JP2655173B2 - Semiconductor wafer separation method and apparatus - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for separating a semiconductor wafer, and more particularly, to a method for immersing a semiconductor wafer in a liquid and applying a high frequency vibration to the liquid. After the liquid penetrates between the respective plates to significantly reduce the frictional force between the semiconductor wafers, the uppermost one is moved along the surface thereof and separated from the second and lower ones to be laminated. The present invention relates to a method and an apparatus for separating a semiconductor wafer, in which the separated semiconductor wafer can be easily separated.

2. Description of the Related Art A semiconductor wafer, for example, a silicon wafer, which is a material for manufacturing a semiconductor device, is usually formed from a single crystal base material purified into a columnar shape, for example, with a diameter of 10 mm to 400 mmφ and a thickness of 200 μm
It is cut into a disk of mm. The surface is mirror-polished in order to manufacture a semiconductor device by performing fine processing on the surface by an etching method or the like. Therefore, when the semiconductor wafers are stacked, the mirror-like surfaces of the semiconductor wafers come into close contact with each other.
Separating each sheet requires considerable skill because it is thin and easily broken, and this operation is also mechanized. However, there are various technical problems and there is room for improvement.

For example, as a conventional semiconductor wafer separating apparatus, the one shown in FIG. 4 is known, and the conventional example will be described below also with reference to FIGS.

The semiconductor wafer separation device 1 is placed on an elevator device 4 in water 3 which is an example of a liquid contained in a container 2 and is stacked on the semiconductor wafer (hereinafter abbreviated as a wafer in the description of the conventional example) 5. Is immersed. The number of stacked wafers 5 is, for example, 50 to 500 in a slicing machine, a beveling machine, or the like, which is a manufacturing process of the wafer.

When the elevator device 4 rises in the direction of arrow A, the detection device 8 detects the surface 5a of the wafer 5 by the detector 8a, and the elevator device stops. Then, the suction device 9 descends and comes into contact with the surface 5a of the wafer 5, and sucks the wafer 5 by the action of the suction air. The elevator device 4
The wafer 5 slightly descends in the direction of arrow B to separate the uppermost one wafer 5 from the second and lower wafers.
The wafer 1 at the top is moved in parallel to the
Take it out of the

The suction device 9 ensures that the suction action is ensured.
For example, since the suction pad 11 having elasticity made of rubber is provided at its tip and the wafer 5 is held by the suction pad, the suction pad 11 is sucked by the suction pad 11 and the arrow C
The wafer 5 moving in the direction moves while performing a complicated movement. Therefore, when the descending amount of the elevator apparatus 4 is small, the stacked wafers 5 and the suction pads 11 as shown in FIG.
The rear ends 5b of the wafers 5 that are attracted to and move parallel to each other come into contact with each other, causing chipping of the rear ends 5b. Further, in order to prevent this, the descending amount of the elevator apparatus 4 must be increased, but this will reduce the work efficiency. Further, since the wafers 5 are mirror-polished as described above, the adhesion between the wafers is strong, only the uppermost one is not separated, and a plurality of wafers 5 may be adsorbed to the suction pad 11. However, if the wafer 5 is moved in the direction of arrow C in such a state, the second and subsequent wafers 5 interfere with the separation guide 10 to cause chipping, and in severe cases, cracks occur. In addition, when fine processing such as etching is performed while small pieces generated by chipping are attached, there is a defect that defective products are generated.

Purpose The present invention has been made in order to eliminate the above-mentioned disadvantages of the prior art, and an object of the present invention is to provide a semiconductor wafer accommodating section for accommodating a laminated semiconductor wafer and a laminated semiconductor wafer. A container containing a liquid, comprising a separation unit for separating and storing one of the separated semiconductor wafers, and an elevator apparatus in which semiconductor wafers are stacked so as to be vertically movable in the semiconductor wafer storage unit; A transfer device in which a roller driven to rotate is provided at an upper portion of the semiconductor wafer accommodating portion and moves the uppermost semiconductor wafer along the surface thereof when the roller comes into contact with the surface of the uppermost one of the semiconductor wafers; ,
The elevator device is stopped after raising the elevator device by a predetermined distance, and the control device for controlling the elevator device and the roller at a predetermined timing by repeating the operation of rotating the roller continuously, and the liquid in the semiconductor wafer storage unit. By providing a high-frequency generator that applies high-frequency vibration and allows the liquid to penetrate between the stacked semiconductor wafers, only the uppermost one from the stacked semiconductor wafers is surely and It should be easy to separate. Another object is to eliminate the interference between semiconductor wafers during the separation operation or between the semiconductor wafer and the separation guide of the semiconductor wafer to prevent chipping and cracking of the semiconductor wafer. The purpose of the present invention is to prevent the occurrence of defective products due to performing fine processing such as etching while adhering to the substrate. Another object is to improve the separating performance of the stacked semiconductor wafers, shorten the operation cycle of the separating device, and improve the working efficiency.

