KR20010020883A - Oxidation processing unit - Google Patents

Abstract

PURPOSE: An oxidizing apparatus is provided to reduce an ozone exhausted from a lamp house to a heat exhaust system. CONSTITUTION: This apparatus comprises a treatment container receiving a body to be treated, treated gas-supplying means (a gas-supplying pipe) for supplying the treatment gas containing ozone to the treatment container, and a lamp house(20) provided on the treatment container via a ultraviolet-ray transmitting window in which a ultraviolet-ray lamp is received, and the ozone in the treatment container is irradiated with the ultraviolet-rays from the ultraviolet-ray lamp to be decomposed so as to oxidize the body to be treated. An inlet port(22) and an exhaust port(23) for circulating cooling air are provided on the lamp house(20), and ozone decomposing means is provided in a thermal exhaust system(50) connected to the exhaust port(23).

Description

Oxidation Processing Equipment {OXIDATION PROCESSING UNIT}

The present invention relates to an oxidation treatment apparatus for performing oxidation treatment on a substrate such as a semiconductor wafer in a processing vessel.

As an oxidation treatment apparatus for performing an oxidation treatment on a substrate such as a semiconductor wafer, a sheet type oxidation treatment apparatus according to Japanese Patent Laid-Open No. 79377/1998 (Pyeongseong 10-79377) or the like is known. The sheet type oxidation treatment apparatus includes: a processing vessel accommodating a semiconductor wafer, a processing gas supply unit for supplying a processing gas containing ozone (O ₃ ) into the processing vessel, and a window of the processing vessel inside the processing vessel. It is provided with a lamp house accommodating an ultraviolet lamp capable of irradiating ultraviolet rays through.

The ozone in the processing vessel is irradiated with ultraviolet rays from the ultraviolet lamp to decompose the ozone to perform oxidation treatment on the semiconductor wafer placed in the processing vessel.

In such an oxidation treatment apparatus, in order to increase the efficiency of ultraviolet irradiation by the ultraviolet lamp in the lamphouse, it is preferable to keep the surface of the ultraviolet lamp at a predetermined temperature range (240 to 270 ° C). Therefore, it was tested to install an inlet and an exhaust port through which the air for cooling flows in the lamp house. In that case, the temperature of the surface of the ultraviolet lamp can be maintained at a predetermined temperature range by adjusting the air amount. In general, the exhaust port is connected to a heat exhaust machine.

However, in the oxidation treatment apparatus, when air for cooling is circulated in the lamp house, oxygen in the circulating air may be chemically ozonated by light of a specific wavelength in the ultraviolet light emitted from the ultraviolet lamp. In this case, ozone may be exhausted from the lamp house to the heat exhaust machine.

In addition, in the case where the distance between the showerhead and the heater of the mounting table is narrow, residual ozone inside the processing vessel can be sufficiently decomposed by heating of the mounting table heater. However, in the case where the distance between the showerhead and the heater of the mounting table is widened to improve the uniformity of the oxidation treatment, residual ozone may not be completely decomposed by the heater of the mounting table. In this case, residual ozone is expected to be discharged from the inside of the treatment vessel.

The present invention is intended to solve the above problems effectively. It is an object of the present invention to provide an oxidation treatment apparatus in which ozone exhausted from a lamp house to a heat exhaust machine can be reduced to an acceptable level. Another object of the present invention is to provide an oxidation treatment apparatus capable of preventing the generation of ozone in a lamp house.

It is yet another object of the present invention to provide an oxidation treatment apparatus in which ozone exhausted from the interior of the treatment vessel can be reduced to an acceptable level.

1 is a schematic longitudinal view of a first embodiment of a sheet type oxidation treatment apparatus according to the present invention;

FIG. 2 is a schematic diagram of a cooling system for a lamphouse of one embodiment of the oxidation treatment apparatus shown in FIG. 1. FIG.

FIG. 3 is a schematic longitudinal view of a catalyst unit in the cooling system shown in FIG. 2. FIG.

4 schematically shows another cooling system for a lamp house;

5 is a longitudinal schematic view of a second embodiment of a sheet type oxidation unit according to the present invention;

FIG. 6 is a schematic diagram of a gas system in a second embodiment of the oxidation treatment apparatus shown in FIG. 5; FIG.

FIG. 7 is a schematic view of the longitudinal direction of the catalyst unit in the gas system shown in FIG. 6. FIG.

FIG. 8 is a schematic longitudinal view of a pyrolysis unit in the gas system shown in FIG. 6. FIG.

