with respect to example I.
Table II
| Mixer entrance | Mixer outlet | The magnetron energy | ||||||
| N 2 | NF 3 | NF 3 | DRE | F 2 | UV | |||
| SLM | SLM | ％ | ％ | ％ | ％ | SLM | ％ | |
| 5.5 | 0.5 | 8.3 | 0.1 | 99.2 | 11.4 | 0.7 | 9.5 | 3500W |
| 5 | 1 | 16.7 | 0.1 | 99.0 | 21.2 | 1.5 | 17.5 | |
| 4.5 | 1.5 | 25.0 | 0.3 | 98.3 | 29.5 | 2.2 | 24.6 | |
| 4 | 2 | 33.3 | 0.7 | 97.3 | 36.5 | 2.9 | 31.2 | |
| 3.5 | 2 | 36.4 | 1.1 | 96.0 | 38.4 | 2.9 | 36.9 | |
| 3 | 2 | 40.0 | 1.3 | 95.4 | 40.9 | 2.9 | 39.6 | |
| 2 | 2 | 50.0 | 3.3 | 90.1 | 45.1 | 2.7 | 43.2 | |
| 2 | 2 | 50.0 | 1.7 | 94.9 | 47.4 | 2.8 | 45.3 | 4000W |
| 2 | 2 | 50.0 | 0.7 | 97.9 | 49.0 | 2.9 | 46.5 | 4500W |
The foregoing description 1 and 2 result demonstrate low-down (not cracking) NF that destroys especially
3Residual speed.
The producer of calorifics form of the present invention comprises three elements, but be heated to attemperation with obtain suitable decomposition kinetics, preliminary election is higher than 500 ℃ stove, with two heat exchangers, the one heating enters gas to be decomposed in the stove in the mode with respect to the decomposition hot gas convection current of leaving stove, another is used for regulating the temperature of clean air (this process is heat release) before injecting chamber to be cleaned on the decomposition gas loop.In two kinds of described configurations, can prepare and use point to be applicable to the compact unit of installation, and can provide nitrogen/fluoride mixture with the flow velocity that is suitable for wafer stove cleaning course.In addition, this molecular fluorine producer can not cause complicated safety problem (product-derived NF on the semiconductor production position
3Usually be stored in this position in a large number).In addition, because decomposition method is simple, control easily, and the therefore difficult loading factor that influences stove to be cleaned unfriendly.
Usually, wherein use the situation of plasma body as all, plasma body is lighted first by initial injected plasma generation gas (for example argon gas or nitrogen) usually, injects before this and treats that single or mixture (with the mixture of above-mentioned gas) the form gas of cracked (is NF herein
3), keep, reduce flow velocity simultaneously or thoroughly cut off the injection of initial plasma-generating gas.
Claims (19)
1, the method that contains the gas or the gaseous mixture of molecular fluorine by gas or gaseous mixture preparation derived from fluorine is characterized in that, makes fluorine-containing gas or gaseous mixture, particularly nitrogen trifluoride NF
3Logical superheated high electron density plasma and decomposing, plasma body generates at normal atmosphere or near under the normal atmosphere, obtains to be higher than the top temperature T of heavier substances in the plasma body of 2000K thus
Max, the mixture with the various materials that exist in the plasma is cooled to temperature T subsequently
h, subsequently at T
hAnd T
bBetween fast the cooling, T
hAnd T
bFor according to fluorine-containing gas or gaseous mixture two temperature, T by measuring
hBe the temperature that the molecule of gas in the initial injected plasma or gaseous mixture can be begun to reformulate by their division fragment, T
bFor surpassing 90% the fluorine atom that generates by division bonded temperature once more in the plasma body, obtain to contain molecular fluorine F thus
2Gaseous mixture.
2, the method for claim 1 is characterized in that, the top temperature of heavier substances (ionic and neutral) is 3000K～10000K in the discharge that generates plasma body.
3, the method for claim 2 is characterized in that, plasma electron density is greater than 10
12Electronics/cm
3, be preferably 10
12～10
15Electronics/cm
3
4, the method for claim 3 is characterized in that, temperature T
hAnd T
bBetween quick cooling time equal 5 * 10
-2Second or lower is with a large amount of reformulations and the promotion fluorine molecule F that prevents parent material
2Formation.