Configuration In short, the method of the present invention involves immersing a laminated semiconductor wafer in a liquid contained in a container, applying high-frequency vibration to the liquid, allowing the liquid to penetrate between the plates of the semiconductor wafer, and After significantly reducing the frictional force between the semiconductor wafers by a lubricating action of a liquid, the uppermost one of the semiconductor wafers is moved along the surface thereof to be separated from the second one or less. It is.

Further, the apparatus of the present invention comprises a semiconductor wafer storage section for storing the stacked semiconductor wafers and a separation section for separating and storing one semiconductor wafer separated from the second or less of the semiconductor wafers. And an elevator device provided in the semiconductor wafer storage portion, the elevator device being loaded in the semiconductor wafer storage portion so as to be movable in the vertical direction, and a roller driven to rotate is provided at the upper portion of the semiconductor wafer storage portion. When the roller comes into contact with the surface of the uppermost one of the semiconductor wafers, the transfer device moves the uppermost one along the surface, and the elevator device is raised after a predetermined distance and then stopped. And a control for controlling the elevator device and the roller at a predetermined timing by repeating the operation of rotating the roller. And a high-frequency generator configured to apply high-frequency vibration to the liquid in the semiconductor wafer accommodating section so that the liquid permeates between the stacked semiconductor wafer plates. .

Hereinafter, the present invention will be described based on embodiments shown in the drawings. 1 to 3, the semiconductor wafer separating apparatus 12 according to the present invention includes a container 13, a high-frequency generator 14, an elevator device 15, a transport device 16, and a control device 18.

The container 13 is a container in which water 3, which is an example of a liquid, is stored. The container 13 has a semiconductor wafer storage unit 19 for storing 50 to 500 semiconductor wafers 5 in a stacked manner, and is separated from the stacked semiconductor wafers 5. The uppermost semiconductor wafer 5 is separated by a separation guide 21 into a separation unit 20 for separating and storing the semiconductor wafer 5. The separation guide 21 is a rod-shaped member fixed to the bottom portion 22 of the container 13, and only the uppermost semiconductor wafer 5A stored in the semiconductor wafer storage portion 19 moves above the separation guide 21 in the direction of arrow G. , Can be moved to the separation unit 20,
The second and lower stacked semiconductor wafers 5 are configured not to move.

The high-frequency generator 14 is an oscillator that generates ultrasonic waves, and the generated frequency is, for example, 26 kHz to 36 kHz. The high-frequency generator 14 is provided in the container 13, applies the generated vibration to the water 3, and loads the semiconductor wafer 5 loaded thereon.
The water 3 is allowed to enter between the plates.

The elevator device 15 has a diameter of 10 mm to 400 mm and a thickness of 200 μ.
An arm 24 loaded with a stack of disk-shaped semiconductor wafers 5 each having an orientation flat OF with a length of 10 mm to 10 mm is provided in the semiconductor wafer storage portion 19, and is moved in the direction of arrow E by a driving device (not shown). It is configured to be able to. Further, the semiconductor wafer 5 loaded on the arm 24
Is the bottom of the container 13 with the movement of the arm 25 in the direction of the arrow E.
It is configured to be guided and raised by two semiconductor wafer guides 25 fixed to 13a.

The transfer device 16 is controlled by a drive device such as a motor so that a roller 28 that rotates in the direction of arrow F about a shaft 26 is controlled to a fixed position by the operation of a control device 18 described later. 5a, and the roller 28 is rotated so that the top one semiconductor wafer
5A is configured to be conveyed in the direction of arrow G. The separation unit 20 is provided with a basket-shaped transfer device 29 that holds the semiconductor wafer 5A separated and transferred by the rollers 28 and supplies the semiconductor wafer 5A to the next process.

The control device 18 is a detection device for detecting the presence or absence of the wafer 5.
The elevator device 15 is raised in the direction of arrow E until the detecting device detects the surface 5a of the semiconductor wafer 5A, and the operation of the elevator device 15 is stopped by the semiconductor wafer detection signal sent from the detecting device 30. Control the elevator device so that the topmost semiconductor wafer
It is configured to keep the position of the surface 5a of 5A constant.

