JPH06115906A - Ozone-beam generation apparatus - Google Patents

Abstract

PURPOSE:To provide an ozone-beam generation apparatus capable of continuously supplying ozone to a desired apparatus. CONSTITUTION:An ozone-containing gas is introduced from an ozone gas generation and exhaustion apparatus 1 into an ozone-liquefaction chamber 37 of an ozone chamber 27 through an ozone-containing gas introducing pipe 42. The introducing pipe 42, an exhaustion pipe 43 to exhaust oxygen, etc., and an ozone-exhaustion pipe 44 to exhaust ozone to an oxidation treatment tank 12 are connected to the ozone chamber 27. The opening at the lower end of the ozone-exhaustion pipe 44 is placed in the liquefied ozone in the liquefaction chamber 37 to separate the inside of the exhaustion pipe 44 from the liquefaction chamber 37 storing the liquefied ozone. Since the inside of the exhaustion pipe 44 is maintained at a low pressure below the saturated vapor pressure, ozone is successively gasified and continuously supplied to the oxidation treatment tank 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozone beam generator for generating ozone, which is widely used in water treatment, sterilization treatment, semiconductor manufacturing process and the like.

[0002]

BACKGROUND OF THE INVENTION As an ozone beam generator capable of stably supplying a high concentration of ozone and having high safety, it is disclosed in Japanese Patent Laid-Open No. 4-87.
The one described in Japanese Patent No. 245 is known. As shown in FIG. 5, this ozone beam generator is composed of an ozone gas generating / exhausting device 1 and an ozone cryostat 2.

The ozone gas generation / exhaust device 1 sends oxygen from the oxygen cylinder 3 to the ozonizer 5 through the pressure regulating valve 4 to generate an ozone-containing gas in which oxygen and ozone are mixed, and the ozone-containing gas is mass flow controller 6 It is configured to be introduced into the ozone cryostat 2 via the particulate removal filter 7.

In the ozone cryostat 2, the ozone-containing gas introduced from the ozone gas generating / exhausting device 1 is introduced into the ozone chamber 60 of the cryostat 25 through the flow rate adjusting valve 8 and the ozone-containing gas introducing pipe 61.
The ozone chamber 60 is in thermal contact with the cold head 11 of the refrigerator unit 10 that operates in the compressor unit 9, and is maintained at a low temperature of about 80K to 100K.

In the ozone chamber 60, only ozone is liquefied or solidified due to the difference in saturated vapor pressure. Therefore, the conductance valve 13 provided between the ozone discharge pipe 62 connected to the ozone chamber 60 and a desired device such as the oxidation treatment tank 12 is closed, and the ozone discharge pipe 62 is connected to the vacuum pump 14 of the ozone gas generation / exhaust device 1. By opening the valve 15 connected to the valve and operating the vacuum pump 14, oxygen and nitrogen that are not liquefied are exhausted. In addition, between the valve 15 and the vacuum pump 14, an ozone killer 16 that heats ozone to convert it into oxygen in order to prevent the exhaust of ozone to the outside.
There is provided a cooler 17 for cooling the heated oxygen, and a liquid nitrogen trap 18 for preventing contamination from the vacuum pump 14, in particular, inclusion of carbide in the ozone chamber 60.

As shown in FIG. 6, the ozone chamber 60 has a flange 63 welded with a stainless ozone-containing gas introduction pipe 61 and an ozone discharge pipe 62, and a stainless steel container 64 welded with the flange 63. It has and. The cold head 11 made of a copper block is brazed and brought into thermal contact with the periphery of the ozone chamber 60, and the ozone chamber 60 is cooled by the refrigerator unit 10 via the cold head 11. .

The cold head 11 is provided with a temperature sensor 20 and a heater 21 which are controlled by a temperature controller 19, and controls the temperature of the liquid ozone stored in the chamber 60 with an accuracy within 0.1K at 80K-100K. However, it is configured so that ozone can be gasified by obtaining a predetermined ozone saturated vapor pressure. This gasified ozone is
By closing the valves 8 and 15 and opening the valve 13, the ozone is supplied to the oxidation treatment tank 12 through the ozone discharge pipe 62. The pressure at this time is measured by the vacuum gauge 22. In case of an explosion, the destruction valve 23 is installed above the ozone chamber 60.
Is provided.

[0008]

By the way, in such a conventional ozone beam generator, the ozone-containing gas is introduced into the ozone chamber 60 with the valve 13 closed until a predetermined amount of liquefied ozone is stored. After a predetermined amount of ozone was stored and oxygen and nitrogen were exhausted, the valves 8 and 15 were closed and the valve 13 was opened to supply ozone gas to the oxidation treatment tank 12.

