JP2003534112A - Hazardous gas treatment in emissions - Google Patents

Abstract

  (57) [Summary] An apparatus and a method for reducing a dangerous gas discharged from a process chamber are disclosed. An exhaust gas treatment system having a gas energy delivery reactor and an additional gas source. An additive gas having a reactive gas is introduced into the effluent from the process chamber at a volume flow rate related to the content of the hazardous gas in the effluent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an apparatus and method for removing hazardous gases in effluent from a process chamber.

[0002]

[Prior art]

Fluorocarbons, chlorofluorocarbons, hydrocarbons, and other fluorine-containing gases are used or by-produced in the manufacture of active and passive electronic circuits within process chambers. These gases are toxic to humans and dangerous to the environment. Further, they strongly absorb infrared rays and have a high possibility of global warming. Particularly infamous is the fluorinated or perfluorinated compounds (PFCs) that do not decompose
However, it has a long life and is chemically stable, and its life often exceeds several thousand years. Examples of PFCs include carbon tetrafluoride (CF ₄ ), hexafluoroethane (C ₂ F ₆ ), octafluorocyclopropane or perfluorocyclobutane (C ₄ F ₈ ).
, Difluoromethane (CH ₂ F ₂ ), hexafluorobutadiene or perfluorocyclobutene (C ₄ F ₆ ), parafluoropropane (C ₃ F ₈ ), trifluoromethane (CHF ₃ ), sulfur hexafluoride (SF ₆ ). , Nitrogen trifluoride (NF ₃ ) and the like. For example, the lifetime of CF _{4 in} the environment is about 50,000 years, contributing 6.5 million years to global warming. Therefore, an apparatus or method that can reduce the content of dangerous gases, especially PFCs, in the effluent released from the process chamber is desired.

Perfluorinated compounds are used in many semiconductor processing processes, for example, for etching layers such as oxide layers, metal layers, dielectric layers, etc. on a substrate. Perfluorinated compounds can also be used during the chemical vapor deposition process. Also, the use of perfluorinated compounds can clean the process chamber from etch and deposition residues. These hazardous compounds can be carried into the process chamber or can be generated as a by-product within the process chamber and released from the chamber in a stream of exhaust gas.

[0004]

[Problems to be Solved by the Invention]

Plasma devices are used to reduce the PFC content in the effluent,
There is a limit to its success. Attempts have been made in the past to remove PFCs from effluents, but significantly higher percent sufficient removal has not been demonstrated. For example, A
Gas containing r, O ₂ and PFC was introduced into the plasma chamber at a volumetric flow ratio of Ar to O ₂ of 3
There is a typical method of adding them at the same time. The volumetric flow ratio of Ar to O ₂ required to ignite and maintain the plasma well is high with conventional methods. However, the reduction efficiency in this process is less than 95% for many PFC gases and significantly less than 95% for complex mixtures of various PFC gases. As a result, the conventional method may be forced to release a high level of PFCs exceeding the desired level into the environment.

Therefore, it is desirable to minimize the introduction of such harmful gases and by-products into the environment. It is also necessary to minimize harmful substances in the exhaust gas released into the atmosphere in an effective and cost-effective manner. Furthermore, it is necessary to reduce PFC and other harmful gases to the lowest possible levels. Especially in industries that extensively use PFCs, it is preferable to reduce at least 95% even if the amount of use is small compared to the total consumption or emission of PFCs in the world. is necessary.

[0006]

[Means for Solving the Problems]

A method for treating a perfluorinated compound-containing exhaust gas, comprising the step of introducing the exhaust gas into a reactor, wherein an additive gas having at least one oxygen-containing gas is used, and oxygen atoms in the additive gas and carbon in the perfluorinated compound are added. Selecting a volumetric flow rate of the oxygen-containing gas into the reactor such that the atomic ratio is at least about 2.4: 1, and imparting energy to the exhaust gas and the additive gas in the reactor, A method comprising the step of reducing the content of perfluorinated compounds in the exhaust gas.

A method of treating a perfluorinated compound-containing exhaust gas, comprising the step of introducing the exhaust gas into a reactor, wherein an additive gas having at least one oxygen-containing gas is added to oxygen atoms in the additive gas and a perfluorinated compound. Introducing the oxygen-containing gas into the reactor at a volumetric flow rate such that the ratio of sulfur atoms in the reactor is at least about 2.4: 1, and imparting energy to the exhaust gas and the additive gas in the reactor. A method comprising the steps of:

A method of treating a chamber effluent gas containing a perfluorinated compound, comprising the step of introducing the effluent gas into a reactor, the additive gas having at least one oxygen-containing gas,
The ratio of oxygen atoms in the additive gas to nitrogen atoms in the perfluorinated compound is at least about 2.4.
1. A method comprising the steps of selecting a volumetric flow rate of the oxygen-containing gas to introduce into the reactor so that the ratio becomes 1: and imparting energy to the exhaust gas and the added gas in the reactor.

A method of imparting energy to the exhaust gas from a chamber, wherein an additive gas having an inert or non-reactive gas is introduced into the reactor at a first volume flow rate,
A method comprising the steps of changing a volumetric flow rate of an inert or non-reactive gas to a second volumetric flow rate, introducing an exhaust gas into a reactor, and imparting energy to a gas group in the reactor.

A method for imparting energy to an exhaust gas from a chamber, wherein a step of introducing an additive gas having a reactive gas into a reactor at a first volume flow rate, a volume flow rate of the reactive gas at a second volume flow rate. A method comprising the steps of changing to a flow rate, introducing exhaust gas into the reactor, and imparting energy to the gas group in the reactor.

Having a reactor having an inner surface having a fluorine-containing compound and adapted to receive gas, and a gas energy applicator for providing energy to the gas in the reactor,
Gas energy giving device.

A gas treatment device capable of treating exhaust gas from a process chamber, comprising:
Gas treatment device having a reactor having an inner surface with F ₂ or CaF ₂ and adapted to receive exhaust gas, and a gas energy donor to energize the gas in the reactor to treat the exhaust gas .

A gas, having a reactor having an inner surface with a substance having an oxide and a stabilizer and adapted to receive gas, and a gas energy impartor for imparting energy to the gas in the reactor Energy giving device.

[0014]

DETAILED DESCRIPTION OF THE INVENTION

The features, aspects, and advantages of the present invention will be better understood with reference to the following detailed description, claims, and the accompanying drawings, which illustrate representative features of the invention. However, it should be understood that each of the features is applicable to the invention in general and is not relevant to the specific drawings only, and that the invention encompasses any combination of these features.

The present invention relates to a gas treatment device for use in a process chamber and a method of reducing the hazardous gas content of effluent from the process chamber. The detailed description and accompanying drawings illustrate embodiments of the invention and are not intended to limit the invention.

A typical substrate processing apparatus 20 shown in FIG.
Santa Clara, Applied Materials' commercially available MxP, MxP + or M
It has a chamber 25 such as xP Super e chamber and is a commonly transferred C
Heng et al., US Pat. Nos. 4,842,638 and 5,215,619, and Ma.
It is generally described in US Pat. No. 4,668,338 to ydan et al., the entire text of which is incorporated herein by reference. These chambers can be used in multi-chamber integrated process systems, such as US Patent 4,951, Maydan et al.
No. 601, which is also incorporated herein by reference. The particular embodiment of chamber 25 shown here is suitable for processing a substrate 30, such as a semiconductor wafer. This representative example is presented only to illustrate the invention and should not be used to limit the scope of the invention.

During processing, the chamber 25 is depressurized to a low pressure of less than about 500 mTorr, and the substrate 30 is moved from the load lock transfer chamber (not shown) under reduced pressure to the plasma zone 35 of the chamber 25. The substrate 30 is held on a support 40 optionally having a mechanical or electrostatic chuck 45. A typical electrostatic chuck 45 has an electrostatic member 50, which has a dielectric layer 52 having a surface 53 suitable for receiving a substrate 30. The dielectric layer 52 covers an electrode 55, which may be a single conductor or multiple conductors, the electrode being chargeable and electrostatically holding the substrate 30. After the substrate 30 is mounted on the chuck 45, the electrode voltage supply unit 60
The electrode 55 is electrically biased with respect to the substrate 30, and the substrate 30 is electrostatically held. A base 65 under the electrostatic chuck 45 carries the chuck,
Although optional, the base is also electrically biased by the RF bias voltage. Grooves 54 may be present on the surface 53 and a heat transfer gas such as helium is retained in the grooves to control the temperature of the substrate 30. The heat transfer gas is the gas conduit 66.
Supplied through the conduit, the conduit has one or more outlets 68 from which gas is conveyed to the surface 53 of the chuck 45 and spreads through the one or more electrodes 55 and the insulating layer 52. The heat transfer gas supplier 67 supplies heat transfer gas to the conduit 66 via the gas supply passage.

