JP2003332293A - Spinning dryer and apparatus for polishing outer periphery of wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spinning dryer in which wafer holding is surely and safely canceled without providing a complicated and expensive detector and without substantially requiring maintenance in the spinning dryer of a centrifugal force clamp type. <P>SOLUTION: When moving a turn table 73 to the upside of a scatter-proofing cover 75 in order to load/unload a work W to/from the spinning dryer, a part of the scatter-proofing cover 75 is abutted with a turn hook member 74 and turns the hook member to forcibly disengage the hook member. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spin dryer of the type in which after cleaning a semiconductor wafer, the wafer is rotated at high speed and the adhered droplets are shaken off by centrifugal force to dry.

[0002]

2. Description of the Related Art In a spin dryer, a wafer is held on a wafer mounting frame that rotates at high speed. Conventionally, a vacuum suction type holding means or a mechanical holding means for externally applying energy for holding the wafer has been used for holding the wafer. In recent years, a centrifugal holding means has been used which has a simple structure and can hold a wafer without applying special energy from the outside by utilizing the centrifugal force of rotation required for spin drying. It has started to be done. An example of a spin dryer adopting such a centrifugal holding means is disclosed in JP-A-62-166517 and JP-A-2-
It can be found in Japanese Patent Publication No. 209731.

FIG. 1 is an explanatory view for briefly explaining the principle of the centrifugal force type wafer holding means. Here, FIG. 1 (A) shows a state in which no wafer is held, and FIG. 1 (B) shows the same. Shows the state of holding the wafer. The spin dryer includes a rotary drive source 71, a spin shaft 72 that rotates about a substantially vertical axis by the rotary drive source, a turntable 73 provided on the spin shaft 72 for supporting the work W, and a plurality of spin dryers. The rotating hook member 74 is provided.

The rotating hook member 74 is used for the turntable 7
3 is rotatably supported around a substantially horizontal rotating shaft 743, and has a claw portion 741 for engaging with the periphery of the work piece at one end and a weight portion 742 at the other end. With this configuration, the rotating hook member 74 is provided with the support piece 7
When the work W is loaded / unloaded onto the 31, that is, when the spin shaft 72 does not rotate, the weight portion 7
When the spin shaft 72 rotates due to the gravity g applied to the work piece 42 and the spin shaft 72 rotates, the claw portion 741 engages with and holds the work piece W by the centrifugal force c applied to the weight portion 742. Take a posture.

The work W is held only when the spin shaft 72 rotates, and when the rotation is stopped, the work W is automatically released due to the gravity applied to the weight portion 742. Can be loaded / unloaded.

[0006]

As described above, the centrifugal force type wafer holding means is a clever one that can automatically hold and hold the work without taking a complicated structure. However, the rotary shaft 7
The rotation hook member 74 may not return to the position shown in FIG. 1A even though the rotation of the spin shaft 72 is stopped due to wear of the 43rd part or other unspecified reason.

When the transport device unloads the work W in this state, since the pawl portion 741 remains on the work W, an accident such as breakage or drop of the work W may occur. In order to recover the manufacturing line from this accident, it is necessary to stop part of the line and perform work to remove the damaged wafer. If loading / unloading is continued, the subsequent wafer may be damaged. Wafers, especially device wafers, are so expensive that the loss from losing them becomes a huge problem.

In order to prevent such an accident in advance,
It is also possible to provide a detection device for confirming that the turning hook member 74 has released the grip, and take a measure to stop the unloading of the work W when the release is not confirmed. However, there is a problem in that it is expensive to provide the detection device itself, and it is further expensive to perform maintenance so that the detection device always operates normally.

In view of the above problems, the present invention does not require complicated and expensive detection devices in a spin dryer, and requires substantially no maintenance. The spin drying can reliably and safely release the wafer. The challenge is to provide machines.

[0010]

The above-mentioned problems can be solved by the following means. That is, the spin dryer according to the first aspect of the present invention includes a rotary drive source, a spin shaft that rotates about a substantially vertical axis by the rotary drive source, and a spin shaft that supports a disk-shaped work. A turntable provided, which is rotatably supported on the turntable about a substantially horizontal rotation axis, and has a claw portion for engaging the vicinity of the work peripheral edge at one end and a weight portion at the other end, When the spin shaft does not rotate, the rotation hook member takes a posture of being disengaged from the work by gravity, and when the spin shaft rotates, it has a posture of engaging the work by a centrifugal force, and a plurality of rotating hook members, and When the spin shaft rotates the work, the spin provided with an annular anti-scattering cover located around the turntable to receive droplets scattered by centrifugal force. In 燥機,
When either the turntable or the shatterproof cover is moved so that the turntable is above the shatterproof cover for loading / unloading the work, a part of the shatterproof cover is rotated. The above-mentioned engagement is disengaged by abutting on the hook member and rotating the hook member.

