JPH04199655A - Vacuum piping of vacuum-chuck wafer holding device - Google Patents

Abstract

PURPOSE:To make a pressure difference between a suction pressure and an atmospheric pressure large enough to hold a wafer by sucking by a method wherein vacuum lines are branched off from a vacuum suction line, and throttling valves are provided between the distributor of vacuum-chuck wafer holding devices and valves. CONSTITUTION:The suction line 3 of a pump 1 is connected to a distributor 2, where the line 3 is branched off into four vacuum lines 15, 25, 35, and 45 which communicate with transfer chucks 11, 21, and 31 and a wafer chuck 41 respectively, and throttle valves 14, 24, 34, and 44 are provided to the vacuum lines 15, 25, 35, and 45. Therefore, when a vacuum-chuck wafer holding device holds a wafer by sucking, gas of high pressure can be restrained from flowing into the wafer holding device concerned from other vacuum-chuck wafer holding devices by the throttle valve. By this setup, a pressure difference between a suction pressure and an atmospheric pressure can be set large enough constantly to hold a wafer by sucking, so that a wafer transferring action can be safely carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vacuum piping that connects a vacuum suction type substrate holding device and a suction source for vacuum suction used in a semiconductor exposure apparatus.

[Prior Art] FIG. 3 shows an example of a conventional substrate holding device that holds a wafer using a vacuum suction method.

As shown in FIG. 3, a transport chuck 51 that sucks and holds a wafer 61 is connected to a Z stage 54 that moves the transport chuck 51 in two directions (directions perpendicular to the plane of the paper) and in an X direction (
It is attached to a substrate transport device consisting of an The wafer 61 is transferred to and from the wafer chuck 52, and the substrate transfer device, the transfer chuck 51, and the wafer chuck 52 are housed in a vacuum chamber 62 in a reduced pressure atmosphere.

The transport chuck 51 has a vacuum line 55 and a valve 57.
The wafer chuck 52 is connected to a pump 60 disposed outside the vacuum chamber 62 via a distributor 59 and a vacuum line 56 , a valve 5
8 and a pump 60 via a distributor 59, and is connected to a pump 60 via a transfer chuck 51 and a wafer chuck.
The wafer 61 is attached and detached from both the hook 52 and the wafer 61 by a suction operation by the pump 60. The valves 57 and 58 are both three-way valves, and are used to communicate the transfer chuck 51 and the pump 60, the wafer chuck 52 and the pump 60 (a), and the atmosphere (a) in the transfer chuck 51 and the vacuum chamber 62, respectively.
(hereinafter referred to as chamber atmosphere), and the state (b) in which the wafer chuck 52 and the chamber atmosphere are communicated.

Here, the case where the wafer 61 is transferred from the transport chuck 51 to the wafer chuck 52 will be described.

First, in order to suck the wafer 61 by the transfer chuck 51, the valve 57 is set to the (a) state, that is, the transfer chuck 51 communicates with the pump 60, and the pump 60 is operated, and the transfer chuck 51 holds the wafer 61 by suction. do. At this time, the valve 58 is in the state (b), the wafer chuck 52 is in communication with the chamber atmosphere, and the pressure in the vacuum line 56 is the same as the chamber atmosphere pressure.

Next, the X stage 53 is driven to move the wafer 61 held by the transport chuck 51 onto the chuck surface of the wafer chuck 52. Thereafter, the Z stage 54 is driven to move the transport chuck to a position where the wafer 61 contacts the chuck surface of the wafer chuck 52. Then, when the valve 58 is switched to the state (a) with the wafer 61 in contact with the chuck surface of the wafer chuck 52,
The wafer 61 is attracted by the wafer chuck 52.

At this time, the wafer 61 is attracted to the transport chuck 51 as well as the wafer chuck 52, so the valve 57 is switched to the state (b) to communicate the transport chuck 51 with the chamber atmosphere, and the transport chuck 51
The suction force of 1 is eliminated, and the wafer 61 is removed from the transport chuck 51.
to leave. When the wafer 61 is attracted only by the wafer chuck 52, the two stages 54 and
The stages 53 are sequentially driven to return the transport chuck 51 to its original position, and the transfer of the wafer 61 to the sea urchin hachi and the tsuk 52 is completed.

