JP4037751B2 - Exhaust gas dry detoxification apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry-type abatement apparatus for treating exhaust gas containing an organometallic compound and ozone discharged from a treatment apparatus, and in particular, it is suitable for installation in an exhaust system of a semiconductor processing system. Relates to the device. Here, the semiconductor processing means that a semiconductor device, an insulating layer, a conductive layer, etc. are formed in a predetermined pattern on a substrate to be processed such as a semiconductor wafer or an LCD substrate. The various processes performed in order to manufacture the structure containing the wiring connected to a semiconductor device, an electrode, etc. are meant.
[0002]
[Prior art]
As a film forming process for forming a silicon oxide film on a semiconductor wafer, a first gas containing TEOS (tetraethylorthosilicate: (OC ₂ H ₅ ) ₄ Si) and a second gas containing ozone (O ₃ ) are used. Thermal CVD (Chemical Vapor Deposition) using gas is known. In order to obtain a practical silicon oxide film only by the reaction between TEOS and O ₂ , a temperature of 600 to 650 ° C. is necessary. However, by containing several percent of O _{3 in} O ₂ , the temperature is 400 ° C. or less. It becomes possible to form a film with this. This film forming process also has an advantage of excellent step coverage.
[0003]
Conventionally, metal oxides such as copper oxide and manganese oxide have been used as adsorbents in order to treat exhaust gas containing organometallic compounds and ozone discharged by this type of film formation treatment by a dry detoxification method. . However, the adsorption capacity of this type of adsorbent for organometallic compounds is not very high. Further, when the organometallic compound is excessively adsorbed on the adsorbent, the temperature of the adsorbent rises rapidly. Furthermore, there is a risk that the adsorbed organometallic compound and ozone react violently and lead to ignition.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the problems of the prior art. In the dry detoxification apparatus or method for treating exhaust gas containing an organometallic compound and ozone discharged from a treatment apparatus, detoxification is performed. The aim is to improve both processing capacity and safety.
[0005]
[Means for Solving the Problems]
A first aspect of the present invention is a dry abatement apparatus for treating exhaust gas containing an organometallic compound and ozone discharged from a treatment apparatus,
A first hermetic chamber through which the exhaust gas from the processing device passes;
In order to decompose ozone in the exhaust gas, a heater for heating the exhaust gas in the first hermetic chamber, wherein the exhaust gas is heated at a first temperature of 80 to 300 ° C. for a time of 1 second to 30 minutes. And
A second hermetic chamber through which the exhaust gas after being treated in the first hermetic chamber is passed;
In order to adsorb the organometallic compound in the exhaust gas, a solid-phase adsorbent housed in the second hermetic chamber;
It is characterized by comprising.
[0006]
According to a second aspect of the present invention, in the apparatus according to the first aspect, the adsorbent contains activated carbon as a main component.
[0007]
According to a third aspect of the present invention, in the apparatus according to the first or second aspect, the first temperature is 200 to 300 ° C., and the exhaust gas is heated for a period of 10 seconds to 1 minute. Features.
[0008]
A fourth aspect of the present invention is a dry abatement apparatus for treating exhaust gas containing an organosilane compound mainly composed of alkylsilane or alkoxylsilane and a decomposition product thereof and ozone discharged from the treatment apparatus. There,
A first hermetic chamber through which the exhaust gas from the processing device passes;
A heater for heating the exhaust gas in the first hermetic chamber to decompose ozone in the exhaust gas, wherein the heater has an ozone concentration of 1% or less at the outlet of the first hermetic chamber; Heating the exhaust gas,
A second hermetic chamber through which the exhaust gas after being treated in the first hermetic chamber is passed;
In order to adsorb the organometallic compound in the exhaust gas, an adsorbent in a solid state that contains activated carbon contained in the second hermetic chamber as a main component;
It is characterized by comprising.
[0009]
According to a fifth aspect of the present invention, in the apparatus according to any one of the first to fourth aspects, the exhaust gas is cooled to 50 ° C. or lower, and is disposed between the first hermetic chamber and the second hermetic chamber. The apparatus further includes a cooler provided.
[0010]
A sixth aspect of the present invention is a dry detoxification method for treating exhaust gas containing an organometallic compound and ozone discharged from a treatment apparatus,
Passing the exhaust gas from the processing apparatus through a first hermetic chamber;
Heating the exhaust gas in the first hermetic chamber to decompose ozone in the exhaust gas, and heating the exhaust gas at a first temperature of 80 to 300 ° C. for 1 second to 30 minutes; And
Passing the exhaust gas after being treated in the first hermetic chamber through a second hermetic chamber;
Adsorbing an organometallic compound in the exhaust gas with an adsorbent in a solid state stored in the second hermetic chamber;
It is characterized by comprising.