For this reason, only a so-called batch type process of supplying ozone to the oxidation treatment tank 12 at regular intervals can be performed, and ozone cannot be continuously supplied. For this reason, there is a problem in that it cannot be applied even when it is desired to continuously supply ozone, such as in a semiconductor manufacturing process.

An object of the present invention is to provide an ozone beam generator capable of continuously supplying ozone.

[0011]

DISCLOSURE OF THE INVENTION The present invention is an ozone beam generator for ozone-generating a gas containing oxygen to generate ozone, wherein the ozone-containing gas is introduced into an ozone chamber for storing liquefied ozone. An ozone-containing gas introduction path, an ozone discharge path for discharging ozone gas to a desired device, and an exhaust path connected to an exhaust means for exhausting gases such as oxygen and nitrogen in the ozone chamber. The lower end opening of the is placed in the liquefied ozone in the chamber.

[0012]

In the present invention, the ozone-containing gas introduced into the ozone chamber from the ozone-containing gas introduction passage is cooled by an appropriate cooling means, and only ozone is liquefied due to the difference in saturated vapor pressure. This liquefied ozone is stored in the chamber. Oxygen or nitrogen gas which is not liquefied is exhausted from the ozone chamber through the exhaust passage by the exhaust means.

On the other hand, since the lower end opening of the ozone discharge passage is arranged in the liquefied ozone, the oxygen gas and the nitrogen gas in the ozone chamber are blocked by the liquefied ozone. Therefore, if the pressure and temperature in the ozone discharge passage are controlled, the liquefied ozone in the ozone discharge passage is gasified, and high-purity ozone gas is supplied to the desired device from the discharge passage. At this time, the ozone discharge path is blocked from oxygen and nitrogen in the chamber by the liquefied ozone,
It is not necessary to switch the valve to exhaust oxygen and nitrogen in the ozone chamber before supplying ozone as in the conventional case, and the ozone gas is continuously supplied while the lower end of the ozone discharge path is placed in liquefied ozone. Can be supplied.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same components as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted or simplified. As shown in FIG. 1, the ozone beam generator of the present embodiment has an ozone gas generating and exhausting device 1 and an ozone cryostat 2 which are the same as those of the conventional one.
It has and. The ozone cryostat 2 includes the cryostat 25, the destruction valve 23, the valve 8,
It is composed of 13, 15 and the like.

The cryostat 25 comprises a refrigerator unit 10, a vacuum container 26, and an ozone chamber 27 which is arranged in the vacuum container 26 and in which the cold head 11 of the refrigerator unit 10 is thermally bonded and cooled. .

As shown in FIG. 2, the ozone chamber 27 is provided with a stainless steel container 40 and a stainless steel lid 41 that closes the upper opening of the container 40. The lid 41 includes an ozone-containing gas introduction pipe 42 connected to the ozone gas generation / exhaust device 1 via the valve 8 and the valve 1
An exhaust pipe 43 connected to the ozone gas generation / exhaust device 1 via 5 and an ozone discharge pipe 4 connected to the oxidation treatment tank 12 via the valve 13 and connected to the destruction valve 23.
4 and 4 are fixed by welding. Each of these tubes 42-
Of the 44, only the ozone discharge pipe 44 is provided so as to project from the lower end surface of the lid 41 and extends to near the bottom of the container 40.

Around the container 40 and the lid 41, a heat transfer member 45 made of a material having a high thermal conductivity such as copper or aluminum is provided. The heat transfer member 45 is in thermal contact with the cold head 11 of the refrigerator unit 10, and is provided so as to cool the ozone chamber 27 to a low temperature of about 80 to 100K. Further, the container 40, the lid 41, the heat transfer member 4
5 are joined by bolts and nuts screwed through the through holes 46. At this time, an indium plate is interposed on each joint surface to prevent a gap from being formed between the joint surfaces, thereby preventing a decrease in thermal conductivity. Further, the container 40 and the heat transfer member 45 are brazed so that the thermal conductivity does not decrease. A stainless steel seal 47 is interposed between the container 40 and the lid 41 so that the ozone-containing gas inside the container 40 does not leak outside. This container 40
The ozone liquefaction chamber 37 is surrounded by the space surrounded by the lid 41.
Are formed.

In the heat transfer member 45, a temperature sensor 20 and a heater 21 connected to a temperature controller 19 are built in like the conventional ozone beam generator so that the temperature of the heat transfer member 45 can be controlled to a predetermined temperature. Is configured.

