JP4320158B2 - Local cleaning transfer chamber and local cleaning processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a local cleaning transfer chamber and a local cleaning processing apparatus, and more particularly, in a local cleaning semiconductor processing apparatus, it is easy to adjust the air pressure in the transfer chamber and to create a clean environment without greatly increasing the air blowing rate. The present invention relates to a locally cleaned wafer transfer chamber that can be held.
[0002]
[Prior art]
A wafer used as a material for a semiconductor IC is inspected by an optical foreign matter inspection apparatus because the quality deteriorates when foreign matter adheres to the surface. The inspection is performed by a flow operation, and the wafer stored in the wafer cassette is transferred to, for example, an inspection stage, air-adsorbed on the chuck portion, and rotated.
Therefore, conventionally, a pre-alignment stage or inspection stage of a wafer is provided with a rotation mechanism using a motor or the like. Using this rotating mechanism, the wafer is rotated for angle positioning (θ positioning). In particular, in the case of V-notch positioning, angle positioning and center positioning are performed by a side chuck system that contacts the outer periphery of the wafer at three points. (For example, refer to Patent Document 1). However, since the wafer is rotated by using a rotating mechanism such as a motor, there is a problem of dusting of metal particles due to sliding of the rotating part.
[0003]
On the other hand, when the wiring pattern formed on the wafer is miniaturized, the process becomes 0.25 μm or more, and the diameter of the wafer becomes a large diameter of about 300 mm, the influence of the foreign matter increases accordingly. Accordingly, the yield of the wafer itself and the chips formed on the wafer are also reduced. For this reason, it is not possible to clean only the room where the conventional semiconductor manufacturing apparatus is installed. No matter how much the cleanliness in the room is raised, there is a limit to this, so the processing of semiconductor wafers is performed with a local clean system, so-called mini-en system.
The local cleaning device is usually a device with a high degree of sealing, and prevents the entry of foreign substances from the outside by maintaining the inside at a positive pressure. The degree of cleanliness is cleaned to about class 0.01. The positive internal pressure is obtained by sending clean air through the filter with air from the fan.
Loading of workpieces such as wafers into and out of the apparatus is usually carried in a sealed pod, and the pod is independently sealed and is securely attached to the apparatus and covered with a lid. An opening mechanism FOUP (FRONT OPENING UNIFIED PAD) is equipped (see, for example, FIGS. 1 and 8 of Patent Document 2). In addition, a wafer transfer device for transferring the wafer, pre-aligning it with the pre-alignment stage, and transferring it to the inspection stage is incorporated.
Foreign matter caused by dust generated on the wafer transfer device or pre-alignment stage is externally exposed from the lower side of the device by clean downflow air discharged from an air cleaning fan filter unit (FFU) provided on the ceiling of the device. (For example, refer to FIG. 3 and FIG. 7 of Patent Document 3).
[0004]
[Patent Document 1]
JP-A-4-320043 [Patent Document 2]
JP 2000-173911 A [Patent Document 3]
JP 2000-188320 A
[Problems to be solved by the invention]
The air volume of clean downflow air discharged from the FFU for air cleaning is controlled so that the atmospheric pressure in the wafer transfer chamber becomes a constant positive pressure in order to maintain a clean environment.
The locally cleaned wafer transfer chamber is periodically cleaned, but normally, as the usage period becomes longer, the exhaust pressure increases and the amount of air discharged from the FFU increases to keep the pressure in the wafer transfer chamber constant. .
When the amount of air discharged from the FFU increases, the filter is more likely to be clogged, and dust contained in the filtered air is not sufficiently removed, resulting in a decrease in cleanliness. Further, when the air volume discharged from the FFU increases, the air flow is disturbed by colliding with the conveying device or the like, and the foreign matter stays and dances. That causes contamination of the wafer.
An object of the present invention has been made in view of the above, and is a local cleaning transfer chamber that can easily adjust the atmospheric pressure in the transfer chamber and can maintain a clean environment without greatly increasing the amount of air blown. It is to provide a local cleaning treatment apparatus.
