JP2004186555A - Wafer suction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer suction device capable of preventing a wafer from being dropped or damaged due to pressure variation and capable of surely attaching/detaching and carrying the wafer. <P>SOLUTION: The wafer suction device is provided with a suction holding part 6 having a suction port 6B for vacuum suction and capable of approximately vertically sucking a wafer 11 in vacuum to hold the wafer 11. Groove parts 7 for connecting the end part of a wafer loading surface 6A to the suction port 6B are formed on the wafer loading surface 6A of the suction holding part 6. When vacuum suction is stopped at the time of attaching/detaching the wafer 11, negative pressure in a pipe or the like is quickly removed by the groove parts and the suction of the wafer 11 is immediately removed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wafer suction device for vacuum chucking a vertically transported wafer.
[0002]
[Prior art]
For example, in a semiconductor manufacturing apparatus, when performing various processes such as film formation, a wafer is held by vacuum chucking. Taking a sputtering apparatus as an example, a wafer as a substrate on which a film is to be formed is transported to a wafer holder in the sputtering apparatus, and the wafer is suction-held by vacuum suction and then formed. At this time, a technique for forming a film while holding the wafer vertically is known. In this case, it is necessary to transfer the wafer in the vertical direction and vacuum-suction the wafer vertically to the wafer holder (for example, see Patent Document 1). ).
[0003]
[Patent Document 1]
JP-A-9-272975
[Problems to be solved by the invention]
In the meantime, when the wafer is vertically vacuum-chucked as described above, if the suction pressure fluctuates, there is a possibility that the wafer may drop or the wafer may be cracked. If the suction force is weak, the wafer will fall, and if the suction force is too strong, the wafer will break. In vacuum equipment used in factories, the vacuum suction of each device is performed by centralized supply using a large pump, so the vacuum suction force is weakened at the end of the pipe, and the operating conditions of peripheral equipment (frequency of vacuum use) ) Causes pressure fluctuations.
[0005]
Further, when the suction pressure of the vacuum chucking is high, there is also a problem that, when the vacuum suction is stopped and the wafer is transferred, a negative pressure remains, which hinders the transfer. Specifically, the negative pressure cannot be quickly released in a state where the wafer is chucked, and the pressure in the piping becomes negative even when the vacuum suction is stopped. As a result, the wafer remains sucked, which hinders smooth transfer. For example, if an attempt is made to peel the wafer against the negative pressure, the wafer may be damaged.
[0006]
The present invention has been proposed for the purpose of overcoming such disadvantages of the prior art. That is, an object of the present invention is to provide a wafer suction device capable of preventing a wafer from falling or being damaged due to a pressure change, and capable of realizing smooth attachment / detachment and transfer of a wafer.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a wafer suction apparatus of the present invention includes a suction port for vacuum suction, a suction holding unit for holding a wafer by vacuum suction substantially vertically, and holding the wafer. A groove is formed on the wafer mounting surface of the portion to communicate the suction port with the end of the wafer mounting surface.
[0008]
By forming a groove communicating the suction port and the end of the wafer mounting surface, the groove functions as a buffer against pressure fluctuation. Therefore, even if a pressure fluctuation occurs in the vacuum supply means for vacuum suction, the pressure fluctuation does not directly affect the suction pressure, and the wafer is always suctioned at a substantially constant suction pressure. . As a result, falling off or breakage of the wafer is eliminated.
[0009]
Further, when the vacuum suction is stopped during the transfer of the wafer, the negative pressure in the piping or the like is quickly eliminated by the groove portion, and the suction of the wafer is immediately eliminated. Therefore, the transfer of the wafer can be performed smoothly.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a wafer suction device to which the present invention is applied will be described with reference to the drawings.
[0011]
The wafer suction device of the present invention can be applied to, for example, a wafer holder in a sputtering device. FIG. 1 shows an example of a sputtering apparatus. The sputtering apparatus 1 is provided therein with a vacuum chamber (not shown) for forming a film by sputtering. Is installed.
