JPH1096332A - Clean room - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a semiconductor device manufacturing process, it is possible to completely prevent diffusion of a chemical substance from a manufacturing apparatus using a chemical substance, and to prevent chemical contamination at the time of transporting or storing a semiconductor wafer. Provide a clean room that can perform air conditioning management as needed at low cost. SOLUTION: A manufacturing apparatus 6 which separates a clean room 1 into a plurality of areas having independent air conditioning systems and leaks chemical substances.
In the second clean room 1b in which a is disposed, a chemical filter is installed in the circulation duct 13 and an air-conditioning system is adopted in which the air from which the chemical mist generated in the work zone 5 is removed is circulated to the ceiling chamber 4, and an area having a different air-conditioning system is used. Prevents chemical mist from spreading to the environment. In the first clean room 1a in which the transfer devices 7a and 7b and the storage devices 8a and 8b are installed, an air-conditioning system in which chemical free air is locally supplied only to a necessary area is adopted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a clean room in which semiconductor devices and the like are manufactured.

[0002]

2. Description of the Related Art Conventionally, semiconductor devices are manufactured in a clean room in which the temperature and humidity are controlled and foreign substances of several microns are removed, because the product yield is reduced due to contamination from the environment of the clean room.

FIG. 2 is a view showing a conventional clean room. In the figure, reference numeral 1 denotes a clean room, 2 denotes an external air conditioner which takes in outside air, controls temperature and humidity, and supplies air to the clean room 1, and has an outside air introduction fan, a heating / cooling fan, and a humidifier. The clean room 1 includes a ceiling chamber 4 to which air is supplied from the external conditioner 2, a manufacturing apparatus 6,
6a, a work zone 5 in which a transfer device 7 such as a ceiling traveling system, a storage device 8 with a built-in circulation device, etc. are arranged and work is performed.
And a utility zone 9 in which power supply equipment, environmental protection equipment, and the like are arranged. Between the ceiling chamber 4 and the work zone 5, foreign matters such as dust of several microns level are removed from the air in the ceiling chamber 4. HEPA to do
A ceiling filter 10 such as a (High Efficiency Particulate Air) filter or an ULPA (Ultra Low Penetration Air) filter is disposed. The work zone 5 is in contact with the utility zone 9 via a floor grating 12, and the utility zone 9 has a work zone. A circulation duct 13 is arranged to suck the air 5 through the grating 12 by the circulation fan 14 and circulate the air from the utility zone 9 to the ceiling chamber 4. Fifteen
Is a circulating air temperature control device installed in the circulation duct 13. In addition, for a manufacturing apparatus 6a that generates chemical mist such as a wet processing apparatus using sulfuric acid, hydrofluoric acid and the like and a coating apparatus and a developing apparatus using an organic solvent, forced exhaust is performed to an exhaust processing apparatus 6b. A partition 17 such as a curtain is provided in an area where the manufacturing apparatus 6a that generates the chemical mist is disposed to prevent the chemical mist generated from the used chemical from diffusing into the work zone 5. Further, the clean room 1 is in a more positive pressure state than the outside air in order to prevent foreign substances from entering from the outside air. However, since the pressure in the clean room 1 is reduced due to opening / closing of doors and exhaust from devices, etc. Detects the atmospheric pressure of
The pressure is controlled by changing the number of rotations of the blower fan so that the pressure becomes a constant positive pressure state compared to outside air.

[0004] With the miniaturization of patterns and the reduction in film thickness due to the high integration of semiconductor devices, chemical contamination by submicron-level chemical mist composed of organic and inorganic substances contained in air in a clean room where semiconductor devices are manufactured. Also began to be problematic. Chemical mist that causes chemical contamination includes not only evaporating gas from chemicals used in wet processing equipment in the clean room, but also sulfide-based gas and acid-based gas mixed into the outside air taken in, as well as clean room walls. And the evaporative gas from the coating of the manufacturing equipment, etc., have the following adverse effects on the semiconductor device. 1. A chlorine-based gas or an acid-based gas causes corrosion of a metal or the like used in a semiconductor device, and lowers the reliability of the semiconductor device. In particular, in the case of Al wiring, corrosion causes an increase in wiring resistance or disconnection, which causes a change in transistor characteristics or loss of function. 2. In film formation by the CVD method, abnormal growth of the film formation layer due to contamination of the film formation surface occurs, and pattern formation abnormality is likely to occur. 3. Fluorine-based gas alters the surface state, and sodium ions cause the oxide film to multiply and oxidize, causing an oxide film thickness abnormality and changing transistor characteristics.