<Description of the symbols for the main parts of the drawings>

1,101: Treatment container 2,102: Exhaust port

3,103 mounting table 5,105 shower head

6,106 gas supply pipe 7: wafer inlet and outlet

8: gate valve 10, 110: UV transmission window

11,111: opening 15: exhaust system

20,120: Lamp house 21, 121: UV lamp

22,122: air supply port 23, 123: exhaust port

24,124 blower 50: heat exhaust machine

50a: main exhaust pipe 50b: sub exhaust pipe

59y: confluence 51: catalyst unit

52: ozone sensor 53: blower

61,62: casing 61a, 62a: flange

61b, 62b: connection pipe part 61c, 62c: peripheral flange

63,64: mesh 65: catalyst

70: inert gas distribution system 71: circulation pipe

72: radiator 150: exhaust system

151: vacuum pump 152: exhaust pipe

153: switching valve 155: pyrolysis unit

155a: Tube 155b: Heat Block

155c: Ceramic Heater 155d: Water Cooled Pipe

155e: insulation cover 156: catalyst unit

156a: upper catalyst 156b: lower catalyst

156c: Upper ozone sensor 156d: Upper ozone sensor

160: gas introduction pipe 161: ozone generator

162: initial line 164: switching valve

According to the present invention, there is provided a treatment container having an interior in which a substrate is accommodated and a window through which ultraviolet rays are transmitted; A lamp house having an ultraviolet lamp capable of irradiating ultraviolet rays into the processing vessel through the window; A processing gas supply unit for supplying a processing gas containing ozone into the processing container; An air supply port for introducing air for cooling into the lamp house; An exhaust port for exhausting cooling air from the lamp house; And an ozone decomposing unit connected to the exhaust port, wherein the ultraviolet rays from the ultraviolet lamp are irradiated with the processing gas supplied into the processing vessel to oxidize the substrate in which the ozone in the processing gas is placed in the processing vessel. An oxidation treatment apparatus is characterized in that it is decomposed so as to.

According to the above feature, even if ozone is generated in the lamphouse, ozone is decomposed by the ozone decomposition unit and reduced to an acceptable level when ozone is exhausted through the exhaust port.

Preferably, the ozone decomposition unit is composed of a catalyst unit containing a catalyst mainly containing manganese dioxide. Optionally, the ozone decomposition unit consists of a thermal decomposition unit with a heater. By using such a simple ozone decomposing unit, ozone can be easily decomposed.

In addition, according to the present invention, there is provided a treatment container having an interior in which a substrate is accommodated and a window through which ultraviolet light is transmitted; A lamp house having an ultraviolet lamp capable of irradiating ultraviolet rays into the processing vessel through the window; A processing gas supply unit for supplying a processing gas containing ozone into the processing container; An air supply port for introducing an inert gas for cooling into the lamp house; And an exhaust port for exhausting the cooling inert gas from the lamp house, wherein the ultraviolet rays from the ultraviolet lamp are irradiated with the processing gas supplied into the processing container so that ozone in the processing gas is placed in the processing container. There is provided an oxidation treatment apparatus, which is decomposed so as to perform oxidation treatment.

According to this feature, ozone can be prevented from occurring in the lamphouse.

Preferably, the air supply port and the exhaust port are connected to a circulation flow system for circulating the inert gas, characterized in that the circulation flow system is provided with a radiator for dissipating heat of the inert gas circulated by the circulation flow system. In this case, the usage amount of the inert gas can be reduced, and the price can be lowered.

Also, according to the present invention, there is provided a processing container having an interior in which a substrate is placed; A processing gas supply unit for supplying a processing gas containing ozone into the processing container; A heater for heating the substrate placed inside the processing vessel; An exhaust system for evacuating the exhaust gas and the interior of the processing vessel from the interior of the processing vessel under reduced pressure; And a pyrolysis unit provided in the exhaust system to thermally decompose ozone, wherein ozone contained in the processing gas introduced into the processing vessel to perform oxidation treatment on the substrate placed inside the processing apparatus. An oxidation treatment apparatus is provided which is decomposed.

According to this feature, the ozone exhausted from the inside of the processing vessel is reduced to an acceptable level.

Preferably, the pyrolysis unit is characterized by comprising a heat transfer medium made of alumina. In this case, even if nitrogen oxides (NO _x ) are included in the gas exhausted from the inside of the processing vessel, the pyrolysis unit is prevented from being corroded, which can enhance durability.