The spin dryer of the second invention is the spin dryer of the first invention, and further, when the work is loaded / unloaded, particularly, the upper edge portion of the scattering prevention cover has the rotating hook. It is designed to come into contact with the member. A spin dryer according to a third aspect of the present invention is the spin dryer according to the first aspect of the present invention, wherein the protrusion provided on the scattering prevention cover is the turning hook member when the work is loaded / unloaded. It is made to abut. A spin dryer according to a fourth invention is the spin dryer according to the first invention, wherein the protrusion is provided in the vicinity of the upper edge portion of the scattering prevention cover, and when the work is loaded / unloaded, The projection is in contact with the rotating hook member. A spin dryer according to a fifth aspect of the present invention is the spin dryer according to the fifth aspect, wherein at least the upper edge portion of the scattering prevention cover or the inside of the protrusion is engaged with the rotating hook member and the work. The inner diameter is such that the turntable and the rotating hook member do not come into contact with each other.

A sixth aspect of the present invention is a wafer peripheral portion polishing apparatus which is substantially entirely covered by a machine frame, wherein the first to fifth spin drying units are provided in the machine frame. Up to one of the above spin dryers is installed, a wafer receiving / ejecting unit for receiving and ejecting a wafer cassette containing wafers, a wafer position aligning unit for determining the position of the wafer and the direction of its notch. A wafer notch polishing unit for polishing a notch of a wafer, a wafer peripheral polishing unit for polishing a peripheral portion of a wafer, a wafer cleaning unit for cleaning a wafer with a cleaning liquid, and a wafer between these units The wafer outer peripheral portion polishing apparatus is provided with an internal transfer unit for transferring the wafer.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment will be described based on an example in which the spin dryer of the present invention is incorporated as a wafer drying unit in a wafer polishing apparatus. First, the shape and part of the wafer W will be briefly described. 2A,
(B) and (C) are a plan view of a semiconductor wafer, a partial cross-sectional view of a semiconductor wafer W, and a perspective view showing the periphery of an enlarged notch N, respectively. Since the pattern forming surface Sp, the circumferential bevel surface Sb, and the circumferential end surface (cylindrical surface of the outer circumference) Sc of the semiconductor wafer, as they are, cause dust to be generated in the subsequent process, the notch bevel surface of the notch N including the notch end surface Then, it is mirror-finished by polishing.

FIG. 3 is an external view showing a wafer polishing apparatus incorporating the present invention. As shown in this figure, the wafer outer peripheral polishing apparatus 1 is substantially entirely machine frame 10.
The wafer cassette receiving / ejecting unit 2 is partially covered with the wafer cassette receiving / ejecting unit 2. Only a limited part of the wafer cassette receiving / exhausting unit 2 is open.

The wafer peripheral portion polishing apparatus 1 is controlled by a control device for controlling the entire apparatus including other devices, and the operation panel 1 is provided at an appropriate height position on the outer surface of the machine frame 10.
1 and a display device 12 are provided so that an operator can manually operate them. The plurality of transparent windows 13 are windows for properly observing the operating condition of the wafer outer peripheral portion polishing apparatus 1 from the outside in addition to the function of covering the whole, and are removable for repair, adjustment and the like.

The wafer cassette receiving and discharging unit 2 has a shelf-like structure. A wafer cassette 211 loaded with unprocessed wafers W is placed on the receiving / discharging shelf 21 with the wafers W in a substantially horizontal state.
It is taken in and mirror-polished. The wafer W that has been mirror-polished is again stored in the same slot of the same wafer cassette 211. Then, the wafer cassette 21
The wafer W is transferred to the next process for each one. That is, in the receiving / discharging shelf 21, the wafer W can be moved in and out of the apparatus by placing the wafer cassette 211 therein.

FIG. 4 is a plan view for explaining the outline of the wafer peripheral portion polishing apparatus 1. In the machine frame 10, a wafer cassette receiving / exhausting port unit 2, a wafer position aligning unit 3, a wafer notch polishing unit 4, a wafer circumferential portion polishing unit 5, a wafer cleaning unit 6, a wafer drying unit 7, an internal transfer unit, 2 Two slurry supply devices (a first slurry supply device 49 and a second slurry supply device 59) are arranged, and each unit is attached to a predetermined position of the machine casing 10. In this example, as described later, the internal transport unit includes three transport units, that is, a first transport unit 81, a second transport unit 82, and a third transport unit 83.

