JP7264536B2 - Humidity control gas generator - Google Patents

Description

The present invention relates to a humidity control gas generator that generates gas adjusted to a desired humidity.

Patent Literature 1 discloses a saturating tank of a constant humidity gas generator. According to that disclosure, a gas outlet is provided within the saturation tank body. The inside of the saturation tank body is filled with water, leaving an upper space. The gas lead-out pipe passes through the water from the space inside the saturator main body to reach the gas outlet under the water surface.

The temperature of the water in the saturation tank body is controlled to the desired temperature, and the temperature of the space is controlled to be higher than the water temperature. Gas is introduced into the water in the form of bubbles from the bottom of the saturation tank. The bubbles become saturated gas while passing through the water and reach the upper space. The gas is humidified in the headspace and then enters the gas outlet tube. While the gas passes through the gas lead-out pipe, excess water vapor is condensed into gas with a saturated water vapor pressure corresponding to the temperature of the water, and sent out from the gas outlet.

The use of this saturated bath eliminates the need for a constant temperature water bath, so the constant humidity gas generator can be downsized.

JP-A-63-123109

An example of the application of the constant humidity gas generator is dry cleaning of silicon wafers in the semiconductor manufacturing process, in which gas whose humidity has been adjusted to a predetermined value is used.

A humidity-controlled gas generator that generates a humidity-controlled gas for dry cleaning in a semiconductor manufacturing process must meet a plurality of highly demanded performance requirements. For example, good durability to pure water, easy maintenance for long life, high cleanliness of output gas (extremely low concentration of impurities such as metal ions contained), high accuracy of humidity control, small size performance and low cost.

The disclosure of Patent Document 1 teaches a constant humidity gas generator excellent in compactness and low cost, but it is insufficient to enable application to semiconductor manufacturing processes, and further improvements are needed. requested.

One object of the present invention is to provide an improved humidity-controlled gas generator that is applicable to semiconductor manufacturing processes.

Another object of the present invention is to provide an improved humidity control gas generator that is excellent in water resistance, maintainability, cleanliness of the output gas, or controllability of the humidity of the output gas.

A humidity-conditioning gas generator according to one embodiment includes a saturation tank body having therein a gas region and a water reservoir below the gas region, and a gas reflux device disposed inside the saturation tank body.

The gas recirculation device has a gas return pipe, a gas delivery pipe, a drain pipe and a trap box. A gas return line passes from a gas inlet located in the gas area through the water reservoir to a gas outlet located in the trap box. The gas delivery pipe extends from the gas delivery port arranged in the trap box to the gas delivery port arranged outside the saturation tank main body. A drain pipe leads from a water inlet located within the trap box to a water outlet located outside the saturation tank body.

The humidity-controlled gas generator configured as described above is superior to conventional humidity-controlled gas generators in terms of water resistance, maintainability, cleanliness of output gas, and controllability of humidity of output gas. It can be expected to be superior to the humidity control gas generator of

1 is a longitudinal sectional view of a humidity-conditioning gas generator according to one embodiment; FIG. Fig. 3 is a longitudinal sectional view showing an enlarged flange portion of the humidity-conditioning gas generator according to one embodiment; 1 is a cross-sectional view of a gas recirculation device of a humidity control gas generator according to one embodiment; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the embodiments described below do not limit the invention according to the scope of claims, and that all of the elements described in the embodiments and their combinations are essential to the solution of the invention. Not exclusively.

FIG. 1 is a vertical cross-sectional view of a humidity control gas generator according to one embodiment.

As shown in FIG. 1, a humidity-controlled gas generator 1 according to one embodiment includes a saturation tank main body 2 , a reserve water tank 3 , and a gas reflux device 4 .

The saturation tank main body 2 has a shape of a substantially cylindrical or polygonal cylinder (for example, a square cylinder) elongated vertically as a whole. The saturation tank main body 2 is composed of three parts, an upper cap portion 20 , a central body portion 21 and a bottom base portion 22 . The main material of these parts of the saturation tank body 2 is a highly durable metal such as stainless steel.

