JP2021089976A - Frame cleaning mechanism and coating device - Google Patents

Abstract

To provide a frame cleaning mechanism and a coating device that can suppress the scattering of cleaning liquid from a frame onto a wafer when cleaning the frame.SOLUTION: A frame cleaning mechanism 100 for cleaning an annular frame 18 with a workpiece 12 fixed thereto includes a table 14 on which the frame 18 is placed, a table rotation device 40 for rotating the table 18, and a cleaning fluid holding plate 21 that faces the frame 18 and is disposed with a gap between the cleaning fluid holding plate 21 and the frame 18 to hold a cleaning fluid supplied to the gap by surface tension.SELECTED DRAWING: Figure 2

Description

The present invention relates to a frame cleaning mechanism and a coating device for cleaning a frame for fixing a wafer.

In the manufacture of semiconductors, a wafer (workpiece) is fixed to an annular frame using a dicing tape, the wafer is transported to various processing devices while being fixed to the frame, and various films are formed on the surface of the wafer. , Wafer is being processed. For example, a resist film is formed on the surface of the wafer during exposure, and a protective film that protects the device layer is formed during grooving (grooving).

Various coating devices are used to form these films. For example, in a rotary coating device, a coating liquid is supplied near the center of the surface of the object to be processed, and the object to be processed is rotated around the central axis of the object to be processed (the central axis of the rotary table) to centrifuge. The coating liquid is applied to the entire surface of the object to be processed by using force. Since the frame is on the outer peripheral side of the wafer, the coating liquid may be scattered on the frame when the coating liquid is applied to the wafer by the rotary coating device. In addition, dirt may adhere to the frame during wafer transfer.

If the frame is contaminated with a coating liquid or the like and the process proceeds to the subsequent processing process, the dirt adheres to the wafer and causes defects in the chips formed on the wafer. There may be a problem that the frame is difficult to be detached from the suction pad during transportation. To avoid such problems, the process of cleaning the frame is performed during the processing process.

For example, Patent Document 1 discloses a water-soluble resin removing step of removing a water-soluble resin (coating liquid) scattered on a frame by blowing air from an air nozzle onto the frame while supplying a cleaning liquid to the frame.

JP-A-2017-092379

However, Patent Document 1 has a problem that the quality of the coating film formed on the wafer is deteriorated (contaminated by the cleaning liquid) because the cleaning liquid blown off by the air is scattered from the frame onto the wafer.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a frame cleaning mechanism capable of suppressing scattering of a cleaning liquid when cleaning a frame.

In order to achieve the above object, the frame cleaning mechanism according to the present invention is a cleaning mechanism for cleaning the frame with the object to be processed fixed, and the table on which the frame is placed and the table on which the table is rotated are rotated. It includes a rotating device and a cleaning liquid holding plate which is a cleaning liquid holding plate which faces the frame and is arranged with a gap between the frame and the cleaning liquid and which holds the cleaning liquid supplied to the gap by surface tension.

According to the frame cleaning mechanism according to the present invention, the frame is cleaned with the cleaning liquid held in the gap between the cleaning liquid holding plate and the frame by surface tension. As a result, when cleaning the frame, it is possible to clean the frame satisfactorily while suppressing the cleaning liquid from being scattered on the object to be processed fixed to the frame.

Here, preferably, the cleaning liquid holding plate is held parallel to the table. Further, the distance between the cleaning liquid holding plate and the frame placed on the table is preferably several mm, more preferably 2 mm to 3 mm.

Preferably, the cleaning liquid holding plate faces only a part of the circumferential direction of the frame and has a width larger than the width of the frame, and the relative position between the cleaning liquid holding plate and the frame is set by rotating the table. Clean the frame while changing it in the circumferential direction.

Further, the distance between the cleaning liquid holding plate and the table may be changed according to the radial position of the table. For example, the distance between the cleaning liquid holding plate and the table at the central end of the cleaning liquid holding plate is D1, and the distance between the cleaning liquid holding plate and the table at the central portion of the cleaning liquid holding plate is D2. Assuming that the distance between the cleaning liquid holding plate and the table at the outer peripheral end of the table is D3, D1> D2> D3 may be used.