When the exposure of the wafer 61 held by the wafer chuck 52 is completed, the X stage and the second stage 54 are driven again to move the transport chuck 51 to the position of the wafer chuck 52, and the wafer 61 is moved from the wafer chuck 52. Transfer to the transport chuck 51 is performed. In this case, from the above-described transport chuck 51 to the wafer chuck 5
The wafer 61 can be transferred from the wafer chuck 52 to the transport chuck 51 by performing the reverse operation to the transfer to the transfer chuck 51.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, when transferring a substrate between substrate holding devices, for example, the above-mentioned transfer chuck 5
When transferring the wafer 61 from the wafer chuck 52 to the wafer chuck 52, the valve 58
By switching the valve 58, the wafer chuck 52 is brought into communication with the pump 60, but the vacuum line 56 passing through the wafer chuck 52 had previously been at the same pressure as the chamber atmosphere, and when the valve 58 was switched, the pressure The gas having a high temperature flows into the distributor 59, and the pressure in the distributor 59 becomes high. As a result, the pressure of the transport chuck 51 increases, and the suction force weakens. As a result, if the differential pressure between the transport chuck 51 and the chamber atmosphere becomes insufficient, there is a problem that the substrate may fall.

The present invention has been made in view of the problems that exist in the conventional technology, and is based on the pressure difference between the suction pressure and the atmospheric pressure when the vacuum suction substrate holding device is suctioning and holding the substrate. It is an object of the present invention to provide vacuum piping for a vacuum suction substrate holding device that can be maintained sufficiently for suction and holding.

[Means for Solving the Problems] The present invention provides a suction source for vacuum suction that is distributed by a distributor from a suction line of a suction source and connected to each of a plurality of vacuum suction substrate holding devices, and that is connected to each of the vacuum suction substrate holding devices. In a vacuum piping in which a valve of a vacuum suction substrate holding device for attaching and detaching a substrate is interposed, a throttle valve is arranged between the distributor and the valve, and a throttle valve is arranged between the valve of the vacuum suction substrate holding device and the valve of the vacuum suction substrate holding device. A vacuum sensor was installed to detect the suction pressure of the vacuum suction substrate holding device.

[Function] The vacuum piping of the vacuum suction substrate holding device of the present invention throttles the inflow of high pressure gas from other vacuum suction substrate holding devices when the vacuum suction substrate holding device is holding a substrate by suction. It can be suppressed by a valve. In addition, this throttle valve is
It is placed between the valve and the distributor, so in order to remove the substrate from the vacuum suction substrate holding device,
When eliminating the difference between the suction pressure of the vacuum suction substrate holding device and the atmospheric pressure, gas can be made to flow without using a throttle valve.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the vacuum piping of the vacuum suction substrate holding device of the present invention.

In this embodiment, four vacuum suction substrate holding devices, ie, transport chucks 11, 21, 31, and wafer chuck 41, are housed in a vacuum chamber (not shown). During the suction operation of the pump 1 disposed outside the vacuum chamber, the transfer chucks 11, 21.31 and the wafer chuck 41 are connected to a vacuum line 15, which communicates with the transfer chucks 11, 21, 31 and the wafer chuck 41, respectively. By opening and closing the valves 13, 23, 33.43 disposed on the conveyance chucks 11.21.25.35 and 45.
31 and wafer chuck 41, and transport and transfer the substrates between them.