Process gas is introduced into the chamber 25 via a gas source 70 and a gas supply 69 having one or more gas nozzles 72 terminating within the chamber 25. The gas in the chamber 25 is basically maintained at a low pressure. A plasma is generated in the plasma zone 35 from the gas by applying electromagnetic energy to the process gas.
In order to capacitively generate plasma in the chamber 25, an RF voltage is applied to the electrode 55 (
Acting as a cathode) and electrically grounding the sidewall 75 of the chamber 25 to form another electrode (anode). In another chamber embodiment (not shown),
An RF current may be applied to an induction coil (not shown) adjacent chamber 25 to inductively apply energy into chamber 25 and generate a plasma in plasma zone 35 to impart energy to the process gas. The frequency of the RF current applied to electrode 55 or the induction coil (not shown) is typically about 50 KHz.
To about 60 MHz. Enhancement of the capacitively generated plasma is also possible by electron cyclotron resonance in a magnetically enhanced reactor. A magnetic field is applied by a magnetic field generator 77 such as a permanent magnet or an electromagnetic coil, and this magnetic field increases the density and uniformity of plasma in the plasma zone 35. US Patent 4,842
, 683, the magnetic field preferably includes a rotating magnetic field, the magnetic field axis of which rotates parallel to the plane of the substrate 30.

Effluent 100, which comprises process gases and process byproducts, exits chamber 25 through a release system 80, which can create a low pressure within chamber 25. The discharge system 80 has a discharge pipe 85, which leads to one or more pumps 125, for example roughing and high vacuum pumps, which eliminate the gas in the chamber 25. The discharge pipe is equipped with a throttle valve 82, and the chamber 2
The gas pressure in 5 is controlled. Also, to determine the completion of the etching process,
Optical end point measurements may also be used by measuring the change in the radiation emission intensity of the gas species in the chamber 25 or by measuring the intensity of the radiation reflected from the processed layer on the substrate 30. it can.

During operation of the chamber 25 in a typical process, the substrate 30 is placed on the support 40 in the process chamber 25 and the process gas is introduced into the process zone 35 through the gas supply 69. The process gas includes, for example, CF ₄ , C ₂ F ₆ , C ₃ F ₈ , CHF ₃ , SF ₆ , NF ₃ , CH ₃ F, C ₄ F ₈ , CH ₂ F ₂ , C ₄ F ₆ and these. Halogen-containing gases such as fluorine-containing gases such as equivalents are included. The process gas is energized in the chamber 25 by a gas energy applicator 60, for example, treating the substrate 30 in an electromagnetically energized plasma gas or microwave energized gas. Alternatively, the gas can be energized in a separate chamber (not shown) and introduced into the chamber 25. An exhaust gas flow 100 consisting of the consumed process gas and gaseous by-products is discharged from the process chamber 25 to the discharge pipe 85 during and after the processing. The fluorine-containing gas can also be used in the process chamber cleaning process.

To treat the effluent 100 to reduce hazardous and undesirable gases, such as PFC, from the effluent 100, the effluent 100 is passed through a gas treatment system 200 having a gas energy donation reactor 210. May be. The effluent 100 may be transported via a discharge tube 85 to a gas energy donation reactor 210, such as the plasma reactor illustrated in FIG. The gas energy imparting reactor 210 is a reactor that imparts energy to gas, and includes, for example, a microwave activation reactor, and is not limited to a plasma generation reactor. Energy is supplied to the chamber 215 from the gas energy delivery system 220 so that the effluent 100 within the reactor chamber 215 is energized as it flows from the reactor inlet 211 to the reactor outlet 212. The energized gas produces a plasma within the reactor chamber 215 that produces free radicals from the components of the effluent 100. In the gas energy donation reactor 210, these free radicals combine to produce a detoxified effluent 101 with a reduced hazardous gas content.

In one form, RF energy is inductively or capacitively applied to the gas energy donation reactor 210 by the gas energy donation system 220 such that charged ion species are generated in the reactor chamber 215. Good. In the example of FIG. 2, the gas energy delivery system 220 has a gas energy delivery power supply 222 and an inductive antenna 224 around or adjacent to the reactor chamber 215. The gas energy delivery power supply 222 provides an RF energy coupling system having an RF source and an RF matching network that provides a gas energy delivery RF voltage to the antenna to form an energy delivery gas or plasma in the reactor chamber 215. Can also have In an alternative arrangement, as shown in FIG. 3, a pair of electrodes 226a, b can be placed within the reactor chamber 215 (as shown) or outside the reactor chamber 215 (not shown). The gas energy delivery system 220 in this example includes a gas energy delivery output supply 222 that supplies an RF bias voltage to one electrode 226a and another electrode 226.
b is maintained at another potential, such as ground, to capacitively couple electrodes 226a, b. In yet another configuration, shown in FIG. 4, combined inductive and capacitive energy may be used to donate energy to the emissions 100. A suitable integration of the gas energy delivery reactor 210 and the gas energy delivery system 220 is the atomic fluorine generator ASTRON ™. It is obtained from Massachusetts, Uoven and Applied Science and Technology.

The inductively or capacitively operating gas energy delivery system 220 may be designed to energize the effluent 100 within the reactor chamber 215 sufficiently to reduce hazardous gas content. . In one form, the gas energy delivery power supply 222 includes an RF gas energy delivery device capable of outputting at least 500 watts. The gas energy delivery output supply 222 may be equipped with a variable output device that can be remotely adjusted by an operator or controller from about 500 to about 5000 watts. Induction antenna 224 may include one or more induction coils whose central axis is circularly symmetric with the long axis passing through the center of reactor chamber 215. For example, the inductive antenna 224 can have a longitudinal spiral coil that wraps around the reactor chamber 215 and imposes RF energy on the effluent 100 passing through the reactor chamber 215. The inductive antenna can be extended to a length sufficient to impart energy to the passage length of the exhaust gas 100 passing through the reactor chamber 215, and the exhaust 100 is exhausted in the process of passing through the gas energy imparting reactor 210. Almost all dangerous gas species in the object 100 are reduced.
Optionally, the inductive antenna can be installed inside the reactor chamber 215. In the configuration shown in FIGS. 3 and 4, the electrodes 226a, b are symmetrical and the central axis is coincident with the long axis passing through the center of the reactor chamber 215. In one form, the electrodes 226a, b form parallel flat plates and the distance separating them is sufficiently small that energy is provided to the exhaust gas 100 flowing between the plates 226a, b. In another form, the electrodes 226a, b have opposing semi-cylindrically curved plates that line the wall of the reactor chamber 215. Induction antenna 224
Is used to energize the elongate passage of the exhaust gas 100 through the reactor chamber 215 such that the length of each of the facing electrodes 226a, b is substantially long, so that the hazardous gas species in the exhaust 100 are substantially All reduced.

In another form, the gas energy donation system 220 includes a gas activator 227, which is provided with microwaves, which generate highly dissociated gas to create a gas within the reactor chamber 215. The exhaust gas 100 is chemically activated. In this form, the gas activator 227 is powered by a microwave generator 229, such as "ASTEX", which can be purchased from, for example, Massachusetts, Oven, Applied Science and Technology, as schematically illustrated in FIG. It has a microwave waveguide 228. Generally, microwave generator 2
29 has a microwave tuning member and a magnetron microwave generator capable of generating microwaves at a frequency of 2.54 Ghz. Generally, a magnetron has a high-power microwave oscillator in which the potential energy of the electron cloud near the central cathode is in a series of cavity resonators radially located in the space around the cathode. Is converted into microwave energy. The resonance frequency of the magnetron is determined by the physical dimensions of the cavity of the resonator. The cross section of the waveguide 228 may be rectangular and the internal dimensions are selected so that the transmission of radiation is optimized at frequencies corresponding to the operating frequency of the microwave generator. For example, for a microwave generator operating at 2.45 GHz, the waveguide 228 forms a 5.6 cm x 11.2 cm rectangle. The tuning member may have a short piece of waveguide (not shown) collinear with the waveguide 228 and opposite the reactor chamber 215 from that point of view. A plunger (not shown) may be used to change the axial length of the cavity determined by the tuning member, changing the point where the density of the electromagnetic field is high. The plunger is positioned during start-up, rather than moved during daily operation, to achieve the highest electric field possible within the reactor chamber 215.