FIG. 3 shows a chemical filter 16 capable of removing chemical mist in the air circulation system of the clean room 1.
The example which arrange | positioned a, 16b, 16c is shown. 16a
Is a chemical filter arranged below the grating 12, 16b is a chemical filter arranged in a circulation duct 13 for circulating air from the utility zone 9 to the ceiling chamber 4, and 16c is a chemical filter added to the ceiling filter 10. Chemical filters 16a, 1
By disposing at least one of 6b and 16c in the clean room 1, the chemical mist is removed from the work zone 5.

[0006]

The conventional clean room is constructed as described above, and there is a problem of chemical contamination of a semiconductor wafer in a semiconductor device manufacturing process, and generation of chemical mist causing chemical contamination. In order to prevent diffusion of chemical mist from a chemical mist generating device 6a such as a wet processing device using one of the sources such as sulfuric acid and hydrofluoric acid, and a coating device and a developing device using an organic solvent, A partition 17 such as a curtain is provided in the area where the chemical mist is generated, and the chemical mist cannot be completely diffused. There has been a problem that the semiconductor wafer during storage is chemically contaminated. In addition, chemical filters 16a to 16c capable of removing chemical mist are disposed in the air circulation system of the clean room 1, and all the air circulating in the clean room 1 is passed through the chemical filters 16a to 16c, so that the clean room 1 Although a method of removing the chemical mist from the work zone 5 has been proposed, there have been problems such as an increase in the initial cost and running cost of the air conditioning equipment.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems.
Low-cost air conditioning control as needed to completely prevent chemical mist diffusion from equipment that uses chemicals such as acids and organic solvents, and to prevent chemical contamination when transporting and storing semiconductor wafers. The purpose of the present invention is to provide a clean room that can be operated in a room.

[0008]

A clean room according to the present invention comprises: a ceiling chamber to which air whose temperature and humidity are controlled by an external controller is supplied; a ceiling filter section in which a high-performance filter is disposed; A plurality of areas each having a work zone in which air is supplied by being cleaned by a ceiling filter unit, a utility zone located below the grating floor of the work zone, and in which power supply facilities, environmental protection facilities, and the like are arranged; A circulation duct for circulating the air in the work zone from the utility zone to the ceiling chamber is provided for each area, and the area is individually air-conditioned. Further, the plurality of areas are adjacent to each other with a partition therebetween. Furthermore, between adjacent areas, the air pressure on the area side which is managed with higher cleanliness,
The pressure is adjusted to be more positive than the air pressure in another adjacent area.

[0009] Further, in the work zone of the first area which is one of the areas, a device which hardly uses a chemical substance or has a low possibility of leaking the chemical substance is arranged. Further, an air-conditioning system is used in which a predetermined area of the work zone in the first area is supplied with air managed with a higher degree of cleanliness than other areas of the work zone. The air managed to have a higher degree of cleanliness is air that has passed through a high-performance filter in the ceiling filter unit and a fan filter unit that is additionally provided with a chemical filter and a blower fan. In addition, air controlled to a higher degree of cleanliness is supplied from a chemical-free air supply device provided with a separate chemical filter and a high-performance filter, and is directly prescribed through a guide path installed in the work zone. Is supplied to the area.