The suction line 3 of the pump 1 is connected to a distributor 2 in which it is distributed into four vacuum lines 15.25, 35.45 leading to the transport chuck 11.21.31 and the wafer chuck 41. . On each vacuum line 15, 25, 35.45, in order from the distributor 2 side, there are throttle valves 14.24, 34.44 and valves 13.23.33.
43 valves are arranged, and each valve 13.23,
33.43 and each transfer chuck 11.21.31 and wafer chuck 41, there are vacuum sensors 12, 22, 32.42 that detect the suction pressure of each substrate holding device.
are arranged respectively. In addition, each valve 13, 23
゜33.43 are all three-way valves, and are used for each transfer chuck 11, 21.31 and wafer chuck 41, respectively.
The valves 1 are switched between the state (a) in which the valves are opened to the pump 1 and the state (b) in which the valves are opened to the atmospheric pressure in the vacuum chamber.
By setting 3.23, 33.43 to state (a), each transport chuck 11, 21, 31 and wafer chuck 4
1 is capable of adsorbing a substrate, and in state (b), the adsorption of the substrate is released and the substrate can be detached.

The throttle valves 14.24, 34.44 are connected to the valve 13.
．． This is provided in order to reduce the pressure increase in other transfer chucks or wafer chucks when any one of the chucks 23, 33, and 43 is opened or closed.

As for the position where the throttle valves 14, 24, 34, 44 are arranged, the vacuum sensors 12, 22, 32,
．． In the vacuum lines 15, 25, 35.45, which are respectively provided with a valve 13.42 and a valve 13.33.43, as shown in FIG.
1° 31 and between the wafer chuck 41 and the vacuum sensor 12, 22, 32.42 (position), the vacuum sensor 12, 22, 32.42 and the valve 13.23.3
3.43 (position ■), valve 13, 23.33.
43 and the distributor 2 (position ■). In the present invention, each throttle valve 14, 24, 34.4
4 is arranged between the valve 13.23.33.43 and the distributor 2 (position ■).

Here, a case will be described in which throttle valves are arranged at the three locations mentioned above.

First, in the case of position (3), since there is a pressure drop part due to the throttle valve between each chuck and the vacuum sensor, the vacuum sensor does not indicate the vacuum pressure of each chuck, but the vacuum level on the pump side from the throttle valve. This indicates the pressure at the high point. In this case, there is a high possibility that the vacuum pressure on the chuck surface has not reached the pressure required to attract the substrate and the differential pressure with the atmospheric pressure is insufficient, and the substrate may fall.

In addition, when placed in position ■, the vacuum sensor is closer to the chuck than the throttle valve, so it either indicates the vacuum pressure of each chuck, or it can be used to switch the valve to release the substrate from the chuck's suction state. When opening to pressure, since the throttle valve is located closer to the chuck than the valve, it takes time to reach atmospheric pressure, which causes throughput to drop. When placed in position ■, the vacuum sensor is
Since it is on the chuck side compared to the throttle valve, it indicates the vacuum pressure of each chuck.Furthermore, even when the valve is opened, since it is on the valve or each chuck side, the pressure on each chuck surface quickly changes to the atmosphere. The pressure is reached, and the adverse effects caused by the above-mentioned positions (1) and (3) are eliminated and the pressure is optimized.

Next, the board transfer operation according to this embodiment will be explained.

In this embodiment, three transport chucks 11, 21° 31 and a wafer chuck 41 are provided, but since the transfer operation of the substrate between each chuck can be performed in the same way, here, the transport chuck 11 to the transport chuck 21 is provided. This section explains the transfer to.

First, the pump 1 is put into a suction operation state, and the transport chuck 11 is
The valve 13 on the vacuum line 15 communicating with is set to the state (a). In this state, the transport chuck 11 is passed through the pump 1 via the vacuum line 15, and a suction force is generated, so that the wafer 61 is suctioned and held. At this time, the other valves 23, 33, and 43 are in the (b) state, and the transfer chuck 21.31 and the wafer chuck 4 are
1 is equal to the atmospheric pressure inside the vacuum chamber.

When transferring the substrate from the transfer chuck 11 to the transfer chuck 21 in this state, the valve 23 disposed on the vacuum line 25 communicating with the transfer chuck 21 is set to the state (a) to allow the transfer chuck 21 and the pump 1 to communicate. This causes the transport chuck 21 to generate suction force. At this time, since the pressure in the transfer chuck 21 was equivalent to the atmosphere inside the vacuum chamber, high pressure gas was transferred from the transfer chuck 21 to the vacuum line 2.
5 and moves to the distributor 2, and this high-pressure gas increases the suction pressure of the transport chuck 21 that holds the substrate by suction, weakening the suction force and causing the held substrate to fall. There is a possibility that the distributor 2
The throttle valve 14 disposed between the valve 13 and the valve 13 can reduce the influence of high-pressure gas on the transport chuck 21 side.

