JPH03256677A - Thin piece suction holding device - Google Patents

Abstract

PURPOSE:To prevent contamination of the back of a wafer through proper exchange of a clean pad by sucking and holding a thin piece, e.g. a semiconductor, on the clean pad through the third adsorption port and the third suction groove of the clean pad. CONSTITUTION:A first suction port 2, a second suction port 3 in the vicinity of the first suction port 2, and first suction grooves 4 connected to the second suction port 3 are formed in a sucking member 1 surface. A third suction port 22 and second suction grooves 23 connected to the third suction port 22 are formed in a clean pad 21 surface. The clean pad 21 is sucked by the member 1 in a state that the first suction port 2 coincides with the third suction port 22, and a thin piece 25, e.g. a semiconductor wafer, is sucked and held on the clean pad 21 through the third suction port 22 and the second suction grooves 23 of the clean pad 21. During contamination of the surface of the clean pad 21, a second valve 15 is closed to release the member 1 from an suction force, and the clean pad 21 is removed from the member 1. This constitution prevents contamination of the back of a wafer 25.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is applicable to thin sections (semiconductor wafers, glass photomasks,
This is related to suction and holding devices for glass substrates for optical disks, ferrite substrates for thin film heads, etc., and is particularly useful for suctioning thin pieces when used in surface processing equipment (photoresist coating, exposure, development, etching, surface inspection, etc.). This invention relates to a thin piece adsorption/holding device that does not contaminate surfaces.

[Summary of the invention]

The present invention provides a suction cup in which a first suction port, a second suction port near the first suction port, and a first suction groove connected to the second suction port are provided on the board surface; A clean pad with a second suction groove on the top surface connected to the suction port and the third suction port is sucked onto the suction cup so that the first suction port and the third suction port are aligned. This is a thin piece suction/holding device that suctions and holds a thin piece such as a semiconductor wafer on a clean pad using a third suction port and a second suction groove of the clean pad.

[Prior Art] Conventionally, as a device for suctioning and holding a semiconductor wafer (hereinafter referred to as a wafer), which is an example of a thin piece, and treating the surface, a spin coater, which applies photoresist onto the wafer, has generally been used. This is well known, and various proposals regarding spin coaters have been made as described below.

Proposals regarding spin coaters include, for example, a device and structure for chucking a wafer to a spin coater (Japanese Patent Laid-Open No. 61-14
(Refer to Publication No. 919 and Japanese Utility Model Publication No. 102238/1983)
, means for transporting wafers to a spin coater (Japanese Unexamined Patent Publication No. 63-30
8337, Japanese Utility Model Application No. 63-102238), a wafer take-out device (see Japanese Utility Model Application Publication No. 63-38323), and the like.

[Problem to be solved by the invention]

In a spin coater, the wafer is vacuum-adsorbed and held by a thin-piece adsorption/holding device, that is, a spin chuck, and the wafer is held at a relatively high speed (
The photoresist is spin-coded onto the wafer surface by rotating the wafer at a speed of 2,000 to 6,000 rpm.

However, the backside of the wafer is generally contaminated by processing equipment used in processes prior to the spin code, and the dust on the backside of the wafer due to this contamination is transferred to the spin chuck during vacuum suction, contaminating the backside of subsequent wafers. Become.

Recently, semiconductor integrated circuits have become more and more integrated into LSIs.
Due to the miniaturization and scale-up of wafers, it has become necessary to reduce the dust level, and it has become necessary to maintain the same level of cleanliness on the back side of the wafer as on the front side.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a thin piece suction/holding device that can be used in a spin coater or the like and does not contaminate the back surface of a wafer.

[Means to try to solve the problem]

In order to solve the above problems, the present invention provides a first suction port, a second suction port near the first suction port, and a first suction groove connected to the second suction port on the board surface. Suction a suction cup, a third suction port, and a clean band with a second suction groove connected to the third suction port on the top surface so that the first suction port and the third suction port are aligned. A thin piece suction/holding device is employed which suctions a clean pad onto a board and suctions and holds a thin piece such as a semiconductor wafer onto the clean band using a third suction port and a second suction groove of the clean band.