As a result, surface tension can be applied so as to promote the discharge of the cleaning liquid to the outer peripheral side (outer peripheral side of the frame) of the table and to suppress the cleaning liquid from flowing into the center side (wafer side) of the table. it can.

Further, the length of the cleaning liquid holding plate may be extended. In this case, the shape of the cleaning liquid holding plate may be made annular or partially annular according to the annular frame so that the cleaning liquid holding plate can cover (oppose) the frame. When the length of the cleaning liquid holding plate is extended, the cleaning area of the cleaning liquid holding plate is expanded, so that the cleaning efficiency can be improved.

Further, the frame cleaning mechanism may further include a vibrator that applies ultrasonic vibration to the cleaning liquid. Thereby, the cleaning efficiency of the frame can be improved. Further, cleaning liquid holding plates may be provided on both sides of the frame. Since both sides of the frame can be cleaned at once, the cleaning efficiency of the frame can be improved.

Further, the above-mentioned frame cleaning mechanism can be suitably applied to a rotary coating device. Since the equipment provided in the rotary coating device can be diverted (also used), a rotary coating device provided with a frame cleaning mechanism can be realized at low cost.

According to the present invention, it is possible to provide a frame cleaning mechanism capable of suppressing the scattering of the cleaning liquid from the frame.

Top view showing the schematic configuration of the frame cleaning mechanism Front view showing the schematic configuration of the frame cleaning mechanism Functional block diagram of the control unit Diagram illustrating cleaning of the frame The figure which shows the deformation example of the cleaning liquid holding plate The figure which shows the deformation example of the cleaning liquid holding plate The figure which shows the deformation example of the cleaning liquid holding plate The figure which shows the deformation example of the cleaning liquid holding plate The figure explaining the case of cleaning both sides of a frame The figure explaining the case of cleaning a frame using the cleaning part provided with an oscillator.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the object to be processed (work) is used as a wafer as an example, but the purpose is not to limit the object to be processed.

<Embodiment>
First, the configuration of the frame cleaning mechanism 100 will be described. 1 and 2 are a plan view and a front view showing a schematic configuration of the frame cleaning mechanism 100 according to the present embodiment. The X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other, the X-axis direction is the horizontal direction, the Y-axis direction is the horizontal direction orthogonal to the X-axis direction, and the Z-axis direction is the vertical direction (vertical). Direction). The frame cleaning mechanism 100 shown in FIGS. 1 and 2 includes a table 14, a cleaning unit 20, a holding plate driving unit 30, a table rotating device 40, and a control unit 50.

The table 14 is parallel in the horizontal direction, and the wafer 12 (frame 18) is sucked and held by using a suction device (not shown). For example, the substantially disk-shaped wafer 12 is fixed to the substantially annular frame 18 via the dicing tape 16 and is placed on the table 14 so that the center of the wafer 12 substantially coincides with the center of the table 14. It will be placed. That is, the frame 18 is held on the table 14 via the dicing tape 16.

The cleaning unit 20 includes a cleaning liquid holding plate 21 and a support arm 24. The cleaning liquid holding plate 21 is a substantially quadrilateral, for example, a square or rectangular flat plate, and is held parallel to the table 14 (and the frame 18) by the support arm 24. The cleaning liquid holding plate 21 is fixed to the support arm 24 by, for example, welding, gluing, or screwing. Examples of the material of the cleaning liquid holding plate 21 include metal, more specifically stainless steel. When the cleaning liquid holding plate 21 is made of stainless steel, the thickness of the cleaning liquid holding plate 21 is, for example, 1 mm (millimeter). The width of the cleaning liquid holding plate 21 is slightly larger than the width of the frame 18 so as to cover the width of the frame 18 (that is, the difference between the inner diameter and the outer diameter). The length of the cleaning liquid holding plate 21 can be arbitrarily set.

The support arm 24 includes a horizontal arm 22 parallel to the table 14 and a vertical arm 23 parallel to the Z axis. A cleaning liquid holding plate 21 is fixed to the tip of the horizontal arm 22, and the horizontal arm 22 holds the cleaning liquid holding plate 21 so as to be parallel to the table 14 (frame 18). The base end of the horizontal arm 22 communicates with the tip (upper end) of the vertical arm 23. The base end of the vertical arm 23 is connected to the holding plate driving unit 30. The central axis of the vertical arm 23 coincides with the rotation axis when the cleaning liquid holding plate 21 is rotated (rotated).