When assembling the ozone cryostat 2 of the ozone beam generator of this embodiment, first, the ozone-containing gas introduction pipe 42, the exhaust pipe 43, and the ozone discharge pipe 44 are welded to the lid 41. And container 40 and each pipe 42
The lid 41 to which ~ 44 is welded is electrolytically polished so that no unevenness remains in the welded portion or the gas flow path. Next, the container 40,
The lid 41 and the heat transfer member 45 are bolted to form an ozone chamber 27, and the chamber 27 is placed in the vacuum container 26 and brought into thermal contact with the cold head 11 to assemble the cryostat 25.

The ozone cryostat 2 is assembled by attaching the destruction valve 23 and the valves 8, 13, 15 and the like to the cryostat 25 thus constructed, and further connecting the ozone gas generating and exhausting device 1 and the oxidation treatment tank 12 and the like. Assemble the ozone beam generator.

In such an ozone beam generator, the oxygen cylinder 3, the pressure adjusting valve 4, the ozonizer 5, the mass flow controller 6, the filter 7, the valve 8, the ozone-containing gas introduction pipe of the ozone gas generating and exhausting device 1 are used as in the conventional case. Ozone liquefaction chamber 3 of ozone chamber 27 via 42
An ozone-containing gas is introduced into 7.

In the ozone liquefaction chamber 37, the cold head 1
1, the temperature is maintained at a low temperature of 80K to 100K, and only ozone is liquefied due to the difference in saturated vapor pressure. The liquefied ozone is stored in the ozone liquefaction chamber 37, and the unliquefied oxygen and nitrogen are exhausted by the vacuum pump 14 through the exhaust pipe 43, the ozone killer 16, the cooler 17, and the liquid nitrogen trap 18.

On the other hand, the ozone discharge pipe 44 is arranged in the ozone whose lower end opening is liquefied. At this time, the inside of the ozone liquefaction chamber 37 is kept at a pressure of about 2 to 3 Torr, while the inside of the ozone discharge pipe 44 connected to the oxidation treatment tank 12 is set at a low pressure of about 0.08 Torr, so that the ozone is The water level of the liquefied ozone in the discharge pipe 44 is higher than the water level of the liquefied ozone in the ozone liquefaction chamber 37, and since it is below the saturated vapor pressure, the liquefied ozone is sequentially gasified from the upper surface side. It is continuously supplied to the oxidation treatment tank 12.

According to this embodiment as described above, the ozone-containing gas introducing pipe 42, the exhaust pipe 43,
The ozone exhaust pipe 44 is connected to the three pipes to connect the ozone exhaust pipe 4
Since the lower end opening of 4 is arranged in the liquefied ozone in the ozone liquefaction chamber 37, the inside of the ozone discharge pipe 44 can be shut off from the ozone liquefaction chamber 37 of the ozone chamber 27 by the liquefied ozone. Therefore, the oxygen and nitrogen gas in the ozone liquefaction chamber 37 does not mix into the ozone discharge pipe 44, and the valves 13 and 15 are used when the oxygen and nitrogen are exhausted and the ozone gas is supplied as in the conventional case. Since it is not necessary to switch, ozone gas can be continuously supplied. At this time, the pressure in the ozone discharge pipe 44 is set lower than that in the ozone liquefaction chamber 37 to be equal to or lower than the saturated vapor pressure of ozone, so that the liquefied ozone enters the ozone discharge pipe 44 to a high water level. Oxygen and nitrogen can be surely prevented from being mixed, and since the vapor pressure is equal to or lower than the saturated vapor pressure, it is possible to sequentially gasify the ozone gas from the upper surface and continuously and automatically supply the ozone gas to the oxidation treatment tank 12. Therefore, in the semiconductor manufacturing process or the like, the processing efficiency can be improved and the production efficiency of the semiconductor or the like can be improved as compared with the conventional case where ozone can be supplied only at regular intervals.

Further, since each of the tubes 42 to 44 is electrolytically polished including the welded portion with the lid 41, the gas flow path can be finished to have a smooth surface without irregularities. Therefore,
Impurities and the like do not remain and do not flow into the oxidation treatment tank 12 or the like as in the case where there are uneven portions. In particular, the ozone discharge pipe 4
Since the inside of 4 is shielded from the ozone liquefaction chamber 37 by the liquefied ozone, impurities are prevented from entering the ozone discharge pipe 44, and high-purity ozone containing no impurities can be supplied. . Therefore, generation of defective products such as semiconductors can be prevented.

A second embodiment of the present invention is shown in FIGS. In this embodiment, the exhaust pipe 43 is arranged in the ozone-containing gas introduction pipe 42, the ozone discharge pipe 44 is arranged in the exhaust pipe 43, and the ozone chamber 27 is constituted by these triple pipes. The lower end of the ozone-containing gas introduction pipe 42 is closed and used as an ozone liquefaction chamber 37 for storing the liquefied ozone.

