KR200306936Y1 - Mini environment - Google Patents

Abstract

A local cleaning device installed in a clean room for locally supplying a high degree of air to only a minimum space of a wafer area in the clean room.

The local cleaner includes a fan unit for forcibly drawing room air in a clean room and distributing it along a suction passage installed therein, and ULPA for collecting and removing particles suspended in the room air sucked by the fan unit. A local clean space in which wafers are processed and conveyed using a filter, an ionizer generating positive air ions in the clean air passing through the ULPA filter, and process air generated from the ionizer; An air flow controller for controlling the speed and direction of the process air so as not to generate an unsupplied area when the process air is supplied to the local clean space, and detecting a pressure difference between the clean room and the local cleaner Steady state It consists of a ME controller to recover to the pressure difference.

Description

Local cleaning device {MINI ENVIRONMENT}

In the mini-clean environment of the present invention, in order to isolate the wafer from contamination (gas / particle) and humans, the cleanliness of air only around the wafer is locally. ), A local cleaning device that actively protects the wafer surface from the operator and the clean room indoor environment by supplying high clean air only to the minimum space of the wafer area. It is about.

Recently, due to the rapid technological innovations in semiconductor manufacturing technology, the current standards are increasingly becoming more stringent on the cleanliness of air in clean rooms, which greatly affects the yield improvement of semiconductors. Accordingly, researches for efficiently improving the cleanliness of air have been conducted in various fields.

Conventionally, in order to increase the cleanliness of the air in the clean room, a method of increasing the cleanliness of the air with respect to the entire space in the clean room 100 is used as shown in FIG. Therefore, this conventional method requires a lot of installation costs and operating costs because the cleanliness of the air must be increased for the entire space in the clean room 100. However, according to the results of the present inventors, there is no need to supply a high degree of clean air to the entire space in the clean room. In other words, in order to efficiently improve the cleanliness of the air, stricter conditions are applied to the areas where high cleanliness is required to supply more clean air than the conventional method, and other areas to reduce the conditions for cleanliness of the air. will be.

Accordingly, an object of the present invention is to provide a local cleaning device installed in a clean room in order to locally supply high-purity air only to the minimum space of the wafer area in the clean room.

The present invention is a fan unit, a ULPA filter, an ionizer, a local clean space, and an air flow controller to solve the above problems. An object of the present invention is to provide a local clean device provided with a flow controller, an ME controller, and the like installed in the clean room to locally supply high-clean air only to the minimum space of the wafer area in the clean room.

Fig. 1 is a block diagram showing the construction of a main part of a mini environment of the present invention.

2 is a cross-sectional view showing a local cleaning device of the present invention.

3 is an external view of a local cleaning device of the present invention.

4 is a sectional view showing a first embodiment of a local cleaning apparatus according to the present invention, showing a floor supported type local cleaning apparatus.

Fig. 5 is a sectional view showing a second embodiment of a local cleaning apparatus of the present invention, showing a local cleaning apparatus of a tool supported type.

6 is a sectional view showing a third embodiment of a local cleaning apparatus according to the present invention, showing a sealing hung type local cleaning apparatus.

7 is a sectional view showing a fourth embodiment of a local cleaning apparatus of the present invention, showing a tunnel type local cleaning window value.

Fig. 8 (a) is a sectional view showing a conventional cleaning apparatus, and Fig. 8 (b) is a sectional view showing a local cleaning apparatus of the present invention.

Explanation of symbols on the main parts of the drawings

1: mini environment 2: fan unit

3: ULPA filter

4: tear drop lighting 5: ionizer

6: enclosure 7: door

8: local clean space

21: ionizer controller

22: air flow controller

23: ME controller 100: clean room

101: process tool 102: access floor

In order to achieve the above object, the local clean device according to the present invention has a high clean air only in the minimum space of the wafer area in a clean room. ) Is a local cleaning device installed in a clean room to locally supply), and is forcedly sucked into room air in the clean room and distributed along the suction passage installed therein. A fan unit for separating, a ULPA filter that collects and removes particles suspended in the room air sucked by the fan unit, and a clean that has passed through the ULPA filter Wafer using ionizer to generate process air by generating positive ion in clean air and process air generated in the ionizer A local clean space in which processing and conveying operations are performed, an air flow controller for adjusting the speed and direction of the process air so that the process air is evenly supplied to the local clean space, and the clean And a ME controller that detects the pressure difference between the room and the local cleaner and restores it to the steady state pressure difference.