The gas energy donation reactor 210 is used to control the emissions 10 in the gas treatment system 200.
The energy over zero is best designed and the emissions are designed to flow through the gas treatment system 200 in a continuous stream of emissions 100. The shape and dimensions of the reactor chamber 215 are such that the effluent 100 is the process chamber 25.
The effluent 100 may be selected to have a continuous, unconstrained flow from the reactor chamber 215 while preventing back diffusion into it. The cross-sectional area of the discharge pipe 85 and the reactor chamber 215 (in the plane perpendicular to the flow of the exhaust 100) is made sufficiently large so that the flow rate of the exhaust gas is equal to or higher than the supply rate of the process gas to the chamber. Good to do. Otherwise, a back pressure of the process gas will occur in the process chamber 25. In one form, the discharge tube 85 and the reactor chamber 215 have a diameter of at least about 5 mm, more preferably at least about 35 mm. The reactor inlet 211 and the reactor outlet 212 of the reactor chamber 215 may be staggered as illustrated in FIGS. 2 and 3 to prolong the residence time of the effluent 100 in the reactor chamber 215. Alternatively, as shown in FIG. 4, the discharge 1 is oriented in a straight line.
Obstruction to the 00 flow may further reduce effluent 100 from flowing back into the reactor chamber 215. In one form, a throttle valve 218 may be installed in or near the reactor chamber 215 to control the flow of effluent 100 into and out of the gas energy donation reactor 210. Placing the throttle valve 218 under control of the controller is optional. In yet another form, a throttle valve or a one-way valve is installed at or near the inlet 211 and the exhaust 1
00 backflow may be prevented.

In one form, the reactor chamber 215 has a central longitudinal axis of the effluent 1
It has a hollow cylinder that is oriented parallel to the 00 channel direction and can be easily adapted to existing process chamber designs. The length of the plasma reactor is sufficiently large so that the effluent stays in the tube for a sufficient amount of time, reducing the content of almost all hazardous gases in the effluent. The exact length of the reactor chamber 215 depends on a combination of factors including the diameter of the discharge tube, the composition and maximum flow rate of the effluent 100 and the power level across the ablated plasma. If the effluent 100 has a total flow rate of about 1000 sccm CF ₄ and O ₂ and the RF gas energy delivery power supply 222 operates at about 1500 watts, a sufficient residence time is at least about 0.01 seconds, and It is preferably about 0.1 seconds. A reactor chamber 215 of suitable length to provide such residence time has a cylinder with a cross-sectional diameter of 35 mm and a length of about 20 cm to 50 cm.

In the embodiment of the gas treatment system 200 shown in FIG. 5, the discharge pipe 85 functions as the reactor chamber 215. The discharge pipe 85 in this example has an enclosed conduit through which the effluent 100 flows in a continuous air stream, the effluent 100 being energized by a gas energy imparting system 220, and a hazardous gas in the effluent 100. The content is reduced. The discharge pipe 85 has an inlet forming a hermetic seal with the outlet of the process chamber 25 and an outlet forming a hermetic seal with the pump 125 or an intermediate member.

In one embodiment, the discharge tube 85 and / or the reactor chamber 215 is vertically installed directly below the process chamber 25. In this example, there is more laminar flow of effluent and less turbulence along the flow path. The laminar flow eliminates turbulence in the exhaust gas stream and reduces the likelihood that the exhaust gas will back diffuse into the process chamber 25. Further, when the effluent becomes laminar, the intensity of the energy-imparting radiation imposed on the region immediately adjacent to the inner surface of the reactor chamber 215 is higher, and the density of the energy-conferring exhaust gas or plasma is higher. Also, the by-products deposited on the inner surface of the reactor chamber 215 accumulate and prevent the ionizing radiation from binding, but since the effluent flows continuously and uniformly through the inner surface of the reactor chamber 215, The need for frequent cleaning of the reactor chamber 215 is eliminated.

In one form, the reactor chamber 215 and / or the discharge tube 85 comprises single crystalline sapphire, which is a single crystalline alumina, which is used in corrosive gas environments, especially compounds containing fluorine. It is highly resistant to chemicals and corrosion, even in exhaust gases with races. Single crystal sapphire has several advantages over polycrystalline materials because it provides a single structure with a chemically homogeneous composition. Usually, the term "single crystal" is a single crystalline material or a material that has several large ceramic crystals oriented in the same crystallographic direction, i.e. the Miller indices in which the crystal faces are parallel to one another. Say a substance with. Since the ceramic crystals in the single crystal sapphire reactor chamber 215 are substantially identical and oriented in a single crystallographic direction, exposed surfaces can be rapidly corroded in corrosive fluorine-containing environments. There are few or no boundary regions between organic impurities and vitreous particles. The continuous, uniform crystal structure provided by single crystalline sapphire reduces corrosion and particulate generation. Further, since the melting point of single crystalline sapphire is high, the reactor chamber 215 is set to 100
It is possible to use at a high temperature above 0 ° C, and even above 2000 ° C.

The gas treatment system 200 of the present invention includes a cooling chamber that at least partially encloses the reactor chamber 215 and forms a ring through which a refrigerant to remove excess heat generated by the abatement plasma is passed. A jacket (not shown) may be included. The material for the cooling jacket is selected to withstand the mechanical and thermal stress of the application. In one form, the coefficient of thermal expansion of the material of the cooling jacket and the material of the reactor chamber 215 are approximated so that the dimensions of the cooling ring are constant. In one form,
The cooling jacket is further provided with a window of material that is transparent to microwave and RF radiation to allow the gas energy delivery system 220 to pass ionizing radiation to the effluent 100 in the reactor chamber 215 through the cooling jacket and refrigerant. Allows imposition. Suitable materials for the cooling jacket include aluminum oxide, quartz, sapphire and single crystal sapphire.

The reactor chamber 215 comprises an inner surface 280 composed of a gas impermeable material that is sufficiently strong to withstand a reduced pressure working pressure of about 5 to about 10 mTorr and a working temperature of about 50 ° C. to about 500 ° C. Have. Further, when using an external antenna, electrode, or microwave device, the inner surface 280 is sufficiently permeable to the energy to be applied that the energy passes through the surface of the gas within the reactor chamber 215. It must be possible to contribute energy to.

In one form, the reactor chamber 215 has an inner surface 280 with a fluorine-containing compound. Inner surface 280 is any surface within reactor chamber 215 that is exposed to gas, and may be, for example, in the form of a wall of reactor chamber 215, or a liner or coating on the wall of reactor chamber 215. It may be in the form of. Inner surface 280 may be the surface of reactor chamber 215 that defines or partially defines the plasma zone within reactor chamber 215, or may be the surface that is within or in contact with the plasma zone. Inner surface 280
May include, in one form, a fluoride such as BeF ₂ , MgF ₂ , CaF ₂ , SrF ₂ , BaF ₂ , RaF ₂ .

The inner surface 280 with the fluorine-containing compound has been found to be highly resistant to corrosion in the reactor chamber 215. For example, when a fluorine-containing hazardous gas, such as PFCs, is introduced into the reactor chamber 215, the fluorine-containing gas decomposes to produce corrosive radicals and CxFy type polymerizable species. The corrosive radicals can cause the inner surface 280 of the reactor chamber 215 to corrode by etching the inner surface 280. The polymerizable species lead to the deposition of polymer on the inner surface 280. Furthermore, fluorine-containing reaction products such as HF and COF ₂ can be corrosive, especially when heated. If oxygen such as O ₂ gas is present in the introduced gas, the oxygen is decomposed and oxygen species that react with the chamber surface and oxidize the surface are generated in the plasma, which may cause corrosion. Fluorine-containing inner surface 2
80 has been found to be significantly more resistant to corrosive environments than conventional interior surface materials such as quartz and aluminum oxide. It is due to the favorable and strong dynamic balance established between polymer deposition and etching. For example, MgF ₂ is about 3.5 to about 16 times more resistant to corrosion than conventional materials. The other fluorine-containing inner surface 280 is up to about 12,000 times more resistant to corrosion than conventional materials. The longer the life of the inner surface 280, the longer the operational life of the reactor chamber 215, and the significant savings in replacement costs of the inner surface 280 and the reactor chamber 215 and associated equipment downtime.

In another form, the inner surface 280 comprises barium or calcium fluoride.
BaF _2, barium or calcium such as CaF ₂ fluoride, in the polymerizable species environment, has been found to result in unexpectedly high corrosion resistance, particularly in the polymerizable species and oxygen environment. It is believed that the high corrosion resistance of BaF ₂ and CaF ₂ is due to polymer formation and passivation. Passivation is believed to depend on the thermal properties of the material. BaF ₂ and CaF _{2 have} the same thermal conductivity, but MgF ₂
(It has lower thermal conductivity than Al ₂ O ₃ ) and has a smaller thermal conductivity. The lower the thermal conductivity,
Passivation polymerization is accelerated.

The high corrosion resistance of BaF ₂ and CaF ₂ has been found by tests on various substances carried out in the reactor chamber 215. A 1 cm ² sample of each substance was placed in the reactor chamber 215 under individual control conditions that energize the hazardous gas containing emissions 100. The etch rate for each material was determined from the weight loss of that material. Samples were exposed to PFC and O ₂ plasma and weighed 1.5 and 2.5 hours after exposure. For accuracy, the experiment was repeated for each substance. Samples were treated at 400 ° C. for 3 hours before exposure to plasma to remove absorbed water. The sample was transferred and stored in a desiccator.