[Effect]

The present invention provides a suction cup in which a first suction port, a second suction port near the first suction port, and a first suction groove connected to the second suction port are provided on the board surface; A clean pad with a second suction groove on the top surface connected to the suction port and the third suction port is sucked onto the suction cup so that the first suction port and the third suction port are aligned. We have adopted a thin piece suction and holding device that suctions and holds thin pieces such as semiconductor wafers on the clean pad using the third suction port and second suction groove of the clean pad, and by replacing the clean band as appropriate, the back side of the wafer can be Contamination can be prevented.

[Embodiment] Hereinafter, a thin piece suction and holding device according to an embodiment of the present invention will be described with reference to the drawings, taking as an example a spin chuck for a spin coater that applies photoresist to a wafer.

FIG. 1 is a partial sectional view of a thin piece suction and holding device according to an embodiment of the present invention, and FIG. 2 is a perspective view of a spin chuck and a clean pad portion of the thin piece suction and holding device of the present invention.

In Figures 1 and 2, 1 is a spin chuck;
A rotating shaft 9 is attached to the lower surface, and a predetermined rotation speed is applied by a motor IO. 2 is a first suction port provided at the center of the spin chuck l; 3 is a second suction port provided near the first suction port 2; In this direction, suction grooves 4 are provided radially and concentrically with the first suction port 2, avoiding the first suction port 2. Reference numeral 5 denotes a first rotary vacuum seal provided on a rotary shaft 9, and the rotary shaft 9 freely rotates with respect to the first rotary vacuum seal 5, and performs vacuum sealing. 6 is also a second rotary vacuum seal, 7 is a first exhaust hole provided on the rotating shaft 9 and connects the first suction port 2 and the first rotary vacuum seal 5, and 8 is a second rotary vacuum seal. This is a second exhaust hole that connects the second suction port 4 and the second rotary vacuum seal 6. Further, the first rotary vacuum seal 5 and the second rotary vacuum seal 6 are provided with a first exhaust port 11 and a second exhaust port 12, respectively. The second exhaust port 12 is connected to a negative pressure generating device 16 such as a vacuum pump through a valve 14, and the second exhaust port 12 is connected to a second valve I5 via a hose 13.
It is connected to the negative pressure generating device 16 via.

As shown in FIG. 2, the Clean Bad 2I has a third suction port 22 for wafer suction in the center and a third suction port 22 on the top surface.
Second suction grooves 23 are provided radially toward the periphery and concentrically with the third suction port 22 .

The operation of the thin piece suction and holding device of the present invention is performed as described below.

First, the clean bud 21 is transported to the spin chuck l by a clean band transport device (not shown), and the first suction port 2 and the third suction port 22 are aligned as shown in FIG. placed in Then, the second valve 15 is opened, and the clean bud 2I is sucked onto the spin chuck I by the second suction port 3 and the first suction groove 4. Next, the wafer 25 is transported to the clean pad 21 by a wafer transport device (not shown) and placed on the clean pad 21. Then, the first valve 14 is opened and the wafer 25 is sucked onto the clean pad 21 by the third suction port 22 and the second suction groove 23 of the clean pad 21 .

After the wafer 25 is attracted onto the clean pad 21,
The motor 10 rotates at a predetermined rotational speed, and the wafer 25 is spin-coded with photoresist. When the spin code is completed, the motor 10 stops rotating, the first valve 14 is closed, and the spin coded wafer 25 can be removed from the clean pad 21. It is removed from above 21, transported and sent to the next process. Then, the new wafer 25 is transferred to the clean bud 2 by the wafer transfer device.
1, the photoresist is spin-coded by suction, the suction is released and removed, and the same operation is repeated.

