JP7376555B2 - Wafer holding structure and holding method for both wafers and wafer stacks - Google Patents

Description

The present invention can be used to change the setup even if the wafer is a bare wafer or a wafer stack having a diameter larger than the wafer by attaching a support member to the wafer with an adhesive. The present invention relates to a wafer holding structure and a holding method that can be used for both wafers and wafer stacks in a spin processing apparatus, which eliminates the need for wafers and wafer stacks.

2. Description of the Related Art Conventionally, in a semiconductor manufacturing process, a process (also called a spin process) is performed in which a semiconductor wafer (hereinafter referred to as a "wafer") of silicon or the like is rotated.

Examples of spin processing apparatuses for performing such spin processing include, for example, Patent Document 1 and Patent Document 2.

On the other hand, the thickness of wafers, which are semiconductor substrates, is becoming thinner and thinner, and wafers with a thickness of 100 μm or less, for example, ultra-thin wafers with a thickness of about 60 μm or even thinner to 50 μm or less, are also used. It's starting to look like this.

To thin the wafer, the wafer is back-grinded to thin the wafer. However, when the wafer is thinned to about 100 μm to 50 μm by back grinding, problems such as wafer warping and wafer strength occur.

Grinding the wafer thin makes it difficult to handle, so we grind only the back surface of the wafer, which corresponds to the device area, to make it thinner, and leave a ring-shaped reinforcing part in the excess outer area surrounding the device area to make the wafer into a concave shape. A technique has been proposed for processing (for example, see Patent Document 3). Such a technique for processing a wafer into a concave shape is sometimes called TAIKO grinding or TAIKO process. In TAIKO grinding, only the central part of the wafer is mechanically ground and thinned, leaving about a few millimeters of the outer edge of the wafer, resulting in a wafer with protrusions formed on the outer circumferential edge. .

Furthermore, in the case of ultra-thin wafers, if only silicon wafers are used, the semiconductor substrate wafer is likely to break due to warping or distortion of the wafer, making it difficult to handle. Therefore, before the wafer is subjected to a process such as mechanical polishing or chemical erosion, a support plate is attached to the wafer with an adhesive, and then the process is performed on the wafer. For processing such as mechanical polishing and chemical erosion on the wafer, a spin process is performed while the wafer is held in a spin process apparatus.

A glass support made of glass is often used as the support plate, and an adhesive is often used as the pasting agent. An example of a wafer stack in which such a support glass is attached to a wafer is disclosed in Patent Document 4, for example.

Examples of these wafers are shown in FIG. 5 of the present application. FIG. 5(a) is an example of a wafer stack in which a support glass is attached to an ultra-thin wafer. The support glass 104 is attached with an adhesive.

FIG. 5B shows a bare wafer W2, which is the most common wafer with all flat surfaces. In this specification, a wafer with only flat surfaces is referred to as a "bare wafer."

FIG. 5C shows an outer peripheral edge convex portion formed wafer W1 in which a convex portion 102 is formed at the outer peripheral edge.

As wafers have become extremely thin in recent years, it is necessary to perform spin processing by holding various types of wafers and wafer stacks in a wafer rotation and holding device as shown in FIG. In the case of a laminate in which a support glass is attached to a wafer as shown in FIG. 5(a), due to its structure, the diameter becomes larger by the amount of the support glass 104 compared to the outer peripheral edge convex formed wafer W1. . A support glass may be attached to a normal flat wafer W2 (bare wafer) as shown in FIG. 5(b) to form a wafer stack. The diameter becomes larger.

In the case of a 300 mm diameter wafer, if a support glass is attached to form a wafer stack, the diameter will be 301 mm. If this 1 mm difference is ignored and the wafer stack is placed in the same spin processing apparatus and subjected to spin processing, the wafer stack with a diameter of 301 mm will be eccentric.

For example, when spin processing is performed by placing a 301 mm diameter wafer body, which is a wafer stack with the above-mentioned support glass attached, on a spin processing apparatus having a wafer holding structure for 300 mm diameter wafers, the eccentricity deviation may occur. Since the amount is 1 mm, the centrifugal force at a rotation speed of 1500 rpm reaches approximately 1.5 kg. Therefore, if a wafer with a diameter of 301 mm is subjected to spin processing in such an eccentric state, uneven spin processing such as etching may occur, or it may lead to equipment failure. .

