JP3896539B2 - Filter and clean room using it - Google Patents

Description

[0001]
BACKGROUND 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 contaminants and molecular contaminants adsorbed on a semiconductor or liquid crystal device at a high removal rate and a clean room using the same.
[0002]
[Prior art]
In recent years, along with the advancement of the degree of integration of semiconductors and the miniaturization of liquid crystal devices, it is important to reduce not only particles but also gaseous and molecular pollutants in a clean room as a production facility.
[0003]
However, in conventional clean rooms, various organic gases such as ester compounds, silicon compounds, DBP plasticizers and DOP plasticizers, and gas and molecular pollutants such as acid / alkaline gases and metal elements are clean rooms. It is diffused into the room by components, indoor equipment, chemicals used, workers, etc., and adsorbed on silicon wafers and liquid crystal substrates produced in clean rooms, resulting in poor circuit formation and electrical resistance. Therefore, the indoor concentration of the pollutant in the clean room is also required to be controlled to about several ng to several hundred ng / m ³ .
[0004]
Therefore, in conventional clean rooms, chemical filters are used as high-performance filters to remove gaseous pollutants and molecular pollutants, and air washers, scrubbers, etc. are used. Among them, low-molecular siloxanes, antioxidants, phosphate esters, low-boiling plasticizers, etc. are substances that easily adsorb on the silicon wafer and liquid crystal substrate from the air, and are particularly harmful. It has been said that it is an urgent need to remove the substance as a chemical filter.
[0005]
However, even if it is attempted to remove gaseous pollutants and molecular pollutants with a high-performance filter such as a chemical filter, removal using a high-performance filter is not limited to gaseous pollutants or molecular pollutants, but also silicon wafers and liquid crystal substrates. Since other substances that are difficult to adsorb on the surface are removed at the same time, the adsorption performance of the high-performance filter is reduced and its life is shortened, so the high-performance filter is frequently replaced. This requires a large amount of money, leading to an increase in running costs.
[0006]
Accordingly, the present inventors have newly developed a filter that can selectively remove only organic gas having a large adverse effect, and applying this to a clean room, while 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 extend the life of the vehicle 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, thereby 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 air is supplied to the clean room 26 after being cleaned again with the filter 10 constituted by the conventional high-performance filter 25 and the adsorbent 11 attached thereto.
[0007]
A part of the air is exhausted 27 from the clean room 26, and a large amount of air is returned to the supply side by the blower 29 as the circulating air 28. After being purified through the high-performance filter 30, freshly sucked outside air 21.
[0008]
The proposed clean room 20 can set an environment in which gaseous contaminants and molecular contaminants are reduced by the filter 10 described above, and highly accurate semiconductors and miniaturized liquid crystal devices can be used with high precision. However, it is not necessary to frequently replace the filter 10 because other substances that are difficult to adsorb on the silicon wafer or the liquid crystal substrate are not adsorbed.
[0009]
As shown in FIG. 4, the filter 10 utilizes the characteristic that gaseous contaminants / molecular contaminants are easily adsorbed to a silicon wafer or a liquid crystal substrate, and forms the silicon wafer or liquid crystal substrate into a plate-like body. The container 12 in which the fragments 11 are enclosed is attached to the high-performance filter 25, and the air supplied to the clean room is between the high-performance filter 25 and the plate-shaped body or the fragments 11 in the container. It circulates in the gap formed.
[0010]
The cylindrical container 12 is partitioned into a plurality of small rooms 14, and one side 16 of the partition plate 15 is connected to a clean room and a supply / exhaust fan system 17, so that the air communicating with 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 silicon wafers or liquid crystal substrate fragments 11 filled in the small chambers 14. is doing.
[0011]
In addition, when connected to the filter heating regeneration system 19 configured on the other side 18 of the partition plate 15, an inert gas such as air, He gas, or N 2 gas heated to high temperature is present in the small chamber 14. The gaseous contaminants and molecular contaminants that are distributed and adsorbed are removed from the crushed pieces 11 of the silicon wafer and the liquid crystal substrate to enable reuse.
[0012]
FIG. 5 is a result of examining contaminants adsorbed on the surface of a silicon wafer exposed in the proposed clean room 20, and is a chart of analysis results measured by a gas chromatograph-mass spectrometer.