Since the surface of the clean pad 21 becomes contaminated each time a wafer 25 is spin-coded, it is necessary to replace it depending on the degree of contamination. The clean pad 21 from which the wafer 25 has been removed can then be removed from the spin chuck 1 by closing the second valve 15, and is sent to the next process by the clean pad transfer device. Depending on the cleanliness requirements for the wafer 25, the clean pad 21 may need to be replaced every spin code or may be used several times, and the frequency of replacement is determined according to the cleanliness requirements. Also clean bad 2
As for the material of wafer 1, clean pad 21 is used to clean wafer 2.
In order to prevent contamination of the wafer 25, it is desirable that the material does not self-generate dust and has a certain degree of hardness so that it is less self-deformed when it adsorbs the wafer 25, and is made of a material similar to that of clean wipers used in semiconductor wafer processes. By using this material, the requirements for the material of the clean pad 21 can be satisfied.

The first suction groove 4 or the second suction groove 23 provided in the spin chuck l or the clean bud 21 of the thin piece suction holding device of the present invention extends from the second suction port 3 or the third suction port 22 to the periphery. Although the suction grooves are provided radially towards the direction of the suction grooves and concentrically with the first suction port 2 or the third suction port 22, the suction grooves are provided with only radial grooves without providing concentric grooves. The shape may be simplified.

Although the thin piece suction and holding device of the present invention has been described as a spin chuck for a spin coater that applies photoresist to a wafer, the thin piece that is suctioned and held by the thin piece suction and holding device of the present invention is not limited to a wafer, and may be a glass photo mask. It can be applied to most thin pieces, such as glass substrates for optical disks, ferrite substrates for thin film heads, etc., which do not like contamination of the suction surface, and if the suction power of the suction holding device is increased, it can be applied not only to thin pieces but also to plate-shaped pieces. It is possible to suction and hold precision parts. Further, the surface treatment apparatus is not limited to a photoresist coating apparatus, but can be applied to apparatuses for exposing, developing, cleaning, transporting, inspecting, measuring, etc. plate-shaped precision parts after adsorption.

〔Effect of the invention〕

The present invention provides a suction cup in which a first suction port, a second suction port near the first suction port, and a first suction groove connected to the second suction port are provided on the board surface; A clean pad with a second suction groove on the top surface connected to the suction port and the third suction port is sucked onto the suction cup so that the first suction port and the third suction port are aligned. We have adopted a thin piece suction and holding device that suctions and holds thin pieces such as semiconductor wafers on the clean pad using the third suction port and second suction groove of the clean pad, and by replacing the clean pad as appropriate, the back side of the wafer can be Since contamination can be prevented, the quality of LSI can be ensured and productivity can also be improved.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a thin piece suction and holding device according to an embodiment of the present invention, and FIG. 2 is a perspective view of a spin chuck and a clean pad portion of the thin piece suction and holding device of the present invention. In the figure, l... Spin chuck 2... First suction port 3... Second suction port 4... First suction groove 5... First rotary vacuum seal 6...
Second rotary vacuum seal 7...First exhaust hole 8...Second exhaust hole 9...Rotary shaft 10...Motor 11...No. First exhaust port 12, 13, 14, 15, 16, 21, 22, 23, 25, ・Second exhaust port, hose, first valve, second valve, negative pressure generator, clean pad, second Third suction port, second suction groove, wafer Fig. 1 Partial cross-sectional view of a thin piece suction and holding device according to an embodiment of the present invention 534-

Claims (1)

[Scope of Claims] A suction cup having a first suction port, a second suction port near the first suction port, and a first suction groove connected to the second suction port on a board surface; A clean pad having a third suction port and a second suction groove connected to the third suction port on the top surface is placed in the clean pad so that the positions of the first suction port and the third suction port match. A pad is placed on the suction cup, the clean pad is suctioned by the second suction port and the first suction groove on the suction cup, and the clean pad is suctioned by the third suction port and the second suction groove of the clean pad. A thin piece suction/holding device for suctioning and holding a thin piece such as a semiconductor wafer on the clean pad.