The support arm 24 also serves as a cleaning liquid supply pipe, and the inside of the support arm 24 is hollow. The cleaning liquid holding plate 21 fixed to the tip of the support arm 24 has a hole 25 (not shown) that communicates with the inside of the support arm 24. The base end of the support arm 24 is connected to the cleaning liquid tank 28 via a pipe 26, and a flow rate control valve 27 is provided on the pipe 26. When cleaning the frame 18, the cleaning liquid from the cleaning liquid tank 28 flows inside the support arm 24 and is supplied to the surface of the frame 18 through the holes 25 provided in the cleaning liquid holding plate 21. Examples of the cleaning liquid include water (pure water). In the present embodiment, the support arm 24 is described as also serving as a cleaning liquid supply pipe, but of course, the support arm and the cleaning liquid supply pipe may be provided separately.

The holding plate drive unit 30 includes a motor (not shown) and a position sensor (encoder) (not shown). The holding plate driving unit 30 moves the cleaning liquid holding plate 21 by rotating the vertical arm 23 using a motor. For example, when cleaning the frame 18, the holding plate driving unit 30 moves the cleaning liquid holding plate 21 above the table 14 (cleaning position) so that the cleaning liquid holding plate 21 faces the frame 18 (in FIG. 2). Position indicated by solid line). When the cleaning of the frame 18 is completed, the cleaning liquid holding plate 21 is retracted from above the table 14 to another position (evacuation position) (the position indicated by the dotted line in FIG. 2).

The direction in which the cleaning liquid holding plate 21 is retracted is not limited to the rotational movement of the rotation axis parallel to the Z axis. For example, the holding plate driving unit 30 may use an actuator (not shown) to linearly move the cleaning liquid holding plate 21 in a direction parallel to the X-axis or the Y-axis. Further, the frame cleaning mechanism 100 (or the rotary coating device described in the modified example 7) prevents liquids such as cleaning liquid from scattering around the table 14 when the table 14 is rotated (not shown). In addition to horizontal movement (rotational movement and linear movement) parallel to the XY plane, the cleaning liquid holding plate 21 is moved up and down (direction parallel to the Z axis) using an actuator (not shown). The holding plate driving unit 30 may be configured so that the holding plate drive unit 30 can be configured.

The table rotation device 40 uses a motor (not shown) to rotate the table 14 around a rotation axis (parallel to the Z axis) that passes through the center of the table 14 and is perpendicular to the surface of the table 14. The control unit 50 controls the flow rate control valve 27, the holding plate driving unit 30, and the table rotating device 40 (described later).

FIG. 3 is a functional block diagram of the control unit 50. The control unit 50 includes, for example, an interface 51, a holding plate drive control unit 52, a flow rate control unit 53, and a table rotation control unit 54. The interface 51 is a means for exchanging commands and data with a user and each device, and is, for example, a keyboard, a mouse, a touch panel, a display, a speaker, a data communication device (network connection device), and the like.

The holding plate drive control unit 52 controls the motor of the holding plate driving unit 30 based on a command from the user and data from the position sensor of the holding plate driving unit 30. The flow rate control unit 53 controls the flow rate of the cleaning liquid supplied to the nozzle 20 by controlling the flow rate control valve 27 based on a command from the user or a predetermined set value. The table rotation control unit 54 controls the table rotation device 40 based on a command from the user or a predetermined set value. The holding plate drive control unit 52, the flow rate control unit 53, and the table rotation control unit 54 are realized by using, for example, a processor. In FIG. 3, the holding plate drive control unit 52, the flow rate control unit 53, and the table rotation control unit 54 are shown separately according to their functions, but in reality, it can be realized by one processor. Further, the control unit 50 includes a ROM (Read Only Memory) (not shown), a RAM (Random Access Memory) (not shown), and the like. Various programs such as control programs stored in the ROM are expanded in the RAM, and the programs expanded in the RAM are executed by the processor to execute various control processes.