For this reason, conventionally, it has been necessary to change the setup to a spin processing apparatus in which the position of the pin for holding down the wafer placed on the rotary table in the spin processing apparatus is different. Such setup change takes about 30 minutes, and including operation confirmation and trial run, a total of about 1 hour is lost, which causes a problem of lowering the operating rate.

Patent No. 6634154 JP2018-67684 JP2013-141032 JP2004-64040

The present invention has been made in view of the above-mentioned prior art, and even if it is only a wafer, a support member is attached to the wafer with an adhesive, thereby stacking wafers having a diameter larger than that of the wafer. An object of the present invention is to provide a wafer holding structure and a holding method for a wafer body and a wafer stack in a spin processing apparatus, in which the center of rotation does not shift even when the body is a wafer body, and there is no need for setup changes. .

In order to solve the above problems, a wafer body holding structure for both wafers and wafer stacks of the present invention is a wafer body holding structure for both wafers and wafer stacks in a spin processing apparatus, and is a wafer body holding structure for both wafers and wafer stacks. a rotary table on which a wafer body is placed; a first outer circumferential pin member, a second outer circumferential pin member, and a third outer circumferential pin member provided on the rotary table and arranged at approximately equal intervals around the outer circumference of the wafer body; a member, wherein each of the first outer circumferential pin member, the second outer circumferential pin member, and the third outer circumferential pin member is movable such that each of the first outer circumferential pin member, the second outer circumferential pin member, and the third outer circumferential pin member is in a state of contacting with the outer circumferential portion of the wafer body and a state of being separated from the outer circumferential portion of the wafer body. The first outer circumferential pin member, the second outer circumferential pin member, and the third outer circumferential pin member each cover the outer circumferential portion of the wafer body placed on the rotary table, and
Pressing force of the first outer circumferential pin member>Pressing force of the second outer circumferential pin member>Pressing force of the third outer circumferential pin,
This is a wafer body holding structure that can be used for both a wafer and a wafer stack, in which the wafer body is centered on the rotary table by pressing the outer peripheral part of the wafer body so as to have a correlation of .

Preferably, the diameter of the wafer is 300 mm, and the diameter of the wafer stack is 301 mm.

When the wafer body placed on the rotary table is the wafer stack, the wafer stack is held down by a first outer pin member toward the second outer pin member and the third outer pin member, The pressing force of each of the first outer circumferential pin member, the second outer circumferential pin member, and the third outer circumferential pin member is
Pressing force of the first outer circumferential pin member>Pressing force of the second outer circumferential pin member>Pressing force of the third outer circumferential pin,
It is preferable that the wafer body is centered on the rotary table by pressing the outer circumference of the wafer body so as to have a correlation of .

When the wafer body placed on the rotary table is the wafer, the wafer is held down by a third outer pin member toward the first outer pin member and the second outer pin member, and the first outer pin member The pressing force of each of the pin member, the second outer circumferential pin member, and the third outer circumferential pin member is
Pressing force of the first outer circumferential pin member>Pressing force of the second outer circumferential pin member>Pressing force of the third outer circumferential pin,
It is preferable that the wafer body is centered on the rotary table by pressing the outer circumference of the wafer body so as to have a correlation of .

The wafer holding method for both wafers and wafer stacks of the present invention is a method for holding wafers for both wafers and wafer stacks in a spin processing apparatus, using the wafer holding structure for both wafers and wafer stacks, and the rotary table The pressing force of each of the first outer circumference pin member, the second outer circumference pin member, and the third outer circumference pin member that presses the outer circumference of the wafer body placed on the wafer body is
Pressing force of the first outer circumferential pin member>Pressing force of the second outer circumferential pin member>Pressing force of the third outer circumferential pin,
In this wafer holding method for both a wafer and a wafer stack, the wafer body is centered on the rotary table by pressing the outer circumference of the wafer body so as to have a correlation of .

Preferably, the diameter of the wafer is 300 mm, and the diameter of the wafer stack is 301 mm.