The outline of the movement of the wafer W (shown by the arrow in FIG. 4) is as follows. First, the wafer W is stored in the wafer cassette 211 and placed in the wafer cassette receiving and discharging unit 2. The wafer W is taken out from the wafer cassette 211 and transferred to the wafer position aligning unit 3. In the wafer position aligning unit 3, the center of the wafer W is positioned so as to come to a predetermined position, and its notch is oriented so as to face a predetermined direction.

After the position and orientation are adjusted in this way, the wafer is moved to the wafer notch polishing unit 4, where notch polishing is performed. The parts of the wafer to be polished are the upper and lower notch bevel surfaces Sbn and notch end surfaces Scn shown in FIG. After that, the wafer is moved to the wafer circumference polishing unit 5. Here, the circumferential portion, that is, the upper and lower circumferential bevel surfaces Sb and the circumferential end surface Sc, as shown in FIG. 2, is polished.

Then, the wafer is transferred to the wafer cleaning unit 6,
Dirt adhering to the wafer W by the polishing operation in the wafer notch polishing unit 4 and the wafer circumferential polishing unit 5 is cleaned by the cleaning liquid and the cleaning roller. Further, the wafer W is transferred to the wafer drying unit 7,
The cleaning liquid is removed from the wafer W by rotating the wafer to which the cleaning liquid is attached in the wafer cleaning unit 6 described later at high speed.

The internal transport unit includes the first transport unit 81, the second transport unit 82, and the
Although it comprises the third transport unit 83, it is also possible to perform these functions by a larger number of units or a smaller number of units, for example, one transport unit in some cases.

The first transport unit 81 has a traveling platform 812 capable of traveling on two linear tracks 811, a body 814 rotatable on the platform 812, and a multi-joint 2 provided on the body 814. It is a transfer robot with one arm and two grips. Since this transport robot looks like a person's torso and arms, it can be said that it has a right arm and a left arm when the lower part of the drawing is considered to be forward in the state shown by the solid line in FIG.

The specific operation or function of each unit will be described below with reference to the drawings. FIG. 5 shows the essential parts of the wafer cassette receiving / ejecting port unit 2 and the first transfer unit 81. The first transfer unit 81 is the wafer cassette 2
11. Move to the front of 11, extend the left arm, and hold the left hand suction plate 813.
By L, the wafer W placed in a substantially horizontal state is pulled out from the wafer cassette 211 on the receiving / discharging shelf 21. At this time, the right hand suction plate 813R is empty.

With the arm retracted, the first transfer unit 81 moves leftward (FIG. 4) and stops in front of the wafer position aligning unit 3. The wafer position aligning unit 3 is in a state of being loaded with the aligned wafers W whose positions and directions are adjusted (the state of being placed on the table 31), and the right-hand suction plate 813R has nothing. Therefore, the wafer W is picked up by extending the right hand suction plate 813R. In this way, the aligned wafer W is placed on the right hand suction plate 813R, and the left hand suction plate 81
There is an unfinished wafer W in 3L.

Next, the left-hand suction plate 813L is extended, and the wafer W that has not been aligned is placed on the table 31 of the wafer position aligning unit 3. The state at this time is shown in FIG. When the wafer W is placed, the first transfer unit 81 is in a state where the right hand suction plate 813R holds the wafer W and the left hand suction plate 813L does not hold anything.

Wafer position aligning unit 3
Is a table 31, a positioning device 32, an orientation device 3
Equipped with 3. FIG. 7 is a top view of an essential part of the wafer position aligning unit 3. The table 31 has a suction mechanism for sucking and gripping the wafer. Since the suction mechanism is not operating when the wafer W is placed on the table 31, it can be moved on the table 31 with a light force by pushing it in the lateral direction. The positioning device 32 operates in this state. The positioning device 32 has a contour along the outer diameter contour of the wafer W, and presses the pair of left and right positioning devices 32 so as to sandwich them so that the center of the wafer W coincides with the center of the table 31.

After the center of the wafer W and the center of the table 31 are aligned with each other, the suction mechanism operates and the wafer W is suctioned and held by the table 31. When the positioning device 32 retracts, the table 31 starts rotating at a low speed. The orientation device 33 includes a drive mechanism for driving and controlling the notch detector 331 and the table 31. Notch detector 331
Monitors the periphery of the rotating wafer W, and when it is detected that the notch has reached a predetermined position, the orientation device 33 stops the rotation of the table 31.

The notch detector 331 includes a photo sensor consisting of a light emitting portion and a light receiving portion, a mechanical sensor which gives a signal when a pin is lightly pressed and fitted into the notch portion, or any other device capable of detecting the notch. Can be used.

Next, the wafer W whose direction is thus determined
As described above, is sucked and gripped by the right hand suction plate 813R of the same first transfer unit 81 and removed from the wafer position aligning unit 3.