Preferably, a catalytic unit for decomposing ozone is provided in the exhaust system at a portion downstream from the pyrolysis unit. In this case, residual ozone not decomposed by the pyrolysis unit can be sufficiently decomposed by the catalyst unit. In addition, even if a backflow occurs inside the processing vessel due to a pressure change in the exhaust system, the substrate may be prevented from being contaminated metallicly.

Preferably, an inert gas introduction unit for diluting the gas exhausted from the inside of the processing vessel with the inert gas is provided in the exhaust system at a portion upstream of the pyrolysis unit. In this case, even if the gas exhausted from the inside of the processing vessel contains nitrogen oxides (NO _x ), the catalyst in the exhaust system and / or the catalyst in the catalyst unit is prevented from being corroded or eroded by the nitrogen oxides. This is because the exhausted gas is diluted with an inert gas.

(Example)

1 to 4 will be described in detail the first embodiment of the present invention.

1 is a longitudinal cross-sectional schematic diagram of a first embodiment of an oxidation treatment unit for a sheet type oxidation treatment apparatus according to the present invention. 2 is a schematic diagram of a cooling system for a lamphouse of the first embodiment. 3 is a longitudinal cross-sectional schematic diagram of a cooling system.

First, with reference to FIG. 1, the principal part structure of a single type oxidation unit is demonstrated. This sheet type oxidation treatment apparatus has a processing container 1 made of a material having heat resistance and corrosion resistance such as aluminum. The exhaust port 2 is provided in the bottom part of this processing container 1. The exhaust port 2 is connected to an exhaust system 15 having a vacuum pump and a pressure control mechanism in order to depressurize the inside of the processing container 1 to a predetermined pressure and exhaust the gas from the interior of the processing container 1. It is. This process gas exhaust system 15 is connected to a process heat exhaust machine of a factory equipped with a decontamination apparatus.

In the processing container 1, a mounting table (referred to as a susceptor or an object to be processed) 3 for holding an object, for example, a semiconductor wafer w, is rotatably provided. It is preferable that the mounting table 3 be provided with an electrostatic chuck for holding and holding a semiconductor wafer. In addition, the mounting table 3 is provided with a heater (not shown) made of a resistance heating element (not shown) for uniformly heating the semiconductor wafer w to a desired temperature in plane.

On one side of the side wall of the processing container 1, a wafer carry-out port 7 is provided. The gate valve 8 is disposed adjacent to the outside of the wafer unloading opening 7. The opening 11 is provided in the other side of the side wall of the processing container 1. The opening 11 is used for inspection and the like in the processing container 1. The lid 12 is normally provided adjacent to the outside of the opening 11. The processing container 1 is connected to a transfer chamber 13 having a transfer arm (not shown) via a gate valve 8, and the carry-in and carry-out of the semiconductor wafer w is performed by the transfer arm. .

The shower head 5 is installed in the ceiling of the processing container 1. This shower head 5 is provided with an internal space and a plurality of injection holes (not shown). Process gas containing ozone is supplied to the internal space. The processing gas supplied therein is adapted to be injected from a plurality of injection holes toward the upper surface (processing surface) of the semiconductor wafer w placed on the mounting table 3 in the processing space S. Since the shower head 5 is provided under the ultraviolet ray transmission window 10 mentioned later, it is preferable that it is formed of the material which permeate | transmits an ultraviolet-ray, for example, quartz.

The shower head 5 is connected to a gas supply pipe 6 that is a process gas supply unit. A known ozone generator (not shown) is connected to this gas introduction pipe 6 via a mass flow controller (not shown). As the ozone generator, oxygen gas, which is a raw material for ozone generation, is adopted. In addition, a small amount of additive gas, such as nitrogen gas (N ₂ ), is provided to improve the generation efficiency of ozone.

Further, a circular opening larger than the diameter of the semiconductor wafer w is formed in the ceiling of the processing container 1. In this opening, an ultraviolet transmission window 10 made of a material which transmits ultraviolet rays, for example, quartz, is hermetically attached. In the upper portion of the processing container (1), a box-shaped lamp house (20) for accommodating the ultraviolet lamp (21) through the ultraviolet transmission window (10) is provided.

Inside the lamp house 20, a plurality of ultraviolet lamps 21 that transmit ultraviolet rays through the ultraviolet transmission window 10 in the processing container 1 are disposed. When the ultraviolet rays are irradiated from the ultraviolet lamp 21 into the atmosphere in the processing container 1, ozone (O ₃ ) in the atmosphere is decomposed into oxygen (O ₂ ) and active oxygen (O ⁺ ), and the active oxygen The semiconductor wafer w is oxidized by this.

