JPH09298181A - Substrate rear surface washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To wash the rear surface of a substrate and wash the edge of the substrate in a same station by a method wherein a spinner chuck is employed as a chuck which holds the substrate so as to be able to rotate and, further, a mechanism for washing the circumferential edge of the substrate is provided. SOLUTION: A spinner chuck 6 is made to ascend above a washing table 2 and, at that position, a substrate W is attracted and held by the spinner chuck 6 at the center of the rear surface. Then the spinner chuck 6 is made to descend a little and, when the level of the substrate W reaches a level a little lower than the level of the upper edge of a case 1, the descend of the spinner chuck 6 is temporarily stopped and, at that position, washing solution is spouted out of an edge washing nozzle 15 against the edge part of the substrate W while the substrate W is made to rotate by the spinner chuck 6 to remove excessive coating film formed along the circumferential edge of the upper surface of the substreate W. Then the spinner chuck 6 is further made to descend and the substrate W is transferred onto the washing table 2. In this state, a gap is formed between the upper surface of the spinner chuck 6 and the rear surface of the substrate W. Then, in that state, the washing solution is spouted out of a washing nozzle against the rear surface of the substrate W to wash the whole rear surface of the substrate w.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for cleaning the back surface of a semiconductor substrate or glass substrate.

[0002]

2. Description of the Related Art For example, in order to form a mask having a predetermined pattern by photolithography, there is a step of setting a substrate on a stage and exposing it. If dust or the like adheres to the back surface of the substrate in this exposure step, the levelness of the substrate cannot be obtained when it is set on the stage, and the exposure accuracy is reduced. Therefore, a technique for cleaning the back surface of the substrate is disclosed in Japanese Patent Laid-Open No. 3-30426.

On the other hand, application of a photosensitive resin by a spinner or edge cleaning for removing a coating film formed on the peripheral portion of the substrate is performed while rotating the substrate. In order to perform the work while rotating the substrate in this manner, conventionally, it is performed in a state where the center of the back surface of the substrate is suction-held by a spinner chuck.

[0004]

When the above-mentioned spin coating and edge cleaning and the back surface cleaning of the substrate are performed on the same stage, the back surface of the substrate is always sucked and held by a chuck in the conventional case. The part in contact with the chuck cannot be cleaned. If dust or the like adheres to the portion in contact with the chuck, it will be carried over to the exposure process as it is.

[0005]

SUMMARY OF THE INVENTION To solve the above problems, a substrate backside cleaning apparatus according to the present invention includes a cleaning table having a protrusion for supporting the lower surface of the substrate and having an opening formed in the center, and A chuck that can be retracted and supports the backside of the substrate at a position higher than the cleaning table in the ascending position, transfers the substrate on the cleaning table at the descending position, and then forms a gap between the backside of the substrate and the center of this chuck. A cleaning device was configured with a cleaning nozzle that was placed in the hole and that had a cleaning liquid ejection port formed at its upper end.

In the substrate backside cleaning apparatus according to the present invention, the chuck is a spinner chuck, the substrate is rotatable, and the substrate peripheral edge cleaning mechanism is provided, so that the backside cleaning and the edge cleaning are the same. It can be done at the station.

Further, by making the cleaning table rotatable, the cleaning liquid sprayed on the central portion of the back surface of the substrate can be scattered by the centrifugal force over the entire back surface of the substrate.

Further, the central hole of the chuck in which the cleaning nozzle is arranged serves as a cleaning liquid recovery passage, and the cleaning liquid passage in the cleaning nozzle also serves as a passage for the drying gas, so that the backside of the substrate after drying can be dried quickly. Can be done in time.

Further, by making the shape of the projection on the upper surface of the chuck, which comes into contact with the back surface of the substrate during adsorption, to be tapered, it is possible to prevent the cleaning liquid from staying on the side surface of the projection and to prevent the cleaning liquid from transferring from the projection to the back surface of the substrate.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a plan view of a substrate backside cleaning apparatus according to the present invention, FIGS. 2A to 2C are vertical cross-sectional views illustrating the operation of the substrate backside cleaning apparatus according to the present invention, and FIG. FIG. 4 is a plan view of the chuck, and FIG. 4 is a vertical sectional view of the chuck.

The substrate backside cleaning device includes a case 1. The case 1 is open at the top so that the substrate W can be moved in and out, and the cleaning table 2 is arranged inside. The cleaning table 2 has an opening 3 formed in the center, a projection 4 for supporting the back surface of the substrate W at a point on the upper surface, and the cleaning table 2 is rotated around the periphery of the cleaning table outside the projection 4. A stopper 5 is provided to prevent the substrate W from coming off when it is opened.

Further, a spinner chuck 6 is disposed so as to be retractable from the opening 3 of the cleaning table 2. This spinner chuck 6 is rotatable and vertically movable,
As shown in FIG. 2A, the back surface of the substrate W is supported at a position higher than the cleaning table 2 in the raised position, and the substrate W is placed on the cleaning table 2 in the lowered position as shown in FIG. 2C. A gap is formed between the transferred substrate W and the back surface of the substrate W.

Further, a double pipe 8 is attached to a central hole 7 formed in the spinner chuck 6 so that a concentric space 13 is provided so as to be inscribed in the central hole 7. It communicates with the vacuum suction hole 14 on the upper surface and is connected to the suction device at the bottom. On the upper surface of the spinner chuck 6, the substrate W
Is formed with a tapered protrusion 9 that contacts the back surface of the. Here, by making the protrusion 9 tapered, the cleaning liquid is less likely to stay on the side surface of the protrusion 9, and when the substrate W is placed, the cleaning liquid is transferred from the upper surface of the spinner chuck 6 to the rear surface of the substrate W. Never. In the illustrated example, the pipe 8 is attached, but instead of attaching the pipe, the same can be done by extending the cylindrical portion at the center of the spinner chuck 6 downward and attaching the single pipe inside.

A cleaning nozzle 10 is provided inside the pipe 8.
Has been arranged. The cleaning nozzle 10 has a protrusion 9 at its upper end.
It is designed to be lower than. Further, the upper end of the cleaning nozzle 10 is provided with a non-circular cleaning liquid ejection port 11 that is narrowed and opens upward, and a circular cleaning liquid ejection port 12 that opens obliquely upward. Cleaning liquid spout 1 having such a structure
By including 1 and 12, the cleaning liquid can be sprayed onto the back surface of the substrate W in a state of being spread to some extent, and cleaning can be efficiently performed.

By the way, the inside of the pipe 8 and the cleaning nozzle 10
The passage 7 between the outside and the outside serves as a discharge passage for the cleaning liquid, and the inside passage of the cleaning nozzle 10 serves as a passage for the cleaning liquid, as well as a jet passage for the cleaning liquid, and a passage for drying air after the cleaning is completed. The passage between the inside of the pipe 8 and the outside of the washing nozzle 10 can be used as a passage for the drying air. However, in this case, the washing liquid comes out of the nozzle as the drying air is blown out. Since it is possible that it adheres to the back surface of the substrate and delays drying,
It is advantageous for the inner passage of the washing nozzle 10 to be the passage for the drying air.

In order to clean the substrate W as described above, first, as shown in FIG. 2A, at the position where the spinner chuck 6 is raised with respect to the cleaning table 2, the center of the back surface of the substrate W is sucked and held, Next, the spinner chuck 6 is slightly lowered, and once the substrate W is lower than the upper end of the case 1, the spinner chuck 6 is stopped from descending. The cleaning liquid is discharged toward the edge portion of the substrate to remove the excess coating film formed on the peripheral portion of the upper surface of the substrate W.

Next, when the edge cleaning is completed, the spinner chuck 6 is further lowered to transfer the substrate W onto the cleaning table 2. In this state, spinner chuck 6
A gap is formed between the upper surface and the back surface of the substrate W as shown in FIG. Then, in this state, the cleaning liquid is discharged from the cleaning nozzle 10 to the back surface of the substrate W to clean the entire back surface of the substrate W.

After that, by switching the cleaning liquid passage to the drying air passage by operating a valve or the like, the drying air is blown from the cleaning nozzle 10 toward the rear surface of the substrate W,
The back surface of the substrate W is dried in a short time.

[0019]

As described above, according to the present invention, a cleaning table having a projection for supporting the lower surface of the substrate and having an opening formed in the center, and a cleaning table which can be retracted into and raised from the opening and which is higher than the cleaning table are provided. A chuck that supports the backside of the substrate at a high position and transfers the substrate onto the cleaning table at a lowered position to form a gap between the backside of the substrate and a chuck that is placed in the center hole of this chuck and has a cleaning solution sprayed on the upper end. Since the backside cleaning device for the substrate is configured by the cleaning nozzle having the outlet, it is possible to clean the entire backside of the substrate while having a chuck for sucking and holding the backside of the substrate, and it is possible to improve the exposure accuracy.

Further, by using the chuck as a spinner chuck to rotate the substrate and having a cleaning mechanism for the peripheral portion of the substrate, the back surface cleaning and the edge cleaning can be performed at the same station, which is efficient. is there.

Further, by making the cleaning table rotatable, the cleaning liquid sprayed on the back surface of the substrate can be scattered by the centrifugal force, and further, the central hole of the chuck in which the cleaning nozzle is arranged serves as the cleaning liquid recovery passage, By making the cleaning liquid passage in the cleaning nozzle also serve as the passage for the drying gas, the back surface of the substrate after cleaning can be dried in a short time.

Further, by making the shape of the protrusion on the upper surface of the chuck which comes into contact with the back surface of the substrate at the time of adsorption to be tapered, the cleaning liquid can be prevented from staying on the side surface of the protrusion, and the cleaning liquid remaining on the upper surface of the chuck during transportation or the like. Will not adhere to the back surface of the substrate.

[Brief description of drawings]

FIG. 1 is a plan view of a substrate backside cleaning apparatus according to the present invention.

2A to 2C are vertical sectional views for explaining the operation of the substrate back surface cleaning apparatus according to the present invention.

FIG. 3 is a plan view of the chuck.

FIG. 4 is a vertical sectional view of a chuck.

[Explanation of symbols]

1 ... Case, 2 ... Washing table, 3 ... Washing table opening, 4 ... Protrusion, 5 ... Stopper, 6 ... Spinner chuck, 7 ... Spinner chuck center hole, 9 ... Projection, 10
... washing nozzles, 11, 12 ... washing liquid jets, 15 ... edge washing nozzles, W ... substrate.

Claims (5)

[Claims] 1. A cleaning table having a projection for supporting the lower surface of the substrate and having an opening formed in the center, and a back surface of the substrate supported at a position higher than the cleaning table at a rising position which can be retracted and retracted, and descends. After the substrate is transferred onto the cleaning table at the position, a chuck that forms a gap between the substrate and the back surface of the substrate, a cleaning nozzle that is arranged in the center hole of the chuck, and has a cleaning liquid ejection port formed at the upper end thereof. An apparatus for cleaning a back surface of a substrate, comprising: 2. The backside cleaning apparatus for a substrate according to claim 1, wherein the cleaning apparatus includes a cleaning mechanism for a peripheral portion of the substrate, and the chuck is a spinner chuck capable of rotating the substrate. Backside cleaning device for the substrate. 3. The backside cleaning apparatus for a substrate according to claim 1, wherein the cleaning table is rotatable while the substrate is placed on the cleaning table. 4. The backside cleaning apparatus for a substrate according to claim 1, wherein the central hole of the chuck is a cleaning liquid recovery passage,
Further, the cleaning liquid passage in the cleaning nozzle also serves as a passage for the drying gas, which is a backside cleaning device for a substrate. 5. The backside cleaning apparatus for a substrate according to claim 1, wherein the chuck upper surface is formed with a tapered protrusion that comes into contact with the backside of the substrate during adsorption.