In the method of the present invention, the laminated semiconductor wafers 5 are immersed in the water 3 accommodated in the container 13, and high-frequency vibration is applied to the water to cause the water 3 to enter between the plates of the semiconductor wafer 5.
After the frictional force between the semiconductor wafers 5 is significantly reduced by the lubricating action of the infiltrated water, the uppermost one of the semiconductor wafers 5 is moved along the surface thereof to be separated from the second or lower one. is there.

The present invention is configured as described above, and its operation will be described below. 1, 2 and 3, the surface 5 a of the semiconductor wafer 5 stacked on the elevator device 15 is mirror-polished and the surface roughness is extremely good. 5a are in close contact with each other and are difficult to separate.

Then, the laminated semiconductor wafers 5 are immersed in a container 13 filled with water 3 and subjected to ultrasonic waves of 26 kHz to 36 KHz for about 15 seconds by the high frequency generator 14, as shown in FIG. Water 3 penetrates between the plates of the wafers 5, the adhesion between the semiconductor wafers 5 is remarkably weakened, and the respective semiconductor wafers 5 are separated.

When the elevator device 15 is moved upward in the direction of arrow E,
Since the semiconductor wafer 5 loaded on the arm 24 is also guided by the semiconductor wafer guide 25, it rises without breaking. When the front surface 5a of the uppermost wafer 5A eventually reaches a position detected by the detector 30a of the detection device 30, the elevator device 15 is stopped by the operation of the control device 18.

This stop position is a position where the detection device 30 always detects the surface 5a of the uppermost wafer 5A regardless of the number of the stacked semiconductor wafers 5, so that the surface 5a of the uppermost semiconductor wafer 5A is constant. It will stop at the position. In the stop position, the surface 5a of the uppermost wafer 5A and the roller 28
When the roller 28 is rotated in the direction of arrow F by rotating a driving device such as a motor based on a driving signal from the control device 18, the roller 28 and the uppermost semiconductor wafer are in contact with each other.
A force in the direction of arrow G acts on the uppermost semiconductor wafer due to the frictional resistance of the surface 5a of 5A with the surface 5a. Here, water 3 penetrates between the plates of the semiconductor wafer 5 and is in a separated state, and since the water 3 penetrating between the semiconductor wafers 5 acts as a lubricant, the uppermost semiconductor can be formed with a very small force. The wafer 5A starts moving in the direction of arrow G.

At this time, since the second semiconductor wafer 5B from the top also serves as a guide for the uppermost semiconductor wafer 5A, there is no need to lower the elevator device 15 unlike the prior art. Further, as the roller 28 rotates in the direction of the arrow F, the uppermost semiconductor wafer 5A moves while being guided by the surface 5a of the second semiconductor wafer 5B, and moves between the roller 28 and the rear end 5b of the semiconductor wafer 5a. After the contact disappears, it moves on the separation guide 21 in the direction of arrow G by inertia force and is conveyed to the separation unit 20.

When the separation guide 21 and the separation unit 20 are slightly inclined, the semiconductor wafer 5A can be moved more smoothly.

The semiconductor wafer 5A conveyed to the separation unit 20 slowly descends in the water 3 by the action of gravity. However, since the cage-like conveyance device 29 is provided below the separation unit 20, the conveyance device 29 Transported by a drive device
It is conveyed in the direction of arrow H together with 29, lifted from the water 3 into the air, and supplied to the next step.

During the supply of the transfer device 29, the compressed air is blown onto the semiconductor wafer 5A to remove the water 3 attached to the semiconductor wafer 5A.

Further, in the semiconductor wafer storage unit 19, since the uppermost semiconductor wafer 5A is transported to the separation unit 20,
Since the second semiconductor wafer 5B is at the top and a gap is formed between the second semiconductor wafer 5B and the roller 28 by the thickness of the semiconductor wafer 5, the elevator device 15 is again moved in the direction of arrow E to the detection device 30.
Is raised until the semiconductor wafer 5B is detected, and the roller 28
The operation of transferring the wafer 5B to the separation unit 20 is repeated until the semiconductor wafer 5 loaded on the elevator device 15 is exhausted. In addition, since all of the above-mentioned separation action is performed in the water 3, the water acts as a cushion and does not damage the thin semiconductor wafer 5.