In addition, the ionizer of the present invention is composed of a bipolar ionizer (bipolar ionizer), it is possible to adjust the amount and time of ions to be generated by referring to the data input inside the bipolarizer.

In addition, the ME controller of the present invention is based on a pressure transmitter for detecting a minute pressure difference between the inside of the local cleaning device and the clean room, and on the data received from the pressure transmitter. The pressure difference in the steady state between the interface unit for adjusting the air volume inside the local cleaning device and the pressure change accompanying opening and closing the door according to the processing and conveyance of the wafer. It consists of intelligent difference control to recover to

Next, the type of the local cleaning device (mini environment: hereinafter referred to simply as ME) 1 will be described with reference to FIGS. ME1 is classified as follows according to the type installed in the clean room 100. Floor supported type ME installed on access floor 102 in clean room 100, tool supported type installed on process tool 101 in clean room 100 Tunnel installed in access floor 102 in clean hung type ME, which is installed in connection with ceiling of ME, clean room 100, and tunnel installed with door 7 for operator access. Tunnel type ME and the like.

ME1 of the present invention as described above will be described in detail below through (Example 1) to (Example 4).

Example 1

The ME of the floor supported type, which is one of classification according to the installation type of ME1, will be described in detail with reference to FIGS.

1 is a block diagram showing the main parts for explaining the operation flow of the ME1 according to the present invention, Figure 2 is a cross-sectional view showing the configuration of the main part of the ME1 according to the present invention, Figure 3 It is an external view of ME1. 4 is a cross-sectional view showing the configuration of a floor supported type ME according to the present invention. The floor supported type ME, which is installed on the access floor 102 in the clean room 100 as shown in FIG. 4, is a general ME1 that can be applied to all equipment other than a clean machine.

First, the overall configuration and operation of the ME1 of the present invention will be briefly described with reference to Figs.

ME1 according to the present invention includes a fan unit 2 for forcibly drawing room air in a clean room 100 and dispersing it along a suction passage installed therein, and a fan. ULPA filter 3 which collects and removes particles suspended in the room air sucked by the unit 2, and positive air ion in clean air passing through the ULPA filter 3 Local clean space in which wafers are processed and transported using ionizers 5 to generate process air and process air generated in the ionizers 5. And an air flow controller for adjusting the speed and direction of the process air so that the process air is evenly supplied to the local clean space 8. troller 22, an ME controller 23 which detects a pressure difference between the clean room and the local cleaning device and recovers the pressure difference in a steady state, and a plurality of enclosures 6 and the like.

ME1 refers to clean room air in which air surrounding ME1 (in most cases, ME1 is installed in a clean room, which is simply referred to as room air) by fan unit 2 installed on the upper part of ME1. Later, through the ULPA filter 3, the concentration of particles suspended in the room air is supplied to the local clean space 8 as high clean air suitable for the wafer manufacturing environment within a predetermined cleanliness level. The local clean space 8 is a super clean region in which wafer processing and conveying operations are performed, and a flow in which high clean air flows in a constant direction in parallel and minimizes a turbulent region. It becomes the local clean room of the state.

Next, the detailed operation of the ME1 of the present invention will be described in detail.

First, a process of generating clean air with high degree of cleanness by suctioning room air in the clean room 100 will be described.

Fan unit 2 is attached to the upper part of ME1 and consists of a fan for sucking the room air in the clean room 100 into the inside of ME1 and a suction passage for supplying the air sucked from the fan to ULPA filter 3. It is. In addition, the lower part of the fan unit 2 is provided with a ULPA filter 3 for collecting and removing particles suspended in the air sucked by the fan unit 2. ULPA filter 3 is a mechanism for collecting dust composed of filter filter paper and frame, and it is 99.9995 for particles having a particle diameter of 0.1 μm at a rated air volume. It is an ultra-high performance air filter with a particle capture rate of more than% and a pressure loss of 25 mmAq (245 Pa) or less.