The ultraviolet lamp 21 irradiates ultraviolet rays efficiently when the temperature of the lamp surface is in a predetermined temperature range (240 to 270 ° C). Therefore, the lamp house 20 is a cooling means for maintaining the surface temperature of the ultraviolet lamp 21 in a predetermined temperature region, for example, an air cooling system, and an air supply port 22 and an exhaust port 23, and a blower for forced exhaust. 24 is installed. A heat exhaust machine 50 is connected to the exhaust port 23. The heat exhaust machine 50 includes ozone decomposing means for decomposing ozone when the air for cooling in the lamp house 20 is ozone by light of a specific wavelength (185 nm) of ultraviolet rays emitted from the ultraviolet lamp 21. As a catalyst unit 51 is provided.

2 shows a configuration of a cooling system of a lamp house. In the lamp house 20 corresponding to each processing container, an air supply port 22 for introducing cooling air into the lamp house 20 and an exhaust port 23 for exhausting air in the lamp house 20 are provided. In the lamp house 20, a blower 24 for forcibly evacuating air from the exhaust port 23 to the heat exhaust machine 50 is provided.

The heat exhaust machine 50 includes a main exhaust pipe 50a connected to a heat exhaust machine (not shown) of a factory, and a sub branch branched from the main exhaust pipe 50a and connected to an exhaust port 23 of each lamp house 20. It consists of a conduit for connecting the exhaust pipe 50b, the main exhaust pipe 50a, and the sub exhaust pipe 50b. Each of the sub exhaust pipes 50b is provided with the catalyst unit 51, and an ozone sensor 52 for detecting ozone is provided on the downstream side of the catalyst unit 51.

Dampers (not shown) for preventing reverse flow are provided at the confluence portion 50y of each sub exhaust pipe 50b to the main exhaust pipe 50a. The blower 53 is provided in the main exhaust pipe 50a. The blower 53 is set in capacity (power) in consideration of the displacement of each lamp house 20, the exhaust resistance of the catalyst unit 51, and the exhaust resistance of the pipe.

As shown in Fig. 3, the catalyst unit 51 has a pair of bowl-shaped casings 61, in which connecting pipe portions 61b and 62b having flanges 61a and 62a are protruded at the center thereof. And (62) are bolted together at the peripheral flanges (61c) and (62c), and the catalyst 65 is accommodated in the state of being fitted with two meshes 63 and 64 therein. As this structure, the gas flow area of the catalyst 63 is secured widely. As the catalyst 65, activated carbon or the like can also be used, but manganese dioxide is preferably used in consideration of heat resistance to ignition prevention.

Next, the operation of the oxidation treatment apparatus will be described.

In the case where the semiconductor wafer w is processed by this oxidation treatment apparatus, first, the semiconductor wafer w is transported through the gate valve 8 by the transfer arm (not shown) in the transfer chamber 13. Bring in) The semiconductor wafer w is placed on the mounting table 3 and held by the electrostatic chuck. Then, the semiconductor wafer w is heated to a predetermined process temperature by the heater of the mounting table 3. Then, ozone is supplied as the processing gas and the treatment is started while maintaining the inside of the processing container 1 at a predetermined process pressure. The ozone gas generated in the ozone generator is introduced into the shower head 5 through the gas introduction pipe 6 and is directed from the plurality of injection holes toward the semiconductor wafer w on the mounting table 3 in the processing space S. Blown out.

At the same time, the ultraviolet lamp 21 in the lamp house 20 is turned on to irradiate ultraviolet rays. This ultraviolet light penetrates the ultraviolet transmission window 10 made of quartz, enters the processing container 1 maintained at a predetermined pressure (at a predetermined vacuum level), and passes through the quartz shower head 5, It enters into the process gas atmosphere whose main component is ozone in process space S. As shown in FIG. Here, ozone is decomposed into oxygen and active oxygen by irradiation of ultraviolet rays, and the semiconductor wafer w on the mounting table 3 is oxidized by the active oxygen.

During this process, in order to maintain the surface temperature of the ultraviolet lamp 21 in a certain range, air is circulated through the air supply port 22, the exhaust port 23, and the blower 24 in the lamp house 20 for cooling. do. In this case, oxygen in the circulation air may be ozonated by the light having a specific wavelength of ultraviolet light emitted from the ultraviolet lamp 21. In this case, the ozone is exhausted from the exhaust port 23 to the heat exhaust machine 50 together with the exhaust. In this embodiment, however, the subunit exhaust pipe 50b continuous to the exhaust port 23 is a catalyst unit for decomposing ozone. Since 51 is provided, ozone in the exhaust gas is decomposed by the catalyst 65 in the catalyst unit 51, and can be reduced below the allowable value (0.1 ppm).