[0011]
According to a seventh aspect of the present invention, in the method according to the sixth aspect, the adsorbent contains activated carbon as a main component.
[0012]
According to an eighth aspect of the present invention, in the method according to the sixth or seventh aspect, the first temperature is 200 to 300 ° C., and the exhaust gas is heated for a time of 10 seconds to 1 minute. And
[0013]
According to a ninth aspect of the present invention, there is provided a dry detoxification method for treating exhaust gas containing alkylsilane or alkoxylsilane and an organometallic compound mainly composed of a decomposition product thereof and ozone discharged from a treatment apparatus. And
Passing the exhaust gas from the processing apparatus through a first hermetic chamber;
Heating the exhaust gas in the first hermetic chamber to decompose ozone in the exhaust gas, and wherein the ozone concentration in the exhaust gas at the outlet of the first hermetic chamber is 1% or less, Heating the exhaust gas,
Passing the exhaust gas after being treated in the first hermetic chamber through a second hermetic chamber;
Adsorbing the organometallic compound in the exhaust gas with an adsorbent in a solid state containing activated carbon contained in the second hermetic chamber as a main component;
It is characterized by comprising.
[0014]
A tenth aspect of the present invention is the method according to any one of the sixth to ninth aspects, further comprising the step of cooling the exhaust gas to 50 ° C. or less between the first hermetic chamber and the second hermetic chamber. It is characterized by comprising.
[0015]
Further, the embodiments of the present invention include various stages of the invention, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, when an invention is extracted by omitting some constituent elements from all the constituent elements shown in the embodiment, when the extracted invention is carried out, the omitted part is appropriately supplemented by a well-known common technique. It is what is said.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
In the course of the development of the present invention, the present inventors have studied a dry detoxification apparatus and method suitable for treating exhaust gas containing an organometallic compound and ozone. As a result, the present inventors have obtained knowledge as described below.
[0017]
The organometallic compound to be studied was an alkylsilane or an alkoxysilane containing TEOS, which is likely to be used with ozone in semiconductor processing. Specific examples thereof include tetramethoxysilane ((CH ₃ O) ₄ Si), triethoxysilane ((OC ₂ H ₅ ) ₃ SiH), and trimethylsilane (trimethylsilane: (CH ₃ ) ₃ SiH. ), Tetramethylsilane (tetramethylsilane: (CH ₃ ) ₄ Si), 2,4,6,8-tetramethylcyclotetrasiloxane (2,4,6,8-tetramethylcyclotetrasiloxane: ((CH ₃ ) HSiO) ₄ ) Etc.
[0018]
[Experiment 1]
In order to examine the adsorption ability of the adsorbent to alkylsilane or alkoxylsilane, an experiment was conducted using the apparatus shown in FIG. As shown in FIG. 1, a gas source 14 of source gas containing alkylsilane or alkoxylsilane and a gas source 16 of N ₂ gas are connected to the upstream side of the cartridge 12 containing the adsorbent, and a concentration detector 18 is connected to the downstream side. Connected. Various adsorbents were individually accommodated in the cartridge 12, and a raw material gas was supplied to each adsorbent using N ₂ as a carrier gas, and the adsorption ability for the organometallic compound in the raw material gas was examined. At this time, the following conditions were used.
[0019]
Experimental conditions Organometallic compound in raw material gas: TEOS,
TEOS initial concentration: 0.2%
Gas linear velocity: 2 cm / sec,
Adsorbent weight: 10 g.
[0020]
FIG. 2 is a table showing the experimental results of Experiment 1. In FIG. 2, “adsorption capacity” indicates the processing capacity (cc / g-cat.) Of TEOS in 1 g of the adsorbent. “N140”, “N170B”, and “Cu-13X” are trade names of Sudden Chemie Catalyst Co., Ltd. “MAX-20” is a trade name of Mitsui Chemicals, Inc. “Functional activated carbon” is a trade name of Takeda Pharmaceutical Company Limited. As shown in FIG. 2, “N140” and “N170B” are 10 to 13 cc / g-cat. Some adsorption capacity was obtained. However, in “functional activated carbon” and “activated carbon”, 33.3 cc / g-cat. As a result, the adsorption capacity about 3 times the above was obtained.