Next, cleaning of the frame 18 by the frame cleaning mechanism 100 will be described with reference to FIG. First, before cleaning the frame 18, the frame 18 is placed on the table 14. Subsequently, the holding plate driving unit 30 moves the cleaning liquid holding plate 21 to a position (cleaning position) parallel to the frame 18 (table 14) as shown in FIG. At the cleaning position, the cleaning liquid holding plate 21 and the frame 18 are not in contact with each other, and the distance between the cleaning liquid holding plate 21 and the frame 18 is about several mm (millimeters).

Generally, due to the action of surface tension, the liquid injected into the gap tries to stay in the gap. In the frame cleaning mechanism 100 according to the present embodiment, the cleaning liquid holding plate 21 is provided with a gap (interval) at a position facing the frame 18 so that the gap between the cleaning liquid holding plate 21 and the frame 18 is filled with the cleaning liquid due to surface tension. Deploy. At that time, the distance D between the cleaning liquid holding plate 21 and the frame 18 is appropriately set according to the viscosity of the cleaning liquid. When the cleaning liquid is water, the distance between the cleaning liquid holding plate 21 and the frame 18 is preferably 2 mm to 4 mm, more preferably 3 mm.

When cleaning the frame 18, the table rotating device 40 makes one or more turns of the table 14 while supplying the cleaning liquid to the gap between the cleaning liquid holding plate 21 and the frame 18 with the cleaning liquid holding plate 21 facing the frame 18. Rotate (360 ° or more). As a result, the entire circumference of the ring-shaped frame 18 is cleaned. It is not necessary to pressurize the cleaning liquid to be supplied. As shown by the arrow A in FIG. 4, the cleaning liquid can be supplied onto the frame 18 through the holes 25 provided in the cleaning liquid holding plate 21. Further, for example, as shown by arrow B in FIG. 4, the cleaning liquid may be supplied to the gap between the cleaning liquid holding plate 21 and the frame 18. In this case, the support arm 24 does not need to serve as the cleaning liquid supply pipe, and the hole 25 on the cleaning liquid holding plate 21 is not required.

The rotation speed of the table 14 is not particularly limited, but it is desirable that the rotation speed is low enough to hold the cleaning liquid in the gap between the cleaning liquid holding plate 21 and the frame 18 due to surface tension.

As described above, according to the frame cleaning mechanism 100 according to the present embodiment, the frame 18 is cleaned while the cleaning water is held in the gap between the cleaning liquid holding plate 21 and the frame 18 by surface tension. Therefore, it is possible to prevent the cleaning liquid from scattering from the frame 18. As a result, it is possible to prevent the wafer 12 and peripheral devices from being contaminated by the scattered cleaning liquid.

<Modification example 1>
Subsequently, a modified example of the cleaning liquid holding plate 21 will be described with reference to FIGS. 5 to 8. As shown by reference numeral 5A in FIG. 5, the cleaning liquid holding plate 21 may be a bent plate. For example, in the cleaning liquid holding plate 21, the end portion (inner circumference) of the wafer 12 side (the inner peripheral side of the frame 18 and also the central side of the table 14) so as to widen the distance between the cleaning liquid holding plate 21 and the frame 18. The side end) may be bent upward in the Z-axis direction. Further, the outer peripheral side end portion (outer peripheral side end portion) of the frame 18 may be bent downward in the Z-axis direction so as to narrow the distance between the cleaning liquid holding plate 21 and the frame 18. That is, the maximum distance between the end of the cleaning liquid holding plate 21 on the wafer 12 side and the frame 18 is set to D1, and the cleaning liquid holding plate 21 and the frame 18 near the center of the cleaning liquid holding plate 21 (near the middle of the width of the frame 18). If the distance between the two is D2 and the shortest distance between the end of the cleaning liquid holding plate 21 on the outer peripheral side of the frame 18 and the frame 18 is D3, D3 may be narrower than D2 or D2 may be narrower than D1. It may be done (D3 <D2 <D1). More specifically, for example, when D2 is 3 mm, D1 is preferably about 6 mm, and D3 is between 2 mm and 3 mm.