5, the method for claim 4 is characterized in that, is shorter than 10 cooling time fast
-2Second, preferably be shorter than 5 * 10
-3Second.
6, each method in the claim 1～5 is characterized in that, fluorine-containing gas is nitrogen trifluoride NF
3, T
hBe about 1200K, T
bBe about 800K.
7, each method in the claim 1～6 is characterized in that, plasma body is the plasma body that approaches thermodynamic(al)equilibrium, particularly by the rf wave of induction coupled modes or the plasma body of microwave generation.
8, each method in the claim 1～7 is characterized in that, plasma is at normal atmosphere or 10
14～10
16Generating down between the pascal near normal atmosphere.
9, each method in the claim 1～8 is characterized in that, before the cracking step, fluorine-containing gas or gaseous mixture is mixed with the first preferred rare gas element.
10, each method in the claim 1～9 is characterized in that, during fluorine-containing gas of cracking or gaseous mixture or afterwards, and with second gas, particularly inert gas dilution gas or gaseous mixture.
11, the method for claim 10 is characterized in that, the temperature of second gas makes it be used for carrying out at least in part to promoting molecular fluorine to form the necessary quick cooling step of possibility.
12, each method in the claim 1～11 is characterized in that, after the cooling, gaseous mixture is mixed with the 3rd preferred rare gas element.
13, each method in the claim 1～12 is characterized in that, first, second and/or the 3rd gas are selected from nitrogen, argon gas, helium, krypton gas, xenon, CO
2, CO, NO, hydrogen, it is pure gas or its mixture.
14, each method in the claim 1～13 is characterized in that, the gaseous mixture that contains molecular fluorine comprises the molecular fluorine F of 75mol%～1ppm
2
15, each method in the claim 1～14 is characterized in that, the gaseous mixture that will contain molecular fluorine contacts with surface or volume.
16, the method for claim 15 is characterized in that, surface or volume are made by metal, polymkeric substance and/or dielectric materials.
17, the fluoro-gas producer of the gas that contains molecular fluorine is provided, it is characterized in that it comprises: gaseous state nitrogen trifluoride NF
3The source; Generate the device of the high electron density plasma of heat, to decompose the fluoro-gas molecule and neutral and ionic substance top temperature T at the heavy that is higher than 2000K
MaxUnder generate plasma body; Cool off the device of the gaseous mixture of this decomposition generation; Be cooled to be lower than T with recovery
bTemperature contain fluorine molecule F
2The device of gaseous mixture.
18, the producer of claim 17 is characterized in that, it also comprises inert gas source, as the source of nitrogen, argon gas, helium and/or its mixture.
19, claim 17 or 18 producer is characterized in that it comprises and being used for gaseous mixture and second gas such as rare gas element or hydrofluoric acid gas blended device.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR0451378 | 2004-06-30 | ||
| FR0451379A FR2872506B1 (en) | 2004-06-30 | 2004-06-30 | PROCESS FOR THE PREPARATION OF A GAS OR MIXTURE OF GAS CONTAINING MOLECULAR FLUORINE |
| FR0451379 | 2004-06-30 | ||
| FR0551676 | 2005-06-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1980859A true CN1980859A (en) | 2007-06-13 |
Family
ID=34945706
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200580022253 Pending CN1980859A (en) | 2004-06-30 | 2005-06-29 | Method for the preparation of a gas or mixture of gases containing molecular fluorine |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN1980859A (en) |
| FR (1) | FR2872506B1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112672810A (en) * | 2018-07-13 | 2021-04-16 | 普拉斯尼克斯 | Method and apparatus for treating exhaust gas containing target gas in plasma phase |
| CN113606820A (en) * | 2021-08-27 | 2021-11-05 | 中船重工（邯郸）派瑞特种气体有限公司 | Direct and indirect refrigeration combined nitrogen trifluoride electrolysis gas ultralow temperature cold trap device |