[0012]
On a front surface of the sputtering apparatus 1, a vacuum gauge 2 for displaying a degree of vacuum in a vacuum chamber, an operation handle 3 for performing a manual operation of a vacuum, and the like are provided. The pressure in the vacuum chamber can be grasped from the outside by the vacuum gauge 2.
[0013]
As shown in FIG. 2, for example, the wafer suction apparatus 4 installed in the sputtering apparatus 1 is provided with a pickup section 6 for sucking and holding a wafer at the center of a support base 5 called a wafer door. The pickup section 6 is formed in a columnar shape at the center of the support substrate 5, and its tip end surface serves as a wafer suction surface 6 </ b> A.
[0014]
A suction port 6B for performing vacuum suction at the time of wafer suction is provided at the center of the wafer suction surface 6A, and the wafer is suction-supported from the back through the suction port 6B.
[0015]
Here, the wafer suction surface 6A is basically a flat surface, but in the present invention, as shown in FIG. A plurality of grooves 7 are cut radially. As shown in FIG. 3B, these grooves 7 have a V-shaped cross section, and connect the suction port 6 </ b> B and the space in the vacuum chamber on the outer peripheral surface of the pickup 6.
[0016]
The wafer is vacuum-chucked to the pickup section 6 having the above structure. At this time, the action of the groove section 7 makes it easy to take out the wafer, and the operation of removing the wafer from the pickup section 6 and carrying it can be performed smoothly. That is, when the vacuum suction by the vacuum pump is stopped and the wafer is taken out, since the groove 7 is formed, when the negative pressure remains, air flows in from the groove 7 and the chuck portion becomes the atmospheric pressure. . Therefore, when the vacuum suction is stopped, the wafer is quickly peeled off from the pickup unit 6 and transferred.
[0017]
The provision of the groove 7 allows air (carrier gas) to flow during vacuum chucking of the wafer. However, by adjusting the suction pressure with a vacuum regulator or the like, a good vacuum chucking state can be obtained. Can be kept. In particular, by adjusting the suction pressure to be 50 to 60 mmHg, a good vacuum chucking state can be stably maintained.
[0018]
The formation of the groove 7 is also effective in eliminating pressure fluctuation during vacuum suction of the wafer. As described above, in a vacuum device used in a factory, since vacuum suction of each device is performed by centralized supply using a large pump, for example, the pressure is determined by the operation status of peripheral devices (the frequency of use of vacuum). Cause fluctuations. It is considered that the provision of the groove 7 allows the vacuum system to communicate with the space in the vacuum chamber, and serves as a buffer for the inflow of air during the vacuum chucking of the wafer, thereby eliminating pressure fluctuations. In short, when the suction pressure of the vacuum system increases, the inflow of the air (carrier gas) increases, and the increase in the suction pressure is suppressed. Conversely, when the suction pressure of the vacuum system decreases, the inflow of air (carrier gas) also decreases, and a decrease in the suction pressure is suppressed.
[0019]
Next, a description will be given, with reference to FIG.
[0020]
FIG. 4A shows a transfer process for mounting the wafer 11 on the wafer suction device 4. In order to mount the wafer 11 on the wafer suction device 4, the wafer 11 is mounted on the wafer elevator 12, and the wafer 11 is raised from below the wafer suction device 4. At this time, the wafer 11 is sucked and supported by the suction holes 12A provided in the wafer elevator 12 and does not fall off.
[0021]
When the wafer 11 is lifted vertically from the lower portion of the support base 5 of the wafer suction device 4 and transferred to the center position of the support base 5, suction of the suction port 6B provided on the wafer suction surface 6A is started. You. As a result, the wafer 11 is sucked and held by the pickup unit 6 at the center of the support base 5 in a substantially vertical state. After the wafer 11 is sucked and held by the pickup unit 6, the suction by the suction hole 12A of the wafer elevator 12 is stopped, the wafer 11 is opened, and the wafer elevator 12 is lowered. Thus, the mounting of the wafer 11 on the wafer suction device 4 is completed. FIG. 4B shows the mounted state of the wafer 11.