[0006]
[Means for Solving the Problems]
In order to achieve such an object, the feature of the local cleaning transfer chamber and the local cleaning processing apparatus of the present invention is that air from the fan filter unit provided on the floor surface of the local cleaning transfer chamber is sandwiched between the handling units. A plurality of openings to be discharged and an opening ratio adjusting mechanism that covers at least a part of these openings and adjusts the opening ratio.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
As described above, in the present invention, a large number of openings for discharging the air from the FFU are provided on the floor surface in the transfer chamber with the handling unit interposed therebetween, and the opening ratio of the openings is adjusted. When the air flow rate increases greatly, the internal pressure of the transfer chamber can be adjusted by increasing the aperture ratio without increasing the air flow rate.
As a result, it is possible to easily realize a local cleaning transfer chamber and a local cleaning processing apparatus that can easily adjust the atmospheric pressure in the transfer chamber and can maintain a clean environment without greatly increasing the amount of air blown.
[0008]
【Example】
FIG. 1 is a schematic diagram for explaining an internal state of a wafer inspection apparatus having a local cleaning transfer chamber according to the present invention, FIG. 2 is a longitudinal sectional view of FIG. 1, and FIG. 3 is a wafer inspection apparatus of a mini-en system. It is an external view.
In FIG. 3, 20 is a wafer inspection apparatus of a mini-en system, and 10 is a locally cleaned wafer transfer chamber. A fan filter unit (FFU) 11 for sending air into the room is provided at the upper part of the locally cleaned wafer transfer chamber 10, and a filter for purifying air is provided on the front surface of the air blowing side. 12a and 12b are pods containing 13 or 25 wafers, and are placed on the FOUP openers 13a and 13b.
The pods 12a and 12b have a confidential lid at the opening on the front side of the apparatus. The lids are opened by the respective openers when the pods 12a, 12b are mounted on the FOUP openers 13a, 13b.
[0009]
The FOUP opener 13a on the right side of the apparatus on which the pod 12a is mounted in FIG. 3 is at the wafer load position (load port) and corresponds to the pre-alignment stage side inside the apparatus. The left FOUP opener 13b on which the pod 12b is placed is at the wafer unload position (unload port).
In FIG. 1 showing the inside of the locally cleaned wafer transfer chamber 10, reference numeral 14 denotes a wafer handling unit, which takes out the wafer after the inspection from the inspection stage 16 and transfers it to the pod 12b. Then, the next inspection wafer is taken out from the pod 12 a and sent to the pre-alignment stage 15, and the wafer is transferred to the inspection stage 16 after pre-alignment. Reference numeral 14a denotes a unit moving mechanism (guide rail portion) of the wafer handling unit.
The pre-alignment stage 15 is a stage that places a wafer on a table and performs center positioning (centering) and positioning in a V notch or orientation flat (OF) direction (θ positioning). This has an XY stage 15a having an XY moving mechanism and a rotating θ stage 15b.
[0010]
In the floor plate 1 of the locally cleaned wafer transfer chamber 10, rectangular openings 2, 2, 2 are provided at predetermined intervals with the guide rail 14 a of the wafer handling unit 14 interposed therebetween as openings for discharging air from the FFU 11 (see FIG. 2). ... are arranged in an evenly arranged two rows. A movable cover 3, 3 that covers a part of the opening 2 is provided on the floor board 1 corresponding to these openings 2 so as to cover the two openings 2.
FIG. 2 is a longitudinal sectional view of the locally cleaned wafer transfer chamber 10. A wafer handling unit 14 is provided at the center. The FFU 11 provided on the ceiling side includes a fan 11a and a filter 11b.