[0013]
This result reveals that the air passing through the filter 10 is cleaned by using the filter 10, and the spectrum of pollutants due to the air passing through the surface of the silicon wafer without passing through the filter 10 is shown. Compared to the chart, it is reduced to about 1/10.
[0014]
[Problems to be solved by the invention]
The present invention has been studied to further improve the performance of the previously proposed filter described above and the clean room using the same, and as a result of the inventors' progress in research, low molecular weight siloxane, antioxidant It is effective to allow water molecules to function like a binder in order to adsorb contaminants such as agents, phosphate esters, and low-boiling plasticizers to silicon wafers and liquid crystal substrates. It is based on having confirmed that this function is more effective by setting to.
[0015]
Therefore, the inventors further improved the performance of the filter that can selectively remove only the organic gas having a large adverse effect by applying the above knowledge to the previously proposed filter, and applied this filter to a clean room. Thus, the performance of reducing the concentration of a substance having a large adverse effect is further ensured, and a filter and a clean room using the same that can extend the life of the filter and the clean room to reduce the running cost are provided.
[0016]
[Means for Solving the Problems]
The filter according to the present invention basically includes an adsorbent formed by processing a semiconductor, a high-performance filter attached to the adsorbent, and a humidity adjusting device arranged in front of the adsorbent, and a low-molecular siloxane, A filter that supplies air containing any one of an antioxidant, a phosphate ester, and a low-boiling point plasticizer to the gap of the adsorbent and a filter having a configuration, and the humidity adjusting device adjusts the relative humidity of the air. A humidity control unit that sets water molecules to a range that functions as a binder. Specifically, the humidity control unit sets the relative humidity range to, for example, 40 to 80%, and processes a semiconductor. It is characterized in that the adsorbent is a plate-like body or a container in which a fragment of semiconductor is enclosed, or the semiconductor is composed 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 a clean room are reliably adsorbed and removed by the adsorbent, reducing the running cost by extending the life of the filter. .
[0018]
Further, the clean room according to the invention, the outside air sucked by the air conditioner through at least medium performance filters, in a clean room to be air supply through the filter, it is constructed by disposing the filter as the filter.
[0019]
In this way, in a clean room that produces semiconductors and liquid crystal devices that are miniaturized and highly integrated, the product quality is improved by reducing the indoor concentration of not only particles but also gaseous and molecular pollutants. At the same time, the running cost of the clean room is reduced while extending the filter life.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Clean room according to the invention, the outside air sucked by the air conditioner through at least medium performance filters are air supply via a filter, to its filter medium the plate-like body and crushed pieces of silicon wafer or liquid crystal substrate Consists of an adsorbent consisting of a container enclosed in a container, a high-performance filter attached to the adsorbent, and a humidity control device arranged in front of the adsorbent to supply air of a predetermined humidity to the adsorbent gap and the high-performance filter The filter of this invention comprised is used.
[0021]
Hereinafter, embodiments of a clean room according to the present invention will be described in detail with reference to the drawings. In order to facilitate understanding, the same parts as those already proposed are represented 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, the outside air 21 is sucked in by the air conditioner 23 through the medium performance filter 22 and cleaned by the high performance filter 24 as described above, and is returned later. After joining the circulating air 28, the air is purified again by the filter 1 including the adsorbent 2, the humidity adjusting device 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 most of the air is returned to the air supply side by the blower 29 as the circulating air 28, and is freshly sucked outside air 21 while being purified through the high-performance filter 30. Have joined.
[0024]
Accordingly, the clean room 5 is set in an environment in which gaseous contaminants and molecular contaminants are reduced by the filter 1 described in detail below, and a highly integrated semiconductor and a miniaturized liquid crystal device are highly enhanced. Although it is produced with accuracy, the filter 1 does not need to be frequently replaced because other substances that are difficult to adsorb on the silicon wafer or 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 embodiment, various organic gas, acid / alkaline gas, metal, and the like, which are in a gaseous / molecular state on a semiconductor fragment. By adsorbing contaminants such as elements, it is removed from the supply air 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 includes 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 allows ventilation at a predetermined humidity to be high between the gap between the adsorbent and the high. Contained by supplying to the performance filter, the adjusted humidity range is set to 40-80%, or the adsorbent formed by processing the semiconductor is sealed in the plate or semiconductor fragments Alternatively, the semiconductor is composed of 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 drawings. In order to facilitate understanding, the same parts as those already proposed are represented by the same reference numerals.