The semiconductor wafer separation device 12 according to the present invention operates as described above, and when transported in the direction of arrow G, the semiconductor wafer 5A and the next semiconductor wafer 5B do not interfere with each other. It is not. Further, since the semiconductor wafer 5A is transported after being separated by the intrusion of the water 3 by the high frequency vibration, only one semiconductor wafer 5A is transported without fail, and a plurality of semiconductor wafers 5 are transported simultaneously and interfere with the separation guide 21. Nothing to do.

Effects The present invention comprises a semiconductor wafer storage unit for storing the semiconductor wafers stacked as described above, and a separation unit for separating and storing one semiconductor wafer separated from the stacked semiconductor wafers, wherein the liquid is stored. Container, and an elevator device in which semiconductor wafers are stacked so that they can be moved vertically in the semiconductor wafer storage unit, and a roller that is driven to rotate is provided at the upper part of the semiconductor wafer storage unit, and the roller is a semiconductor wafer storage unit. When the uppermost semiconductor wafer comes into contact with the surface, the uppermost semiconductor wafer is moved along the surface thereof, and the elevator device is moved up to a predetermined height and then stopped, and then the rollers are rotated. A control device for controlling the elevator device and the rollers at a predetermined timing by repeating a driving operation; (C) a high-frequency generator that applies high-frequency vibration to the liquid in the storage section so that the liquid penetrates between the stacked semiconductor wafers, so that the topmost one from the stacked semiconductor wafers Just make sure
In addition, there is an effect that separation can be easily performed. Further, interference between the semiconductor wafers during the separation operation or with the semiconductor wafer separation guide can be eliminated, and there is an effect that chipping and cracking of the semiconductor wafer can be completely prevented. Further, since fine processing such as etching is not performed while small pieces generated by chipping are adhered to the semiconductor wafer, there is an effect that occurrence of defective products due to this can be prevented. Further, since the separation performance of the stacked semiconductor wafers can be improved, the effect of shortening the operation cycle of the separation device and improving the work efficiency can be obtained.

[Brief description of the drawings]

FIGS. 1 to 3 relate to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of an essential part showing an operation state of a semiconductor wafer separating apparatus, and FIG. Main part enlarged vertical sectional view showing a state in which the uppermost one is separated by a roller in a state where the respective semiconductor wafers are separated.
4 is a plan view showing the positional relationship between a semiconductor wafer, a wafer guide and a separation guide, and the state of transport of the semiconductor wafer. FIGS. 4 to 6 relate to a conventional example, and FIG. FIG. 5 is a partial longitudinal sectional view showing a state in which the ends of the semiconductor wafer interfere with each other during the transfer operation of the semiconductor wafer by the semiconductor wafer separating apparatus, and FIG. FIG. 4 is a partial vertical sectional view showing a state in which the sheet is being conveyed. 3 is water as an example of a liquid, 5 is a semiconductor wafer, 5a is a surface, 12 is a semiconductor wafer separation device, 13 is a container, 14 is a high frequency generator, 15 is an elevator device, 16 is a transport device, 18
Is a control device, 19 is a semiconductor wafer storage unit, 20 is a separation unit,
28 is a roller.

Claims (3)

(57) [Claims] 1. A method for manufacturing a semiconductor device comprising the steps of: immersing a laminated semiconductor wafer in a liquid contained in a container, applying high-frequency vibration to the liquid to cause the liquid to penetrate between the plates of the semiconductor wafer, and lubricating the penetrated liquid. And after significantly reducing the frictional force between the semiconductor wafers by the action, moving the uppermost one of the semiconductor wafers along the surface thereof to separate them from the second and lower ones. Separation method. 2. A liquid storage device comprising: a semiconductor wafer storage portion for storing stacked semiconductor wafers; and a separation portion for separating and storing one semiconductor wafer separated from the second or less of the semiconductor wafers. A container to be accommodated, an elevator device provided in the semiconductor wafer storage portion, which can load and move the semiconductor wafer vertically, and a roller that is driven to rotate is provided at an upper portion of the semiconductor wafer storage portion. When the roller comes into contact with the surface of the uppermost one of the semiconductor wafers, a transport device that moves the uppermost one along the surface thereof, and stops the elevator device after raising the elevator device by a predetermined distance. A control device that controls the elevator device and the roller at a predetermined timing by repeating an operation of rotating and driving the roller. A high-frequency generator for applying a high-frequency vibration to the liquid in the semiconductor wafer accommodating section so that the liquid penetrates between the stacked semiconductor wafer plates. . 3. The semiconductor wafer separating apparatus according to claim 2, wherein the high frequency generated by said high frequency generator is an ultrasonic wave having a frequency of 26 kHz to 36 kHz.