A controller 17 that controls the wafer handling unit 14 and the pre-alignment stage 15 in the locally cleaned wafer transfer chamber 10 is provided below the pre-alignment stage 15. Further, the floor surface of the locally cleaned wafer transfer chamber 10 has a double structure as shown in FIG. The floor board 1 is a floor surface located above the bottom board 5 a on the bottom surface of the housing 5. Openings 2 are provided at predetermined intervals in the floor plate 1 at the upper portion, and a moving cover 3 is installed on the openings 2.
As a result, the air 6 from the FFU 11 is discharged to the outside through the opening 2, the space between the upper floor plate 1 and the bottom plate 5 a, and the exhaust hole 7.
[0011]
As shown in the enlarged view of the relationship between the floor board 1 and the movable cover 3 shown in the lower side of FIG. 2 and the plan view of FIG. 1, the movable cover 3 is arranged so as to slide on the floor board 1, thereby opening it. 2 can be adjusted. In other words, an adjustment mechanism is formed in which the aperture ratio of the opening 2 is adjusted by the movable cover 3. Therefore, long holes 3a (see FIG. 1) are provided at both ends of the moving cover 3, and fixing screws 4 that pass through the long holes 3a and fix the moving cover 3 are attached to the floor plate 1 of the moving cover 3. Screwed at both ends.
Therefore, the opening ratio of the opening 2 can be adjusted by loosening the fixing screws 4 on both sides and manually sliding the moving cover 3. The initial aperture ratio is suppressed to about 40% and is kept low, and when the control is such that the amount of air blown greatly increases, the aperture ratio is increased from 50% to a higher aperture ratio. As a result, the control of the air flow rate is restored, and the air volume does not have to be increased greatly. Whether or not the control is such that the amount of air blown greatly increases is detected by, for example, the fan current or voltage of the FFU 11.
Note that the air volume of the FFU 11 may be measured directly with an air flow meter, and a scale indicating the aperture ratio is provided around the long hole 3a in order to confirm the adjustment position of the movable cover 3. As a result, the amount of air flowing down by the FFU 11 that sends air into the apparatus can be adjusted by adjusting the aperture ratio of the opening 2.
[0012]
Further, since the moving cover 3 is provided along the floor plate 1, it may be controlled not to be manually, but to be automatically moved by a moving mechanism according to the current air volume so that the air volume does not increase. In this case, the moving cover 3 and its moving mechanism may be arranged on the back side of the floor board 1. Thereby, the problem of inflow of dust generation into the transfer chamber by the moving mechanism does not occur.
Further, in this embodiment, since the controller 17 of the wafer handling unit 14 is provided below the pre-alignment stage 15, the locally cleaned wafer transfer chamber 10 has a small number of uneven portions inside thereof, and the opening 2. Is provided with the guide rail 14a of the wafer handling unit 14 interposed therebetween, so that the downflow air flow is less likely to be disturbed. Therefore, it becomes a structure in which dust does not easily rise up.
[0013]
As described above, in the embodiment, an example in which the opening on the floor surface is rectangular is given, but the opening is not limited to a rectangle.
Further, in the embodiment shown in FIG. 1, the locally cleaned wafer transfer chamber of the present invention is used in a wafer inspection apparatus. However, the present invention includes a wafer inspection apparatus, a wafer exposure apparatus, and the like. Of course, the present invention can be applied to general wafer processing apparatuses. Furthermore, the present invention is not limited to such a wafer processing apparatus, but can be applied to a processing apparatus that conveys various workpieces including a liquid crystal substrate.
[0014]
【The invention's effect】
As described above, in the present invention, a large number of openings for discharging the air from the FFU are provided on the floor surface in the transfer chamber with the handling unit interposed therebetween, and the opening ratio of the openings is adjusted. When the amount of air blown greatly increases, the internal pressure of the transfer chamber can be adjusted by increasing the aperture ratio without increasing the amount of blown air.
As a result, it is possible to easily realize a local cleaning transfer chamber and a local cleaning processing apparatus that can easily adjust the atmospheric pressure in the transfer chamber and can maintain a clean environment without greatly increasing the amount of air blown.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an internal state of a wafer inspection apparatus having a local cleaning transfer chamber according to the present invention.