[0021]
Thus, activated carbon has a high adsorption capacity for alkylsilane or alkoxylsilane. However, bringing activated carbon into contact with ozone (O ₃ ) can cause a fire and involves a very high risk. Therefore, when ozone is contained in the exhaust gas, it is necessary to remove the ozone from the exhaust gas. If the ozone concentration in the exhaust gas is 1% or less, it is considered safe even if the exhaust gas is brought into contact with the activated carbon.
[0022]
The present inventors paid attention to ozone thermal decomposition by simple and reliable heating of exhaust gas as a method for decomposing ozone. FIG. 3 is a table showing the relationship between the heating temperature and the half-life (sec) of ozone. As shown in FIG. 3, when the heating temperature is 50 ° C., it takes almost a day for the ozone concentration to become half, for example, from 4% to 2%. On the other hand, when the heating temperature is 80 ° C., the ozone concentration is halved in one hour. Furthermore, when the heating temperature is 200 ° C., the ozone concentration is halved in 8 seconds.
[0023]
[Experiment 2]
In order to investigate the relationship between the heating temperature of the exhaust gas and the thermal decomposition of ozone in more detail, an experiment was conducted using the apparatus shown in FIG. As shown in FIG. 4, an ozone generator 24 was connected to the upstream side of the heating chamber 22, and an ozone monitor 28 was connected to the downstream side via a cooler 26. The temperature of the heating chamber 22 was variously changed, and a gas containing ozone was supplied to the heating chamber 22 set to each temperature, and the decomposition degree of ozone was examined. At this time, the following conditions were used.
[0024]
Experimental conditions Initial concentration of ozone: 5%
Gas linear velocity: 2 cm / sec,
Heating time (gas heating chamber residence time): 70 sec.
[0025]
FIG. 5 is a table showing the experimental results of Experiment 2. In FIG. 5, “temperature (° C.), (in / out)” indicates the temperature of the inlet and outlet of the heating chamber 22. “Ozone concentration” indicates the ozone concentration (ppm) detected by the ozone monitor 28. As shown in FIG. 5, when the temperature of the heating chamber 22 was about 200 to 300 ° C., the ozone concentration after the treatment was several tens of ppm or less. This value was much lower than the ozone concentration in the exhaust gas of 1%, which is a safety measure when contacting the exhaust gas with activated carbon. Further, it was found that when the heating temperature is about 300 ° C., the thermal decomposition of ozone is almost completed, so that further heating is unnecessary.
[0026]
The thermal decomposition of ozone correlates not only with the heating temperature, but also with the heating time (the residence time of the exhaust gas in the heating environment). When considering exhaust gas treatment, it is also possible to store exhaust gas in a large-capacity heating tank. On the other hand, when considering downsizing of the apparatus, it is desirable that the heating chamber 22 for determining the heating time of the exhaust gas having a constant linear velocity has a small length and capacity. In consideration of such various conditions, for the thermal decomposition of ozone, the exhaust gas is heated at a temperature of 80 to 300 ° C., preferably 200 to 300 ° C., for 1 second to 30 minutes, preferably 10 seconds to 1 minute. It is thought that it may be heated over the time. As described above, the heating time can be set by adjusting the linear velocity of the exhaust gas and the length and capacity of the heating chamber 22.
[0027]
Hereinafter, an embodiment of the present invention configured based on such knowledge will be described with reference to the drawings.
[0028]
FIG. 6 is a schematic view showing a CVD apparatus for forming a silicon oxide film, to which an exhaust gas dry-type abatement apparatus according to an embodiment of the present invention is attached. The CVD apparatus 50 includes an airtight processing chamber 52 for storing a substrate to be processed (semiconductor wafer). In the processing chamber 52, a heating mounting table (supporting member) 54 for placing and heating the substrate to be processed is disposed. A shower head 56 for supplying a processing gas is disposed in the upper part of the processing chamber 52. The shower head 56 is connected to a gas source 58 of a source gas containing an alkylsilane or alkoxylsilane such as TEOS and a gas source 62 of an ozone gas. The raw material gas and the ozone gas are discharged from the shower head 56 through separate routes and mixed in the processing chamber 52 (so-called postmix). An exhaust pump 64 for exhausting the interior and setting a vacuum is connected to the lower portion of the processing chamber 52.
[0029]
An exhaust gas dry-type abatement device 70 configured as an independent unit is detachably connected to the downstream side of the exhaust pump 64. The abatement apparatus 70 includes an airtight heating chamber (first airtight chamber) 72 through which the exhaust gas from the processing chamber 52 passes. The heating chamber 72 is connected to an outlet pipe 66 of the exhaust pump 64 via an upstream pipe 74 in which a flow rate control valve 76 is disposed. A flange 75 is disposed at the end of the upstream pipe 74 and is detachably attached to the flange 67 of the outlet pipe 66.