Next, the first transfer unit 81 turns while facing the wafer notch polishing unit 4 while holding the wafer W removed from the wafer position aligning unit 3 in the right hand suction plate 813R, and turns the wafer notch polishing unit 4 toward the wafer notch polishing unit 4. The table 44 is loaded. The wafer notch polishing unit 4 includes, for example, JP-A-8-168947.
An appropriate device can be selected from many types as disclosed in Japanese Patent Application Publication No. 2001-186523.

An example of the wafer notch polishing unit 4 will be briefly described with reference to FIGS. 8 and 9. FIG. 8 shows a table 44
FIG. 9 is a perspective view showing three inclined states of FIG.
3 is a partially enlarged view of 3 and 2 polishing disks. The wafer notch polishing unit 4 includes the table 44 and the headstock 4
The polishing disc 41 and the polishing disc 42 mounted on the rotary spindle of the headstock 43 perform polishing. The tips of the two polishing discs are formed at angles α and β different from each other. A polishing disc 41 having a small angle α has a notch end surface Scn, and a polishing disc 42 having a large angle β has a notch bevel surface S.
It is for mirror-polishing bn. Each polishing disk is brought to the polishing area by moving the headstock 43 in the spindle direction.

The table 44 can take three angular positions as shown by the dotted line in FIG. 8, and the upper and lower notch bevel surfaces Sbn are mirror-polished at the two inclined positions and the notch end surface Scn is mirror-polished at the horizontal position. During the polishing operation, the first slurry supply device 49, which has been at the retracted position (solid line in FIG. 4) until then, rotates to supply the slurry to the polishing section.
When the polishing is completed, it is swiveled and retracted to the first position where it does not hinder the transport operation.

The wafer W whose mirror polishing of the notch is completed is carried by the second carrying unit 82. FIG. 10 is an explanatory diagram showing an outline of the second transfer unit 82, the wafer notch polishing unit 4, and the wafer circumferential portion polishing unit 5. In this example, the second transport unit 82 is a linear traveling type transport unit, and includes a linear track 821 provided on the ceiling of the machine casing 10 and a traveling body 822 that hangs and travels below this.

The traveling body 822 is a gripping shaft 823 that can move up and down.
And a grip portion 824 including three grip claws provided at the tip (lower end) thereof. The traveling body 822 can move to a position above the wafer notch polishing unit 4, the wafer circumferential portion polishing unit 5, and the wafer cleaning unit 6 described later. The traveling body 822 lowers the grip shaft 823 on the wafer notch polishing unit 4, and moves the table 44.
The wafer W whose upper notch has been polished is gripped by its outer periphery, and the gripping shaft 823 is raised again to form a straight track 821.
Along the circumference of the wafer circumferential polishing unit 5 and then descends and holds the wafer W held by the wafer circumferential polishing unit 5.
Place it on the rotary table 55.

At this time, the second slurry supply device 59
Is retracted to the position indicated by the solid line in FIG. 4 which does not hinder the wafer transfer, and during polishing, the slurry is swung to the position indicated by the dotted line in FIG. 4 to supply the slurry.

The rotary table 55 has a vacuum chuck, and the wafer W is fixed and rotated by this. The wafer circumferential polishing unit 5 includes three or more semi-cylindrical first polishing tools 5 around the rotary table 55.
It has a first polishing tool 52, a second polishing tool 52, and a third polishing tool 53. The first polishing tool 51 has a lower circumferential bevel surface Sb.
The second polishing tool 52 has a circumferential end surface Sc, and
The polishing tool 53 has a curved polishing surface that is substantially along the curvature of the surface to be polished because the polishing tool 53 presses the upper circumferential bevel surface Sb for polishing. Each polishing tool is retracted to the non-polishing position to avoid interference during wafer transfer.

After the mirror-polishing of the circumferential bevel surface Sb and the circumferential end surface Sc is completed, the respective polishing tools 51, 52, 53 are set as shown in FIG.
To the position indicated by the dotted line in FIG.
The wafer W is removed from the rotary table 55 by 2. When the second transfer unit 82 holds the wafer W,
Further, the wafer is moved above the wafer cleaning unit 6 on the right side of the wafer circumferential polishing unit 5. The center positions of the wafer notch polishing unit 4, the wafer circumference polishing unit 5, and the wafer cleaning unit 6 for wafer loading are on a straight line, and the interval between the front two is equal to the interval between the rear two. Thus, control for wafer transfer is simplified.

