JPH09181156A - Vacuum chuck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chuck which can be used in liquid and air without a vacuum energy source. SOLUTION: A bank-shaped part 13 is made to abut against the surface of an object 103 to be held (the back of a wafer) and surrounds an area of the surface. A diaphragm 14 is spread on an aperture part of the bank-shaped part 13. The diaphragm 14 is energized to the direction isolating from the surface of the object 103 to be held, by a diaphragm energizing means 15 (by reduced pressure of a cavity). Then negative pressure is generated in a space between the diaphragm 14 and the surface of the object 103 to be held, and the object 103 to be held is sucked and held.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum chuck, and more particularly to a vacuum chuck suitable for adsorbing and holding an object in a liquid, for example, a vacuum chuck suitable for adsorbing and holding a semiconductor wafer in a chemical solution. Semiconductor wafer "
Hereinafter referred to as "wafer").

[0002]

2. Description of the Related Art A wafer is usually held in a semiconductor manufacturing process by a carrier, a mechanical chuck, or a vacuum chuck. Whether done by a robot,
Of these, the vacuum chuck is the most suitable for holding the wafer, even if it is done manually.

Because the carrier and the mechanical chuck hold the wafer by leaning against the frame or grasping the peripheral edge. For this reason, there is a risk that a part of them will come into contact with the surface of the wafer (circuit forming surface), and certain measures must be taken to prevent this.

In the vacuum chuck, this is adsorbed on the back surface of the wafer. Therefore, there is no such possibility,
Wafers can be handled with confidence.

FIG. 7 shows an example 101 of a conventional vacuum chuck. (A) of the figure shows the vacuum chuck 101 viewed from the opening surface (front side), and (B) shows the vacuum chuck 101 viewed from the back side.
(C) shows a cross section taken along line 7C-7C of (A).

The overall shape is a disk with a little thickness and has a cavity 102 inside. The annular grooves 104 and 105 and the central concave portion 1 are provided on the opening side for holding the wafer 103 by suction.
06 are provided, and a plurality of vent holes 107 that communicate the annular groove and the cavity 102 are bored in the bottom of these.

The members of the annular bank portions 108, 109 and 110 forming the annular grooves 104 and 105 are made of a material such as Teflon or ceramics, or a SUS / aluminum base material coated with Teflon or ceramics.

In use, this opening surface is pressed against the wafer 103. After that, the air in the cavity 102 is sucked from the exhaust port 111 by a vacuum pump (not shown). Cavity 1
02 and the inside of the annular grooves 104 and 105 become negative pressure, and the wafer 103 is held by the vacuum chuck 101.

It is to be noted that the term "vacuum" as used in the present specification, for example, "vacuum" in the title of the invention means "a negative pressure with respect to the surroundings" and means "high vacuum".
Does not mean

This is because this kind of tool is generally called a "vacuum chuck", and it is easier to understand if it is followed. In this specification, the term "vacuum" is used in accordance with this general definition.

[0011]

However, the conventional vacuum chuck 101 described above still has some points to be improved. First, this conventional device sucks the surrounding liquid or gas even if it is carefully handled, for example, by starting suction after it is brought into close contact with the object to be held.

Therefore, the sucking of the chemical solution, the corrosion of the intake system,
Damage and the like occur, and it cannot be used especially in a liquid, for example, in an etching liquid for the wafer 103.
In addition, since the gas is sucked out, it cannot be used even in a closed space filled with an inert gas or the like.

Secondly, the conventional one always requires a vacuum energy source (vacuum pump or the like). For this reason, the equipment cost was high, and the installation location and maintenance were required.

The object of the present invention is to eliminate the drawbacks of these conventional vacuum chucks and to be usable in liquid or air.
Moreover, it is to provide a vacuum chuck that can be used without a vacuum energy source.

[0015]

In order to achieve the above object, in Claim 1 and the invention cited therein, a bank-shaped portion which is in contact with an object to be held and surrounds a certain area of the surface of the object to be held, In the space surrounded by the diaphragm extended in the opening of the bank-shaped portion and the diaphragm and biasing the diaphragm in the direction away from the surface of the holding object, the bank-shaped portion, the diaphragm and the surface of the holding object. And a diaphragm urging means for generating a negative pressure.