[0030]
A heater 78 for heating the exhaust gas in the heating chamber 72 is disposed around the heating chamber 72 in order to decompose ozone in the exhaust gas. The heater 78 can heat the exhaust gas in the heating chamber 72 to 80 to 300 ° C., preferably 200 to 300 ° C. The length and capacity of the heating chamber 72 are set so that the exhaust gas stays in the heating chamber 72 for a time of 1 second to 30 minutes. For example, when the linear velocity of the exhaust gas is 1 cm / sec, the capacity of the heating chamber 72 is set to 1 to 1800 cm ³ .
[0031]
The heating chamber 72 is connected via an intermediate pipe 84 to an airtight cartridge (second airtight chamber) 82 through which exhaust gas treated in the heating chamber 72 passes. The intermediate pipe 84 is provided with a cooler 86 for cooling the exhaust gas to 100 ° C. or lower, preferably 50 ° C. or lower. As the cooler 86, a type having a radiation fin or a spiral tube type can be used. In addition, if the connecting pipe 84 itself from the heating chamber 72 to the cartridge 82 is lengthened, it can function as the cooler 86 itself. Valves 85 and 87 are disposed in the intermediate pipe 84 between the heating chamber 72 and the cooler 86 and between the cooler 86 and the cartridge 82.
[0032]
The cartridge 82 contains a solid-phase adsorbent 88 that adsorbs the organometallic compound in the exhaust gas, for example, activated carbon. In the present embodiment, the organometallic compound in the exhaust gas is mainly composed of alkylsilane or alkoxylsilane and its decomposition product. Further, as the adsorbent 88, instead of activated carbon, ones such as “N140” and “N170B” shown in FIG. 2 can be used.
[0033]
The cartridge 82 is connected to an exhaust system 98 of, for example, a semiconductor manufacturing factory via a downstream pipe 92 in which a valve 94 is disposed. A flange 75 is disposed at the end of the downstream pipe 92 and is detachably attached to the corresponding flange 99 of the piping of the factory exhaust system 98.
[0034]
The usage mode of the exhaust gas dry-type abatement apparatus 70 having the above-described configuration is as follows. First, the abatement apparatus 70 is assembled between the exhaust pump 64 of the CVD apparatus 50 and the factory exhaust system 98. Next, exhaust gas from the exhaust pump 64 is passed through the heating chamber 72 during the film forming process in the CVD apparatus 50. Then, the exhaust gas is heated in the heating chamber 72 to decompose residual ozone in the exhaust gas. The processing conditions at this time are as described above. Thereby, the ozone concentration in the exhaust gas is set to 1% or less at the outlet of the heating chamber 72.
[0035]
Next, the exhaust gas is cooled by the cooler 86 to 100 ° C. or lower, preferably 50 ° C. or lower, and then passed through the cartridge 82. Then, the residual organometallic compound in the exhaust gas is adsorbed by the solid-phase adsorbent accommodated in the cartridge 82. After processing with the cartridge 82, the exhaust gas is discharged to the exhaust system 98 of the factory.
[0036]
In the present embodiment, the dry-type abatement apparatus 70 is configured as an independent unit and is detachably connected to the CVD apparatus 50. However, the dry abatement apparatus 70 may be fixedly incorporated in a processing system including the CVD apparatus 50. Moreover, the processing apparatus to which the dry-type abatement apparatus 70 is applied is not limited to a CVD apparatus, and can be applied to any processing apparatus as long as it exhausts exhaust gas containing an organometallic compound and ozone. It is.
[0037]
In addition, in the category of the idea of the present invention, those skilled in the art can conceive of various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention. .
[0038]
【The invention's effect】
As described above, according to the present invention, in the dry abatement apparatus or method for treating the exhaust gas containing the organometallic compound and ozone discharged from the treatment apparatus, the abatement capacity and safety can be reduced. Both can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing an experimental apparatus used in Experiment 1 for examining the adsorption ability of an adsorbent to alkylsilane or alkoxylsilane.
FIG. 2 is a table showing experimental results of Experiment 1.
FIG. 3 is a table showing the relationship between heating temperature and ozone half-life (sec).
FIG. 4 is a diagram showing an experimental apparatus used in Experiment 2 for examining the relationship between the heating temperature of exhaust gas and the thermal decomposition of ozone in more detail.