[0022]
After the wafer 11 is mounted, a film is formed on the wafer 11 in the case of a sputtering apparatus, and necessary processing is completed. After the processing (film formation) is completed, the wafer 11 is removed from the wafer suction device 4 and transferred to the outside of the sputtering device 1.
[0023]
To remove the wafer 11 from the wafer suction device 4 and transport it, as shown in FIG. 4C, the wafer elevator 12 is raised from below, suction of the suction holes 12A is started, and the wear 11 is sucked and held. Next, the suction of the suction port 6B of the wafer suction device 4 is stopped, and the suction of the wafer 11 by the wafer suction device 4 is released. At this time, since the groove 7 is formed on the wafer suction surface 6A, the negative pressure is immediately released, and the wafer 11 is released from the suction. In this state, the wafer elevator 12 is moved downward, and the wafer 11 is transferred.
[0024]
In the attachment / detachment and transfer, the wafer 11 is mounted on the wafer mounting device 4 from below, and after the film formation, the wafer 11 is transferred downward. When considering such a transfer mode, it is desirable to change the number of grooves 7 formed on the wafer suction surface 6A of the wafer mounting device 4 between the upper portion and the lower portion of the wafer suction surface 6A. In particular, it is preferable to design such that the number of the grooves 7 is increased above the wafer suction surface 6A. As shown in FIG. 3A, when five grooves 7 are formed, three grooves 7 are arranged above the center of the wafer suction surface 6A and two are arranged below. The present invention is not limited to this, and the number of the grooves 7 may be changed. Further, instead of changing the number of the grooves 7, the depth of the grooves 7 may be changed. Specifically, the depth of the groove 7 arranged above the center of the wafer suction surface 6A is made deep, and the depth of the groove 7 arranged below is formed shallow.
[0025]
In any of the above cases, the amount of air (carrier gas) flowing from above can be increased when the wafer 11 is removed from the wafer suction surface 6A while being transported downward. Therefore, when the vacuum suction is stopped, the wafer 11 is easily detached from the upper portion of the wafer 11 first, and the transfer operation downward is facilitated. As a result, breakage of the wafer 11 is prevented.
[0026]
【The invention's effect】
As is clear from the above description, according to the present invention, it is possible to prevent the wafer from falling or being damaged due to the fluctuation in the pressure of the vacuum system, and to realize the smooth attachment / detachment and transfer of the wafer. It is.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a schematic configuration of a sputtering apparatus.
FIG. 2 is a schematic perspective view showing an example of a wafer suction device.
3A is a plan view of a wafer suction surface, and FIG. 3B is a cross-sectional view of the wafer suction surface.
4 (A) is a perspective view showing a wafer mounting operation, FIG. 4 (B) is a perspective view showing a wafer mounting state, and FIG. 4 (C) shows a wear removing operation. It is a perspective view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sputtering device 4 Wafer suction device 5 Support base 6 Pickup part 6A Wafer suction surface 6B Suction port 7 Groove 11 Wafer

Claims (8)

It has a suction port for vacuum suction, and has a suction holding section for holding the wafer by vacuum suction substantially vertically and holding the wafer,
A wafer suction device, wherein a groove for communicating the suction port with an end of the wafer mounting surface is formed on a wafer mounting surface of the suction holding unit. 2. The wafer suction device according to claim 1, wherein a plurality of the grooves are formed radially around the suction port. 3. The wafer suction device according to claim 2, wherein the number of grooves in the upper part of the wafer mounting surface is larger than the number of grooves in the lower part. 3. The wafer suction device according to claim 2, wherein the depth of the groove at the upper portion of the wafer mounting surface is greater than the depth of the groove at the lower portion. 2. The wafer suction apparatus according to claim 1, further comprising a transfer unit that moves up and down with respect to the suction holding unit and detaches the wafer from the suction holding unit. 6. The wafer suction apparatus according to claim 5, wherein the transfer means has a suction hole for sucking and holding the wafer during transfer. 2. The wafer suction apparatus according to claim 1, wherein the suction pressure at the time of vacuum suction of the wafer by the suction holding unit is adjusted to be 50 to 60 mmHg. 2. The wafer suction device according to claim 1, wherein the wafer is a semiconductor wafer.

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