[0028]
The filter 1 according to the present invention utilizes the characteristic 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 of a silicon wafer or a liquid crystal substrate, or by forming a container 12 containing the fragment 11 therein. It is formed so as to be attached to the filter 25, and air supplied to the clean room is circulated through the gap formed between the plate-like body or the crushed pieces 11 in the container and the filter 25.
[0030]
In the air 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 silicon wafers 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 supplied air is detected by the detector 7, the humidity control unit 8 adjusts the relative humidity to 40 to 80%. In order to adsorb contaminants such as low-molecular siloxane, antioxidants, phosphate esters and low-boiling plasticizers to silicon wafers and liquid crystal substrates, water molecules are used as binders. By utilizing the knowledge that it is effective to function, the most efficient adsorption of gaseous and molecular contaminants such as various organic gases contained in the air to silicon wafers and liquid crystal substrates It is set to let you.
[0032]
In the present embodiment, a cylindrical container 12 is filled with a fragment 11 of a silicon wafer or a liquid crystal substrate. Therefore, the fragment 11 of the silicon wafer or the liquid crystal substrate needs to be made fine because the adsorption performance is proportional to the increase in the specific surface area. On the other hand, if it is too fine, the air pressure loss increases and the energy load increases. In order to increase the 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 rooms 14 as shown in the figure, and each small room 14 can be moved in order on the opposite side of the partition plate 15 by rotating the container 12. Has been.
[0034]
One side 16 of the partition plate 15 is connected to the clean room and the supply / exhaust fan system 17 so that the air communicating with the clean room flows to the small room 14 and the ULPA / HEPA filter 25. Gaseous contaminants and molecular contaminants are adsorbed and removed by the pieces 11 of silicon wafers and liquid crystal substrates filled in the small chambers 14.
[0035]
In addition, the other side 18 of the partition plate 15 is connected to a heating regeneration system 19 of the filter, so that the gas adsorbed on the silicon wafer or the crushed piece 11 of the liquid crystal substrate is accommodated in the small chamber 14 moved by the rotation. In order to liberate gaseous pollutants and molecular pollutants, air and inert gas heated to high temperatures are circulated, and adsorbed gaseous pollutants and molecular pollutants are removed from silicon wafers. In addition, the silicon wafer or the liquid crystal substrate fragment 11 is removed from the liquid crystal substrate fragment 11 and can be reused.
[0036]
The gas to be circulated at this time is preferably He gas or N 2 gas. However, the high-performance filter according to the present invention is not limited to the above-described embodiment, and HEPA, ULPA, coarse dust, etc. -It can also be used by adsorbing it with a suitable binder on a medium performance filter or the like and circulating air, or filling it in some container or mixing it with activated carbon like 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 is cut into a plate shape and arranged in a louver-like rectifying plate system so that air can flow. In order to improve the removal performance of gaseous contaminants and molecular contaminants, plate-like silicon wafers and liquid crystal substrates can be combined in multiple stages.
[0038]
Thus, the air supplied to the clean room from the supply / exhaust fan system 17 has a relative humidity value set in a predetermined range as described above, and thus flows through the gap between the crushed pieces 11 in the container 12. The incoming air is also generated when the humidity supplied to the clean room 3 is too high.
[0039]
Therefore, in this embodiment, the desiccant filter 9 is disposed in front of the high-performance filter 25. If necessary, the air supplied to the clean room 3 by operating the desiccant filter 9 has a predetermined humidity. It can be adjusted to.
[0040]
With the above configuration, the filter according to the present invention greatly improves its removal performance.
[0041]
That is, when the adsorption energy (kcal / mol) of the plasticizer on the substrate surface of the silicon wafer having a hydroxyl group is verified by the MD method, when the hydroxyl group is uniform without the presence of water molecules, the crystal structure is different. The average values of −42.6 kcal / mol and −48.8 kcal / mol were shown. When 80 water molecules exist on the substrate surface of the silicon wafer, the average value when the crystal structure is different, − 54.1 kcal / mol and -70.0 kcal / mol are shown, 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 absolute value indicates the ease of adsorption. It has been proved that the removal performance of gaseous pollutants and molecular pollutants can be improved by controlling the humidity in the air supplied to the adsorbent formed by processing the semiconductor in a predetermined range.