Alternatively, as shown by reference numeral 5B in FIG. 5, a flat plate-shaped cleaning liquid holding plate 21 is attached to the frame 18 so that the distance between the cleaning liquid holding plate 21 and the frame 18 on the wafer 12 side becomes wider on the outer peripheral side of the frame 18. It may be arranged slightly diagonally. As shown in FIG. 5, the distance between the cleaning liquid holding plate 21 and the frame 18 is changed between the inner peripheral side, the middle vicinity, and the outer peripheral side of the frame 18 (in other words, it is changed according to the radial position of the table 14). As a result, it is possible to obtain a surface tension intensity distribution that suppresses the flow of the cleaning liquid to the wafer 12 side and promotes the discharge of the cleaning liquid to the outer peripheral side of the frame 18.

<Modification 2>
As shown in FIG. 6, the cleaning liquid holding plate 21 may be a parallelogram (diamond). Reference numeral 6A in FIG. 6 indicates the shape of the cleaning liquid holding plate 21 when the rotation direction of the table 14 during cleaning is counterclockwise, and reference numeral 6B in FIG. 6 indicates the rotation direction of the table 14 during cleaning in the clockwise direction. The shape of the cleaning liquid holding plate 21 in the case is shown.

As shown in FIG. 6, the cleaning liquid holding plate 21 may be deformed so that the surface tension guides the cleaning liquid to the outer peripheral side of the frame 18. In the case of the cleaning liquid holding plate 21 shown by reference numeral 6A in FIG. 6, of the four sides of the cleaning liquid holding plate 21 shown in FIG. 1, two sides parallel to the X-axis and facing each other are components in the rotation direction of the table 14. The cleaning liquid holding plate 21 is deformed so as to have. The cleaning liquid holding plate 21 shown by reference numeral 6B is also the same as the cleaning liquid holding plate 21 shown by reference numeral 6A.

When the cleaning liquid holding plate 21 having such a shape is used, surface tension can be applied to the cleaning liquid so as to guide the cleaning liquid to the outer peripheral side of the frame 18. As a result, it is possible to guide the cleaning water to be drained to the outer peripheral side of the frame 18 while suppressing the cleaning liquid from scattering to the wafer 12 side. In this case, it is desirable that the rotation speed of the table 14 is relatively low as compared with other examples.

<Modification example 3>
As shown in FIG. 7, of the parallelograms (diamonds) shown in FIG. 6, two sides facing the radial direction of the frame 18 may be curved. Reference numeral 7A in FIG. 7 indicates the shape of the cleaning liquid holding plate 21 when the rotation direction of the table 14 during cleaning is counterclockwise, and reference numeral 7B in FIG. 7 indicates the rotation direction of the table 14 during cleaning in the clockwise direction. The shape of the cleaning liquid holding plate 21 in the case is shown. The cleaning liquid holding plate 21 shown in FIG. 7 can realize the same effect as the cleaning liquid holding plate 21 shown in FIG.

<Modification example 4>
The length of the cleaning liquid holding plate 21 may be extended. In this case, the shape of the cleaning liquid holding plate 21 is made into an annular shape or a partial annular shape according to the annular frame 18 so that the cleaning liquid holding plate 21 can cover the frame 18. The partial ring may be any partial ring such as a partial ring having a central angle of 90 degrees and a partial ring having a central angle of 180 degrees. Further, for example, as shown in FIG. 8, the cleaning liquid holding plate 21 may have a ring shape (whole circle) covering the entire circumference of the annular frame 18. When the length of the cleaning liquid holding plate 21 is extended, the cleaning area of the cleaning liquid holding plate 21 is expanded, so that the cleaning efficiency can be improved.

<Modification 5>
Next, a modified example of the cleaning method of the frame 18 will be described with reference to FIGS. 9 and 10. FIG. 9 shows a case where two cleaning liquid holding plates 21 are installed above and below the frame 18 in the Z-axis direction to clean both sides of the frame 18. In this case, the shape of the support arm 24 is appropriately changed so that the two cleaning liquid holding plates 21 can be held, such as by increasing the number of horizontal arms 22. Further, it is desirable that the outer diameter of the table 14 is smaller than the inner diameter of the frame 18. Since both sides of the frame 18 can be cleaned at once, the cleaning efficiency of the frame 18 can be improved.