FIG. 11 is a top view showing the outline of the wafer cleaning unit 6. FIG. 12 shows the wafer cleaning unit 6, the wafer drying unit 7, and the third transfer unit 83.
It is a partial side view for explaining. In the wafer cleaning unit 6, a plurality of wafer supporting rollers 61 are arranged in a circle. Each wafer support roller 61 can move forward and backward while maintaining an equivalent relationship with respect to the center of arrangement. Each wafer support roller 61 includes a cylindrical portion 612 and a flange portion 611, and all (or every other one) of them are provided.
The wafer support roller 61 can be rotationally driven by a drive source (not shown).

When all the wafer supporting rollers 61 are in the retracted position, the wafer W is placed on the flange portion 611, and then all the wafer supporting rollers 61 move forward while maintaining the above-mentioned equivalent relationship. If the notch of the wafer W happens to coincide with one of the wafer support rollers 61, that roller will not enter the notch. Wafer support roller 6
1 moves forward and the cylindrical portion 612 comes into contact with the circumferential end surface of the wafer W, whereby the wafer W can be rotationally driven by the wafer supporting roller 61.

A pair of cleaning rollers 62 are arranged above and below the wafer W with the wafer W interposed therebetween. Each cleaning roller 62 is rotatably supported on the tip end side of a pair of roller arms 621, and the other end of the roller arms 621 is fixed to an arm shaft 622. The arm shaft 622 is rotatable with respect to the machine frame 10 by an arm driving device 623. The cleaning roller 62 is a roller driving device 624.
Is rotatably driven by any transmission mechanism, such as pulleys and belts.

With the wafer W being rotatably driven by the wafer supporting roller 61, the arm driving device 623 is driven to rotate the roller arm 621, and the two cleaning rollers 62 sandwich the wafer W in a sandwich shape. . The wafer support roller 61 is in a position where it does not interfere with the cleaning roller 62.

Then, the roller driving device 624 starts rotating the cleaning roller 62 and the wafer supporting roller 61 starts rotating the wafer W, and the cleaning liquid is poured from the cleaning liquid nozzle 63 toward the wafer W. The wafer W is cleaned by rotating the cleaning roller 62 and the cleaning liquid while rotating itself, and the slurry attached in the previous step is removed.

The cleaning roller 62 has an outer surface made of sponge or non-woven fabric and has an appropriate elasticity, and by the rotation of the roller arm 621, the internal transfer unit (the second transfer unit 82 and the third transfer unit 83) is moved.
It is possible to evacuate to a position that does not hinder the transport operation of.

The wafer W which has been cleaned by the wafer cleaning unit 6 is taken out from the wafer cleaning unit 6 by the third transfer unit 83. Third transport unit 8
3 is a linear traveling type transport unit substantially the same as the second transport unit, and is provided with a linear track 831 provided on the ceiling of the machine casing 10 and a traveling body 832 that hangs and travels below this. The traveling body 832 has a vertically movable gripping shaft 833,
A grip portion 834 including three grip claws provided at its tip (lower end) is provided. The traveling body 832 can move to a position above the wafer cleaning unit 6 and the wafer drying unit 7.

The traveling member 832 lowers the gripping shaft 833 on the wafer cleaning unit 6 to move the wafer supporting roller 61.
Hold the cleaned wafer W on the outer periphery,
The gripping shaft 833 is again raised, moved along the straight track 831 onto the wafer drying unit 7 and lowered, and the held wafer W is held by the turntable 73 of the wafer drying unit 7.
Put it on top.

FIG. 13 is an explanatory view of a spin dryer which constitutes the wafer drying unit 7. The spin dryer includes a rotary drive source 71, a spin shaft 72, a turntable 73, a rotating hook member 74, a scattering prevention cover 75, and a vertical movement device 7.
6 is provided. A supporting piece 731 is fixed near the outermost part of the turntable 73, and a rotating hook member 74 is supported on the supporting piece 731 so as to be rotatable around a rotating shaft 743. The turning hook member 74 has a claw portion 741 formed at one end and a weight portion 742 formed at the other end. Due to the gravity applied to the weight portion 742, the rotating hook member 74 normally takes the posture shown by the solid line on the left side of FIG. 13. When the rotation hook member 74 is rotated while the work (wafer) is placed on the support piece 731, the work W is gripped between the claw portion 741 and the support piece 731. The turntable 73
This can be moved up and down by a height h by a vertical movement device 76 together with the fixed spin shaft 72. When the turntable 73 is in the upper position, the work W is loaded onto the support piece 731 as described above, and at this load / unload position, the work W is unloaded as described later.

When the work W is placed while the turntable 73 is in the load / unload position, the turntable 73 descends and moves to a position (spin position) below the upper side of the shatterproof cover 75. To do. Then, when the rotation driving source 71 is driven and the rotation is transmitted to the spin shaft 72, the turntable 73 fixed to this starts to rotate. Centrifugal force c (Fig. 13 left) as the rotation speed increases
Is generated, and a force is generated that causes the weight portion 742 to jump out. For this reason, the rotating hook member 74 is attached to the rotating shaft 74.
By rotating around 3, the claw portion 741 comes to grip the work W.