The room air in the clean room 100 is forcibly sucked into the inside of the ME1 by the fan of the fan unit 2, and then dispersed along the suction path and flowed to the ULPA filter 3. When the air sucked by the fan unit 2 passes through the filter paper of the ULPA filter 3, the clean air of high cleanness is generated by controlling the concentration of particles suspended in the air within the cleanliness level of the ULPA filter 3 itself. In other words, the air sucked by the fan unit 2 passes through the ULPA filter 3 to become high clean air and is supplied to the local clean space 8.

Subsequently, the process in which the clean air becomes the process air via the ionizer 5 and is supplied to the local clean space 8 will be described in detail.

As described above, the clean air passing through the ULPA filter 3 is supplied to the ionizer 5 installed under the ULPA filter 3. Ionizer 5 is a bipolar ionizer, which controls the amount and time of ions to be generated by referring to the performance curve level input inside the ionizer controller 21. It is. Therefore, after determining the amount and time of ions to be generated, adjust the ionizer controller 21 to clean air passing through the ULPA filter 3 to generate positive air ions to generate process air to generate local clean air. Supply to Space 8. In addition, when the generated process air is supplied to the local clean space 8, the air flow controller controls the speed and direction of the process air so that an area where the process air is not supplied does not occur, that is, a dead zone does not occur. (air flow controller) 22 can be adjusted.

In other words, ionizer 5 maintains the ion balance in ME1, thereby suppressing the generation of static electricity on the surface of ME1, and particles accumulate on the surface of ME1 including wafers. Prevent it. Therefore, the process air is a process air of ultra-clean air in which the concentration and air flow of particles suspended in the air within the set cleanliness are controlled, and flows in one direction around the wafer. As a result, contaminated air can't reach the wafer, which protects the wafer and quickly expels particles generated during the wafer process.

In addition, in this embodiment, the amount and time of ions to be generated through the ionizer controller 21 are determined, and the air flow controller 22 is adjusted to adjust the speed and direction of process air. When the operator inputs a condition such as desired cleanliness by making a base, the ionizer controller 21 and the air flow controller 22 may be automatically operated based on the input data.

In addition, the local clean space 8 to which the process air is supplied is a super clean region in which wafer processing and conveying operations are performed, and the process air flows in a constant direction in parallel to minimize the turbulent region. It becomes the local clean room of the flow state. In other words, by controlling the concentration of particles suspended in the air within a predetermined cleanliness, it becomes a process clean room in which pollution control is performed.

Next, the ME controller 23 will be described in detail. The ME controller 23 adjusts the air volume inside the ME1 based on a pressure transmitter for detecting a minute pressure difference between the inside of the ME1 and the clean room, and data received from the pressure transmitter. Intelligent difference control (intelligent difference) for restoring the pressure change in the case of opening and closing the interface unit and the door 7 due to the processing and conveying of the wafer to the steady state pressure difference control).

The pressure transmitter detects the difference in pressure between the inside of the ME1 and the clean room through a diagram. The detected analog signal is sent to the interface unit. Then, the interface unit uses a power factor such as a calculator (proportional derivative) and a triac to convert the analog signal received from the feedback back into the phase angle of the motor installed in the interface unit. To change. As the phase angle of the motor changes, the rotation speed of the motor is changed to adjust the air volume in the ME1. In other words, the interface unit is a rotation speed control apparatus by setting the set difference pressure (SDP) according to the P-V (pressure-voltage) conditions by converting the phase angle of the primary power of the motor.

Intelligent differential control is a feedback proportional control that maintains a constant pressure inside the ME1 uniformly against the pressure in the clean room 100. More specifically, after the pressure transmitter detects the change in pressure between the inside of the ME1 and the clean room according to the change in the surrounding environment, the number of rotations of the motor in the interface unit is added to the process air inside the ME1. The flow rate of air is controlled, and the change in pressure is restored to a normal pressure change within a predetermined recover time, thereby maintaining a constant flow of air in the inside of ME1.

Next, the simulation will be described. Simulation is to analyze the air flow by analyzing and predicting the air flow around the wafer (object to be protected from external contamination) in the local clean space 8 to effectively design the above, It can be used to verify the design of local clean space 8. The simulation analyzes the airflow passing through the local clean space 8 while maintaining the airflow in one direction to prevent dead zones. It plays a role. In more detail, the air flow is analyzed so that the process air flows out of the inside of the local clean space 8 so that the flow of air in the local clean space 8 maintains the constant air flow in one direction. will be.