The upper end surface of the peripheral wall of the central barrel portion 21 is in close contact with the lower end surface of the peripheral wall of the upper cap portion 20, and the upper surface of the central portion of the bottom base portion 22 is in close contact with the lower end surface of the peripheral wall of the central barrel portion 21. The two parts are joined in sequence to form the saturator body 2 . The connection between these three parts consists of bolting between the flange 20a at the lower end of the peripheral wall of the upper cap portion 20 and the flange 21a at the upper end of the peripheral wall of the central body portion 21, and the lower end of the peripheral wall of the central body portion 21. A bolt connection between the flange 21b of the bottom base portion 22 and the flange 22a of the bottom base portion 22 on the outer edge side. Therefore, when the bolts are released, the saturation tank main body 2 can be disassembled into three parts.

When the humidity control gas generator 1 is in operation, the inside of the saturating tank main body 2 is filled with water, leaving an upper area where the gas should exist. When the humidity control gas generator 1 is used for dry cleaning of silicon wafers, the water filled in the saturation tank main body 2 is ultrapure water. The area filled with water in the saturation tank main body 2 is hereinafter referred to as a water storage area W, and the upper gas area is hereinafter referred to as a gas area G.
The height dimension of the upper cap portion 20 and the central body portion 21 of the saturation tank main body 2 is selected so as to satisfy the following conditions. That is, the water surface is almost in the upper half height region of the central body portion 21 and does not reach the upper cap portion 20, so the inside of the upper cap portion 20 always corresponds to the gas region G.

A gas heater (heating section) 5 for heating the gas in the gas region G is provided on the outer surface of the peripheral wall of the upper cap section 20 of the saturation tank main body 2 . Most of the outer surface of the upper cap portion 20 may be covered with the gas heater 5 .

A water heater 6 for heating the water in the reservoir area W is arranged at a lower portion inside the saturation tank main body 2, for example, at a height position close to the bottom base portion 22. As shown in FIG. The heater may be arranged on the wall of the saturation tank main body 2, for example, the outer surface of the peripheral wall of the central body portion 21. Instead of the water heater 6 , a water heater/cooler capable of heating and cooling water, such as a heat pump using the Peltier effect, may be in close contact with the outer surface of the wall of the saturation tank main body 2 .

A gas introduction passage 22b is formed in the wall of the bottom base portion 22 of the saturation tank body 2 . A gas inlet 22c of the gas introduction path 22b opens to the outer surface of the wall of the bottom base portion 22, and a gas outlet 22d thereof opens toward the water reservoir W of the wall of the bottom base portion 22. As shown in FIG. The gas outlet 22d is provided with a porous body 7 for forming fine bubbles B in the gas discharged from there into the water reservoir W. As shown in FIG.

A spare water tank 3 is arranged outside the saturation tank main body 2 . The reserve water tank 3 has an upper portion 30 and a lower portion 31 . The spare water tank 3 is formed by connecting these two parts in such a manner that the upper surface of the wall of the lower part 31 is in close contact with the lower end surface of the peripheral wall of the upper part 30 . The connection between these two parts is made by a bolt connection between a flange 30a at the lower end of the peripheral wall of the upper part 30 and a flange 31a at the outer edge of the lower part 31. As shown in FIG. Therefore, the reserve water tank 3 can be disassembled into two parts by releasing the bolts.

The main material of the reserve water tank 3 is a durable metal such as stainless steel.

An opening 30b is provided in the wall of the upper part 30 of the reserve water tank 3, for example, the ceiling wall, and an opening 20b is also provided in the upper wall of the upper cap part 20 of the saturation tank main body 2. They are connected by a communicating pipe 8 . An opening 31b is provided in the wall of the lower part 31 of the preliminary water tank 3, for example, the bottom wall, and an opening 21c is provided in the lower wall of the saturation tank main body 2, for example, the lower peripheral wall of the central body part 21. , and both openings 31b and 21c are connected by a water communicating pipe 9. As shown in FIG.

The height dimension of the reserve water tank 3 and the height of its arrangement with respect to the saturation tank main body 2 are selected so as to satisfy the following conditions. That is, the height of the water surface is within the internal height dimension of the reserve water tank 3 . Therefore, the height of the water surface inside the reserve water tank 3 and the height of the water surface inside the saturation tank main body 2 are equal, and the gas area G and the water storage area W are similarly present inside the reserve water tank 3 .