FIG. 6 is a bar graph showing the test results for each substance. The BaF ₂ and CaF ₂ samples had etch rates of 0.0025 and 0.02 mil RF / hr, respectively.
s, which is far superior to the other test substances, and thus proved to be corrosion resistant. BaF ₂ was 60 times and CaF ₂ was 7.5 times more corrosion resistant than any other material, both of which were several orders of magnitude more resistant to corrosion than conventional quartz and aluminum oxide. More unexpectedly, BaF ₂ and CaF ₂ were more than 150 times and more than 20 times and more corrosion resistant than MgF ₂ , respectively.

As shown in FIG. 6, substance 3Y ₂ O ₃ .5Al ₂ O ₃ has demonstrated corrosion resistance that is one order of magnitude greater than conventional substances. 3Y ₂ O ₃ .5Al ₂ O ₃ is a stable solution of yttrium oxide and aluminum oxide. When an oxide such as aluminum oxide or zirconium oxide is mixed with a thermal transfer stabilizer such as another oxide, the mixture has a tightly packed lattice structure forming a diffusion barrier-like passivation layer, It is believed to have better corrosion resistance than pure oxides (eg, aluminum oxide with a purity greater than about 80%). In the test sample, the mixture consisted of 50% Y ₂ O ₃ and 50% Al ₂ O ₃ .

Therefore, in another embodiment of the invention, the inner surface 280 of the reactor chamber 215 comprises a mixture of an oxide and a heat transfer stabilizer. In another form, the inner surface 280 comprises a material that is a mixture of at least two oxides. For example, the inner surface 280 comprises a mixture of materials having at least 20% of two or more oxides. In another form, the inner surface 280 has a material of about 20% to about 80% aluminum oxide or zirconium oxide. In another form, the inner surface 280 comprises a ceramic compound and an oxide of a Group IIIB metal of the Mendeleev periodic table. Periodic table is Gessn
er G. Revised Hawley, “The Condensed Chemical Dictionar” issued by Van Nostrand Reinhold
y ”10th edition, p. 789. In yet another form, the inner surface 280 comprises a stable solution of yttrium oxide or other Group IIIB oxide and aluminum oxide or zirconium oxide.

At least two oxides, an oxide and a heat change stabilizer, or a ceramic and III
It has been found that an inner surface 280 or wall having a material with a Group B oxide has further unexpected benefits. For example, these mixtures provide mechanical strength over pure oxide without significantly changing the dielectric and / or thermal properties of the pure oxide.

When the inner surface 280 or the wall has a ceramic compound and a Group IIIB oxide, the ceramic compound is generally an electrically insulating compound whose crystallinity is amorphous depending on the raw material and its processing. It may be a compound that changes to glassy, microcrystalline or single crystalline. The ceramic compound may be essentially a non-porous material. The ceramic compound may be any ceramic compound suitable for combining with Group IIIB metal oxides to form a highly corrosion resistant structure. The ceramic compound is, for example, silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), boron carbide (B ₄ C), boron nitride (BN), aluminum nitride (AlN), aluminum oxide (Al ₂ O ₃ ), and It may be one or more of these mixtures. Other ceramics can be used instead.

The Group IIIB metal is preferably a metal selected from the group consisting of scandium (Sc), yttrium (Y), cerium subgroup, yttrium subgroup, and mixtures thereof. The cerium subgroup includes lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm).
). Europium (Eu), Gadolinium (Gd) for the yttrium subgroup
, Terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (L
u).

At least two oxides, an oxide and a heat distortion stabilizer, or a ceramic and III
The inner surface 280 or wall having a material having a Group B oxide may be made by any process suitable for making ceramics. In one form, the inner surface is manufactured by the following steps. (1) A powdery ceramic compound, a powdery Group IIIB metal oxide having a suitable additive, and a suitable binder are mixed to produce a powdery raw material mixture. (2) A powdery raw material mixture is prepared. Molding to produce a shaped powdered raw material mixture, (3) heat treating (ie, sintered) the shaped powdered raw material mixture to produce a ceramic crude product, (4) finishing the ceramic crude product to produce a ceramic Manufacture finished products. The powdered raw material mixture will subsequently be shaped, but the proportions of ceramic compound, Group IIIB metal oxide, suitable additives, suitable binders can be any suitable ratio. The powdered raw material mixture contains about 10 ceramic compounds.
% To about 85% by weight, Group IIIB metal oxides from about 3% to about 60% by weight
Suitable additives may be included from about 0.1% to about 6% by weight and suitable binders from about 5% to about 35% by weight. In one form, the powdered raw material mixture comprises about 20% to about 75% by weight ceramic compound, about 5% to about 55% by weight Group IIIB metal oxide, and about 0% by weight suitable additives. To about 5% by weight, suitable binders from about 0% to about 30% by weight. After the powdery raw material mixture is manufactured, it is subsequently molded into a molded powdery raw material mixture. Molding can be accomplished by any suitable process (casting, extrusion, dry pressing, etc.) that compresses the powdered raw material mixture into a porous shape to achieve maximum particle packing and a high degree of homogeneity. . In one form, the shaped powdery raw material mixture is produced by dry pressing, die pressing or uniaxial compression. The shaped powdered raw material mixture may be heat treated in any suitable manner, for example, by sintering to create an interparticle bond that produces the attractive force necessary to hold the loosely bonded shaped powdered raw material mixture together. Good. After heat treating the shaped powdered raw material mixture, a ceramic crude product is produced. The ceramic crude product is subsequently finally shaped by grinding, lapping, polishing or the like.

Referring again to FIG. 2, the gas treatment system 200 may further include an additive gas source 230. The additive gas source 230 may include an additive gas supply 235 and a control valve 240 in a conduit 245 leading from the additive gas supply 235 to the discharge pipe 85. The valve 240 may be operated under the control of the controller 250 described later,
Alternatively, it may be operated manually. In another form of the example shown in FIG. 2, the additive gas source 230 may introduce additive gas directly into the reactor chamber 215, as shown in FIG. 3, and / or, as shown in FIG. Multiple additive gas supplies 235 and valves 240 may be included.

Before, simultaneously with, or after the emission 100 is given energy, the additive gas source 2
30 mixes the additive gas into the effluent 100 to help reduce hazardous gas emissions. The additive gas dissociates when energized or produces energized species which react with energetic hazardous gas species and are non-toxic or soluble and are located downstream of the release system in a wet system. It becomes a gas component that is easily removed by the washer. Even if a small amount of added gas is added to the effluent 100, the reduction effect can be significantly improved. The additive gas conduit 245 may be located sufficiently close to the inlet of the discharge tube 85 so that the additive gas is thoroughly mixed and reacts with the hazardous gas in the effluent 100. The additive gas conduit 245 is located less than about 10 cm from the inlet of the discharge pipe 85,
It is better to orient for better mixing. Further, in the additive gas conduit 245, the additive gas is guided to the discharge pipe 85 so that the additive gas forms a laminar flow in the same direction as the laminar flow of the exhaust 100 and along the inner surface of the discharge pipe 85. There should be an outlet for the injection nozzle. For example, the outlet of the conduit 245 may be oriented at an angle relative to the inner surface of the discharge tube 85 that the additive gas enters the discharge tube 85 in the same direction as the exhaust 100.
A valve 240 (or mass flow controller) in the additive gas conduit 245 allows an operator or automated control system to adjust the volumetric flow rate of the reaction gas to a level high enough to reduce almost all emissions of hazardous gases in the emissions. can do.

In order to increase the efficiency of reducing hazardous gas, the additive gas contains one or more reactive gases. In one form, the reactive gas comprises one or more oxygen-containing gases such as O ₂ , O ₃ . The oxygen-containing gas combines with the effluent 100 within the discharge tube or reactor chamber 215. In the reactor chamber 215, the effluent 100 and the added gas are charged with energy as described above. Decomposition products of dangerous gases such as PFCs are oxidized in plasma and converted into reaction products such as CO ₂ and COF _{2 which} can be released or processed into safe releases. For example, CO ₂ can be released safely and COF ₂ can be released or washed before being released. A scrubber 270 having a scrubbing liquid 275 such as H ₂ O can be equipped in the abatement system 200 to convert the reaction products in the abatement 101 after abatement treatment into releasable substances. The additive gas may be H or OH containing gas such as H ₂ or H ₂ O.
, SiH ₄ etc. may additionally or alternatively be included. Addition of such hydrogen-containing species increases the overall efficiency of PFC destruction, as measured by a chemokinetic model.