[0043]
In addition, for the verification, the contaminants adsorbed on the surface of the exposed silicon wafer are examined in the same manner as in the conventional example, and the analysis result of the gas chromatograph-mass spectrometer is confirmed as a spectrum chart of the contaminants. It can also be done.
[0044]
As described above, the filter according to the present invention supplies the ventilation with the adjusted humidity range set to a predetermined value, preferably 40 to 80%, to the gap of the adsorbent by disposing the humidity adjusting device in front of the adsorbent. Therefore, gaseous and molecular contaminants that are easily adsorbed on various silicon wafers and liquid crystal substrates contained in the air can be efficiently and reliably applied to an adsorbent formed by processing a semiconductor. It can be adsorbed, extending the life of the filter and reducing running costs.
[0045]
As described above, the present invention has been described in detail based on the embodiment. The filter according to the present invention is disposed in front of an adsorbent formed by processing a semiconductor, a high-performance filter attached to the adsorbent, and the adsorbent. Constructed from a humidity control device, it is configured to supply air of a predetermined humidity to the gap between the adsorbent and the high performance filter, and the clean room using this has been sucked by the air conditioner through at least the medium performance filter in the clean room when the outside air is the air supply through the filter, because a filter and constitutes by placing the filter is not in any way limited to the above embodiments, in a range not contrary to the spirit of the invention, Naturally, various changes are possible.
[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. A filter that supplies air containing any of low molecular weight siloxane, antioxidant, phosphate ester, and low boiling point plasticizer to the gap of the adsorbent and the filter having the structure, Provided with a humidity control unit for setting the relative humidity of the air to a range in which water molecules function as a binder, the relative humidity range is set to 40 to 80%, or an adsorbent formed by processing a semiconductor is a plate-like body Alternatively, it is characterized by a container containing semiconductor fragments inside, and the semiconductor is composed of a silicon wafer or a liquid crystal substrate. The child-like contaminants are adsorbed to the adsorbent, and an effect of reducing the running cost to extend the life of the high-performance filter.
[0047]
Further, the clean room according to the present invention is configured so that the filter is disposed as a filter in a clean room in which the outside air sucked by the air conditioner is supplied through the filter through at least the medium performance filter. In a clean room that produces highly integrated semiconductors and liquid crystal devices, the quality of products is reduced by reducing the indoor concentration of not only particles but also gaseous and molecular contaminants that are easily adsorbed to various silicon wafers and liquid crystal substrates. At the same time as improving, it has the effect of reducing the running cost of clean rooms by extending the life of high-performance filters.
[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 previously proposed invention. Analysis diagram of gaseous pollutants and molecular pollutants showing the performance of the proposed filter 【Explanation of symbols】
1 filter, 2 adsorbent, 3 clean room, 4 exhaust,
5 Clean room, 6 Humidity adjustment device, 7 Detector,
8 Humidity control unit, 9 Desiccant filter, 10 Filter,
11 Semiconductor fragment, 12 container, 14 container chamber,
15 partition plate, 16 one side,
17 Clean room and supply / exhaust fan system, 18
19 Heating regeneration system, 20 Clean room, 21 Outside air,
22 Medium performance filter, 23 Air conditioner,
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 having a low molecular weight siloxane, an antioxidant, and phosphate esters A filter for supplying air containing any of low-boiling plasticizers to the gap between the adsorbent and the high-performance filter,
The humidity adjusting device includes a humidity control unit that sets a relative humidity of the air to a range in which water molecules function as a binder,
A filter characterized by The humidity controller sets the relative humidity range to 40 to 80%;
The filter according to claim 1. The adsorbent is a plate-like body;
The filter according to claim 1 or 2. The adsorbent is a container enclosing a semiconductor fragment;
The filter according to claim 1 or 2. The semiconductor is a silicon wafer;
The filter according to any one of claims 1 to 4. The semiconductor is a liquid crystal substrate;
The filter according to any one of claims 1 to 4. A clean room in which outside air sucked by an air conditioner through at least a medium performance filter is supplied through the filter, and the filter according to any one of claims 1 to 6 is disposed as the filter.
A clean room.

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