In the thirteenth aspect of the invention and the invention cited therein, a cavity having an opening abutting the object to be held so that the opening encloses a certain area on the surface of the object to be held, and the cavity is expandable and contractable. A volume occupying means for occupying a certain volume therein, and a volume reducing means for reducing the volume occupied by the volume occupying means, the volume reducing means reducing the volume occupied by the volume occupying means in the cavity. Then, the space formed by the cavity and the surface of the object to be held is made to have a negative pressure.

In the first aspect and the inventions cited therein, the bank portion is brought into contact with the surface of the object to be held and surrounds a certain range of the surface. A diaphragm is extended in the opening of the bank, and this diaphragm is a diaphragm urging means,
For example, the lever is urged in a direction away from the surface of the object to be held.

As a result, a negative pressure is generated in the space surrounded by the bank portion, the diaphragm and the surface of the object to be held. As a result, the object to be held is sucked and held by this vacuum chuck.

Since it is blocked by the diaphragm, even if it is used in liquid or air, the liquid or gas is not sucked into the intake system or the like.

According to the thirteenth aspect and the inventions cited therein,
The opening of the cavity is brought into contact with the object to be held. This opening surrounds a certain area of the surface of the object to be held. A volume occupying means, for example, a bellows, which is expandable and contractible and occupies a part of the volume of the cavity, is arranged in the cavity.

The volume reducing means, for example a vacuum pump, sucks, for example, air inside the volume occupying means and reduces its volume. As a result, the closed space formed by the cavity and the surface of the object to be held expands in volume and becomes a negative pressure accordingly. As a result, the cavity is attracted to the surface and the object is held.

Also in these inventions, the surroundings are blocked with, for example, bellows. Therefore, even when used in liquid or air, the liquid or gas will not be sucked into the intake system or the like.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below with reference to illustrated embodiments. FIG. 1 shows a first embodiment example 11. This embodiment is one of the embodiments of the invention of claim 1, specifically, the invention of claim 2 which cites the invention.

FIG. 1A shows the front surface of the vacuum chuck 11. The same figure (B) shows a cross section, and this is 1B of the same figure (A).
It is cut along the line -1B (in a state where the wafer 103, which is an object to be held, is sucked). FIG. 6C shows a state before the suction holding.

Since it is difficult to see, the hatching of the cross section in each drawing is omitted as appropriate (for example, the handle 18 and the wafer 103 in FIG. 1).

Reference numeral 12 denotes a vacuum house, which has a shallow bottomed cylindrical shape. An opening seal 13 made of an elastic material such as silicon rubber is attached to the opening. This corresponds to the bank portion as claimed in claim 1 and the like.

A diaphragm 14 is stretched over the opening seal 13. This is also formed of the same elastic member, and the opening seal 13 and the vacuum house 1
The cavity 15 is formed by 2 and.

An exhaust pipe 16 connects the cavity 15 and the outside. A tube 17 is connected to the exhaust pipe 16, and the other end is connected to a vacuum pump (not shown).

The handle 18 is extended to the vacuum house 12, and its other end (not shown) is held by the production robot. Reference numeral 19 is a chemical liquid tank, and 20 is a chemical liquid stored therein.

For example, when the wafer 103 is immersed in the chemical solution 20, the vacuum chuck 11 is used. In this case, the sequence is constructed as follows. First, open a valve (not shown) installed in a vacuum pump or the like to open the cavity 15
Return the internal pressure of to atmospheric pressure. This flattens the diaphragm 14 (FIG. 1 (C)).

Then, the valve of the vacuum pump is closed and suction is performed. Cavity 1 through tube 17 and exhaust pipe 16
The air in 5 is sucked out, and this becomes a predetermined negative pressure. This negative pressure may be a value necessary to hold the wafer 103 as in the conventional case.