It has been found that by properly selecting the volumetric flow rate ratio of the reactive gas to the dangerous gas in the effluent, the dangerous gas reduction efficiency is substantially improved, and the improved amount is more than expected. There is. For example, when using a reactive gas having an oxygen-containing gas, it has been found that the volumetric flow ratio of oxygen atoms in the additive gas to carbon atoms in the effluent 100 is preferably at least about 2.4: 1. Has been done. The flow rate of CF ₄ is 90
A graph of the effect of oxygen to carbon ratio on CF ₄ reduction efficiency at sccm and 165 sccm is shown in FIG. As shown in the graph, an unexpectedly high level of PFC reduction occurs when the oxygen to carbon ratio is at least about 2.4: 1, above which it levels. Similar or similar results have been shown with other PFC gases. The expression "carbon atoms in the effluent" is simply cited for all gases consistently PFC but sulfur "effluent if sulfur-containing gas such as SF ₆ gas is present The term “atom” can be read as “atom”, and when a nitrogen-containing gas such as NF ₃ gas is present, it can be read as “nitrogen atom in effluent”.

Therefore, in one embodiment of the present invention, when the reactive gas having an oxygen-containing gas is introduced into the PFC-containing exhaust 100 by the additive gas source 230, the reactive gas for carbon atoms in the exhaust is changed. The volumetric flow ratio is selected such that the ratio of oxygen atoms is at least about 2.4: 1. In one form, the volumetric flow rate of the oxygen-containing gas may be determined by contrasting the stoichiometric formula of the oxygen-containing gas with the stoichiometric formula or formulas of the PFC gas or gases. 1. The number of carbon atoms in the chemical formula of PFC is divided by the number of oxygen atoms in the chemical formula of oxygen-containing gas, and the result is 2.
The coefficient can be calculated by multiplying by 4. Next, using this coefficient, PFC
The volumetric flow rate of the gas can be multiplied by a factor to determine the minimum volumetric flow rate of the oxygen containing gas. In one embodiment, the reactive gas contains O _2, in determining the volume flow rate of the O _2, the ratio of oxygen atoms to carbon atoms in the effluent of at least about 2.
Multiply the volumetric flow rate of the PFC gas by a factor suitable for being 4: 1. For example, in one of PFC such atoms such as CF _4, volumetric flow rate of O ₂ is at least about 1.2 times the volumetric flow rate of CF _4. For PFCs with 2 carbon atoms, such as C ₂ F ₆ , the O ₂ volume flow rate is at least about 2.4: 1. In another form, the reactive gas in the additive gas contains ozone O ₃ . Since ozone has 3 oxygen atoms, the minimum volumetric flow ratio of ozone to carbon atoms in the effluent is 0.8: 1. Therefore, C
In the case of F ₄ , in determining the flow rate of ozone, the coefficient by which the volumetric flow rate of CF ₄ gas in the emission is multiplied is 0.8 times the number of carbon atoms in PFC gas. In the case of having no PFC such carbon atoms, such as SF _6, NF ₃ is oxygen to sulfur ratio or oxygen-nitrogen ratio of each of at least about 2.4: should be 1.

Representative coefficients for determining the desired minimum flow rates of reactive gases for certain PFCs are shown in Table 1 below. To utilize this table in accordance with aspects of the invention, P
The FC gas volumetric flow rate is multiplied by the corresponding factor in the table to determine the minimum reactive gas volumetric flow rate. For example, if the effluent 100 contains 100 sccm of C ₂ F ₆ , at least about (2.4) (100) or 240 sccm of the O ₂ -containing reactive gas is introduced by the additive gas source 230.

[0049]

[Table 1] In the case where the exhaust gas 100 contains a plurality of types of PFC gas, the minimum flow velocity of the reactive gas is determined by summing the minimum flow velocity of the reactive gas obtained for each component of the PFC gas. For example, 45sccmCF ₄ / 45sccmCHF ₃ / 45s
The flow rate of the O ₂ containing reactive gas that can be introduced into the effluent with ccm C ₂ F ₆ is a minimum of about (1.2) (45) + (1.2) (45) + (2.4) (45). ), Or about 216 sccm. Table 2 shows typical minimum flow rates of the O ₂ -containing reactive gas corresponding to various compositions of PFCs in the effluent 100.

[0050]

[Table 2] The amount of reactive gas in the additive gas introduced into the effluent 100 may be controlled by the controller 250. In one form of the invention, the hazardous gas content of the effluent 100 and the volumetric flow rate (or equivalent mass flow rate) of the hazardous gas in the effluent 100 are tested for a particular process running in the process chamber 25. To make a decision. Next, the additive gas source 230 is controlled by the controller 250 so that the reactive gas-containing additive gas is introduced at the volume flow rate (or equivalent mass flow rate) selected as described above based on the experimentally determined gas flow rate. Control.

The input device 255 associated with the controller 250 allows an operator to enter data into the controller 250 to control the operation or change the software of the controller 250. For example, as shown in FIG. 2, the interface between the operator and the computer system is a CRT monitor 256 and light pen 257. The light pen 257 is an optical sensor at the tip of the pen 257 and is used for the CRT monitor 25.
The light emitted by 6 is detected. To select a particular screen or function, the operator touches a designated area on the CRT monitor 256 and presses a button on the light pen 257. The touched area changes color or a new menu or screen appears to authorize communication between the light pen and the CRT monitor 256. Other devices, such as a keyboard or mouse, or instructional information devices may also be used to communicate with the controller 250. The operator may use the input device 255 to enter a value associated with a desired gas flow rate of the reactive gas, or a value associated with a particular process in the process chamber 25. The controller 250 then executes the pre-programmed process code and the desired amount of reactive gas is automatically introduced. This will be discussed below.

In another embodiment, the gas analysis probe 277 can be installed in the discharge pipe 85 between the process chamber and the gas energy imparting reactor 210 to automatically control the introduction of the additional gas. As illustrated in FIG. 3, the gas analysis probe 277 is a gas analyzer 27.
8 and the analyzer provides the gas analysis data to the controller 250. Gas analyzer 278 may include any commercially available gas analyzer, such as R available from Stanford Research Systems, Sunnyvale, Calif.
There is a GA300 system, which can detect the volume flow rate or mass flow rate of a particular gas in a gas mixture. The controller 250 monitors the gas flow rate of the PFC's in the effluent 100 and automatically determines the desired volume (or equivalent mass) gas flow rate of the reactive gas in the additive gas, which is programmed according to the program code. 100
Guide inside. For example, the gas analyzer 278 has 100 sccm for the effluent 100.
Of the CF ₄ is included, the controller 250 automatically activates to introduce at least about 120 sccm of O ₂ into the effluent 100. When the gas analyzer detects a mixture of PFC gases, the controller 250 is operated as described above.
Calculates the desired flow rate of the reactive gas in the additive gas.

The additive gas may additionally or alternatively include one or more inert or non-reactive gases. For example, it is an inert gas such as Ar, Ne, He or Xe, or a non-reactive gas such as a hydrogen-containing gas or a hydrogen oxygen-containing gas or a carrier gas. By “non-reactive” gas is meant one or more gases that are less reactive with the effluent 100 than the reactive gas, including inert and non-inert gases. The non-reactive gas may help convey the reactive gas to the reactor chamber 215 and / or help stimulate and maintain the plasma in the reactor chamber 215, or the reactor chamber. It may assist in exciting and stabilizing the activated gas species in 215.

When the volume flow rate of the inert or non-reactive gas is high, the gas energy imparting reactor 21
It has further been found that the effects of reducing hazardous gases at zero, eg PFC reduction, are reduced. The reason for this is believed to be that excess inert or non-reactive gas deprives the energized gas of its ability and thus prevents the reactive gas from maximizing the reduction of hazardous gases. Thus, in one embodiment, the volumetric flow ratio of inert or non-reactive gas to reactive gas in the additive gas is less than 3: 1. In another form, the volumetric flow ratio of inert or non-reactive gas to reactive gas is less than about 2: 1. A range of volumetric flow ratios of inert or non-reactive gas to reactive gas suitable to adequately reduce hazardous gases is from about 1: 1 to about 2.9: 1, more preferably about 1.5. It has been found to be from 1: 1 to about 2: 1.

In one particular embodiment, an additive gas having an inert gas such as Ar and a reactive gas such as an oxygen containing gas is introduced into the effluent 100 having one or more PFC gases.
In this example, the volumetric flow rate of the reactive gas is selected such that the ratio of oxygen atoms in the reactive gas to carbon atoms in the PFC gas is at least 2.4: 1. Also,
The volumetric flow rate of the inert gas is selected such that the volumetric flow rate ratio of the inert gas to the reactive gas is about 1.5: 1 to about 2: 1, and more preferably about 1.8. Figure 8 shows the reduction efficiency when using this embodiment to reduce processing Four different exhaust gas 100 having the PFC mixture: 45sccmC ₂ F ₆ / 45sccmC
_{F 4; 80sccmC 2 F 6 /} 90sccmCF 4; 85sccmCHF 3/165
sccmCF ₄ ; and 45sccm CHF ₃ / 45sccm C ₂ F ₆ / 45sccm
CF ₄ . In all cases, PFC gas no CF ₄ it will be reduced 99.9%, CF ₄
Gas has been reduced by at least 96%.