When the wafer body placed on the rotary table is the wafer stack, the wafer stack is held down by a first outer pin member toward the second outer pin member and the third outer pin member, The pressing force of each of the first outer circumferential pin member, the second outer circumferential pin member, and the third outer circumferential pin member is
Pressing force of the first outer circumferential pin member>Pressing force of the second outer circumferential pin member>Pressing force of the third outer circumferential pin,
It is preferable that the wafer body is centered on the rotary table by pressing the outer circumference of the wafer body so as to have a correlation of .

When the wafer body placed on the rotary table is the wafer, the circular wafer stack is held down by a third outer circumferential pin member toward the first outer circumferential pin member and the second outer circumferential pin member,
The pressing force of each of the first outer circumferential pin member, the second outer circumferential pin member, and the third outer circumferential pin member is
Pressing force of the first outer circumferential pin member>Pressing force of the second outer circumferential pin member>Pressing force of the third outer circumferential pin,
It is preferable that the wafer body is centered on the rotary table by pressing the outer circumference of the wafer body so as to have a correlation of .

The spin etching apparatus for both wafers and wafer stacks of the present invention is a spin etching apparatus for both wafers and wafer stacks, which is equipped with the wafer holding structure for both wafers and wafer stacks.

According to the present invention, even if it is only a wafer or a wafer stack having a diameter larger than that of the wafer by attaching a support member to the wafer with an adhesive, the rotation center of the wafer can be It is possible to provide a wafer holding structure and a holding method for a wafer and a wafer stack in a spin processing apparatus, in which the wafer does not shift and there is no need for setup changes.

Further, according to the present invention, even if it is only a wafer or a wafer stack having a diameter larger than that of the wafer by pasting a support member to the wafer with an adhesive, the This has a significant effect in that it is possible to provide a spin processing apparatus in which the center of rotation does not shift and there is no need for setup changes.

One embodiment of a wafer body holding structure for both a wafer and a wafer stack of the present invention is shown, and the arrangement of a first outer circumferential pin member, a second outer circumferential pin member, and a third outer circumferential pin member provided on a rotary table is shown. FIG. FIG. 3 is a cross-sectional view showing the movement of the first outer peripheral pin member of the wafer body holding structure that can be used for both a wafer and a wafer stack according to the present invention. FIG. 6 is a cross-sectional view showing the movement of the second outer peripheral pin member of the wafer body holding structure that can be used for both a wafer and a wafer stack according to the present invention. FIG. 7 is a cross-sectional view showing the movement of the third outer peripheral pin member of the wafer body holding structure that can be used for both a wafer and a wafer stack according to the present invention. These are schematic cross-sectional views showing various wafers, in which FIG. 5(a) shows a wafer stack in which a support glass is attached to a wafer with a convex portion formed on the outer peripheral edge, and FIG. 5(b) shows a bare wafer, the most common one being a wafer stack. FIG. 5(c) shows a wafer with all flat surfaces, and FIG. 5(c) shows a wafer with a convex portion formed on the outer peripheral edge.

Embodiments of the present invention will be described below, but these embodiments are shown by way of example, and it goes without saying that various modifications can be made without departing from the technical idea of the present invention. In the drawings, the same members are represented by the same symbols.

In FIG. 1, reference numeral 10 indicates one embodiment of a wafer body holding structure that can be used for both a wafer and a wafer stack according to the present invention. The wafer body holding structure 10 is a wafer body holding structure that serves both as a wafer and a wafer stack in a spin processing apparatus. In this specification, the wafer body 12 is a concept that includes all of the various types of wafers shown in FIG. That is, the wafer body 12 includes the wafer stack 100, the bare wafer W2, and the wafer W1 having a convex portion on the outer peripheral end.

The wafer body holding structure 10 is provided with a rotary table 14 on which a wafer body 12, which is a wafer or a wafer stack, is placed, and the rotary table 14, and is arranged at approximately equal intervals around the outer periphery of the wafer body 12. The configuration includes a first outer circumferential pin member 16, a second outer circumferential pin member 18, and a third outer circumferential pin member 20. A suitable method for centering the wafer body 12 is to push it from the equilateral triangular direction. In the example shown in FIG. 1, the first outer circumferential pin member 16, the second outer circumferential pin member 18, and the third outer circumferential pin member 20 are each arranged at 120°.