The inside of the cavity 15 has a negative pressure and the diaphragm 14 is sucked toward the cavity 15. As a result,
A negative pressure is also applied to the space formed by the back surface of the wafer 103 (front surface of the object to be held), the surface of the diaphragm 14 facing the wafer 103, and the external seal 13. The wafer 103 is adsorbed and held by the vacuum chuck 11.

Next, the arm (not shown) of the robot is driven to immerse the vacuum chuck 11 holding the wafer 103 by suction into the chemical solution 20. When the set time has elapsed, the arm of the robot is driven to take out the vacuum chuck 11 that has adsorbed the wafer 103 from the chemical solution. The wafer 103 is released at a predetermined position.

FIG. 2 shows an example 31 of the second embodiment. This embodiment is also one of the embodiments of the invention of claim 1, and more specifically, the invention of claim 3 cited therein.

FIG. 3A shows the plane of the vacuum chuck 31. The same figure (B) shows a cross section, 2B-2B of the same figure (A)
It is cut along a line. FIG. 3C shows the back surface of the lever clamp 32 with only the lever clamp 32 taken out.

A body portion 33 has a plate shape. A through hole 34 is formed in the front end, and a handle portion 35 is formed on the rear end side. 36 is an opening seal, which is made of an elastic material such as silicon rubber. This corresponds to the bank portion as claimed in claim 1 and the like.

A diaphragm 37 is also stretched on the opening seal 36. This is also formed of a similar elastic member. Reference numeral 38 denotes a lever, which has an appropriate repulsive force (elasticity) against bending, and is rotatably supported by a support shaft 39 installed at a portion near the tip of the body portion 33. The tip 40 of the lever 38 is fixed to the center of the diaphragm 37.

Reference numeral 41 is a compression spring, which is inserted between the lever 38 and the body portion 33 and urges them in the direction of separating them.

To hold the wafer 103 by suction,
With the state shown in FIG. 2B, that is, the diaphragm 37 being flat, the opening seal 36 is brought into close contact with the back surface of the wafer 103.

In this state, the lever 38 and the handle portion 35 are gripped against the repulsive force of the compression spring 41. The rear end side 42 of the lever 38 resists the pinching by the tongues on both sides of the lever clamp 32 and fits in between them. This is the lever 38
The rear end side 42 is held by the lever clamp 32 (FIG. 3).

In this state, the lever 38 flexes appropriately. The central portion of the diaphragm 37 is biased in a direction away from the wafer 103 (bending is not essential). A negative pressure is applied to the space formed by the opening seal 36, the lower surface of the diaphragm 37, and the back surface of the wafer 103. Wafer 103
Are sucked and held by the vacuum chuck 31.

When it is desired to remove the wafer 103, the rear end side 42 of the lever 38 is detached from the lever clamp 32.

FIG. 4 shows a third embodiment 51. This embodiment is one of the embodiments of the invention of claim 13, specifically, the invention of claim 14 which is cited therein. Illustration of parts similar to those of the first or second embodiment is omitted.

FIG. 6A shows an opening surface (front surface). (B) and (C) of the figure show cross sections, and 4B-4B of the same figure (A).
It is cut along a line, (B) shows a state before the wafer 103 is adsorbed, and (C) shows a state in which the wafer 103 is adsorbed and held.
(D) shows the principal part of the cross section cut along the 4D-4D line of (C).

In the figure, reference numeral 52 denotes a vacuum house, which has a shallow bottomed cylindrical shape. An opening seal 53 made of an elastic material such as silicone rubber is attached to the opening, and this corresponds to the bank portion as claimed in claim 13. Further, the entire inner volume 68 of the bottomed cylindrical body corresponds to the cavity as claimed in claim 13.

A through hole 54 is formed at the center of the vacuum house 52.
Is provided, and the slide shaft 55 is inserted there. An annular groove is formed on the outer periphery of the slide shaft 55, and an O-ring 56 is fitted therein.

A rotatable joint 57 is provided on the tip end side of the slide shaft 55, and a disc 58 is attached to the tip thereof.