When the capacity of the catalyst 65 in the catalyst unit 51 decreases and ozone flows out downstream of the catalyst unit 51, the ozone sensor 52 detects it (at the site). Therefore, by interlocking the ozone sensor 52 to the safe mode, it is possible to prevent the outflow of ozone. As an example of the safe mode, the ultraviolet lamp 21 is turned off when a predetermined amount of ozone is detected. Alternatively, a warning lamp or the like may be promptly exchanged in advance when a small amount of ozone is detected.

As mentioned above, although embodiment of this invention was described in detail according to drawing, this invention is not limited to the said embodiment, A various design change etc. are possible in the range which does not deviate from the summary of this invention. For example, the ozone decomposition means provided in the heat exhaust chamber of the lamp house may be, in addition to the catalyst unit, for example, a pyrolysis unit having a heater for pyrolyzing ozone. Moreover, in the said embodiment, although air was made to distribute | circulate as a cooling means in a lamp house, you may make it distribute | circulate inert gas other than air, for example.

4 is a view schematically showing another cooling system of the lamp house. In the case shown in FIG. 4, the lamp house 20 is connected to an inert gas flow meter 70 for circulating the inert gas for cooling in the lamp house 20. Preferably, as the inert gas flow system 70, a circulation tube 71 for circulating and circulating an inert gas such as nitrogen gas (N ₂ ) with respect to the lamp house 20, and circulated by the circulation tube 71. And a radiator 72 for dissipating heat of inert gas.

Accordingly, in order to cool the ultraviolet lamp 21, an inert gas such as nitrogen gas (N ₂ ) is flowed into the lamp house 20 instead of air, so that ozone does not occur in the lamp house, and thus the catalyst unit No ozone decomposing means such as In addition, it is expensive to exhaust the inert gas into the heat exhaust machine as it is. Therefore, as shown in FIG. 4, the inert gas is circulated through the lamp house 20, and circulated through the circulation flow statistics 71. Since the heat dissipation means 72 for dissipating the heat of the gas to the outside is provided, the amount of the inert gas is reduced so that the cost can be reduced.

In the above embodiment, a cold-wall oxidation treatment apparatus is shown, but the present invention is also applicable to a hot-wall oxidation treatment apparatus. In addition, although the single type oxidation treatment apparatus is shown in the said embodiment, this invention is applicable also to a batch oxidation treatment apparatus. In addition, as the object to be processed, a glass substrate, an LCD substrate, or the like, in addition to the semiconductor wafer, can be applied.

Next, a second embodiment of the present invention will be described in detail with reference to Figs.

5 is a longitudinal schematic view of a second embodiment of a sheet type oxidation unit according to the present invention. FIG. 6 is a schematic diagram of a gas system in a second embodiment of the oxidation treatment apparatus shown in FIG. FIG. 7 is a schematic longitudinal view of the catalyst unit in the gas system shown in FIG. 6. FIG. FIG. 8 is a schematic longitudinal view of the pyrolysis unit in the gas system shown in FIG. 6.

The main part of the sheet type oxidation treatment apparatus of the second embodiment will be described with reference to FIG. The sheet type oxidation treatment apparatus includes a processing container (process chamber) 101 made of a material having heat resistance and corrosion resistance, such as aluminum. An exhaust port 102 is provided at the bottom of the processing container 101. The exhaust port 102 is connected with a vacuum pump (exhaust unit) 151 and an exhaust system 150 provided with a pressure control mechanism, so that the inside of the processing vessel 101 can be decompressed to a predetermined pressure. have. The exhaust system 150 is connected to a process exhaust line of a factory equipped with a decontamination apparatus.

In the processing container 101, a mounting table (referred to as a susceptor and an object to be processed) 103 for holding a substrate such as a semiconductor wafer w is rotatably provided, and in this mounting table 3, It is preferable that an electrostatic chuck for adsorbing and holding the semiconductor wafer w is provided. In addition, the mounting table 3 is provided with a heater (not shown), and the mounted semiconductor wafer w can be uniformly heated in-plane at a desired temperature.

In the ceiling of the processing container 101, a shower head 105 for supplying a processing gas to the upper surface (to-be-processed surface) of the semiconductor wafer w is provided. The shower head 105 includes a plurality of injection holes (shown) for discharging the processing gas introduced into the shower head 105 toward the semiconductor wafer w on the mounting table 103 in the processing space S. Omission) is installed. The shower head 105 is preferably formed of a heat resistant material that transmits ultraviolet rays, such as quartz. The shower head 105 is supplied with ozone (O ₃ ) as a processing gas from the gas introduction pipe 106 constituting the processing gas supply unit 160.