The first outer circumferential pin member 16 is composed of first outer circumferential pins 22a, 22b, the second outer circumferential pin member 18 is composed of second outer circumferential pins 24a, 24b, and the third outer circumferential pin member 20 is composed of third outer circumferential pins 26a, 26b. It consists of In this way, the first outer circumferential pin member 16, the second outer circumferential pin member 18, and the third outer circumferential pin member 20 each have a double pin structure in which two pins are provided upright. The double pin structure has the advantage of being able to handle even wafers with notches. For example, even if a notch is located on one of the first outer circumferential pins 22a and 22b (for example, the first outer circumferential pin 22a), eccentricity can be prevented by holding it with the other one (for example, the first outer circumferential pin 22b). . In the illustrated example, the pins (first outer circumferential pins 22a, 22b, second outer circumferential pins 24a, 24b, third outer circumferential pins 26a, 26b) have a diameter of 2.4 mm. The distance between the first outer pins 22a, 22b, the second outer pins 24a, 24b, and the third outer pins 26a, 26b is preferably larger than the notch of the wafer, and preferably wider than the diameter of the pins alone. suitable.

(I), (II), and (III) in FIG. 1 respectively correspond to the arrangement of the first outer circumferential pin member 16, the second outer circumferential pin member 18, and the third outer circumferential pin member 20 in the rotary table 14, The movements of the first outer circumferential pin member 16, the second outer circumferential pin member 18, and the third outer circumferential pin member 20 at their respective locations are shown in FIGS. 2 to 4.

As shown in FIGS. 2 to 4, each of the first outer circumference pin member 16, the second outer circumference pin member 18, and the third outer circumference pin member 20 is in a state in which it is in contact with the outer circumference of the wafer body 12, and in a state in which it is in contact with the outer circumference of the wafer body 12. It has a range of motion that allows it to be separated from the body.

<Figure 2: Movement of the first outer pin member>
In the illustrated example, as best shown in FIG. 2(a), the movable range of the first outer circumferential pin member 16 is 4.3 mm, and the first outer circumferential pin member 16 is spaced apart from the outer circumference of the wafer body 12. The rotary table 14 can be tilted up to an angle of 11.1° in the outer circumferential direction so that the rotary table 14 can be tilted up to an angle of 11.1°.

FIG. 2(b) shows the state of the first outer peripheral pin member 16 when the wafer body 12 is a bare wafer W2 with a diameter of 300 mm. FIG. 2C shows the state of the first outer peripheral pin member 16 when the wafer body 12 is a wafer stack 100 with a diameter of 301 mm.

FIG. 2(d) shows the state of the first outer peripheral pin member 16 when the wafer body 12 is transferred to/from the rotary table 14, that is, when the wafer body 12 is supplied/taken out. Opening/closing of the first outer circumferential pin member 16 (maximum tilting operation of the first outer circumferential pin member 16) is required when the wafer body 12 is supplied/taken out. The wafer body 12 is supplied/taken out while the rotary table 14 is stopped at a predetermined rotation angle.

When the rotary table 14 is in a stopped state, the drive cylinder 30 pushes up the lever 28 at the lower part of the rotary table 14 from the lower part of the outer periphery of the rotary table 14 to bring the first outer periphery pin member 16 into the "open" state using the lever principle. In this "open" state, the wafer body 12 can be supplied to the rotary table 14 and can be taken out from the rotary table 14. When the wafer body 12 is supplied to the rotary table 14 in the "open" state, the first outer pin member 16 is moved in the closing direction by the spring set in the rotary table 14 by lowering the drive cylinder 30, and the first outer circumference The pin member 16 is in the "closed" state. The first outer peripheral pin member 16 holds the wafer body 12 in this "closed" state.