In this case, if the conductance of the throttle valve 14 is made smaller, the negative effect can be made smaller;
It is necessary to take into consideration the reduction in throughput required for suctioning and holding the substrate.

Next, the substrate being sucked and held by the transfer chuck 11 is moved onto the suction surface of the transfer chuck 21, so that the substrate is suctioned by the two holding devices, the transfer chuck 11 and the transfer chuck 21.

Next, in order to hold the substrate only by the transport chuck 21, the valve 13 is set to the state (b), and the transport chuck 11
Eliminate the pressure difference between the pressure on the adsorption surface and the atmospheric pressure in the vacuum chamber. At this time, if the throttle valve 14 is placed closer to the transfer chuck 11 than the valve 13 on the vacuum line 15 that communicates with the transfer chuck 11, it may take a long time for the differential pressure to disappear, resulting in poor throughput. In the case of this embodiment, there is no problem because the valve 13 is disposed closer to the pump 1 than the valve 13 as described above.

In this way, by eliminating the differential pressure between the suction surface of the transport chuck 11 and the chamber atmosphere, the suction of the transport chuck 11 is eliminated, and the substrate is held by suction only by the transport chuck 21, and the substrate is transferred. It turns out.

[Effects of the Invention] Since the present invention is configured as explained above,
Produces an effect similar to oneself.

(1) When a vacuum suction substrate holding device is holding a substrate by suction, it is possible to suppress the flow of high pressure gas from other vacuum suction substrate holding devices, so the suction pressure of the vacuum suction substrate holding device can be reduced. The pressure difference between the atmospheric pressure and the atmospheric pressure can always be made sufficient for suction and holding of the substrate. Operations such as delivery can be performed reliably and safely.

(2) The throttle valve is arranged between the valve and the distributor on the vacuum piping, and operates the valve to increase the suction pressure of the vacuum suction substrate holding device in order to detach the substrate from the vacuum suction substrate holding device. When the pressure is made equal to the atmospheric pressure, the gas flows without passing through the navigation valve, so the throughput can be improved.

(3) As described in claim 2, by disposing a vacuum sensor between the valve and the vacuum suction substrate holding device, the suction pressure of the vacuum suction surface can be accurately detected. It becomes possible to check the quality of the adsorption state of the substrate by the vacuum adsorption substrate holding device, and the reliability and safety of the substrate conveyance and delivery operations are improved, and the reliability of the substrate holding device is improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the vacuum piping of the vacuum suction substrate holding device of the present invention, FIG. 2 is a diagram showing the arrangement position of the throttle valve, and FIG. 3 is a diagram showing the vacuum piping of the conventional vacuum suction substrate holding device. It is a figure showing an example of piping. 1--Pump, 2--Distributor, 3--Suction line, 11.21.31--Transportation chuck, 12.22.3
2.42--Vacuum sensor, 13.23.33.4
3--Valve, 14.24, 34.44--One throttle valve, 15.25.35.45--One vacuum line, 41--Wafer chuck. Patent applicant Canon Co., Ltd.

Claims (2)

[Claims] 1. Distributed by a distributor from a suction line of a suction source for vacuum suction and connected to each of a plurality of vacuum suction substrate holding devices, with a valve of the vacuum suction substrate holding device intervening for attaching and detaching the substrate to each of the vacuum suction substrate holding devices. A vacuum piping for a vacuum suction substrate holding device, characterized in that a throttle valve is arranged between the distributor and the valve. 2. 2. The vacuum piping of the vacuum suction substrate holding device according to claim 1, further comprising a vacuum sensor disposed between the vacuum suction substrate holding device and the valve for detecting the suction pressure of the vacuum suction substrate holding device. .