In this way, both the gas area G and the water storage area W are in communication with the interior of the reserve water tank 3 and the interior of the saturation tank main body 2 . Therefore, when the water inside the saturation tank main body 2 is consumed and reduced, water is replenished from the reserve water tank 3 to the inside of the saturation tank main body 2 .

Another opening 30c is provided in the wall of the reserve water tank 3, and the water supply pipe 10 is connected to the opening 30c. When the water level in the saturation tank drops too much, water can be supplied manually or automatically from the water supply pipe 10 into the reserve water tank 3. - 特許庁

A gas reflux device 4 is arranged inside the saturation tank main body 2 . The gas recirculation device 4 includes a gas return pipe 40 , a gas delivery pipe 41 , a drain pipe 42 and a trap box 43 . The main material of the gas recirculation device 4 is a durable metal such as stainless steel.

The gas return pipe 40 has a substantially linear shape and is arranged vertically, for example, substantially vertically, and has a gas inlet 40a at its upper end and a gas outlet 40b at its lower end. A gas inlet 40 a of the gas return pipe 40 is arranged above the gas region G in the saturation tank main body 2 , for example, at a position close to the top wall of the upper cap portion 20 . The gas return pipe 40 passes from the gas inlet 40 a in the gas region G through the reservoir W to reach the gas outlet 40 b inside the trap box 43 .

A gas outlet 40 b of the gas return pipe 40 is arranged at a position lower than the uppermost position inside the trap box 43 , for example, at a position lower than the top wall of the trap box 43 by a predetermined distance. A portion of the gas return pipe 40 in the vicinity of the gas outlet 40b bends obliquely with respect to the vertical to reach the gas outlet 40b (see FIG. 3). The direction of the gas outlet 40b on the horizontal plane is different from the direction of the gas inlet 41a of the gas delivery pipe 41 on the horizontal plane viewed from the gas outlet 40b. Therefore, the gas flow blown out from the gas outlet 40b is directed in a direction different from that of the gas inlet 41a of the gas delivery pipe 41 .

Further, as shown in FIG. 3, the front end face 40c of the gas outlet 40b of the gas return pipe 40 is substantially circular. being cut. More specifically, the gas outlet 40b is located near the inner surface of the inner wall of the trap box 43, faces the inner surface of that wall, and is located at a portion of the gas outlet 40b (e.g., the most forward of the gas outlet 40b). extended tip) is in contact with the inner surface of the trap box 43 .

With the above configuration, when the condensed water comes out from the gas outlet 40b and falls into the trap box 43 while the gas is passing through the gas return pipe 40, it is carried by the gas flow blown out from the gas outlet 40b and the gas is sent out. The problem of getting into the gas inlet 40a of the tube 41 is reduced.

Further, as shown in FIG. 3, the central axis of the gas return pipe 40 at the gas outlet 40b of the gas return pipe 40 is inclined in the circumferential direction with respect to the inner surface of the inner wall of the trap box 43. As shown in FIG.

A gas temperature sensor 11 for detecting the temperature of gas is arranged at approximately the same height as the gas inlet 40a of the gas return pipe 40 in the gas region G. As shown in FIG. A detection signal of the gas temperature sensor 11 is input to a control device (not shown) arranged outside the saturation tank main body 2 and used for gas temperature control by the gas heater.

The gas delivery pipe 41 has, for example, an inverted L-shaped bent shape, is arranged vertically, and has a gas delivery port 41a at the lower end of its substantially vertical portion. It has a gas delivery port 41b at its upper end.

A gas inlet 41 a of the gas delivery pipe 41 is arranged at a position higher than the gas outlet 40 b of the gas return pipe 40 inside the trap box 43 . The gas delivery pipe 41 extends upward from the gas delivery port 41a, goes out of the trap box 43, enters the water storage area W, changes its direction substantially horizontally, and is below the water surface of the wall of the central body portion 21. , and reaches the gas delivery port 41b arranged outside the saturation tank main body 2. As shown in FIG.

A water temperature sensor 12 for detecting the temperature of water is arranged at approximately the same height as the gas delivery pipe 41 in the water reservoir W. As shown in FIG. A detection signal of the water temperature sensor 12 is input to a control device (not shown) arranged outside the saturation tank main body 2 and used for water temperature control by the water heater 6 .

The drain pipe 42 has a water inlet 42a arranged substantially at the bottom inside the trap box 43 and a water outlet 42b arranged outside the saturation tank main body 2 . The drain pipe 42 extends from the water inlet 42 a to the outside of the trap box 43 , passes through the wall of the central body 21 and goes out of the saturation tank main body 2 .

The trap box 43 is arranged within the water storage area W in the central body 21 of the saturation tank main body 2 and at a position higher than the water heater 6 described above.

As shown in FIG. 3, the horizontal cross-sectional area of the trap box 43 is larger than the horizontal cross-sectional area of the gas return pipe 40. Within the trap box 43, the gas outlet 40b of the gas return pipe 40 and the gas inlet 40a of the gas delivery pipe 41 are separated by They are arranged at a predetermined distance in the horizontal direction. As described above, inside the trap box 43, the gas outlet 40b of the gas return pipe 40 faces in a direction different from the direction of viewing the gas inlet 40a of the gas delivery pipe 41 from the gas outlet 40b. Furthermore, the trap box 43 has a height dimension equal to or greater than a predetermined value, and the gas outlet 40b of the gas return pipe 40 is arranged at a position lower than the gas inlet 40a of the gas delivery pipe 41 within the trap box 43 . Furthermore, inside the trap box 43, the gas feed port 41a of the gas feed pipe 41 is arranged at a high position a predetermined height away from the bottom surface of the trap box 43 where water is to be accumulated.

The entire inner surface of the saturation tank body 2 in contact with the gas region G and the water storage region W is made of a corrosion-resistant material such as fluororesin (such as Teflon (registered Trademark)), is coated with a layer of As shown in FIG. 2, the mutual contact surfaces of the upper cap portion 20 and the central body portion 21 of the saturation tank body 2 (the mutually facing contact surfaces of both flanges 20a and 21a), and the central body portion 21 and the bottom The mating surfaces of the base portions 22 (the mating surfaces of both flanges) are also coated with the same layer of corrosion-resistant material.

The inner surfaces of the reserve water tank 3 which are in contact with the gas area G and the water storage area W are also coated with the same layer of corrosion resistant material. The mutual contact surfaces of the upper part 30 and the lower part 31 of the reserve water tank 3 (the facing contact surfaces of both flanges 30a, 31a) are also coated with the same layer of corrosion-resistant material.

The outer surfaces of the gas recirculation device 4 in contact with the gas region G and the water storage region W (for example, the outer surface of the trap box 43) are also coated with the same layer of corrosion resistant material.

Compared to conventional humidity-controlled gas generators, the humidity-controlled gas generator 1 of the present embodiment described above has the following advantages: It can be expected to be superior to conventional humidity control gas generators.

The humidity-conditioning gas generator 1 of the present embodiment can be suitably used in the dry cleaning process of the semiconductor manufacturing process, and can also be used in other semiconductor manufacturing processes, such as the humidity control of the atmosphere in the stepper in the exposure process, and the use of a spin coater. It can also be suitably used for controlling the humidity of the atmosphere in the coating process.

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

In addition, the dimensions, shapes, etc. of each illustrated component are not necessarily illustrated accurately, and may be modified as appropriate to emphasize the features of the present embodiment.

DESCRIPTION OF SYMBOLS 1 -- Humidity-conditioning gas generator 2 -- Saturation tank main body 3 -- Reserve water tank 4 -- Gas recirculation device 5 -- Gas heater (heating part) 20 -- Upper cap part 20a -- Flange 21 -- Center body part 21a -- Flange 22 -- Bottom base Parts 30 Upper part 30a Flange 31 Lower part 31a Flange 40 Gas return pipe 40a Gas inlet 40b Gas outlet 40c Front end face 41 Gas delivery pipe 41a Gas delivery port 41b Gas delivery port 42 Drain pipe 42a... Water inlet 42b... Water outlet 43... Trap box G... Gas area W... Water storage area