Each of the first outer circumferential pin member 16, the second outer circumferential pin member 18, and the third outer circumferential pin member 20 located at three locations is opened/closed by the corresponding drive cylinder 30. In addition, in FIGS. 2 to 4, reference numeral 32 is a stopper, and the stopper 32 controls the movable areas of the first outer circumferential pin member 16, the second outer circumferential pin member 18, and the third outer circumferential pin member 20 at three locations, that is, The stroke amount is adjusted. The drive cylinder 30 is driven up and down by a drive source (not shown).

Further, the first outer circumferential pins 22a and 22b of the first outer circumferential pin member 16 are simultaneously driven by one drive cylinder. The second outer circumferential pins 24a, 24b of the second outer circumferential pin member 18 are also simultaneously driven by one driving cylinder, and the third outer circumferential pins 26a, 26b of the third outer circumferential pin member 20 are also simultaneously driven by one driving cylinder. It will be done.

<Figure 3: Movement of the second outer circumferential pin member>
In the illustrated example, as clearly shown in FIG. 3(a), the movable range of the second outer circumferential pin member 18 is 1.07 mm, and the second outer circumferential pin member 18 comes into contact with the outer circumferential portion of the wafer body 12. The rotary table 14 can be tilted up to an angle of 4.45° toward the center of the rotary table 14 so that the rotary table 14 is in a tilted state.

FIG. 3(b) shows the state of the second outer peripheral pin member 18 when the wafer body 12 is a bare wafer W2 with a diameter of 300 mm. FIG. 3(c) shows the state of the second outer peripheral pin member 18 when the wafer body 12 is a wafer stack 100 with a diameter of 301 mm.

FIG. 3D shows the state of the second outer peripheral pin member 18 when the wafer body 12 is transferred to/from the rotary table 14, that is, when the wafer body 12 is supplied/taken out. Opening/closing of the second outer circumferential pin member 18 (maximum tilting operation of the second outer circumferential pin member 18) is required when the wafer body 12 is supplied/taken out. The wafer body 12 is supplied/taken out while the rotary table 14 is stopped at a predetermined rotation angle.

When the rotary table 14 is in a stopped state, the drive cylinder 30 pushes up the lever 28 at the lower part of the rotary table 14 from the lower part of the outer periphery of the rotary table 14 to bring the second outer periphery pin member 18 into the "open" state using the lever principle. In this "open" state, the wafer body 12 can be supplied to the rotary table 14 and can be taken out from the rotary table 14. When the wafer body 12 is supplied to the rotary table 14 in the "open" state, by lowering the drive cylinder 30, the spring set in the rotary table 14 moves the second outer circumferential pin member 18 in the closing direction. The pin member 18 is in the "closed" state. The second outer peripheral pin member 18 holds the wafer body 12 in this "closed" state.

<Figure 4: Movement of the third outer pin member>
In the illustrated example, as clearly shown in FIG. 4(a), the movable range of the third outer circumferential pin member 20 is 0.54 mm, and the third outer circumferential pin member 20 comes into contact with the outer circumferential portion of the wafer body 12. The rotary table 14 can be tilted up to an angle of 2.22 degrees toward the center of the rotary table 14 so that the rotary table 14 is in a tilted state.

FIG. 4(b) shows the state of the third outer peripheral pin member 20 when the wafer body 12 is a bare wafer W2 with a diameter of 300 mm. FIG. 4C shows the state of the third outer peripheral pin member 20 when the wafer body 12 is a wafer stack 100 with a diameter of 301 mm.

FIG. 4(d) shows the state of the third outer peripheral pin member 20 when the wafer body 12 is transferred to/from the rotary table 14, that is, when the wafer body 12 is supplied/taken out. Opening/closing of the third outer circumferential pin member 20 (maximum tilting operation of the third outer circumferential pin member 20) is required when the wafer body 12 is supplied/taken out. The wafer body 12 is supplied/taken out while the rotary table 14 is stopped at a predetermined rotation angle.

When the rotary table 14 is in a stopped state, the lever 28 at the lower part of the rotary table 14 is pushed up by the drive cylinder 30 from the lower part of the outer periphery of the rotary table 14, and the third outer periphery pin member 20 is brought into the "open" state using the lever principle. In this "open" state, the wafer body 12 can be supplied to the rotary table 14 and can be taken out from the rotary table 14. When the wafer body 12 is supplied to the rotary table 14 in the "open" state, by lowering the drive cylinder 30, the third outer circumferential pin member 20 is moved in the closing direction by the spring set in the rotary table 14, and the third outer circumferential pin member 20 is moved in the closing direction. The pin member 20 is in the "closed" state. The third outer peripheral pin member 20 holds the wafer body 12 in this "closed" state.

<About pressing strength>
The wafer stack 100, which is made by attaching support glass to ultra-thin wafers, is relatively heavy, so it is necessary to press it firmly. On the other hand, the outer circumferential end protrusion-formed wafer W1 and the bare wafer W2, in which the protrusions 102 are formed at the outer circumferential end, are thin, so do not press them too strongly.

<One example of pin configuration>
In the illustrated example, the pins (first outer circumferential pins 22a, 22b, second outer circumferential pins 24a, 24b, third outer circumferential pins 26a, 26b) have a diameter of 2.4 mm. The spacing (pitch) between the first outer circumferential pins 22a, 22b, the second outer circumferential pins 24a, 24b, and the third outer circumferential pins 26a, 26b is set to be wider than the notch and wider than the diameter of the pins alone. The length was approximately 7 mm.
(I) Regarding the first outer circumferential pin member 16 (consisting of first outer circumferential pins 22a and 22b) -Pressing force: 600g
・Movable range (stroke amount): 4 mm or more ・When fully opened (when supplying/unloading): 154.3 mm (distance from the center of the rotary table at the wafer height position of the first outer pin member 16)
- At intermediate stop (when holding the support glass part of a wafer stack with a diameter of 301.0 mm): 150.5 mm (distance from the center of the rotary table at the wafer height position of the first outer peripheral pin member 16)
- When fully closed (when holding a wafer body (bare wafer, etc.) with a diameter of 300.0 mm): 150.0 mm (distance from the center of the rotary table at the wafer height position of the first outer peripheral pin member 16)

(II) Regarding the second outer circumferential pin member 18 (composed of second outer circumferential pins 24a and 24b) -Pressing force: 400g
・Movable range (stroke amount): 0.5mm
- When fully opened (when holding the support glass part of a wafer stack with a diameter of 301.0 mm): 150.5 mm (distance from the center of the rotary table at the wafer height position of the first outer peripheral pin member 16)
- When fully closed (when holding a wafer body (bare wafer, etc.) with a diameter of 300.0 mm): 150.0 mm (distance from the center of the rotary table at the wafer height position of the first outer peripheral pin member 16)

(III) Regarding the third outer circumferential pin member 20 (consisting of third outer circumferential pins 26a and 26b)
・Press force: 200 g
・Movable range (stroke amount): 1.5mm
- When fully opened (when holding the support glass part of a wafer stack with a diameter of 301.0 mm): 150.5 mm (distance from the center of the rotary table at the wafer height position of the first outer peripheral pin member 16)
- At intermediate stop (when holding a wafer body (bare wafer, etc.) with a diameter of 300.0 mm): 150.0 mm (distance from the center of the rotary table at the wafer height position of the first outer peripheral pin member 16)
- When fully closed: 149.0 mm (distance from the center of the rotary table at the wafer height position of the first outer pin member 16)

<How to hold the wafer body>
Next, a method of holding the wafer body will be explained. In order to hold a wafer body with a diameter of 300.0 mm and a wafer body with a diameter of 301.0 mm, it would be necessary to make separate rotary tables with outer peripheral pins for each, but doing so would require a lot of setup changes. It is. It takes more than 30 minutes to change the setup. The present invention is characterized in that the wafer body holding mechanism is compatible with both wafer bodies with a diameter of 300.0 mm and wafer bodies with a diameter of 301.0 mm.

When supplying/unloading the wafer body 12, all the pins of the first outer circumferential pin member 16, the second outer circumferential pin member 18, and the third outer circumferential pin member 20 are set in the "open" state.

[For a wafer body with a diameter of 301.0 mm]
When holding a wafer body with a diameter of 301.0 mm, that is, when holding a wafer stack made of ultra-thin wafers with support glass attached, the wafer body is thick, so hold it firmly. Furthermore, it must be brought to the center of the rotary table 14 to avoid eccentricity. As an example of a wafer body with a diameter of 301.0 mm, a wafer stack 100 (notch The explanation will be based on the case of (none).

The balance of the force pressing down on the wafer body 12 when holding a wafer body with a diameter of 301.0 mm is as follows:
Pressing force of the first outer circumferential pin member 16: 600g>Pressing force of the second outer circumferential pin member 18: 400g>Pressing force of the third outer circumferential pin member 20: 200g,
It has a correlation of
Further, it is preferable that the pressing force of the first outer circumferential pin member 16 is the sum of the pressing force of the second outer circumferential pin member 18 and the pressing force of the third outer circumferential pin member 20.
The wafer stack 100 is held down by the first outer pin member 16 toward the second outer pin member 18 and the third outer pin member 20.

The second outer circumferential pin member 18 and the third outer circumferential pin member 20 are fully opened, and are centered by strongly pressing the support glass 104 with a force of 600 g using the first outer circumferential pin member 16. The first outer circumferential pin member 16 is held at the intermediate stop position. The above-mentioned pressing force is generated in both the fully closed state and the fully open state, as well as in the intermediate stop position. The wafer body is held in this centered state and spin processing is performed.

[For a wafer body with a diameter of 300.0 mm]
When holding a wafer body with a diameter of 300.0 mm, that is, when holding a bare wafer or the like, it is necessary to press it weakly because it is thin. Furthermore, it must be brought to the center of the rotary table 14 to avoid eccentricity. As an example of a wafer body having a diameter of 300.0 mm, a wafer body (diameter 300.0 mm, with a notch) shown in FIG. 5(c) in which a wafer W1 having a convex portion at the outer peripheral end is bonded with tape will be described.

The balance of force pushing the wafer body 12 when holding a wafer body with a diameter of 300.0 mm is as follows:
Pressing force of the first outer circumferential pin member 16: 600g>Pressing force of the second outer circumferential pin member 18: 400g>Pressing force of the third outer circumferential pin member 20: 200g,
It has a correlation of
Further, it is preferable that the pressing force of the first outer circumferential pin member 16 is the sum of the pressing force of the second outer circumferential pin member 18 and the pressing force of the third outer circumferential pin member 20.
The wafer body is held down by the third outer pin member 20 toward the first outer pin member 16 and the second outer pin member 18 .

The first outer circumferential pin member 16 and the second outer circumferential pin member 18 are in a fully closed state, and the third outer circumferential pin member 20 weakly presses the outer circumferential end convex portion forming wafer W1 with a force of 200 g, thereby centering the wafer W1. The third outer circumferential pin member 20 is held at the intermediate stop position. The above-mentioned pressing force is generated in both the fully closed state and the fully open state, as well as in the intermediate stop position. The wafer body is held in this centered state and spin processing is performed.

In this way, in the present invention, centering is performed by changing the outer circumferential pin member that presses the wafer body 12 depending on the size of the wafer body 12, and by changing the force with which the outer circumferential pin member presses the wafer body 12.

In this way, even if it is a bare wafer consisting of only wafers, or a wafer stack having a diameter larger than the wafer due to the support member being attached to the wafer with an adhesive, Since the center of rotation does not shift, there is no need for setup changes. Conventionally, it took about 30 minutes to change the setup, and a total of about 1 hour was lost including operation confirmation and test runs, but according to the present invention, such lost time can be eliminated. This has the advantage that there is no need to reduce the operating rate.

10: Wafer body holding structure, 12: Wafer body, 14: Rotary table, 16: First outer circumferential pin member, 18: Second outer circumferential pin member, 20: Third outer circumferential pin member, 22a: First outer circumferential pin, 22b: First outer circumferential pin, 24a: Second outer circumferential pin, 24b: Second outer circumferential pin, 26a: Third outer circumferential pin, 26b: Third outer circumferential pin, 28: Lever, 30: Drive cylinder, 32: Stopper, 100: Wafer stacking body, 102: convex portion, 104: support glass, W1: wafer with convex portion formed at outer peripheral end, W2: bare wafer.

Claims (7)

A wafer body holding structure that can be used for both wafers and wafer stacks, which is compatible with both wafers in a spin processing apparatus and wafer stacks larger in diameter than the wafers ,
a rotary table on which a wafer body, which is the wafer or the wafer stack , is placed;
a first outer circumferential pin member, a second outer circumferential pin member, and a third outer circumferential pin member provided on the rotary table and arranged at approximately equal intervals around the outer circumference of the wafer body;
including;
The first outer peripheral pin member is in a fully open state, which is the state when the wafer or the wafer stack is being supplied/taken out;
an intermediate stop position for holding the wafer stack, the distance from the center of the rotary table being smaller than in the fully open state;
A fully closed state in which the wafer is held is possible where the distance from the center of the rotary table is smaller than the intermediate stop position;
The second outer circumferential pin member can be in a fully open state in which it holds the wafer stack, and in a fully closed state in which it holds the wafer, and the distance from the center of the rotary table is smaller than in the fully open state;
The third outer circumferential pin member can take a fully open state in which it holds the wafer stack, and an intermediate stop position in which it holds the wafer, the distance being smaller from the center of the rotary table than in the fully open state;
The pressing force of each of the first outer circumferential pin member, the second outer circumferential pin member, and the third outer circumferential pin member is
Pressing force of the first outer circumferential pin member>Pressing force of the second outer circumferential pin member>Pressing force of the third outer circumferential pin,
has a correlation of
When holding the wafer stack, the second outer circumferential pin and the third outer circumferential pin are fully opened, and the first outer circumferential pin is moved from the fully open state to an intermediate stop position to center the wafer stack. ,
When holding the wafer, the first outer circumferential pin and the second outer circumferential pin are in a fully closed state, and the third outer circumferential pin is moved from a fully open state to an intermediate stop position to center the wafer. , a wafer body holding structure that can be used for both wafers and wafer stacks. The wafer body holding structure for both a wafer and a wafer stack according to claim 1, wherein the diameter of the wafer is 300 mm, and the diameter of the wafer stack is 301 mm. A method for holding a wafer for both a wafer and a wafer stack in a spin processing apparatus, using the wafer holding structure for both a wafer and a wafer stack according to claim 1 ,
The pressing force of each of the first outer circumference pin member, the second outer circumference pin member, and the third outer circumference pin member that presses the outer circumference of the wafer body placed on the rotary table is
Pressing force of the first outer circumferential pin member>Pressing force of the second outer circumferential pin member>Pressing force of the third outer circumferential pin,
A wafer holding method for both a wafer and a wafer stack, wherein the wafer body is centered on the rotary table by pressing the outer circumferential portion of the wafer body so as to have a correlation. 4. The method for holding a wafer body for both a wafer and a wafer stack according to claim 3 , wherein the diameter of the wafer is 300 mm, and the diameter of the wafer stack is 301 mm. When the wafer body placed on the rotary table is the wafer stack, the wafer stack is held down by a first outer pin member toward the second outer pin member and the third outer pin member,
The pressing force of each of the first outer circumferential pin member, the second outer circumferential pin member, and the third outer circumferential pin member is
Pressing force of the first outer circumferential pin member>Pressing force of the second outer circumferential pin member>Pressing force of the third outer circumferential pin,
The wafer holder for use as a wafer and a wafer stack according to claim 3 or 4 , wherein the wafer body is centered on the rotary table by pressing the outer peripheral portion of the wafer body so as to have a correlation of Method. When the wafer body placed on the rotary table is the wafer, the wafer is held down by a third outer circumferential pin member toward the first outer circumferential pin member and the second outer circumferential pin member,
The pressing force of each of the first outer circumferential pin member, the second outer circumferential pin member, and the third outer circumferential pin member is
Pressing force of the first outer circumferential pin member>Pressing force of the second outer circumferential pin member>Pressing force of the third outer circumferential pin,
5. The wafer holding method according to claim 3 , wherein the wafer body is centered on the rotary table by pressing the outer peripheral portion of the wafer body so as to have a correlation of . A spin etching apparatus for both wafers and wafer stacks, comprising the wafer holding structure for both wafers and wafer stacks according to claim 1 or 2 .