It also installs a tear drop lighting4, a lighting device, in order to maintain adequate illuminance for working in the local clean space 8. For example, an appropriate illuminance for working in a local clean space 8 is about 1,000 lux.

Next, characteristics of the ME of the floor supported type will be described.

The floor supported type ME is installed on the access floor 102 in the clean room 100, and is a general ME1 that can be applied to all equipment other than a clean machine.

In addition, as shown in FIG. 4, when the room air in the clean room 100 is class 1000, it is effective when the area where a high degree of cleanness of class 1 is required to protect the wafer is required. to be. That is, as described above, since the method of increasing the cleanliness of the room air with respect to the entire space in the conventional clean room 100 is inefficient, it is suitable for supplying high clean air only to the area where high cleanliness is required.

In addition, floor-supported MEs can easily interface with I / O systems. Since most of the I / O systems installed in the clean room 100 use floor supported ME, it is easy to connect at the wafer level of the process tool 101 of the floor supported ME and the wafer level of the I / O system. to be.

In addition, the floor-supported type ME can easily change the layout. Because it is supported by the floor, it is possible to change the layout of the equipment by adjusting only the frame structure of the corresponding part in the structural connection relationship with the equipment.

Example 2

The ME of the tool supported type, which is another one of the classification according to the installation type of ME1, will be described with reference to FIG.

Fig. 5 is a sectional view showing the configuration of a tool supported type ME according to the present invention. Since the configuration and operation of the tool supported type ME are the same as those of the floor supported type ME described in Embodiment 1, description thereof will be omitted.

The following describes the characteristics of the ME of the tool supported type.

The tool supported type ME is installed on a process tool 101 in the clean room 100, as shown in FIG. 5, and requires partial isolation of equipment such as a clean machine or a ULPA filter unit, or the structure of the equipment. It is suitable for the case where the complex air is required to supply clean air quickly to the local clean space 8. That is, since the ME is designed to be used to realize the required cleanliness for the required place and the required space of the equipment, it is suitable for locally cleaning only the working area (process tool 101) of the wafer, not the entire equipment.

It is also easy to change the structure of ME1. Because the tool-supported ME is designed to be used for partial isolation, it is easy to upgrade the ME1 structurally without affecting the operation or functionality of the equipment.

In addition, the main difference between the floor supported type ME and the tool supported type ME is that the floor supported type ME is installed on the access floor 102 in the clean room 100, whereas the tool supported type ME is a process in the clean room 100. It is installed on the tool 101. Therefore, tool-supported MEs are more suitable for applications where partial isolation of equipment is required, or where only process tool 101 is locally cleaned.

Example 3

Referring to FIG. 6, a sealing hung type ME, which is another classification among the installation types of ME1, will be described.

6 is a cross-sectional view showing the configuration of a sealing hung type ME according to the present invention. Since the configuration and operation of the sealing hung type ME are the same as those of the floor supported type ME described in Embodiment 1, description thereof will be omitted.

The following describes the characteristics of the sealing hung type ME.

The sealing hung type ME is installed in connection with the ceiling in the clean room 100 as shown in FIG. 6, and the device is large in size, such as an ion implanter, so that the space of the ceiling of the clean room is narrow. Suitable for one case.

In addition, the sealing-hung type ME is connected to the ceiling in the clean room 100, providing easy access to most floor-mounted equipment.

In addition, it is possible to inspect the equipment and to take out and bring in wafers even under the normal operation of ME1.

Example 4

A tunnel type ME, which is another one of classification according to the installation type of ME1, will be described with reference to FIG.

7 is a cross-sectional view showing the configuration of a tunnel type ME according to the present invention. Since the configuration and operation of the tunnel type ME are the same as those of the floor supported type ME described in Embodiment 1, the description thereof will be omitted.

Next, the characteristics of the tunnel type ME will be described.

The tunnel type ME is installed on the access floor 102 in the clean room 100, as shown in FIG. 7, and a door 7 is installed so that an operator can enter and exit. Therefore, since the wafer is exposed to the worker, it is suitable for the case where the wafer and the worker need to be protected by ultra-clean air at the same time.

In addition, since the tunnel-type ME protects the wafer and the operator's environment with ultra-clean air at the same time as described above, the operator can directly enter the ME and check the operation state of the equipment.