A bellows 60 is arranged between the disk 58 and the bottom 59 of the vacuum house. The bellows 60 is also made of an elastic material such as silicon rubber, and one opening is adhered to the back surface of the disk 58 over the entire circumference and the other opening is adhered to the bottom portion 59 of the vacuum house over the entire circumference.

Disk 58 and bottom 59 of the vacuum house
And the bellows 60 form a stretchable portion 61. This corresponds to the volume occupying means described in claim 13 and the like. Since the O-ring 56 is fitted into the slide shaft 55, the space 62 is hermetically sealed. The slide shaft 55 is claim 1.
This corresponds to the volume reduction means referred to in 3 and the like.

A locking pin 63 is fixed through the slide shaft 55. At the vacuum house hub 66,
A slit groove 64 corresponding to this is formed, and the engaging pin 63 is made to enter the slit groove 64 before adsorbing the object to be held (FIG. 4 (B)). 65 is a pick.

For example, when it is desired to suck and hold the wafer 103, the state shown in FIG. Disk 58 at this time
Is almost at the same position as the opening seal 53.

In this state, the opening seal 53 is attached to the wafer 1.
Abut on the back of 03. Holding the knob 65, the slide shaft 55 is pulled out against the repulsive force due to the contraction of the expandable portion 61.
The locking pin 63 is made to escape from the slit groove 64, and the slide shaft 55 is rotated about 90 degrees.

The locking pin 63 is now engaged by the lip 67 of the hub 66.
get on. The slide shaft 55 is prevented from returning to the original position shown in FIG. 4B, and the state shown in FIG. 4C is obtained.

The slide shaft 55 is pulled out, and the expandable portion 61
The remaining volume 69 of the cavity 68
The volume of the water expands relatively and becomes negative pressure (the remaining space 69
= A space surrounded by the opening seal 53, the inner wall and the bottom of the vacuum house 52, the outer wall of the expandable portion 61, and the back surface of the wafer 103).

Thus, the wafer 103 is suction-held on the vacuum chuck 51. Reverse the procedure to release the hold.

Instead of pulling by the slide shaft 55, the air in the closed space 62 of the expandable portion may be sucked by a vacuum pump.

FIG. 5 shows a fourth embodiment 71. This embodiment 71 is one of the embodiments of the invention described in claims 4 to 6. Illustrations of parts similar to those of the above-described embodiments are omitted.

FIG. 7A shows the front. The figure (B) shows a cross section, which is taken along the line 5B-5B in the figure (A). The vacuum chuck 71 includes a base 72, a plurality of vacuum houses 73, an opening seal 74,
And the diaphragm 75 are arranged.

The vacuum house 73, the opening seal 74, and the diaphragm 75 have the same structures as the vacuum house 12, the opening seal 13, and the diaphragm 14 of the eleventh embodiment.

Each vacuum house 73, opening seal 7
4 and the function of the diaphragm 75 are also the first embodiment 1
It is the same as that of 1. The base 72 is provided with a vent hole 76 communicating with the bottom of each vacuum house 73, from which air in each vacuum house 73 is sucked.

Now, each opening seal 74 is attached to the wafer 10
Adsorb each part of 3. Adsorption part is dispersed and wafer 10
3 etc. can be held flatter.

FIG. 6 shows a fifth embodiment 81. This embodiment is one of the embodiments of the invention of claims 7 to 12 or claims 19 to 24. Illustrations of parts similar to those of the above-described embodiments are omitted.

FIG. 7A shows the front. (B), (C)
Shows a cross section taken along line 6B-6B in (A), (B) shows a state before adsorption, and (C) shows a state in which adsorption is performed.

In this vacuum chuck 81, a central portion of a vacuum house 82 is made into a concave portion 83, and cylindrical walls 84 and 85 are provided around the concave portion 83 and at the periphery of the vacuum house 82. Then, ring-shaped opening seals 86 and 87 are attached to the upper ends of the walls 84 and 85, and a diaphragm 88 is stretched between them.

In this way, the cavity 89 has a donut shape. Air is sucked from the vent hole 90 that communicates the cavity 89 with the outside, and the diaphragm 88 is dented toward the cavity 89.

With this, the wafer 103 can be sucked and held as in the first embodiment. Since the adsorption area becomes wider,
The wafer 103 can be held flatter.

In the above description, holding of the semiconductor wafer is taken as an example. The holding object of the present invention is not limited to this.
It can be used for adsorption holding of any other articles.

Although not specified, the cavity was filled with air in the above-mentioned embodiment, and this was sucked by a vacuum pump to generate a negative pressure. Instead of air, other gas may be used. Not only gas but also water, oil or other liquid may be enclosed in the cavity 15 of FIG. 1, for example, and suctioned to generate a negative pressure.

Materials such as diaphragm and bellows are optional. Anything is acceptable as long as it is resistant to the chemical liquid, gas, etc. to be immersed.

[0070]

As described above, according to claim 1 and the invention cited therein, the diaphragm is extended in the opening of the bank, and the bank is brought into contact with the surface of the object to be held, and the surface thereof is held. The target object is sucked and held by urging the diaphragm in a direction away from the surface of the object to be held by the diaphragm urging means.

Since the diaphragm prevents the inhalation of surrounding substances, it can be used without problems even in liquid or air. Therefore, no harmful liquid or gas is sucked. If the force is applied directly to the diaphragm or bellows, an energy source such as a vacuum pump is unnecessary.

According to the thirteenth aspect and the invention cited therein,
A volume occupying means, which is expandable and contractible and occupies a part of its volume, is arranged in the cavity, and when its opening is brought into contact with a holding object, the volume of the volume occupying means is reduced to adsorb and hold the object. I did it. In this invention, the same effect as above can be expected.

[Brief description of the drawings]

1 shows a first embodiment example 11, (A) is a front view, (B) and (C) show cut surfaces along line 1B-1B in (A), and (B) is a wafer. The state where 103 is absorbed,
FIG. 6C is a sectional view showing a state before adsorption and holding.

FIG. 2 shows a second embodiment example 31, (A) is a plan view, (B) is a cross-sectional view showing a cross section taken along line 2B-2B of (A), and (C) is a lever clamp 32. The rear view which shows and takes out only.

FIG. 3 is a right side view showing a state in which a wafer 103 of a second embodiment example 31 is suction-held.

FIG. 4 shows a third embodiment example 51, (A) is a front view showing an opening surface, (B) and (C) are 4B of the same figure (A).
-4B shows a cross section along line B, (B) is before adsorption, (C)
FIG. 3 is a cross-sectional view showing a state in which it is adsorbed and held. (D) is 4 of (C)
Sectional drawing which shows the principal part of the cut surface which follows the D-4D line.

FIG. 5 shows a fourth embodiment example 71, (A) is a front view, and (B) is a sectional view showing a cross section taken along line 5B-5B of (A).

FIG. 6 shows a fifth embodiment example 81, (A) shows the front surface, (B) and (C) show cut surfaces taken along line 6B-6B of (A), and (B) shows before adsorption. , (C) are cross-sectional views showing a state of adsorption.

FIG. 7 shows an example 101 of a conventional vacuum chuck, (A)
Is a front view, (B) is a rear view, (C) is (A) 7C-7.
Sectional drawing which shows the cut surface which follows the C line.

[Explanation of symbols]

 11 Vacuum Chuck 31 Vacuum Chuck 51 Vacuum Chuck 71 Vacuum Chuck 81 Vacuum Chuck 13 Levee 36 36 Levee 53 53 Levee 74 Levee 86 Levee 87 Levee 14 Diaphragm 37 Diaphragm 75 Diaphragm 88 Diaphragm 15 Cavity ( Diaphragm energizing means) 68 cavity 69 cavity 38, 39 mechanical force applying means 55 volume reducing means, mechanical force applying means 61 volume occupying means 103 holding object

Claims (24)

[Claims] 1. A ridge-shaped portion that abuts an object to be held and surrounds a certain area on the surface of the object to be held, a diaphragm extended in an opening of the ridge-shaped portion, and a surface of the object to be held. A diaphragm urging means for urging the diaphragm in a direction in which the diaphragm is separated, and generating a negative pressure in a space surrounded by the bank-shaped portion, the diaphragm and the surface of the object to be held. Vacuum chuck. 2. The diaphragm urging means is a mechanical force applying means for directly applying a force to the diaphragm, and the mechanical force applying means urges the diaphragm in a direction away from the surface of the holding object. The vacuum chuck according to claim 1, wherein: 3. The diaphragm urging means is a cavity, and the cavity is disposed on the side of the diaphragm opposite to the side of the object to be held, and is generated by discharging gas or liquid in the cavity. The vacuum chuck according to claim 1, wherein the diaphragm is biased by a negative pressure in a direction of separating from the surface of the object to be held. 4. A plurality of the bank-shaped portions and diaphragms stretched thereon are arranged.
Vacuum chuck as described. 5. The plurality of the bank-shaped portions and the diaphragms stretched on the bank-shaped portions are arranged.
Vacuum chuck as described. 6. The ridge-shaped portion and a plurality of diaphragms extended therefrom are arranged in a plurality.
Vacuum chuck as described. 7. The vacuum chuck according to claim 1, wherein the opening formed by the bank portion is doughnut-shaped, and the diaphragm is extended in the opening. 8. The vacuum chuck according to claim 2, wherein the opening formed by the bank-shaped portion is doughnut-shaped, and the diaphragm is extended in the opening. 9. The vacuum chuck according to claim 3, wherein the opening formed by the bank-shaped portion is doughnut-shaped, and the diaphragm is stretched in the opening. 10. The vacuum chuck according to claim 4, wherein the opening formed by the bank-shaped portion has a donut shape, and the diaphragm is extended in the opening. 11. The vacuum chuck according to claim 5, wherein the opening formed by the bank-shaped portion is doughnut-shaped, and the diaphragm is extended in the opening. 12. The vacuum chuck according to claim 6, wherein the opening formed by the bank portion is doughnut-shaped, and the diaphragm is extended in the opening. 13. An opening is in contact with an object to be held, and the opening is expandable and contractible with a cavity surrounding a certain area of the surface of the object to be held, and occupies a certain volume in the cavity. A volume occupying means and a volume reducing means for reducing the volume occupied by the volume occupying means are provided, and the volume occupying the cavity of the volume occupying means is reduced by the volume reducing means, and the cavity and the holding A vacuum chuck characterized in that the space formed with the surface of the object is negatively pressured. 14. The volume reducing means is a mechanical force applying means for directly applying a force to the volume occupying means, and the volume of the volume occupying means is reduced by the force applied by the mechanical force applying means. 14. The vacuum chuck according to claim 13, wherein: 15. The volume reducing means is a gas or liquid suction means, and the gas or liquid inside the volume occupying means is sucked by the gas suction means to reduce the volume of the volume occupying means. 14. The vacuum chuck according to claim 13. 16. The vacuum chuck according to claim 13, wherein a plurality of the cavities and the volume occupying means occupying the inner volume thereof are arranged. 17. The vacuum chuck according to claim 14, wherein a plurality of the cavities and the volume occupying means occupying the inner volume thereof are arranged. 18. The vacuum chuck according to claim 15, wherein a plurality of the cavities and the volume occupying means occupying the inner volume thereof are arranged. 19. The vacuum chuck according to claim 13, wherein the opening of the cavity has a donut shape. 20. The vacuum chuck according to claim 14, wherein the opening of the cavity has a donut shape. 21. The vacuum chuck according to claim 15, wherein the opening of the cavity has a donut shape. 22. The vacuum chuck according to claim 16, wherein the opening of the cavity has a donut shape. 23. The vacuum chuck according to claim 17, wherein the opening of the cavity has a donut shape. 24. The vacuum chuck according to claim 18, wherein the opening of the cavity has a donut shape.