As shown in FIG. 6, the process gas supply means 160 includes an ozone generator 161. The ozone generated by the ozone generator 61 is supplied to the shower head 105 through the gas introduction pipe 106. In addition, the initial line 162 is branched to the gas introduction pipe 160, and the exhaust system 150 is introduced through the initial line 162 without introducing ozone into the processing container 101 until the generation of ozone is stable. To the exhaust pipe 152.

The gas introduction pipe 106 has a switching valve 153. Similarly, the initial line 162 is also provided with a switching valve (164). The ozone generator 161 is supplied with oxygen gas (O ₂ ) serving as a raw material for ozone generation, and a small amount of nitrogen gas (N ₂ ) is supplied to improve the generation efficiency of ozone.

Further, a circular opening larger than the diameter of the semiconductor wafer w is formed in the ceiling of the corresponding container 101. An ultraviolet transmission window 110 formed of a material that transmits ultraviolet rays, such as quartz, is hermetically attached to this opening. In addition, one side of the side wall of the processing container 101 is provided with a wafer inlet / out port 107 equipped with a gate valve 108, and the other side of the side wall of the processing container 1 is inspected in the processing container 101. The opening part 111 with the cover 112 used for etc. is provided.

The lamp house 120 is installed above the UV transmission window 110. An ultraviolet lamp 121 for irradiating ultraviolet rays toward the inside of the processing container 101 is installed therein. Then, the ultraviolet rays irradiated from the ultraviolet lamp 121 are irradiated into the atmosphere in the processing container 101 through the ultraviolet transmission window 110, so that ozone (O ₃ ) in the atmosphere is converted into oxygen (O ₂ ) and active oxygen. It decompose | dissolves into (O ⁺ ), and the active oxygen is used for the oxidation process of the semiconductor wafer w.

The ultraviolet lamp 121 irradiates ultraviolet rays efficiently when the temperature of the lamp surface is within a predetermined range. Therefore, the lamp house 120 is provided with a cooling means 122, an exhaust port 123, and a blower 124 for forced exhaust as cooling means for maintaining a constant surface temperature of the ultraviolet lamp 121. . The exhaust port 123 is connected to a heat exhaust line (not shown) of the factory.

6, in this oxidation treatment apparatus, the exhaust pipe 152 of the exhaust system 150 is positioned upstream of the vacuum pump 151 to thermally decompose ozone remaining or mixed in the exhaust gas. The pyrolysis unit 155 is installed. Further, it is located downstream of the vacuum pump 151 of the exhaust system 150, and a catalyst unit 156 for ozone decomposition is provided in consideration of further safety. The gas sent through the initial line 162 is discharged to the exhaust pipe 152 through the catalyst unit 156.

The catalyst unit 156 includes a tubular casing 156 made of stainless steel, as shown in FIG. An upper catalyst 156a and a lower catalyst 156b disposed in the axial direction (the flow direction of the exhaust gas); An upper ozone sensor 156c disposed between the upper catalyst 156a and the lower catalyst 156b; And a lower ozone sensor 156d located downstream from the lower catalyst 156b. As the material of the catalysts 156a and 156b, manganese dioxide that is stronger in heat than activated carbon is used.

As illustrated in FIG. 8, the pyrolysis unit 155 includes a heat block 155b made of alumina. That is, this pyrolysis unit 155 is in the shape of a tubular body 155a made of quartz glass. The heat block 155b is made of alumina having a myriad of gas passages. The heat block 155b is disposed in the tube 155a. The ceramic heater 115c is for heating the heat block 155b and is installed outside the tubular body 155a. The water cooling pipe 155d is arrange | positioned at the outer periphery of the ceramic heater 155c, and the outer side is covered with the heat insulation cover 155e.

Some pyrolysis units 155 are made of stainless steel heaters, but those made of alumina heaters are for the following reasons. As described above, since the nitrogen gas (N ₂ ) is supplied to the ozone generator 161 to stably generate ozone, nitrogen oxides (NOx) are generated by the reaction of the nitrogen gas and ozone. Nitrogen oxides (NOx) absorb moisture and form acetic acid (NO ₃ ), which causes corrosion. Therefore, the heat block 155b is made of alumina to prevent corrosion due to nitrogen oxides. As the heat block 155b, an alumina agent is suitable, but a ceramic may be used in addition to the alumina.