In this embodiment as described above, the ozone-containing gas introduced by the ozone-gas generating / exhausting device 1 is provided on the outermost side of the triple pipe, and the ozone-containing gas introducing pipe 42 is provided.
It is introduced into the ozone liquefaction chamber 37 through a gap between it and the exhaust pipe 43. The ozone liquefaction chamber 37 is provided in the refrigerator unit 10
Since it is cooled by the cold head 11, the ozone is liquefied and stored in the ozone liquefaction chamber 37. In addition, oxygen and nitrogen gases that are not liquefied are exhausted from the gap between the exhaust pipe 43 and the ozone exhaust pipe 44 by the vacuum pump 14.

On the other hand, since the lower end opening of the ozone discharge pipe 44 is arranged in the liquefied ozone, it is blocked from the ozone liquefaction chamber 37 as in the first embodiment. Since the inside of the ozone discharge pipe 44 is kept at a saturated vapor pressure or less, the liquefied ozone is sequentially gasified and continuously supplied to the oxidation treatment tank 12.

Also in this embodiment, as in the case of the first embodiment, ozone gas can be continuously and automatically supplied. Further, since each tube 42 to 44 can be electrolytically polished, the gas flow path has no irregularities, and it is possible to supply high-purity ozone gas containing no impurities.

Further, the ozone-containing gas supplied from the ozone generating / exhausting device 1 is introduced into the ozone liquefying chamber 37 through the gap between the ozone-containing gas introducing pipe 42 which is in thermal contact with the cold head 11 and the exhaust pipe 43. The ozone-containing gas is sufficiently cooled by the time it touches the ozone-containing gas introduction pipe 42 and reaches the ozone liquefaction chamber 37, so that the liquefaction efficiency of ozone can be improved.

It should be noted that the present invention is not limited to the above-described embodiments, but includes modifications and improvements as long as the object of the present invention can be achieved. For example, in the first embodiment, the tubes 42 to 44 are separately provided, and in the second embodiment, the tubes 42 to 44 are provided as triple tubes.
The present invention is not limited to these configurations, and for example, the ozone-containing gas introduction pipe 42 and the exhaust pipe 43 may be provided as a double pipe, and the ozone discharge pipe 44 may be provided separately. In short, the present invention is provided with three gas flow paths of an ozone-containing gas introduction path for introducing an ozone-containing gas, an exhaust path for exhausting oxygen or nitrogen gas, and an ozone discharge path for supplying ozone gas. Only the discharge passage may be provided so that the lower end opening is arranged in the liquefied ozone, and its specific configuration may be appropriately set in the implementation.

Further, in the second embodiment, the exhaust pipe 43 is set to the outermost side, and the ozone-containing gas introducing pipe 4 is provided therein.
Two may be arranged. However, when the ozone-containing gas introduction pipe 42 is arranged on the outermost side as in the above-mentioned embodiment, the ozone-containing gas can be introduced while being cooled along the ozone-containing gas introduction pipe 42, and the ozone liquefaction efficiency can be improved. There is an advantage that it can be improved.

Further, the configuration of the ozone generating / exhausting device 1, the ozone cryostat 2, etc. is not limited to that of the above-mentioned embodiment, but may be another configuration. Further, the device for supplying ozone is not limited to the oxidation treatment tank 12, and various devices using ozone may be appropriately selected and connected. In particular, it is suitable for a semiconductor manufacturing apparatus or the like in which continuous supply of ozone is desired.

[0034]

As described above, according to the present invention, it is possible to continuously supply high-purity ozone containing no impurities to a desired apparatus.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an ozone beam generator according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing the ozone chamber of the first embodiment.

FIG. 3 is a diagram showing a configuration of an ozone beam generator according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing an ozone chamber of a second embodiment.

FIG. 5 is a diagram showing the configuration of a conventional ozone beam generator.

FIG. 6 is a cross-sectional view showing a conventional ozone chamber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ozone gas generating and exhausting device 2 Ozone cryostat 12 Oxidation treatment tank 27 Ozone chamber 40 Container 41 Lid 42 Ozone-containing gas introduction pipe 43 Exhaust pipe 44 Ozone exhaust pipe 45 Heat transfer member

Claims (1)

[Claims] 1. An ozone beam generator for ozone-generating a gas containing oxygen to generate ozone, wherein an ozone-containing gas is introduced into an ozone chamber for storing liquefied ozone. A passage, an ozone discharge passage having a lower end opening arranged in the liquefied ozone in the chamber and an upper end opening communicating with a desired device, and an exhaust passage connected to an exhaust means for exhausting gas in the chamber. An ozone beam generator comprising: