JP2004084971A - Filter and clean room using it - Google Patents

Abstract

An object of the present invention is to improve the performance of a filter capable of selectively removing only an organic gas having a large adverse effect, and establish a performance to reduce the concentration of a substance having a large adverse effect by applying the filter to a clean room, and extend the service life to reduce the running cost. Provide a filter that can be reduced and a clean room using the same.
A filter 1 according to the present invention is constituted by an adsorbent 11 formed by processing a semiconductor, an ULPA attached to the adsorbent, a HEPA filter 25, and a humidity adjusting device 6 disposed in front of the adsorbent. The ventilation of the humidity is supplied to the gap between the adsorbents and the ULPA and HEPA filters, the range of the adjusted humidity is set to 40 to 80%, and the adsorbent 11 is made of a plate-like body or a silicon wafer or a liquid crystal substrate. By using a container 12 in which crushed pieces are sealed, gaseous and molecular contaminants that are easily adsorbed on various silicon wafers and liquid crystal substrates are surely adsorbed on the adsorbent.
[Selection] Fig. 2

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a filter and a clean room using the same, and more particularly, to a filter for reducing gaseous and molecular contaminants adsorbed on a semiconductor or a liquid crystal device with high accuracy and a clean room using the same.
[0002]
[Prior art]
In recent years, as the degree of integration of semiconductors increases and the size of liquid crystal devices becomes smaller, it is important to reduce not only particles but also gaseous pollutants and molecular pollutants in a clean room as a production facility.
[0003]
However, in a conventional clean room, various organic gases such as ester compounds, silicon compounds, DBP plasticizers and DOP plasticizers, and gaseous pollutants and molecular pollutants such as acid and alkali gases and metal elements are removed from the clean room. Is diffused into the room by the constituent materials, indoor equipment, chemicals used, workers, etc., and adsorbs on silicon wafers and liquid crystal substrates produced in the clean room, thereby forming a defective state in circuit formation and electrical resistance. Therefore, it has been required to control the indoor concentration of pollutants in the clean room to about several ng to several hundred ng / m ³ .
[0004]
Therefore, in conventional clean rooms, gas filters and molecular pollutants have been removed by using chemical filters as high-performance filters, and air washers and scrubbers have been used. Among them, low-molecular-weight siloxane, antioxidants, phosphates, and low-boiling-point plasticizers are substances that easily adsorb onto silicon wafers and liquid crystal substrates from the air, and thus cause particularly bad pollution. It has been said that it is urgent to remove a substance with a chemical filter or the like.
[0005]
However, even if it is attempted to remove gaseous and molecular contaminants with a high-performance filter such as a chemical filter, the removal by the high-performance filter is not limited to gaseous and molecular contaminants, but also to silicon wafers and liquid crystal substrates. Since the other substances that are difficult to adsorb on the upper surface are also removed at the same time, the adsorption performance of the high-performance filter is reduced and its life is shortened. Requires a large amount of money, which leads to an increase in running costs.
[0006]
Therefore, the present inventors have newly developed a filter capable of selectively removing only an organic gas having a large adverse effect, and applying the filter to a clean room, thereby reliably reducing the concentration of a substance having a large adverse effect. A clean room 20 as shown in FIG. 3 has already been proposed in order to make it possible to extend the life of the device and reduce the running cost. (Japanese Patent Application No. 2000-352425)
In the clean room 20 according to the present proposal, the outside air 21 is sucked into the air conditioner 23 through the medium-performance filter 22, whereby the outside air 21 is cleaned by the high-performance filter 24 such as ULPA, and returned as described later. After merging with the circulating air 28, the clean room 26 is supplied to the clean room 26 after being cleaned again by the conventional high-performance filter 25 and the filter 10 composed of the adsorbent 11 attached thereto.
[0007]
From the clean room 26, a large amount of air is returned to the air supply side by the blower 29 as circulating air 28 while a part of the air is exhausted 27. It merges with 21.
[0008]
The proposed clean room 20 can set an environment in which gaseous pollutants and molecular pollutants are reduced by the above-mentioned filter 10, and can be used for highly integrated semiconductors and miniaturized liquid crystal devices with high precision. However, other substances that are not easily adsorbed on the silicon wafer or the liquid crystal substrate are not adsorbed, so that the filter 10 does not need to be replaced frequently.
[0009]
As shown in FIG. 4, the filter 10 utilizes the property that gaseous contaminants and molecular contaminants are easily adsorbed on a silicon wafer or a liquid crystal substrate. The container 12 in which the crushed pieces 11 are sealed is attached to the high-performance filter 25, and the air supplied to the clean room is supplied between the high-performance filter 25 and the crushed pieces 11 in the plate or the container. And is circulated to the gap formed.
[0010]
The cylindrical container 12 is divided into a plurality of small rooms 14, and one side 16 of a partition plate 15 is connected to a clean room and a supply / exhaust fan system 17, so that air flowing into the clean room is separated from the small room 14. It is configured to circulate through the high-performance filter 25, and removes gaseous pollutants and molecular pollutants in the air by adsorbing them on the crushed pieces 11 of the silicon wafer or liquid crystal substrate filled in each small room 14. are doing.
[0011]
When connected to the filter heating / regenerating system 19 provided on the other side 18 of the partition plate 15, the small room 14 contains an inert gas such as high-temperature heated air, He gas or N2 gas. The gaseous contaminants and molecular contaminants adsorbed by the circulation are removed from the crushed pieces 11 of the silicon wafer or the liquid crystal substrate to enable reuse.
[0012]
FIG. 5 is a chart showing the results of examining the contaminants adsorbed on the surface of the silicon wafer exposed in the proposed clean room 20, and is a chart of analysis results measured by a gas chromatograph-mass spectrometer.
[0013]
The results show that the use of the filter 10 cleans the air that has passed through it, and the spectrum of the contaminants due to air that has passed through the surface of the silicon wafer without passing through the filter 10 It is reduced to about 1/10 compared to the chart.
[0014]
[Problems to be solved by the invention]
The present invention has been studied to further improve the performance of the above-mentioned proposed filter and the clean room using the same, and as a result of promoting research by the inventors, low molecular siloxane, antioxidant In order to adsorb contaminants such as agents, phosphate esters and low-boiling plasticizers on silicon wafers and liquid crystal substrates, it is effective to make water molecules function like a binder, and in particular, the relative humidity is within a predetermined range. Is based on the fact that this feature was confirmed to be more effective.
[0015]
Therefore, the present inventors have applied the above findings to the already proposed filter to further improve the performance of a filter capable of selectively removing only an organic gas having a large adverse effect, and apply the filter to a clean room. By doing so, it is possible to further ensure the performance of reducing the concentration of a substance having a large adverse effect, and to provide a filter capable of extending the life of the filter and the clean room and reducing the running cost, and a clean room using the same.
[0016]
[Means for Solving the Problems]
The filter according to the present invention is basically composed of an adsorbent formed by processing a semiconductor, a high-performance filter attached to the adsorbent, and a humidity adjusting device disposed in front of the adsorbent to adsorb air having a predetermined humidity. The filter is supplied to the gap between the body and the high-performance filter. Specifically, the range of the adjusted humidity is set to, for example, 40 to 80%, and the adsorbent formed by processing the semiconductor is crushed into a plate-like body or a semiconductor. It is characterized in that the container is a container in which pieces are sealed, and the semiconductor is made of a silicon wafer or a liquid crystal substrate.
[0017]
As a result, gaseous and molecular contaminants adsorbed on silicon wafers and liquid crystal substrates in the clean room are reliably adsorbed to the adsorbent and removed, and the running cost is reduced by extending the life of the filter. .
[0018]
Further, the clean room according to the present invention is configured by arranging the filter as a high performance filter in a clean room in which outside air sucked by an air conditioner through at least a medium performance filter is supplied through a high performance filter. I have.
[0019]
This will improve the quality of products by reducing the indoor concentration of not only particles but also gaseous pollutants and molecular pollutants in clean rooms that produce miniaturized and highly integrated semiconductors and liquid crystal devices. At the same time, the running cost of the clean room is reduced while extending the life of the filter.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
The clean room according to the present invention is supplied with at least the outside air sucked by the air conditioner through the medium-performance filter through the high-performance filter, and the high-performance filter includes a silicon wafer or a plate-like body of a liquid crystal substrate or the like. It consists of an adsorbent consisting of a container in which crushed pieces are sealed, a high-performance filter attached to this adsorbent, and a humidity adjusting device arranged in front of the adsorbent. The filter of the present invention, which is configured to be supplied to a performance filter, is used.
[0021]
Hereinafter, an embodiment of a clean room according to the present invention will be described in detail with reference to the drawings. To facilitate understanding, the same parts as those already proposed are denoted by the same reference numerals.
[0022]
FIG. 1 is a schematic diagram showing an embodiment of a clean room according to the present invention.
In the clean room 5 according to the present invention, an air conditioner 23 draws in the outside air 21 through a medium-performance filter 22 and cleans it with a high-performance filter 24 as well as the already proposed one. After merging with the circulating air 28, it is purified again by the filter 1 composed of the adsorbent 2, the humidity controller 6 and the high-performance filter 25, and then supplied to the clean room 3.
[0023]
A part of the air is exhausted 4 from the clean room 3, but much of the air is returned to the air supply side by a blower 29 as circulating air 28, and is purified while passing through a high-performance filter 30 to obtain a new intake outside air 21. Has joined.
[0024]
Therefore, the clean room 5 is set in an environment in which gaseous pollutants and molecular pollutants are reduced by the filter 1, which will be described in detail below. Although the filter 1 is produced with high precision, the filter 1 does not need to be replaced frequently because other substances that are not easily adsorbed on the silicon wafer or the liquid crystal substrate are not adsorbed.
[0025]
As described above, since the clean room 5 according to the present invention is configured as in the above-described embodiment, various types of organic gas, acid / alkali gas, metal, By absorbing contaminants such as elements, they are removed from the air supply to the clean room.
[0026]
Next, the filter according to the present invention will be described in detail.
The filter according to the present invention comprises an adsorbent formed by processing a semiconductor, a high-performance filter attached to the adsorbent, and a humidity adjusting device disposed in front of the adsorbent, so that ventilation at a predetermined humidity is formed between the gap between the adsorbent and the air. A container that is configured by supplying to a performance filter, sets the range of the adjusted humidity to 40 to 80%, or encloses an adsorbent formed by processing a semiconductor in a plate-like body or a crushed semiconductor piece. Or the semiconductor is constituted by a silicon wafer or a liquid crystal substrate.
[0027]
Hereinafter, embodiments of a filter according to the present invention will be described in detail with reference to the accompanying drawings. To facilitate understanding, the same parts as those already proposed are denoted by the same reference numerals.
[0028]
The filter 1 according to the present invention utilizes the property that gaseous contaminants and molecular contaminants are most easily adsorbed to a silicon wafer or a liquid crystal substrate under specific conditions.
[0029]
In the present embodiment, HEPA, ULPA, or the like is used by forming the adsorbent 2 into a plate shape from a silicon wafer or a liquid crystal substrate, or by forming a container 12 in which crushed pieces 11 are sealed. The filter 25 is formed so as to be attached to the filter 25, and the air to be supplied to the clean room is circulated through the gap formed between the crushed pieces 11 in the plate-like body or the container and the filter 25.
[0030]
In the supply / exhaust fan system 17 in which the cylindrical container 12 is disposed, the humidity adjusting device 6 is disposed in front of the cylindrical container 12, and the silicon wafer filled in the cylindrical container 12 and The relative humidity of the air supplied to the crushed pieces 11 of the liquid crystal substrate is controlled to 40 to 80%.
[0031]
The humidity adjusting device 6 includes a humidity detector 7 and a humidity control unit 8. After the humidity of the supply air is detected by the detector 7, the humidity control unit 8 sets the relative humidity to 40 to 80%. Water molecules are used as a binder to adsorb contaminants such as low molecular siloxanes, antioxidants, phosphates and low boiling plasticizers onto silicon wafers and liquid crystal substrates. By utilizing the knowledge that it is effective to function effectively, gas and molecular contaminants such as various organic gases contained in air can be adsorbed to silicon wafers and liquid crystal substrates most efficiently. It is set to let.
[0032]
In the present embodiment, a crushed piece 11 of a silicon wafer or a liquid crystal substrate is filled in a cylindrical container 12. Therefore, the crushed pieces 11 of the silicon wafer or the liquid crystal substrate need to be fine because the adsorption performance is proportional to the increase in the specific surface area. On the other hand, if the crushed pieces 11 are too fine, the pressure loss of air increases and the energy load is reduced. In order to increase the particle size, a material crushed to a particle size of about 0.1 mm to 3 mm is suitable.
[0033]
The cylindrical container 12 is divided into a plurality of small chambers 14 as shown in the drawing, and each of the small chambers 14 can be sequentially moved to the opposite side of the partition plate 15 by rotating the container 12. Have been.
[0034]
One side 16 of the partition plate 15 is connected to a clean room and a supply / exhaust fan system 17 so that air leading to the clean room flows through the small room 14 and the ULPA and HEPA filters 25. The gaseous contaminants and molecular contaminants are removed by being adsorbed on the crushed pieces 11 of the silicon wafer or the liquid crystal substrate filled in each small room 14.
[0035]
The other side 18 of the partition plate 15 is connected to a heating / regenerating system 19 of the filter, so that the small room 14 moved by rotation moves the gas adsorbed on the crushed pieces 11 of the silicon wafer or the liquid crystal substrate. In order to release gaseous and molecular contaminants, air and inert gas heated to a high temperature are circulated, and the adsorbed gaseous and molecular contaminants are removed from the silicon wafer. And the crushed pieces 11 of the liquid crystal substrate can be reused.
[0036]
The gas to be circulated at this time is preferably He gas or N2 gas. However, the high-performance filter according to the present invention is not limited to the above-described embodiment, and may be HEPA, ULPA or coarse dust. The air may be adsorbed on a medium-performance filter or the like with a suitable binder to allow air to flow therethrough, or it may be used by filling it into some container or mixing it with activated carbon as in a conventional activated carbon filter.
[0037]
In addition, in order to reduce the pressure loss that increases the energy load of ventilation, a silicon wafer or a liquid crystal substrate may be cut out into a plate shape and arranged in a louver-type rectifying plate system to allow air to flow. In order to improve the performance of removing gaseous contaminants and molecular contaminants, plate-like silicon wafers and liquid crystal substrates can be combined in multiple stages.
[0038]
Thus, the air supplied from the supply / exhaust fan system 17 to the clean room flows through the gap between the crushed pieces 11 in the container 12 because the value of the relative humidity is set in the predetermined range as described above. The supplied air also occurs when the humidity supplied to the clean room 3 is too high.
[0039]
For this purpose, in the present embodiment, the desiccant filter 9 is disposed in front of the high-performance filter 25, and if necessary, by operating the desiccant filter 9, air supplied to the clean room 3 is supplied with a predetermined humidity. To be adjusted.
[0040]
With the above configuration, the filter according to the present invention greatly improves the removal performance.
[0041]
That is, when the adsorption energy (kcal / mol) of the plasticizer to the base surface of a silicon wafer having a hydroxyl group is verified by the MD method, when the hydroxyl group is uniform without water molecules, the crystal structure is different. The average values, -42.6 kcal / mol and -48.8 kcal / mol, were shown. However, when 80 water molecules were present on the surface of the silicon wafer, the average value was − It shows 54.1 kcal / mol and -70.0 kcal / mol, and a difference of 11.5 kcal / mol and 21.2 kcal / mol appears between the two.
[0042]
However, these numerical values indicate the amount of energy for the plasticizer to be adsorbed on the silicon wafer, and the magnitude of the absolute value indicates the ease of the adsorption, and therefore, as in the present invention, It has been proved that by controlling the humidity in the air supplied to the adsorbent formed by processing semiconductors within a predetermined range, the performance of removing gaseous pollutants and molecular pollutants can be improved.
[0043]
In addition, for the verification, the pollutant adsorbed on the surface of the exposed silicon wafer was examined in the same manner as in the conventional example, and the analysis result of the gas chromatograph-mass spectrometer was confirmed in the spectrum chart of the contaminant. You can do it.
[0044]
As described above, in the filter according to the present invention, by arranging the humidity adjusting device in front of the adsorbent, the ventilation with the adjusted humidity range set to a predetermined value, preferably 40 to 80%, is supplied to the gap between the adsorbents. Gas and molecular contaminants that are easily adsorbed to various silicon wafers and liquid crystal substrates contained in the air can be efficiently and reliably adsorbed to the adsorbent formed by processing semiconductors. It can be adsorbed and extends the life of the filter to reduce running costs.
[0045]
Although the present invention has been described in detail based on the embodiment, the filter according to the present invention is arranged in front of the adsorbent formed by processing a semiconductor, the high-performance filter attached to the adsorbent, and the adsorbent. It is composed of a humidity adjusting device, and is configured to supply ventilation with a predetermined humidity to the gap between the adsorbent and the high-performance filter, and the clean room using this is sucked by the air conditioner through at least the medium-performance filter. In a clean room in which outside air is supplied through a high-performance filter, the above-described filter is arranged as a high-performance filter and configured. Therefore, the present invention is not limited to the above-described embodiment, and is contrary to the gist of the invention. Naturally, various changes are possible within a range not to be performed.
[0046]
【The invention's effect】
The filter according to the present invention basically includes an adsorbent formed by processing a semiconductor, a high-performance filter such as ULPA and HEPA attached to the adsorbent, and a humidity adjusting device disposed in front of the adsorbent. The ventilation of the humidity is supplied to the gap between the adsorbents and the high-performance filter. The range of the adjusted humidity is set to 40 to 80%, and the adsorbent formed by processing the semiconductor is used as a plate or a crushed piece of the semiconductor. Since the semiconductor is composed of a silicon wafer or liquid crystal substrate in a container sealed inside, gaseous and molecular contaminants that are easily adsorbed on various silicon wafers and liquid crystal substrates are adsorbed on the adsorbent. This has the effect of extending the life of high-performance filters and reducing running costs.
[0047]
Further, the clean room according to the present invention is configured such that the filter is disposed as a high-performance filter in a clean room in which outside air sucked by an air conditioner through at least a medium-performance filter is supplied through a high-performance filter. Therefore, in clean rooms that produce semiconductors and liquid crystal devices that are miniaturized and highly integrated, reduce the indoor concentration of not only particles but also gaseous and molecular contaminants that are easily adsorbed on various silicon wafers and liquid crystal substrates. While improving the quality of the product, it also has the effect of reducing the running cost of the clean room by extending the life of the high-performance filter.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a clean room according to the present invention. FIG. 2 is an embodiment diagram of a filter according to the present invention. FIG. 3 is a schematic diagram of a clean room according to a proposed invention. FIG. Analysis diagram of gaseous pollutants and molecular pollutants showing the performance of the filter proposed previously [Explanation of symbols]
1 filter, 2 adsorbent, 3 clean room, 4 exhaust,
5 clean room, 6 humidity controller, 7 detector,
8 humidity control unit, 9 desiccant filter, 10 filter,
11 broken pieces of semiconductor, 12 containers, 14 small chambers of containers,
15 divider, 16 one side,
17 clean room and supply / exhaust fan system, 18 other side,
19 heating regeneration system, 20 clean room, 21 outside air,
22 medium performance filters, 23 air conditioners,
24, 25, 30 high-performance filter, 26 clean room,
27 exhaust, 28 circulating air, 29 blower,

Claims (7)

An adsorbent formed by processing a semiconductor, a high-performance filter attached to the adsorbent, and a humidity adjusting device disposed in front of the adsorbent, and ventilation at a predetermined humidity is applied to the gap between the adsorbent and the high-performance filter. A filter characterized by providing. The filter according to claim 1, wherein the range of the adjusted humidity is set to 40 to 80%. The filter according to claim 1, wherein the adsorbent formed by processing a semiconductor is a plate. 3. The filter according to claim 1, wherein the adsorbent obtained by processing the semiconductor is a container in which crushed pieces of the semiconductor are sealed. The filter according to any one of claims 1 to 4, wherein the semiconductor is a silicon wafer. The filter according to any one of claims 1 to 4, wherein the semiconductor is a liquid crystal substrate. A clean room in which outside air sucked in by an air conditioner through at least a medium performance filter is supplied through a high performance filter, and the filter according to any one of claims 1 to 6 is arranged as a high performance filter. Characterized clean room.

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