The turntable 73 is rotated while blowing air having a velocity component outward from the wafer center from an air nozzle (not shown). The liquid droplets attached to the central portion of the work W, which has a weak centrifugal force, are slightly moved by this air flow, and are then shaken off together with the liquid droplets attached to other portions by the centrifugal force. The scattered droplets are received by an annular scattering prevention cover 75 so as not to spread over the entire apparatus, and in some cases, further sucked and discharged together with air.

When the wafer is dried as described above,
The turntable 73 stops rotating and then rises from the spin position to the initial load / unload position.
Here, the dried work W is unloaded and a new work W is
Is delivered.

Although the rotation of the turntable 73 is stopped due to wear of the rotating shaft 743 or some other cause, the rotating hook member 74 naturally comes to the initial position (position where the work is not gripped). In the present invention, the following is done in order to ensure that the rotating hook member 74 can be opened safely even if it does not return to the above. Weight part 74
When 2 remains spread outward as indicated by the dotted line on the left of FIG. 13, the shatterproof cover 75 is dimensioned inward so that a portion thereof abuts the turntable 73 when it rises. . The state of this contact is shown in the dotted circle on the left side of FIG. Since the weight portion 742 is pushed inward by the contact, the claw portion 741 is forcibly released. With this configuration, when the turntable 73 comes to the load / unload position, the claw portion 741 is always opened, so that the work W is not damaged or dropped when the first transport unit 81 is unloaded, so that it is safe. Work is done. Furthermore, since the motion of the vertical movement device 76 provided in the normal spin dryer is used as it is, no special drive source or complicated structure for forcibly opening the claw 741 is required. There are merits.

The unload window 77 shown in FIG. 13 is
It is an openable and closable window provided in a partition wall between the wafer drying unit 7 and the first transfer unit 81, and the right hand suction plate 813R or the left hand suction plate 813L of the first transfer unit 81 goes in and out through this window. In addition, the scattering prevention cover 7
It is said that at least the inner side of the upper edge of 5 has an inner diameter of such a size that the turntable 73 and the turning hook member 74 do not come into contact with each other when the turning hook member 74 and the work W are engaged with each other. There is no end.

By the time the wafer W is removed from the turntable 73 by the first transfer unit 81, the first transfer unit 81 has moved to the side of the wafer drying unit 7 and is rotated to rotate. Facing in the direction of. Since both the right-hand suction plate 813R and the left-hand suction plate 813L of the first transfer unit 81 are vacant, the wafer W can be removed by either suction plate 8
13 may be used.

First transfer unit 8 with wafer W removed
1 rotates, and further moves on a straight track 811 according to the position on the receiving / discharging shelf 21 where the wafer cassette 211 in which the removed wafer W is to be stored is placed. Wafer W
Are loaded in the same slot of the same wafer cassette 211 from which this wafer W is first taken out. That is, the wafer W received together with the wafer cassette 211 in the wafer outer peripheral portion polishing apparatus 1 remains in the same slot of the same wafer cassette 211 even after the mirror surface polishing of the wafer outer peripheral portion is completed. As a result, the wafer W managed individually
Since the wafer cassettes 211 and the order in which they are stored do not change, the management is simplified and the management load is reduced.

In this example, two wafer cassettes 2 are used.
11 is placed on the receiving and discharging shelf 21.
This is because even if one wafer cassette 211 that has finished polishing all the wafers W is sent to the next process, the mirror-polishing work can be performed on the wafers W in the other wafer cassette 211. It is possible to improve the throughput as a whole without generating a target loss.

The first transfer unit 8 in this polishing apparatus
Since 1 is a transfer robot having two articulated arms and two grips, the arm can be swung with the arms folded and the turning radius can be reduced. Therefore, this type of transfer is performed between the row of the wafer notch polishing unit 4, the wafer circumferential portion polishing unit 5 and the wafer cleaning unit 6 and the row of the wafer cassette receiving / exhausting unit 2 and the wafer position aligning unit 3. Even if the unit is placed, it does not require a large area. Therefore, it is possible to reduce the size of the entire wafer peripheral portion polishing apparatus and reduce the installation area. However, it is of course possible to use another type of transport unit for the first transport unit 81.