FIG. 5 is a table showing experimental results of Experiment 2.
FIG. 6 is a schematic view showing a CVD apparatus for forming a silicon oxide film, to which an exhaust gas dry-type abatement apparatus according to an embodiment of the present invention is attached.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 50 ... CVD apparatus 52 ... Processing chamber 64 ... Exhaust pump 70 ... Exhaust gas dry-type abatement device 72 ... Heating chamber (1st airtight chamber)
78 ... Heater 82 ... Cartridge (second airtight chamber)
86 ... Cooler 88 ... Adsorbent 98 ... Factory exhaust system

Claims (10)

A dry-type abatement device for treating exhaust gas containing an organometallic compound and ozone discharged from a treatment device,
A first hermetic chamber through which the exhaust gas from the processing device passes;
In order to decompose ozone in the exhaust gas, a heater for heating the exhaust gas in the first hermetic chamber, wherein the exhaust gas is heated at a first temperature of 80 to 300 ° C. for a time of 1 second to 30 minutes. And
A second hermetic chamber through which the exhaust gas after being treated in the first hermetic chamber is passed;
In order to adsorb the organometallic compound in the exhaust gas, a solid-phase adsorbent housed in the second hermetic chamber;
An exhaust gas dry-type abatement apparatus comprising: 2. The exhaust gas dry-type abatement apparatus according to claim 1, wherein the adsorbent contains activated carbon as a main component. The said 1st temperature is 200-300 degreeC, The said exhaust gas is heated over the time for 10 second-1 minute, The dry-type abatement apparatus of the exhaust gas of Claim 1 or 2 characterized by the above-mentioned. A dry-type abatement apparatus for treating exhaust gas containing an organometallic compound mainly composed of alkylsilane or alkoxylsilane and its decomposition product and ozone discharged from the treatment apparatus,
A first hermetic chamber through which the exhaust gas from the processing device passes;
A heater for heating the exhaust gas in the first hermetic chamber to decompose ozone in the exhaust gas, wherein the heater has an ozone concentration of 1% or less at the outlet of the first hermetic chamber; Heating the exhaust gas,
A second hermetic chamber through which the exhaust gas after being treated in the first hermetic chamber is passed;
In order to adsorb the organometallic compound in the exhaust gas, an adsorbent in a solid state that contains activated carbon contained in the second hermetic chamber as a main component;
An exhaust gas dry-type abatement apparatus comprising: 5. The apparatus according to claim 1, further comprising a cooler disposed between the first hermetic chamber and the second hermetic chamber in order to cool the exhaust gas to 50 ° C. or less. Exhaust gas abatement system. There is a dry detoxification method for treating exhaust gas containing organometallic compounds and ozone discharged from a treatment device,
Passing the exhaust gas from the processing apparatus through a first hermetic chamber;
Heating the exhaust gas in the first hermetic chamber to decompose ozone in the exhaust gas, and heating the exhaust gas at a first temperature of 80 to 300 ° C. for 1 second to 30 minutes; And
Passing the exhaust gas after being treated in the first hermetic chamber through a second hermetic chamber;
Adsorbing an organometallic compound in the exhaust gas with an adsorbent in a solid state stored in the second hermetic chamber;
A dry detoxification method for exhaust gas, comprising: The exhaust gas dry removal method according to claim 6, wherein the adsorbent contains activated carbon as a main component. The said 1st temperature is 200-300 degreeC, The said exhaust gas is heated over the time for 10 second-1 minute, The dry-type removal method of the exhaust gas of Claim 6 or 7 characterized by the above-mentioned. There is a dry detoxification method for treating exhaust gas containing organosilane compounds mainly composed of alkylsilane or alkoxylsilane and its decomposition products and ozone discharged from a treatment apparatus,
Passing the exhaust gas from the processing apparatus through a first hermetic chamber;
Heating the exhaust gas in the first hermetic chamber to decompose ozone in the exhaust gas, and wherein the ozone concentration in the exhaust gas at the outlet of the first hermetic chamber is 1% or less, Heating the exhaust gas,
Passing the exhaust gas after being treated in the first hermetic chamber through a second hermetic chamber;
Adsorbing the organometallic compound in the exhaust gas with an adsorbent in a solid state containing activated carbon contained in the second hermetic chamber as a main component;
A dry detoxification method for exhaust gas, comprising: The exhaust gas dry abatement according to any one of claims 6 to 9, further comprising a step of cooling the exhaust gas to 50 ° C or lower between the first hermetic chamber and the second hermetic chamber. Method.

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