These results indicate that there was a significant improvement over the prior art in reducing hazardous gases such as PFCs. FIG. 9 shows the CF ₄ reduction effect of the present processes (2) and (4) and the conventional process (1) in which the volume flow ratio of Ar to O ₂ is at least 3: 1 using an additive gas of Ar and O _2. ) And (3) are compared with the CF ₄ reduction effect. In the case of effluent 100 with CF _4, CF ₄ reduction effect for the case of effluent having a C ₂ F ₆ and CF ₄ is increased to about 4% or more by using the present process. Therefore, this process ensures 95% for all PFCs.
% Reduction is achieved, and 99% reduction is definitely achieved with CF ₄ -free PFC gas.

Stimulating and stabilizing the plasma or activating gas in the gas energy donation reactor 210 when the volumetric flow ratio of inert or non-reactive gas to reactive gas is less than 3: 1. It has been found that can be difficult, and can be more difficult if the ratio is less than about 2: 1. To counter this difficulty, we have discovered a multi-step process that reduces the volumetric flow ratio of inert or non-reactive gas to reactive gas while providing sufficient stimulation of the exhaust and additive gas plasmas. And stabilization is possible. In one embodiment of the multi-step process, FIG.
As shown in the flow chart of (1), an inert gas such as Ar is first introduced into the reactor chamber 215 at a high flow rate (300). The high flow rate of inert gas is energized by the gas energy delivery system 220 to stimulate the plasma (310). Once the plasma is sufficiently retained, the desired flow rate of reactive gas is introduced (
320), the effluent 100 is introduced (330), and the flow rate of the inert gas is then reduced (340) to a value where the volumetric flow rate ratio of the inert or non-reactive gas to the reactive gas is the desired ratio. Steps 320, 330, 340 can occur simultaneously or in any order. In one form, the reactive gas in step 320 is
The ratio of oxygen atoms in the reactive gas to carbon atoms in the effluent is at least 2.4:
It is introduced by the method that becomes 1. In another example of a multi-step process, FIG.
As shown in, the intermediate step (315) of introducing a relatively low flow rate of the reactive gas.
Take It has then been found that the plasma can be effectively and reliably held and stabilized throughout the hazardous gas reduction process. In one form, the flow rate of the reactive gas during the intermediate stage is about 10% to about 80% of the flow rate of the reactive gas during stage 320, more preferably about 20% to about 50%. Furthermore, this plasma stimulation method
It has been shown to be advantageous in situations where no reactive gas is added. Some hazardous gases, such as CHF ₃ , can be efficiently reduced by simply providing energy to the emissions. In another form, treating the effluent by energizing it and then passing the energized gas over a catalyst bed or the energized gas over a consumable liner. You can

The following are merely illustrative of processes for reducing PFC content in effluent 100 and are not intended to limit the invention. 45sc using this typical process
cmCHF ₃ / 45sccmCF ₄ / 45sccmC emissions 100 can be reduction processing having ₂ F _6. In step 300, the additive gas containing Ar gas is supplied from the additive gas source 230 at a volume flow rate (or equivalent mass flow rate) of about 600 sccm.
Is introduced at about 900 sccm to stimulate the plasma in the reactor chamber 215 (310). In step 315, the flow rate is about 50 sccm to about 70 sccm.
In at least about 1 second, more preferably from about 5 seconds to about 10 seconds, introducing O ₂ into the reactor chamber 215. Then, the flow rate of O ₂ was increased to about 220 sccm (32
0), introduce effluent 100 (330) and reduce Ar flow rate to about 400 seem (340). Thus, the O: C ratio is at least 2.4: 1 and the volumetric flow ratio of Ar to O ₂ is about 1.8.

The gas composition and flow rate of the additive gas introduced into the effluent 100 by the additive gas source may be controlled by the controller 250. To simplify the description of the invention, the controller 250 is shown as a single representative controller, but the controller 250 may be multiple controllers that are interconnected, It should be appreciated that there may be multiple controllers connected to the chamber 25 and / or another component of the abatement processing system 200.

In one embodiment, the controller 250 includes electronic hardware having electrical circuits, such as integrated circuits, suitable for operating the additive gas source 230. In another form,
Controller 250 is also suitable for operating chamber 25 and its surrounding components. The controller 250 is generally adapted to accept data inputs, develop algorithms, and produce useful output signals, and also detect data signals from detectors and other chamber components to determine process conditions in the chamber 25. It is also used to monitor or control the. For example, the controller 250 includes (1) a central processing unit (C
A computer having a PU) and coupled to a storage system having peripheral control components, (2) an application specific integrated circuit (ASI) for operating specific components of the chamber 25.
C), (3) one or more controller interface boards with suitable support circuitry. A typical central CPU is PowerPC (trademark),
An arithmetic device such as Pentium (trademark) can be used. The ASIC is designed and pre-programmed for specific tasks, such as retrieving data and information from the chamber and manipulating specific chamber components. Typical support circuits include coprocessors, clock circuits, caches, power supplies, as well as well-known components that exchange information with the CPU. For example, CPUs often use random access memory (
RAM), read only memory (ROM), and other storage devices known in the art. RAM can be used to store the execution by the software of the present invention during the execution of the process. The program and subroutine of the present invention are typically stored in a mass storage device, and when executed by the CPU,
Called to be temporarily stored in RAM.

The software execution and computer program code products of the present invention are preferably stored in a storage device, such as a floppy disk or hard drive, and called into RAM during execution by the controller 250. The computer program code is
It may be written in a conventional computer readable programming language such as assembler language, C, C ⁺⁺ , or Pascal. Using a conventional text editor, the appropriate program code is entered into a single file or multiple files and stored or recorded in a computer usable medium, such as the memory of a computer system. If the input code text is written in a high level language, compile the code into compiler code and link it with the target code of a precompiled Windows library routine. To execute the linked and compiled object code, the system user calls the object code to cause the computer system to retrieve the code in memory and perform the tasks specified by the computer program.

As shown in FIG. 11, controller 250 may control the operation of gas treatment system 200, including controlling additive gas source 230, gas energy donation reactor 210, and gas energy donation system 220. The controller 250 controls the device group according to one or more sets of computer instructions that dictate the timing, composition and flow rate of the added gas, pressure and temperature of the reactor chamber, power levels of the gas energy delivery system 220 and other process parameters. The operation of may be controlled.

As shown in FIG. 12, one form of computer program code allows for multiple sets of program code instructions, for example, an operator to register and select a process recipe, and to manipulate the process recipe. Reactor chamber 2
Program code 400 of process selector and sequencer executed in 15
, And gas processing program code 410 and the like for manipulating and managing the priorities of chamber components within the reactor chamber 215. Although these program codes are illustrated as separate program codes that perform a set of tasks, they can be integrated, or the tasks of one program code can be integrated with the tasks of another program code. It should be appreciated that it can be customized to provide the desired set of tasks. Therefore, the controller 250 and the program code described herein should not be limited to the particular embodiments of the program code described herein or contained as illustrated, and perform equivalent functions. Other sets of program code and computer instructions are within the scope of the invention.

In operation, the user registers the selected process in the program code 400 for the process selector via the input device 255. This process
It may include: (1) a manual process, i.e. manually registering a particular additive gas, additive gas volume flow rate and its timing in the controller 250, for example using an input device, (2) an automatic process, That is, the values related to a specific process in the process chamber 25, such as an etching process, a CVD process, or any other substrate processing process or chamber cleaning process, are registered, the timing of the added gas,
Performing automated or programmed operations on the gas treatment system 200, such as composition, volumetric flow rate, or (3) monitoring process, that is, the composition and volumetric flow rate of the effluent 100 is analyzed by the gas analyzer 278 and the gas analysis probe. A controller 250 to control the operation of the gas treatment system 200 in relation to the sensed data as sensed by 277.
To order.

FIG. 13 shows a flowchart of one form of code instructions that may be executed in the third situation. First, an inert gas is introduced into the reactor chamber 215 at a high flow rate to impinge on the plasma (500). Detecting PFC gas in the effluent 100 by the controller 250 and the gas analyzer 278 before, after or during the step 500,
The volume or mass flow rate of the PFC gas is sensed (510). The controller 250 uses the sensing information from step 510 to multiply the PFC flow rate by the coefficient of Table 1 to calculate the desired flow rate of the reactive gas such as O ₂ (520), and the desired flow rate of the reactive gas. Is multiplied by a value less than 3, a value less than 2, or about 1.8 to calculate the desired flow rate of the inert gas (530). Once the plasma is maintained, a reactive gas, such as O ₂ , is introduced (540) at a volumetric flow rate determined by multiplying the desired flow rate of the reactive gas by a value of about 0.25 to about 0.33. After this, introduce the reactive gas at the desired flow rate (
550), introducing the effluent 100 into the reactor chamber 215 and reducing the flow rate of the inert gas to the desired level calculated in step 530. Steps 550 and 560
, 570 may be performed simultaneously or in any order.