In this polishing apparatus, the wafer notch polishing unit 4 and the wafer circumferential portion polishing unit 5 perform mirror surface polishing of the wafer in this order, but this order may be reversed or alternately repeated. You may do it by doing. In order to mirror-finish the wafer notch after polishing the wafer circumferential portion, the direction of the notch must be fixed at that time. Since it is driven to rotate, it is possible to determine the direction when the rotation is stopped. Such a servo is usually adopted in the case of mirror-polishing a wafer with an orientation flat, which will be described later, in order to prevent a failure in gripping when the outer peripheral gripping claw for wafer transfer hits the orientation flat portion. In addition, it is possible to use pins at the time of transportation to determine the orientation of the wafer.

Further, the wafer notch polishing unit 4 and the wafer circumferential portion polishing unit 5 perform mirror polishing of both the end face and the slope of the notch portion or the peripheral portion, respectively, but the end face and the slope are polished. It is also possible to have each performed by a different unit. Further, the wafer may be taken out or loaded in the first transfer unit 81 by either one of the two arms.

So far, the case where the semiconductor wafer is provided with the wafer circumferential portion and the notch has been described. It is known that a semiconductor wafer is not provided with such a notch but is provided with a linear arc-shaped notch called an orientation flat (commonly called an orientation flat). When polishing a wafer provided with this orientation flat, an orientation flat polishing device is used which performs mirror polishing by bringing the side surface of a cylindrical polishing tool into contact with the orientation flat and supplying slurry to the polishing portion. Therefore, when polishing a wafer with such an orientation flat in the wafer outer peripheral portion polishing apparatus 1 according to the present invention,
Instead of the wafer notch polishing unit 4, an orientation flat polishing device can be used as the orientation flat polishing unit.

In the spin dryer disclosed so far, the scattering prevention cover 75 is fixed, and the turntable 73 is movable between the load / unload position and the spin position. Therefore, the turntable 73 may be fixed in the vertical direction, and the scattering prevention cover 75 may be vertically moved by the vertical movement device 76 instead, as shown in FIG. Good.

Although an example in which the weight portion 742 directly contacts the cover portion of the scattering prevention cover 75 is shown,
A member having a cushioning function is attached to one or both of the contact portions, or the projection 751 is attached to the scattering prevention cover 75.
Alternatively, the weight portion 742 may be pressed through the protrusion. In the latter case, this protrusion can be provided in the vicinity of the upper edge of the scattering prevention cover 75 so that the droplets do not collide (FIG. 14). Further, the shatterproof cover 75 does not need to have a linear contour in cross section as shown in FIG.
As shown in FIG. 15, it is also possible to form a buffer layer 752 such as a felt layer or a brushed layer on the inner side, which prevents splashed droplets from bouncing back and adhering to the wafer again. .

The above "contact" (that is, when the scattering prevention cover 75 and the turntable 73 change their relative positions between the load / unload position and the spin position, the weight of the rotary hook member 74 is changed. When the rotation hook member 74 and the work W are not disengaged from each other, a part of the anti-scattering cover 75, a part of the upper edge portion, or the protrusion 751 “contacts” with the portion 742. It does not mean that the "contact" occurs whether the engagement is disengaged or not disengaged.

According to the present invention, while the centrifugal force type wafer holding means is used for a long period of time, the rotating hook member is moved to the open position due to wear of the rotating shaft portion or other unspecified cause. Even if it does not return, the rotating hook member is forcibly opened before loading / unloading, so that the work W is not damaged or dropped, and an expensive wafer is damaged. Alternatively, there is an effect that it is possible to prevent the loss due to the line stop. Further, there is an effect that the maintenance of the wafer is substantially unnecessary and the wafer holding can be released reliably and safely without providing a complicated and expensive detection device in the spin dryer.

[Brief description of drawings]

FIG. 1 is an explanatory view for briefly explaining the principle of a centrifugal force type wafer holding means, in which (A) shows a state in which a wafer is not held and (B) shows a state in which a wafer is held. is there.

2 (A), (B) and (C) are respectively,
A plan view of the semiconductor wafer, a partial sectional view of the semiconductor wafer W,
It is a perspective view showing the circumference of the expanded notch N.

FIG. 3 is an external view showing a wafer polishing apparatus incorporating the present invention.

FIG. 4 is a plan view for explaining the outline of a wafer peripheral portion polishing apparatus.

FIG. 5 is an explanatory diagram showing essential parts of the wafer cassette receiving / ejecting port unit 2 and the first transfer unit 81.

FIG. 6 is an explanatory view showing a state in which an unaligned wafer W is placed on the table 31 of the wafer position aligning unit 3.

FIG. 7 is a top view of an essential part of the wafer position aligning unit 3.

FIG. 8 is a perspective view showing three inclined states of the table 44 in the wafer notch polishing unit 4.

FIG. 9: Headstock 4 in the wafer notch polishing unit 4
3 is a partially enlarged view of 3 and 2 polishing disks.