<Modification 6>
FIG. 10 shows a case where the frame 18 is further cleaned by using the cleaning unit 20 including the vibrator 29. For example, the vibrator 29 is provided so as to come into contact with the surface of the cleaning liquid holding plate 21, and gives vibration suitable for ultrasonic cleaning to the cleaning liquid via the cleaning liquid holding plate 21. Since the frequency of ultrasonic vibration is well known, the description thereof will be omitted. By using the vibrator 29, the cleaning efficiency of the frame 18 can be improved.

<Modification 7>
It is also possible to apply the frame cleaning mechanism 100 according to the present embodiment to the rotary coating device. In this case, since the coating table and the table rotating device provided in the rotary coating device can also be used for frame cleaning, the cleaning unit 20, the holding plate drive unit 30, the control unit 50, etc. of the frame cleaning mechanism 100 can be used. To the rotary coating device. Since the equipment provided in the rotary coating device can be diverted (also used), a rotary coating device provided with the frame cleaning mechanism 100 can be realized at low cost.

<Effect>
As described above, according to the frame cleaning mechanism 100 according to the present embodiment, the frame 18 is cleaned while holding the cleaning liquid in the gap between the cleaning liquid holding plate 21 and the frame 18 by surface tension. As a result, it is possible to prevent the cleaning liquid from scattering from the frame 18 onto the wafer 12.

Further, when the frame cleaning mechanism 100 is applied to the rotary coating device, the equipment provided by the rotary coating device can be diverted (also used), so that the rotary coating device provided with the frame cleaning mechanism 100 can be realized at low cost.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above examples, and it goes without saying that various improvements and modifications may be made without departing from the gist of the present invention. ..

For example, in the above, the case where the frame 18 in which the wafer 12 is fixed is placed on the table 14 and the frame 18 is washed has been described, but only the frame 18 is placed on the table 14 and the frame 18 is washed. Of course it is possible to do so.

12 ... Wafer, 14 ... Table, 16 ... Dicing tape, 18 ... Frame, 20 ... Cleaning part, 21 ... Cleaning liquid holding plate, 22 ... Horizontal arm, 23 ... Vertical arm, 24 ... Support arm, 25 ... Hole, 26 ... Piping , 27 ... Flow control valve, 28 ... Cleaning liquid tank, 29 ... Transducer, 30 ... Holding plate drive unit, 40 ... Table rotating device, 50 ... Control unit, 51 ... Interface, 52 ... Holding plate drive control unit, 53 ... Flow rate Control unit, 54 ... Table rotation control unit, 100 ... Frame cleaning mechanism

Claims (8)

A frame cleaning mechanism that cleans the annular frame in which the object to be processed is fixed.
The table that holds the frame and
A table rotating device for rotating the table and
A cleaning liquid holding plate that faces the frame and is arranged with a gap between the frame and the cleaning liquid holding plate that holds the cleaning liquid supplied to the gap by surface tension.
Frame cleaning mechanism with. The frame cleaning mechanism according to claim 1, wherein the cleaning liquid holding plate is held parallel to the frame. The cleaning liquid holding plate faces only a part of the circumferential direction of the frame and has a width larger than the width of the frame.
The frame cleaning mechanism according to claim 1 or 2, wherein the frame is cleaned while changing the relative position between the cleaning liquid holding plate and the frame in the circumferential direction of the frame by rotating the table. The frame cleaning mechanism according to claim 1 or 2, wherein the cleaning liquid holding plate has a ring shape that follows the shape of the frame. The distance D1 between the cleaning liquid holding plate and the table at the central end of the cleaning liquid holding plate is larger than the distance D2 between the cleaning liquid holding plate and the table at the central portion of the cleaning liquid holding plate.
The frame cleaning mechanism according to any one of claims 1 to 4, wherein the distance D3 between the cleaning liquid holding plate and the table at the outer peripheral end of the table is smaller than the distance D2. The frame cleaning mechanism according to any one of claims 1 to 5, further comprising a vibrator that applies ultrasonic vibration to the cleaning liquid. The frame cleaning mechanism according to any one of claims 1 to 6, wherein the cleaning liquid holding plate is provided on both sides of the frame. A coating device having a nozzle that supplies a coating liquid toward an object to be processed.
A coating device comprising the frame cleaning mechanism according to any one of claims 1 to 7.

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