Claims (10)

a saturation tank body having therein a gas region and a water reservoir below the gas region;
and a gas reflux device disposed inside the saturation tank body,
The gas recirculation device has a gas return pipe, a gas delivery pipe, a drain pipe, and a trap box,
the gas return pipe passes through the water storage area from a gas inlet located within the gas area to a gas outlet located within the trap box;
The gas delivery pipe extends from a gas delivery port arranged in the trap box to a gas delivery port arranged outside the saturation tank main body,
A water temperature sensor used for water temperature control of the water storage area is arranged at approximately the same height as the gas delivery pipe in the water storage area,
The humidity control gas generator, wherein the drain pipe extends from a water inlet arranged in the trap box to a water outlet arranged outside the saturation tank main body. a saturation tank body having therein a gas region and a water reservoir below the gas region;
and a gas reflux device disposed inside the saturation tank body,
The gas recirculation device has a gas return pipe, a gas delivery pipe, a drain pipe, and a trap box,
the gas return pipe passes through the water storage area from a gas inlet located within the gas area to a gas outlet located within the trap box;
The gas delivery pipe extends from a gas delivery port arranged in the trap box to a gas delivery port arranged outside the saturation tank main body,
The drain pipe extends from a water inlet arranged in the trap box to a water outlet arranged outside the saturation tank main body,
The saturation tank body has an upper cap portion and an intermediate body portion coupled to the lower end of the upper cap portion,
The saturation tank body can be disassembled into the upper cap portion and the intermediate barrel portion separated from each other by releasing the mutual connection between the upper cap portion and the intermediate barrel portion,
the water surface of the reservoir area is within the intermediate body portion and does not reach the upper cap portion, and the inside of the upper cap portion is the gas area;
A humidity control gas generator, wherein the saturated layer main body has a first heater for heating the gas in the gas area and a second heater for heating the water in the water storage area. a saturation tank body having therein a gas region and a water reservoir below the gas region;
and a gas reflux device disposed inside the saturation tank body,
The gas recirculation device has a gas return pipe, a gas delivery pipe, a drain pipe, and a trap box,
the gas return pipe passes through the water storage area from a gas inlet located within the gas area to a gas outlet located within the trap box;
The gas delivery pipe extends from a gas delivery port arranged in the trap box to a gas delivery port arranged outside the saturation tank main body,
The drain pipe extends from a water inlet arranged in the trap box to a water outlet arranged outside the saturation tank main body,
the gas return pipe is arranged vertically in the water reservoir;
A humidity control gas generator, wherein the horizontal cross-sectional dimension of the gas return pipe in the water reservoir is smaller than the horizontal cross-sectional dimension of the trap box. The humidity-controlled gas generator according to any one of claims 1 to 3, wherein the gas outlet of the gas return pipe is directed toward the inner surface of the trap box and arranged near the inner surface. Device. 5. The humidity control gas generator according to claim 4 , wherein at least part of the end face of said gas outlet is obliquely cut so as to contact the inner surface of said trap box. The inner surface of the saturation tank body is coated with a layer of corrosion-resistant resin having corrosion resistance to pure water,
The humidity control gas generator according to any one of claims 1 to 5, wherein the outer surface of the gas recirculation device is coated with a layer of corrosion-resistant resin having corrosion resistance against pure water. The lower end of the upper cap portion and the upper end of the intermediate body are formed with flange portions protruding outward from the saturation tank body,
3. A humidity control gas generator according to claim 2, wherein the facing surfaces of these flange portions are coated with a layer of corrosion-resistant resin having corrosion resistance against pure water. A part of the gas return pipe is curved so that the gas discharged from the gas outlet forms a rotating flow inside the trap box when the trap box is viewed from above. 6. The humidity control gas generator according to any one of 1 to 5. The humidity control gas generator according to any one of claims 1 to 5, wherein the lower end of the gas outlet is positioned below the lower end of the gas inlet in the trap box. The humidity control gas generator has a spare water tank,
The humidity-conditioned gas according to any one of claims 1 to 5, wherein the lower portion of the reserve water tank communicates with the water storage area, and the upper portion of the reserve water tank communicates with the gas area. Generator.

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