Further, the catalyst unit 156 is disposed downstream of the pyrolysis unit 155 of the exhaust system 150 when the reverse flow is generated from the exhaust system 150 into the processing vessel 101 due to the pressure variation in the exhaust system 150. This is because if the catalyst unit 156 is located near the processing container 101, manganese dioxide, which is a catalyst, flows back and may cause metal contamination of the semiconductor wafer w.

In addition, in order to prevent corrosion of the structure or mechanism of the exhaust system 150, it is also effective to dilute nitrogen oxides by introducing an inert gas such as nitrogen gas (N ₂ ) in the middle of the exhaust pipe 152. In the apparatus of FIG. 6, an inert gas introduction pipe (inert gas introduction unit) 158 is connected to an upstream side of the pyrolysis unit 155 of the exhaust system 150, and nitrogen gas (N ₂ ) is introduced into the exhaust system 150. To dilute the exhaust. By doing in this way, the damage by corrosion of the vacuum pump 151, the catalyst unit 156, etc. can also be suppressed.

Next, the operation of the oxidation treatment apparatus composed of the above configuration will be described.

In the case where the semiconductor wafer w is processed by the oxidation treatment apparatus, first, the semiconductor wafer w is introduced into the processing chamber 101 through the gate valve 108 by a transfer arm (not shown) in the transfer chamber. Then, it is placed on the mounting table 103 and adsorbed and held by the electrostatic chuck. Then, the semiconductor wafer w is heated to a predetermined process temperature by the heater of the mounting table 103, and the ozone is supplied as the processing gas while the inside of the processing container 101 is vacuumed and maintained at the predetermined process pressure. To start the process. Ozone (O ₃ ) generated by the ozone generator (161) is introduced into the shower head (105) through the gas introduction pipe (106), and the semiconductor on the mounting table (103) in the processing space (S) at the plurality of injection holes. It is ejected toward the wafer w.

At the same time, the ultraviolet lamp 121 in the lamp house 120 is turned on to irradiate ultraviolet rays. This ultraviolet light penetrates the ultraviolet transmission window 10 made of quartz, enters the processing container 101 maintained at a predetermined pressure (at a vacuum pressure level), and passes through the quartz showerhead 105, It is put in the process gas atmosphere whose main component is ozone in the process space (S). Here, ozone is decomposed into oxygen and active oxygen atoms by irradiation of ultraviolet rays, and the semiconductor wafer w on the mounting table 103 is thermally oxidized by the active oxygen.

In this process, since the cooling gas, for example, air is circulated by the air supply 122, the exhaust port 123, and the blower 124 in the lamp house 120, the surface temperature of the ultraviolet lamp 121 is fixed. It can be maintained in the range, and the ultraviolet lamp 121 can be turned on efficiently.

In addition, in the above process, although the gas in the processing container 101 is exhausted to the outside by the exhaust system 150, even if ozone remains in the exhaust, the ozone is the pyrolysis unit 155 in the exhaust system 150. When it passes through, it decomposes and disappears. Even if it is not completely decomposed by the pyrolysis unit 155, since there is also a catalyst unit 156 for ozone decomposition downstream thereof, the residual ozone is decomposed and reduced by this catalyst unit 156. As a result, the ozone in the exhaust gas is reduced to a concentration below the allowable value (0.1 ppm).

In addition, while the ozone generator 161 is stable, the gas containing ozone is exhausted by the initial line 162 directly to the exhaust pipe 152, but even in this case, ozone in the gas is supplied to the catalyst unit 156. It is safe because it is decomposed by. In addition, since the characteristics of the catalyst unit 156 are checked by the upper ozone sensor 156c and the lower ozone sensor 156d, breakdown or deterioration of the catalyst 156a and / or 156b can be easily detected. If deterioration of the catalyst 156a or 156b is confirmed, the catalysts 156a and 156b in the catalyst unit 156 may be replaced with new ones.

Thus, according to the oxidation treatment apparatus, since the pyrolysis unit 155 for pyrolyzing ozone is provided in the exhaust system 150, the ozone remaining in the exhaust can be reduced to an acceptable level.

In addition, since the pyrolysis unit 155 includes alumina heat block (heat transfer medium) 155b, corrosion of the pyrolysis unit 155 can be prevented even when nitrogen oxide (NOx) is mixed in the exhaust gas. It becomes possible and can improve durability.

In addition, since the catalyst unit 156 for decomposing ozone is installed downstream of the pyrolysis unit 155 of the exhaust system 150, the catalytic ozone is not completely decomposed into the pyrolysis unit 155. Can be sufficiently decomposed, and even if a backflow occurs in the processing vessel 101 due to a pressure change in the exhaust pipe 152, there is no fear of causing metal contamination by the catalyst in the semiconductor wafer w.