The program code 400 for the process selector is a special process set.
By passing the parameters to program code 410 for gas treatment, which code controls a number of processing tasks in gas treatment system 200, which control is in accordance with the process set determined by program code 400 for the process selector. To execute. The gas treatment program code 410 controls the execution of various gas treatment program code instruction sets that control the operation of the gas treatment components. In operation, the gas treatment program code 410 selectively calls the gas treatment component instruction set according to the particular process set currently being executed, schedules the chamber component instruction set, Instructions for chamber components that monitor the operation of various chamber components, determine which components need to be operated based on the process parameters for the process set to be performed, and the monitoring and decision steps. Run the book set. The gas energy applier program code 420 includes, for example, a program code instruction set that adjusts the level of power and bias power applied to the operation of the reactor chamber 215. The additive gas program code 430 includes a program code instruction set that controls the gas composition and flow levels through the chamber 25 by adjusting the opening of one or more gas valves 240 in the gas source 230. FIG. 12 is merely an example of the structure of the program code.

In another form, the controller 250 controls the effluent 100 from the gas treatment system 200.
It may be adapted to ensure that the reduction of hazardous gases therein is sufficient and / or to monitor the operation of the system. In this example, gas treatment system 200 includes a control and monitoring system that includes controller 250 or another controller. As shown in FIG. 11, the gas analysis probe 470 is positioned in the air stream of the emission gas subjected to the reduction treatment, preferably downstream of the gas energy imparting reactor 210, and the gas content of the emission substance 101 subjected to the reduction treatment is reduced. May be analyzed.
The gas analysis probe 470 exchanges information with the gas analyzer 475. The gas analyzer 475 is
It may be of the type described above and provides gas analysis data to controller 250. A pressure monitor and a temperature monitor may be provided to provide the controller 250 with data regarding the pressure and temperature conditions of the gas treatment system 200. The controller 250 may control and regulate the operation of the gas treatment system 200 and optionally the process chamber 25 according to the monitor data. This is disclosed in U.S. patent application Ser. No. 09 / 363,302, filed July 28, 1999, and U.S. patent application Ser. No. 09 / 363,250, filed July 28, 1999, both of which Both are quoted and incorporated here.

In operation, the gas analyzer 475 continuously monitors the hazardous gas content in the reduced emission 101 emitted from the gas treatment system 200 and provides a continuous output signal or reduced emission. A safety level output signal may be provided that triggers when the hazardous gas content in the effluent 101 exceeds the safety level. Controller 2
50 has a computer readable medium having a computer readable program code recorded thereon for monitoring the output signal from the analyzer,
Perform at least one of the following steps: (1) Gas energy imparting reactor 2
10 power or other parameter adjustment, (2) additive gas amount or composition adjustment, (3
) Adjustment of process conditions of the process chamber 25, (4) process chamber 2
5 process gasses, (5) gassing the effluent stream from the process chamber 25 by opening a switching valve (not shown) and closing a reduction process valve (not shown) by means of a valve control system. Switching from system 200, and (6) notifying the operator through a monitor or a separate alarm device that the hazardous gas in the emissions is at a highly dangerous level or that the gas treatment system 200 is in a poor operating condition. Providing an alarm signal. Step (5) has the advantage of allowing the gas processing system 200 to be changed on a regular basis or during a malfunction without pausing processing of the substrate in the process chamber 25.

In this regard, the reduced treatment emissions 101 measured by the gas analyzer 475 by including the gas analyzer program code in the gas treatment program code 410.
The composition or concentration of the dangerous gas therein may be monitored, and an output signal of the content and composition of the dangerous gas (or a safety level output signal) is received from the gas analysis probe 470. The gas analyzer program code stores the output signal in an exhaust gas composition table which is periodically inspected by another program code instruction set. Alternatively or in combination with the memory function, the program code for the gas analyzer may output a safety level output signal to another program code instruction if the content of hazardous gas in the exhaust gas exceeds a predefined operational safety level. Pass to the set. The gas analyzer program code may be incorporated into the gas analyzer 475 instead of residing in the controller 250.

The gas treatment program code 410 may further include safe operation program code. The safe operating program code operates in conjunction with another set of program code instructions to regulate the operation of process chamber components or gas treatment equipment in relation to the level of hazardous gases in the reduced treated exhaust air stream 101. To reduce or eliminate the emission of dangerous gases. For example, if the program code for safe operation is programmed and a dangerous gas of a predetermined concentration is detected in the emitted emission, or it is detected that a toxic dangerous gas is present in the emission even at a small level. In some cases, the operation of the process chamber 25 can be stopped. Typically, when toxic gases are used to process the substrate, several safety stop valves are conventionally provided in each gas supply line of gas distributor 72. When the dangerous gas concentration in the reduction-processed emission 101 reaches a predetermined level, the safe operation program code adds a safety stop valve to the process gas control instruction set of the gas processing program code 410. A start signal is issued to close. Alternatively, as noted above, the safe operating program code can divert the effluent stream to an ejector or other abatement system. Conversely, if the safe operating program code receives a low or zero emission level signal from the output of the gas analyzer 475, the program code directs the operation of the process chamber 25 to the gas processing program code 410. It issues a control signal to continue in the current operation mode and to the gas treatment system 200 to continue operation in the current operation mode.

In operation, the safe operation program code repeatedly reads the composition of the latest reduction-treated exhaust gas in the exhaust gas composition table, and the reading and the process chamber 25
To the signal from the mass flow controller that controls the flow of process gas into the exhaust gas, and to adjust the flow rate of the process gas required to reduce or almost completely eliminate the hazardous gas emissions into the emissions. Send an order to. Alternatively, the safe operating program code performs these operations upon receipt of a safe level output signal. Typically, the program code is set to operate when the hazardous gas concentration in the effluent exceeds a pre-defined value, such as about 0.1% to about 10%.

In another embodiment, the safe operating program code operates an alarm or an indicator such as an LED to indicate a dangerous level of toxic or dangerous gas flow in the exhaust gas stream, or A metering display, such as a real-time image of a graphic that displays the emission level in real time, can be provided for operator monitoring. This safety mechanism allows the operator to monitor and prevent accidental release of hazardous gases into the atmosphere. This same signal can be used to keep the processing device in a non-operational mode, or to activate a safety stop valve if an unsafe process condition is detected. In this way, the safe operation program code operates the process chamber and the gas treatment device to provide an environmentally safe device.

During operation of the gas processing system 200 in a typical processing process, a substrate 30, such as a semiconductor wafer, is placed on a support 40 in the process chamber 25, and CF ₄ , C ₂ F ₆ , C ₃ F ₈ , CHF ₃ , SF ₆ , NF ₃ , CH ₃ F, etc., a process gas having a fluorine-containing gas is introduced into the processing zone 35 through the process gas distributor 72. The process gas is energized by the gas energy applicator 60 of the chamber 25, and the substrate 30 is processed in the RF or electromagnetic plasma gas or in the gas energized by the microwave. Alternatively, the gas is energized in a separate chamber. During and after the process, the exhaust gas stream of used process gas and gaseous by-products are discharged from the process chamber 25 through the discharge pipe 85 of the discharge system 80 and the gas treatment device 200.

In the gas treatment system 200, an additive gas having a reactive gas and optionally an inert or non-reactive gas is introduced into the effluent 100. Then, as described above, in the reactor chamber 215, the RF energy or the microwave energy is given to the exhaust 100 and the additive gas flowing from the emission pipe 85, plasma for reduction treatment is generated, and the exhaust 100 is contained in the plasma. As a result of decomposition or mutual reaction of the hazardous gas components of
The content of dangerous gas in the effluent 100 is sufficiently reduced. The radiation raises the electron energy of some of the atoms in the exhaust gas molecule to an energy of 1 to 10 eV, which releases the electrons and breaks the bonds of the gas molecules, producing dissociated atomic gas species. To do. In the energy-imparted plasma gas, individual charged species electrons and charged nuclei are excited by a strong electromagnetic field and collide with other gas molecules to cause avalanche breakdown in the gas flow, further dissociating and ionizing the exhaust gas 100. Cause. The ionized or dissociated gas species of the energy donating effluent react with each other or with other non-dissociated gas species to form a non-toxic gas or a gas that is highly soluble in conventional gas purifiers. For example, the PFC containing effluent may be mixed with an oxygen containing gas such as O ₂ gas and passed through the reactor chamber 215. Gas 101 in gas energy donation reactor 210
Has been measured to have reduced over 100% of PFC gas from emissions 100.