10 is an explanatory diagram showing an outline of a second transfer unit 82, a wafer notch polishing unit 4, and a wafer circumferential portion polishing unit 5. FIG.

11 is a top view showing the outline of the wafer cleaning unit 6. FIG.

FIG. 12 is a partial side view for explaining the wafer cleaning unit 6, the wafer drying unit 7, and the third transfer unit 83.

FIG. 13 is an explanatory diagram of a spin dryer that forms the wafer drying unit 7.

FIG. 14 is an explanatory diagram of a spin dryer according to another embodiment.

FIG. 15 is an explanatory diagram of a spin dryer according to still another embodiment.

[Explanation of symbols]

1 Wafer periphery polishing device 10 machine frames 11 Operation panel 12 Display 13 transparent window 2 Wafer cassette receiving and discharging unit 21 receiving and discharging shelf 211 wafer cassette 3 Wafer position aligning unit 31 table 32 Positioning device 33 Orientation device 331 Notch detector 4 Wafer notch polishing unit 41, 42 Polishing disc 43 Headstock 44 tables 49 First Slurry Supply Device 5 Wafer circumference polishing unit 51 polishing tool 51 First Polishing Tool 52 Second polishing tool 53 Third polishing tool 55 rotating table 59 Second Slurry Supply Device 6 Wafer cleaning unit 61 Wafer support roller 611 Flange part 612 Cylindrical part 62 cleaning roller 621 roller arm 622 arm axis 623 Arm drive device 624 Roller drive device 63 Cleaning liquid nozzle 7 Wafer drying unit 71 rotary drive source 72 Spin axis 73 turntable 731 support piece 74 Rotating hook member 741 Claw 742 Weight section 742 Direct weight part 743 rotation axis 75 Anti-scatter cover 751 protrusion 752 buffer layer 76 Vertical movement device 77 unload window 81 First Transport Unit 811 linear trajectory 812 platform 813 suction plate 813L suction pad 813R Right hand suction board 814 torso 82 Second Transport Unit 821 straight track 822 running body 823 gripping axis 824 grip 83 Third Transport Unit 831 straight track 832 running body 833 gripping axis 834 grip N notch Sb Circumferential bevel surface Sbn notch bevel surface Sc Circumferential end face Scn Notch end face Sp pattern formation surface W work (wafer)

Claims (6)

[Claims] 1. A rotary drive source, a spin shaft rotated about a substantially vertical axis by the rotary drive source, a turntable provided on the spin shaft for supporting a disk-shaped workpiece, and the turn. The table is rotatably supported about a substantially horizontal rotation axis, and has a claw portion at one end for engaging in the vicinity of the work periphery and a weight portion at the other end. When the spin shaft rotates in such a manner that it is disengaged from the work by means of a plurality of rotating hook members, the spin shaft rotates the work by the centrifugal force. In the spin dryer having an annular anti-scattering cover located around the turntable to receive droplets scattered by centrifugal force, When either the turntable or the shatterproof cover is moved for loading / unloading so that the turntable is above the shatterproof cover, a part of the shatterproof cover serves as the turning hook member. A spin dryer characterized in that the above-mentioned engagement is released by abutting and rotating this. 2. The spin dryer according to claim 1, wherein a part of the scattering prevention cover that abuts against the rotating hook member is an upper edge portion of the scattering prevention cover. Dryer. 3. The spin dryer according to claim 1, wherein a part of the shatterproof cover that comes into contact with the rotating hook member is a protrusion provided on the shatterproof cover. Spin dryer. 4. The spin dryer according to claim 1, wherein a part of the scattering prevention cover that abuts the rotating hook member is a protrusion provided near an upper edge of the scattering prevention cover. A spin dryer characterized in that 5. The spin dryer according to claim 1, wherein the rotating hook member and the work are provided at least on the upper edge of the scattering prevention cover or on the inside of the protrusion. A spin dryer having an inner diameter of such a size that the turntable and the rotating hook member do not come into contact with each other when engaged. 6. A wafer peripheral portion polishing apparatus substantially entirely covered by a machine frame, wherein a wafer receiving and discharging unit for receiving and discharging a wafer cassette containing a wafer is provided in the machine frame. Wafer position aligning unit for determining the position of the wafer and the direction of the notch, a wafer notch polishing unit for polishing the notch of the wafer, a wafer for polishing the peripheral portion of the wafer including the circumferential end surface, bevel surface, etc. A circumferential polishing unit, a wafer cleaning unit for cleaning a wafer with a cleaning liquid, and the spin dryer described in any one of claims 1 to 4 are installed as spin drying units, and An outside wafer characterized by having an internal transfer unit for transferring a wafer between these units. Part polishing apparatus.