[0010] Further, in the work zone of the second area which is one of the areas, a device which uses a large amount of chemical substances and has a high possibility of leaking the chemical substances is arranged. Further, in the work zone of the second area, air having the same cleanliness is supplied to the whole, and a chemical filter is additionally arranged in the circulation duct, and the chemical free air from which the chemical mist leaked from the device is removed is supplied to the work zone. It is supplied to. The chemical substance content level of the air supplied from the chemical-free air supply device and the air passing through the fan filter unit is 1 pp.
t to 1f.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, a clean room according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a clean room of the present invention. In the drawing, reference numeral 1 denotes a clean room, 1a and 1b are formed in a clean room 1, and first and second clean rooms having independent air-conditioning systems. 3 is a chemical free air supply device provided with a chemical filter and a HEPA filter or an ULPA filter, and 4 is an external conditioner 2.
Is supplied with air from the ceiling chamber 5, and the manufacturing devices 6, 6a and the transport devices 7a, 7b and the storage devices 8a, 8
b is a work zone in which work is performed and the like, 9 is a utility zone in which power supply equipment and environmental protection equipment are arranged, 10 is a HEPA filter or a ULPA filter installed between the ceiling chamber 4 and the work zone 5 From the air in the ceiling chamber 4
Clean air from which 99.99% or more of foreign matter of a micron or more has been removed is supplied to the work zone 5. Reference numeral 11 denotes a fan filter unit including a chemical filter and a blower fan. The fan filter unit 11 is additionally disposed on the ceiling filter 10 as necessary, and supplies clean chemical-free air from which chemical mist has been removed to a predetermined area of the work zone 5. . 12
Is a grating on the floor of the work zone 5, 13 is a suction of air in the work zone 5 through the grating 12 by a circulation fan 14 provided in the utility zone 9,
A circulation duct for circulating air from the utility zone 9 to the ceiling chamber 4, and a circulation air temperature control device 15 installed in the circulation duct 13. 16 is a circulation duct 13
The chemical free air from which chemical mist has been removed is supplied to the ceiling chamber 4 through the circulation duct 13 by the chemical filter installed in the ceiling chamber 4. In chemical free air, chemical mist that causes chemical contamination is 1 ppt.
The air is controlled to a concentration in the range of 1f.

The clean room 1 is provided with transfer devices 7a, 7b
And hardly use storage devices 8a, 8b and chemicals,
Alternatively, a first clean room 1a in which a device 6 having a low possibility of leaking a chemical substance is disposed, or a second clean room in which a device 6a using a large amount of a chemical substance and having a high possibility of leaking a chemical substance is disposed. 1b and the like, the air conditioning system is separated into independent areas, and the air conditioning system is selected according to the required cleanliness and the area where the cleanliness is required.
Further, in order to prevent foreign matter from entering from outside air, the clean room 1 always detects the air pressure inside the clean room 1 and takes into consideration the decrease in air pressure due to the opening and closing of doors and exhausting.
The pressure is controlled by changing the rotation speed of the blower fan so that it becomes a constant value positive pressure state than the outside air,
Even between the areas formed in the clean room 1 and having independent air conditioning systems, the air pressure on the area side to be managed with higher cleanliness is controlled to be more positive than the air pressure on the other adjacent areas.

The transport devices 7a and 7b and the storage devices 8a and 8b
In the first clean room 1a in which the device 6 that hardly uses chemical substances or has a low possibility of leaking chemical substances is disposed, a fan is installed in the ceiling filter 10 in the area of the work zone 5 where chemical free air is required. A filter unit 11 is additionally arranged, and the overhead traveling type transport device 7 is provided.
a or a storage device 8a that supplies clean chemical-free air to the open storage box 8a or a transfer device 7 that has a transfer path with a closed structure.
An air-conditioning system that supplies locally clean chemical-free air, such as directly supplying chemical-free air supplied from the chemical-free air supply device 3 to the storage 8b having a closed structure, through a pipe, is used. Has been adopted.

In the second clean room 1b in which a large amount of a chemical substance is used and a device 6a which has a high possibility of leaking the chemical substance is disposed, a chemical filter 16 is installed in a circulation duct 13 and a working zone 5 is provided. An air-conditioning system in which chemical free air from which chemical mist generated in the above is removed is circulated to the ceiling chamber 4 is adopted. In addition,
The chemical filter 16 removes the chemical mist at any position of the circulation duct 13 and removes the chemical mist from the ceiling chamber 4.
Although it is possible to supply chemical free air to the duct, by arranging it at the inlet of the circulation duct 13 which is the upstream part of the circulation system, contamination on the duct wall can be prevented. Further, the pressure in the second clean room 1b is set to a lower pressure than in the first clean room 1a in order to prevent the first clean room 1a from being contaminated, and more positive than in the outside air in order to prevent contamination from the outside air. It is controlled to be in a pressure state.