It is also possible to implement a transition area. In other words, the service area (low-clarity area in which machines and equipment other than ME1 are installed as shown in FIG. 7, class 1000) and the process area (wafer inside ME1 as shown in FIG. 7). It is possible to create a transition area using ME when a service area is used as a process area as a buffer area or transition area between the ultra-clean area where the process is performed, class 1 or more).

In addition, the main difference between floor-supported ME and tunnel-type ME is that floor-supported ME cannot be accessed from inside the ME, whereas tunnel-type ME can be accessed from inside the ME. Is there. Therefore, tunnel type ME is suitable when it is necessary to protect wafer and operator at the same time.

As described above, the ME according to the present invention is installed in the clean room so as to locally supply the high clean air only to the minimum space of the wafer area in the clean room, so that the high clean air can be supplied only to the required space. In addition, there is a very excellent effect compared to the conventional purifier in many aspects, such as structural change, maintenance and maintenance, management.

This will be described the advantages of the ME according to the present invention compared to the conventional purifier.

First, it is possible to supply high fresh air locally only to the minimum space required. Conventionally, the method of increasing the cleanliness of the entire space in the clean room has been used, but the ME of the present invention applies more stringent conditions to the areas where high cleanliness is required in order to improve the cleanliness efficiently, and supplies high clean air Areas other than the above alleviate the conditions for air cleanliness. Therefore, by supplying high clean air only to the minimum space in the wafer area, it is possible to proactively protect the surface of the wafer from the indoor environment of workers and clean rooms, as well as save installation and operating costs. have.

Second, partial structural changes and layout changes are easy. The tool-supported ME of the present invention is designed for partial isolation, allowing for easy structural upgrades. In addition, since the floor supported type ME is supported by the floor, the layout can be changed by adjusting only the frame structure of the corresponding part.

Third, even in the event of a partial pressure differential, the ME can always be maintained at a constant pressure. In other words, the intelligent difference control installed in the ME detects the pressure change between the ME and the clean room according to the change of the surrounding environment, and then restores the normal pressure within the preset recovery time.

Fourth, there is no room for gas or the like to be concentrated in the ME by quickly discharging the gas generated during equipment or process. In other words, the ionizer suppresses the generation of static electricity on the surface of the ME, thereby preventing particles from accumulating on the surface of the ME, including the wafer. In addition, the process air flows in one direction around the wafer, so that contaminated air does not reach the wafer and quickly releases particles generated during the wafer process.

Fifth, the operator can enter and exit the ME through the door. Therefore, the wafer and the operator's environment are protected by ultra-clean air at the same time, so that the operator can directly enter the ME and check the operation status of the equipment.

Claims (7)

Local cleaning device (mini) installed in the clean room for supplying high clean air locally only in the minimum space of the wafer area in the clean room. environment) Local cleaning device, A fan unit forcibly drawing room air in the clean room and distributing it along a suction passage installed therein, A ULPA filter for collecting and removing particles suspended in the room air sucked by the fan unit; An ionizer for generating process air by generating positive ion in clean air passing through the ULPA filter, A local clean space in which wafer processing and conveying operations are performed using the process air generated by the ionizer, An air flow controller for controlling the speed and direction of the process air so that the process air is evenly supplied to the local clean space; ME controller that detects a pressure difference between the clean room and the local cleaning device and restores the pressure difference to a steady state. Local cleaning device, characterized in that consisting of. The method of claim 1, The ionizer is composed of a bipolar ionizer (bipolar ionizer), a local cleaning device, characterized in that to adjust the amount and time of ions to be generated by referring to the data input inside the bipolarizer. The method of claim 1, The ME controller, A pressure transmitter for detecting minute pressure differences between the interior of the local cleaner and the cleanroom, An interface unit for controlling the air volume inside the local cleaner based on the data received from the pressure transmitter; Intelligent difference control for restoring the pressure change accompanying the process of processing and conveying the wafer to the normal pressure difference Local cleaning device, characterized in that consisting of. The method of claim 1, The local cleaning device is characterized in that the local cleaning device is installed on an access floor (access floor) in a clean room. The method of claim 1, The local cleaning apparatus is installed on a process tool in a clean room. The method of claim 1, The local cleaning device is characterized in that the local cleaning device is installed in connection with the ceiling in the clean room. The method of claim 1, The local cleaning device is installed on an access floor in a clean room, and the local cleaning device, characterized in that to install a door (door) for the worker to enter and exit.