Thus, in a well-controlled and consistent manner, the gas treater 200 and the gas treatment process allow the hazardous gas content in the effluent 100 to be at least about 95%.
Succeed in reducing%. The gas treatment system 200 may be a self-contained integrated unit compatible with various process chambers 25. Gas treatment system 2
The use of 00 can reduce a wide range of hazardous gases with almost all types of PFCs. The gas processing system 200 includes a process chamber 25.
It may be used with all process chambers that emit hazardous gases without any effect on the operation of. The catalytic abatement system is convenient to handle and has less than 3 cubic feet of space to process emissions from one process chamber and less than 40 cubic feet to process emissions from multiple process chambers. Occupy only.

Although the present invention has been described in considerable detail with its preferred form, other forms are possible. For example, the additive gas source 230 and the gas energy imparting system 220 shown in FIGS. 2-5 are interchangeable. Also, the apparatus of the present invention can be used in other chambers and for other processes such as physical vapor deposition or chemical vapor deposition. Therefore, the scope of the appended claims should not be limited to the preferred versions described herein.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional side view of an exemplary substrate processing apparatus for processing a substrate and producing a hazardous gas-containing effluent, showing a gas treatment system at venting.

FIG. 2 is a schematic diagram of one embodiment of a gas treatment system including a gas energy donation reactor.

FIG. 3 is a schematic diagram of another embodiment of a gas treatment system including a gas energy donation reactor.

FIG. 4 is a schematic diagram of another embodiment of a gas treatment system including a gas energy donation reactor.

FIG. 5 is a schematic diagram of another embodiment of a gas treatment system including a gas energy donation reactor.

FIG. 6 is a graph showing etch rates of different material groups in a gas energy donation reactor.

FIG. 7 is a graph showing a dangerous gas reduction efficiency when a reactive gas in which the ratio of oxygen atoms to carbon atoms is changed is used, corresponding to one example of the dangerous gas reduction process.

FIG. 8 is a bar graph showing the hazardous gas reduction efficiency for hazardous gas mixture-containing emissions using one embodiment of the hazardous gas reduction process.

FIG. 9 is a bar graph showing a comparison of reduction efficiency of hazardous gas-containing emissions in the case of using the conventional method and the case of using one embodiment of the process of reducing hazardous gas.

10A and 10B are flow charts illustrating different embodiments of the hazardous gas reduction process.

FIG. 11 is a schematic diagram of another embodiment of a gas treatment system including a gas energy donation reactor and a controller.

FIG. 12 is a block diagram illustrating a computer program product for operating a controller according to an embodiment of the present invention.

FIG. 13 is a flow chart illustrating an example of a process for treating hazardous gas-containing emissions.

[Explanation of symbols]

20 ... Substrate processing device, 25 ... Chamber, 30 ... Substrate, 35 ... Plasma zone, 40 ... Support, 45 ... Chuck, 50 ... Electrostatic member, 52 ... Dielectric layer,
53 ... Surface, 54 ... Groove, 55 ... Electrode, 65 ... Base, 66 ... Gas conduit, 68 ... Exit, 69 ... Gas supplier, 72 ... Gas nozzle, 75 ... Side wall, 80 ... Emission system, 8
2 ... Throttle valve, 85 ... Emission pipe, 100 ... Emission, 101 ... Reduced emission, 200 ... Gas treatment system, 210 ... Gas energy imparting reactor, 211 ... Reactor inlet, 212 ... Reactor outlet, 215 ... Chamber 218 ... Throttle valve, 220 ... Gas energy imparting system, 224 ... Induction antenna, 226 ... Electrode, 227 ... Gas activator, 228 ... Microwave waveguide, 230 ... Additive gas source,
235 ... Additive gas supplier, 240 ... Control valve, 245 ... Conduit, 255 ... Input device, 256 ... Monitor, 257 ... Light pen, 270 ... Washer, 275 ... Washing liquid, 277 ... Gas analysis probe, 278 ... Gas Analyzer, 280 ... Inner surface, 470 ... Gas analysis probe, 475 ... Gas analyzer.

─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ramas Whammy, Curtic             United States of America, California,             Santa Clara, Number 322, Se             Nt. Ignatius Place 3282 (72) Inventor Corsal, Tony, S.             United States of America, California,             Cupertino, Prune Tree Leh             10416 (72) Inventor Wong, Quark, Manas             United States of America, California,             San Jose, Larkin Avenue             1636 (72) Inventor Chamois Irian, Chamois             United States of America, California,             San Jose, Little Falls Dora             Eve 6536 F-term (reference) 4D002 AA22 AC10 BA05 BA07 DA70                       GA01 GA02 GB01 GB02 GB08                 4G075 AA03 AA37 AA53 BA06 CA25                       CA43 CA51 DA02 EB01 EB42                       EC21 ED01 FB01 FC09 FC15

Claims (19)

[Claims] 1. A step of (a) introducing exhaust gas into a reactor, and (b) adding an additive gas having at least one oxygen-containing gas to oxygen atoms in the additive gas and carbon atoms in the perfluorinated compound. Selecting the volume flow rate of the oxygen-containing gas so that the ratio is at least about 2.4: 1, and introducing it into the reactor, and (c) applying energy to the exhaust gas and the added gas in the reactor. And a step of reducing the content of the perfluorinated compound in the exhaust gas. 2. The method of claim 1, wherein the oxygen containing gas comprises O ₂ . 3. The method of claim 1, wherein the additive gas further comprises an inert or non-reactive gas. 4. The method of claim 3, wherein the volumetric flow rate of the inert or non-reactive gas to the oxygen-containing gas is less than 3. 5. The method of claim 4, wherein the volumetric flow rate of the inert or non-reactive gas to the oxygen-containing gas is from about 1.5 to about 2. 6. The method according to claim 1, wherein a condition of the exhaust gas is detected and the volume flow rate of the additive gas is adjusted in relation to the detected condition. 7. A step of: (a) introducing exhaust gas into the reactor; (b) adding gas having at least one oxygen-containing gas, the ratio of oxygen atoms in the additive gas to sulfur atoms in the perfluorinated compound. Selecting a volumetric flow rate of the oxygen-containing gas such that is at least about 2.4: 1, and introducing into the reactor, and (c) imparting energy to the exhaust gas and the added gas in the reactor. And a method for treating exhaust gas containing a perfluorinated compound. 8. The method of claim 7, wherein the oxygen containing gas comprises O ₂ . 9. A step of (a) introducing exhaust gas into the reactor, (b) adding gas having at least one oxygen-containing gas, the ratio of oxygen atoms in the additive gas to nitrogen atoms in the perfluorinated compound. Selecting a volumetric flow rate of the oxygen-containing gas such that is at least about 2.4: 1, and introducing into the reactor, and (c) imparting energy to the exhaust gas and the added gas in the reactor. A method for treating a chamber exhaust gas having a perfluorinated compound having: 10. The method of claim 9, wherein the oxygen containing gas comprises O ₂ . 11. A step of (a) introducing an additive gas having an inert or non-reactive gas into the reactor at a first volume flow rate, and (b) setting a volume flow rate of the inert or non-reactive gas to a second flow rate. Changing the volumetric flow rate, (c) introducing exhaust gas into the reactor, and (d) applying energy to the gas group in the reactor, and applying energy to the exhaust gas from the chamber. . 12. (a) introducing an additive gas having a reactive gas into the reactor at a first volume flow rate, (b) changing the volume flow rate of the reactive gas to a second volume flow rate, c) introducing exhaust gas into the reactor, and (d) applying energy to the gas group in the reactor, and applying energy to the exhaust gas from the chamber. 13. A gas energy imparting device comprising: a reactor having an inner surface having a fluorine-containing compound and adapted for gas reception; and a gas energy imparting device for imparting energy to a gas in the reactor. 14. The device of claim 13, wherein the fluorine-containing compound comprises a fluorinated compound. 15. The apparatus of claim 13, wherein the gas energy applier is adapted to provide RF energy to the gas in the reactor. 16. A gas treatment device capable of treating exhaust gas from a process chamber, the reactor having an inner surface having BaF ₂ or CaF ₂ and adapted to receive exhaust gas,
And a gas energy applicator for applying energy to the gas in the reactor and processing the exhaust gas. 17. A reactor having an interior surface having a material having an oxide and a stabilizer and adapted to receive gas, and a gas energy applicator adapted to apply energy to the gas in the reactor.
Gas energy imparting apparatus having a. 18. The device of claim 17, wherein the material comprises about 20% to about 80% aluminum oxide. 19. The device of claim 17, wherein the stabilizer comprises a Group IIIB oxide.