According to the first embodiment, the clean room 1 is divided into a plurality of areas having independent air conditioning systems, a large amount of chemical substances are used, and a manufacturing apparatus 6a that generates a chemical mist is collectively provided as one unit. By disposing in the second clean room 1b, the diffusion of chemical mist to areas having different air conditioning systems can be prevented. In the first clean room 1a in which the transport devices 7a and 7b and the storage devices 8a and 8b are arranged, the cost of the air conditioning equipment is reduced by locally supplying clean chemical-free air as needed. can do.

[0016]

As described above, according to the present invention, by separating the clean room into a plurality of areas having independent air conditioning systems, cross contamination between the areas can be prevented and the cleanliness can be further improved. Even when controlled air is required, a minimum amount can be supplied by an air-conditioning method suitable only for a necessary area, so that the cost of the air-conditioning equipment can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a clean room according to Embodiment 1 of the present invention.

FIG. 2 is a schematic view showing a conventional clean room of this type.

FIG. 3 is a schematic view showing another conventional clean room.

[Explanation of symbols]

1 clean room, 1a first clean room, 1
b Second clean room, 2 external air conditioner, 3 chemical-free air supply device, 4 ceiling chamber, 5 working zone, 6 manufacturing device, 6a manufacturing device for generating chemical mist, 7a, 7b transport device, 8a, 8b storage device , 9 utility zones, 10 ceiling filters,
11 fan filter unit, 12 grating, 13 circulation duct, 14 circulation fan, 15 temperature controller, 16 chemical filter, 17 partition.

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Koji Ezaki 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (10)

[Claims] 1. A ceiling chamber to which air whose outside air is controlled to a predetermined temperature and humidity and a predetermined dust removal level by an air conditioner is supplied, a ceiling filter section in which a high-performance filter is disposed, and an air in the ceiling chamber. A plurality of areas each having a working zone where cleaning is performed by the ceiling filter unit and supplied, and a utility zone which is located below the grating floor of the working zone and in which power supply equipment, environmental protection equipment, and the like are arranged. A clean room, comprising: a circulation duct for circulating air in a work zone through the utility zone to the ceiling chamber for each area, wherein the areas are individually air-conditioned. 2. The clean room according to claim 1, wherein the plurality of areas are adjacent to each other with a partition therebetween. 3. The method according to claim 1, wherein an air pressure on an area which is managed with higher cleanliness between adjacent areas is adjusted to be more positive than an air pressure on another adjacent area. Item 2. The clean room according to item 2. 4. The work zone of the first area, which is one of the areas, is characterized in that devices that hardly use chemical substances or have a low possibility of leaking chemical substances are arranged. The clean room according to claim 1. 5. An air-conditioning system for supplying air controlled to a higher degree of cleanliness in a predetermined area of the work zone of the first area than in other areas of the work zone. The clean room according to claim 4, wherein 6. The air controlled to have a higher degree of cleanliness is air that has passed through a high-performance filter in a ceiling filter unit and a fan filter unit including an additionally disposed chemical filter and a blower fan. The clean room according to claim 5, wherein 7. The air controlled to a higher degree of cleanliness is supplied from a chemical-free air supply device provided with a separate chemical filter and a high-performance filter, and passes through a guideway provided in the working zone. The clean room according to claim 5, wherein the clean room is supplied directly to a predetermined area. 8. The method according to claim 1, wherein a device that uses a large amount of a chemical substance and has a high possibility of leaking the chemical substance is disposed in a work zone of the second area which is one of the areas. Item 4. The clean room according to any one of items 1 to 3. 9. The work zone of the second area is supplied with air having the same cleanliness as a whole, and a chemical filter is additionally arranged in a circulation duct to remove chemical mist leaked from the apparatus. 9. The clean room according to claim 8, wherein is supplied to the working zone. 10. The chemical substance content level of the air supplied from the chemical-free air supply device and the air passing through the fan filter unit is 1 ppt to 1f. The clean room according to claim 9.