FIG. 2 is a longitudinal sectional view of FIG.
FIG. 3 is an external view of a wafer inspection apparatus of a mini-en system.
[Explanation of symbols]
1 ... floor board, 2 ... opening,
3 ... moving cover, 3a ... long hole, 4 ... fixing screw,
5 ... casing, 5a ... bottom plate, 6 ... air flow,
7 ... Exhaust hole, 10 ... Locally cleaned wafer transfer chamber,
11 ... Fan filter unit (FFU),
12a, 12b ... pod,
13a, 13b ... FOUP opener,
14 ... Wafer handling unit, 15 ... Pre-alignment stage,
16 ... inspection stage, 17 ... controller, 20 ... wafer inspection device of mini-en system.

Claims (5)

Has a handling unit inside the wafer transfer chamber , blows clean air into the room by the fan filter unit, and controls the air pressure in the wafer transfer room to be a constant positive pressure to maintain a local clean environment. In the local cleaning transfer room
A plurality of openings provided on the floor surface of the local cleaning transfer chamber with the handling unit interposed therebetween, for discharging air from the fan filter unit, and covering at least a part of these openings, and a fan of the fan filter unit When the control is performed such that the air flow rate is greatly increased in order to detect the air flow rate with an air flow meter or fan current or voltage, and to increase the exhaust pressure of the fan filter unit and to keep the positive pressure constant. Is a local cleaning transfer chamber provided with an aperture ratio adjusting mechanism for increasing the aperture ratio of the opening.   Further, the local cleaning transfer chamber is a local cleaning wafer transfer chamber, the handling unit is the wafer handling unit, and has a pre-alignment stage adjacent to the wafer handling unit, and the plurality of openings Are arranged at predetermined intervals, and the aperture ratio adjustment mechanism has a cover that covers the opening, and the cover is slidably adjusted. A controller of the wafer handling unit is below the pre-alignment stage. The locally cleaned wafer transfer chamber according to claim 1, which is provided on the side. Has a handling unit inside the wafer transfer chamber , blows clean air into the room by the fan filter unit, and controls the air pressure in the wafer transfer room to be a constant positive pressure to maintain a local clean environment. In the local cleaning processing apparatus having the local cleaning transfer chamber,
A plurality of openings provided on the floor surface of the local cleaning transfer chamber with the handling unit interposed therebetween, for discharging air from the fan filter unit, and covering at least a part of these openings, and a fan of the fan filter unit When the control is performed such that the air flow rate is greatly increased in order to detect the air flow rate with an air flow meter or fan current or voltage, and to increase the exhaust pressure of the fan filter unit and to keep the positive pressure constant. Is a local cleansing apparatus comprising an aperture ratio adjusting mechanism for increasing the aperture ratio of the aperture. A wafer handling unit is provided inside the wafer transfer chamber, and clean air is blown into the room by the fan filter unit , and the atmosphere in the wafer transfer chamber is controlled to be a constant positive pressure, thereby creating a local clean environment. In a locally cleaned wafer processing apparatus having a locally cleaned wafer transfer chamber for holding ,
A plurality of openings provided on the floor surface of the wafer transfer chamber across the wafer handling unit for discharging air from the fan filter unit, and covering at least a part of these openings, the fan of the fan filter unit When the air flow rate is detected by an air flow meter or fan current or voltage, and the exhaust pressure of the fan filter unit is increased and the positive air pressure is kept constant so that the air flow rate is greatly increased. A locally cleaned wafer processing apparatus comprising: an aperture ratio adjusting mechanism that increases an aperture ratio of the opening.   Further, a pre-alignment stage is provided adjacent to the wafer handling unit, the plurality of openings are arranged at a predetermined interval, and the opening ratio adjusting mechanism has a cover that covers the openings, The locally cleaned wafer processing apparatus according to claim 4, wherein the wafer handling unit controller is slidably adjusted, and a controller of the wafer handling unit is provided below the pre-alignment stage.

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