In addition, since the inert gas introduction means 158 for diluting the exhaust gas is provided upstream of the catalyst unit 156 of the exhaust system 150, that is, upstream of the pyrolysis unit 155, nitrogen oxides (NOx) are included. The exhaust gas can be diluted with an inert gas, and the corrosion and damage of the catalyst of the exhaust system 150 and the catalyst of the catalyst unit 156 due to nitrogen oxides (NOx) can be reduced, and the durability can be improved. Can be.

As mentioned above, although embodiment of this invention was described in detail by drawing, this invention is not limited to the said embodiment, A various design change etc. are possible in the range which does not deviate from the summary of this invention. For example, the above embodiment shows a cold wall type oxidation treatment apparatus, but the present invention is also applicable to a hot wall oxidation treatment apparatus. In addition, the means for decomposing ozone when oxidizing an object to be treated in a processing container is not limited to ultraviolet rays, but may be only heating or a combination of heating and ultraviolet rays. As said embodiment, although the single type oxidation treatment apparatus is shown, this invention can be used also for a batch oxidation treatment apparatus. In addition, as the object to be processed, a glass substrate, an LCD substrate, or the like, in addition to the semiconductor wafer, can be applied.

According to this aspect of the invention, even if ozone is generated in the lamphouse, ozone is decomposed by the ozone decomposition unit and reduced to an acceptable level when ozone is exhausted through the exhaust port. In addition, ozone can be prevented from occurring in the lamphouse, and the ozone exhausted from the inside of the processing vessel is reduced to an acceptable level.

Claims (9)

A processing container having an interior in which the substrate is accommodated and a window through which ultraviolet rays are transmitted; A lamp house having an ultraviolet lamp capable of irradiating ultraviolet rays into the processing vessel through the window; A processing gas supply unit for supplying a processing gas containing ozone into the processing container; An air supply port for introducing air for cooling into the lamp house; An exhaust port for exhausting cooling air from the lamp house; And It comprises an ozone decomposition unit connected to the exhaust port, Ultraviolet rays from the ultraviolet lamp are irradiated with the processing gas supplied into the processing vessel, so that ozone in the processing gas is decomposed to perform oxidation treatment on the substrate placed inside the processing vessel. The oxidation treatment apparatus according to claim 1, wherein the ozone decomposition unit is composed of a catalyst unit having a catalyst mainly comprising manganese dioxide. The oxidation treatment apparatus according to claim 1, wherein the ozone decomposition unit is composed of a pyrolysis unit having a heater. A processing container having an interior in which the substrate is accommodated and a window through which ultraviolet rays are transmitted; A lamp house having an ultraviolet lamp capable of irradiating ultraviolet rays into the processing vessel through the window; A processing gas supply unit for supplying a processing gas containing ozone into the processing container; An air supply port for introducing an inert gas for cooling into the lamp house; And It comprises an exhaust port for exhausting the inert gas for cooling from the lamp house, Ultraviolet rays from the ultraviolet lamp are irradiated with the processing gas supplied into the processing vessel, so that ozone in the processing gas is decomposed to perform oxidation treatment on the substrate placed inside the processing vessel. 5. The air supply port according to claim 4, wherein the air supply port and the exhaust port are connected to a circulation flow channel for circulating an inert gas. And the radiator for dissipating heat of inert gas circulated by the circulation statistics. A processing container having an interior in which the substrate is placed; A processing gas supply unit for supplying a processing gas containing ozone into the processing container; A heater for heating the substrate placed inside the processing vessel; An exhaust system for evacuating the exhaust gas and the interior of the processing vessel from the interior of the processing vessel under reduced pressure; And It comprises a pyrolysis unit provided in the exhaust system to thermally decompose ozone, And an ozone contained in the processing gas introduced into the processing vessel to perform oxidation treatment on the substrate placed inside the processing vessel. 7. An oxidation treatment apparatus according to claim 6, wherein said pyrolysis unit is provided with an alumina heat transfer medium. 7. An oxidation treatment apparatus according to claim 6, wherein a catalytic unit for decomposing ozone is provided in the exhaust system at a portion downstream from the pyrolysis unit. The oxidation treatment apparatus according to claim 6, wherein an inert gas introduction unit for diluting the gas exhausted from the inside of the processing vessel with an inert gas is provided in the exhaust system at a portion upstream of the pyrolysis unit.