| CN116425118A (en) * | 2023-03-31 | 2023-07-14 | 南大光电(淄博)有限公司 | Method for producing high-purity fluorine gas by cracking nitrogen trifluoride and cracking reactor thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103025413B (en) * | 2010-08-02 | 2015-10-14 | 巴塞尔聚烯烃股份有限公司 | The method and apparatus of mixing and separation of the fluid stream |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4213102A (en) * | 1978-03-21 | 1980-07-15 | The United States Of America As Represented By The Secretary Of The Air Force | Fluorine generator for chemical lasers |
| JPS6217025A (en) * | 1985-07-16 | 1987-01-26 | Kokusai Denshin Denwa Co Ltd <Kdd> | Preparation of fluoride glass |
| JPH04323377A (en) * | 1991-04-19 | 1992-11-12 | Hitachi Electron Eng Co Ltd | Cleaning method for chemical vapor deposition equipment |
| FR2751565B1 (en) * | 1996-07-26 | 1998-09-04 | Air Liquide | PROCESS AND PLANT FOR THE TREATMENT OF PERFLUOROUS AND HYDROFLUOROCARBON GASES FOR THEIR DESTRUCTION |
-
2004
- 2004-06-30 FR FR0451379A patent/FR2872506B1/en not_active Expired - Fee Related
-
2005
- 2005-06-29 CN CN 200580022253 patent/CN1980859A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112672810A (en) * | 2018-07-13 | 2021-04-16 | 普拉斯尼克斯 | Method and apparatus for treating exhaust gas containing target gas in plasma phase |
| CN113606820A (en) * | 2021-08-27 | 2021-11-05 | 中船重工（邯郸）派瑞特种气体有限公司 | Direct and indirect refrigeration combined nitrogen trifluoride electrolysis gas ultralow temperature cold trap device |
| CN116425118A (en) * | 2023-03-31 | 2023-07-14 | 南大光电(淄博)有限公司 | Method for producing high-purity fluorine gas by cracking nitrogen trifluoride and cracking reactor thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2872506B1 (en) | 2007-02-02 |
| FR2872506A1 (en) | 2006-01-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100495783B1 (en) | Parallel plate apparatus for in-situ vacuum line cleaning for substrate processing equipment | |
| CN101248506B (en) | Method of treating a gas stream | |
| CN1301342C (en) | Application of dense plasmas generated at atmospheric pressure for treating gas effluents | |
| KR100271694B1 (en) | Method and apparatus for reducing perfluorocompound gases from substrate processing equipment emission | |
| US6962679B2 (en) | Processes and apparatuses for treating halogen-containing gases | |
| CN1917932B (en) | Method and apparatus for treating a fluorocompound-containing gas stream | |
| US6981508B2 (en) | On-site cleaning gas generation for process chamber cleaning | |
| US8343317B2 (en) | In situ cleaning of CVD System exhaust | |
| US7394041B2 (en) | Apparatus for treating a waste gas using plasma torch | |
| US20060144820A1 (en) | Remote chamber methods for removing surface deposits | |
| EP1716912A1 (en) | Method and apparatus for treating exhaust gas | |
| WO2005090638A9 (en) | Remote chamber methods for removing surface deposits | |
| US20080110744A1 (en) | Method for the Preparation of a Gas or Mixture of Gases Containing Molecular Fluorine | |
| KR20080032089A (en) | Method for plasma treatment of gas effluents | |
| JP7217056B2 (en) | Method and apparatus for treating exhaust gas containing target gas in plasma phase | |
| CN1980859A (en) | Method for the preparation of a gas or mixture of gases containing molecular fluorine | |
| CN103889553A (en) | Perfluoride decomposition treatment method and treatment device | |
| US20070284242A1 (en) | Method For Treating Gases By High Frequency Discharges | |
| US20030161774A1 (en) | Processes and apparatuses for treating halogen-containing gases | |
| JPH1176740A (en) | Decomposing method of organic fluorine based waste gas and decomposing device | |
| JP2004160312A (en) | Pfc gas decomposition system and method used for the same | |
| US20140079617A1 (en) | Apparatus for treating a gas stream | |
| JP2008506516A (en) | Atmospheric pressure plasma treatment of gas emissions | |
| US20110073282A1 (en) | Method for cooling microwave plasma and system for the selective destruction of chemical molecules using said method | |
| US20060144819A1 (en) | Remote chamber methods for removing surface deposits |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |