Wet processing system, wet processing method and storage medium

• US 7,752,999 B2
• Filed: 10/24/2007
• Issued: 07/13/2010
• Est. Priority Date: 10/25/2006
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Kinoshita, Michio, Nakamichi, Kousuke, Nakashima, Tsunenaga
• Primary Examiner(s): Lamb; Brenda A
• Application Number:
  US11/877,991
• Publication Number:
  US 20080100809A1
• Time in Patent Office: 993 Days
• Field of Search: 118/712, 118/707, 118/679, 118/699, 118/682, 118/684, 118695-698, 118/52, 118/64, 118/302, 118/315
• US Class Current: 118/712
• CPC Class Codes: H01L 21/6715 Apparatus for applying a liquid, a resin, an ink or the like H01L21/67126 takes precedence
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring

Abstract

A wet processing system detects a globule of a process solution in a drippy or dripping state from the tip of any one of process solution pouring nozzles being moved to a pouring position for pouring the process solution onto a substrate by obtaining image data on the process solution pouring nozzle, and takes proper measures to prevent the process solution from dripping. A wet processing system 1 pours a process solution, such as a resist solution, through one of process solution pouring nozzles 10 onto a surface of a substrate, such as a wafer W, held substantially horizontally by a substrate holding device 41 surrounded by a cup 5 to process the surface by a wet process. A nozzle carrying mechanism 10a carries the process solution pouring nozzles 10 between a home position on a nozzle bath 14 and a pouring position above the substrate held by the substrate holding device 41. An optical image of the tips of the process solution pouring nozzles 10 is obtained by an image pickup means, such as a camera 17. Predetermined measures are taken according to the level of a drippy or dripping state of a globule of the process solution.

Claims

1. A wet processing system for pouring a process solution supplied by a process solution supply unit through a process solution pouring nozzle onto a surface of a substrate held substantially horizontally by a substrate holding device surrounded by a cup to process the surface by a wet process, said wet processing system comprising:

a nozzle bath for holding process solution pouring nozzles thereon at a home position;

a nozzle carrying mechanism for carrying the process solution pouring nozzles between the home position on the nozzle bath and a position above the substrate held by the substrate holding device;

an image pickup means for taking a picture of tips of the process solution pouring nozzles while the process solution pouring nozzles are being carried by the nozzle carrying mechanism;

a decision means for deciding whether or not a globule of the process solution is in a drippy state, in which the globule of the process solution protrudes down from a tip of a process solution pouring nozzle prior to being discharged, and whether or not the globule of the process solution is in a dripping state, in which the process solution has dripped off a tip of a process solution pouring nozzle, on the basis of image data provided by the image pickup means; and

a control means for making the process solution supply unit and/or the nozzle carrying mechanism execute a drip preventing operation to cope with a drippy state where a globule of the process solution is drippy or a dripping state where a globule of the process solution is dripping when the decision means decides that the globule of the process solution is in the drippy or the dripping state.

2. The wet processing system according to claim 1, wherein the nozzle carrying mechanism carries the plural process solution pouring nozzles simultaneously, and the decision means identifies each of the process solution pouring nozzles by image data provided by the image pickup means, and decides whether or not the process solution is in the drippy or dripping state on the basis of the image data.

3. The wet processing system according to claim 1, wherein the control means stops making the process solution supply unit and/or the nozzle carrying mechanism execute the drip preventing operation on the basis of the image data on the process solution pouring nozzle in a process solution pouring operation.

4. The wet processing system according to claim 1, wherein the image pickup means is combined with the nozzle carrying mechanism.

5. The wet processing system according to claim 1, wherein the image pickup means is a camera provided with an image sensor.

6. The wet processing system according to claim 1 further comprising a light source for illuminating the process solution pouring nozzle when the image pickup means obtains an image of the process solution pouring nozzle.

7. The wet processing system according to claim 1 further comprising a first storage means storing reference information including a criterion for deciding whether or not a globule of the process solution is in the drippy state and determines the size of a globule of the process solution formed at the tip of the process solution pouring nozzle on the basis of results of comparison of the image data and the reference information.

8. The wet processing system according to claim 7, wherein the reference information and the image data are those relating to a curvature or a sectional area of the globule of the process solution in the drippy state.

9. The wet processing system according to claim 1 further comprising a second storage means for storing image data obtained in the past;

wherein the decision means compares the past image data obtained at a past time a predetermined period ago and the present image data obtained at the present, and decides that a globule of the process solution has dripped when the size of a globule represented by the present image data is smaller than that of a globule represented by the past image data.

10. The wet processing system according to claim 1, wherein the decision means decides that a globule of the process solution has dripped when image data obtained at a position in an image pickup area at a predetermined distance below the tips of the process solution pouring nozzles indicates a part or the whole of a globule of the process solution.

11. The wet processing system according to claim 1, wherein the process solution pouring nozzles are made of a transparent material, and the decision means further decide whether or not bubbles are found in the process solution in an end part of each of the process solution pouring nozzles on the basis of the image data provided by the image pickup means.

12. The wet processing system according to claim 1, wherein the decision means calculates an amount of the process solution poured through each of the process solution pouring nozzles on the basis of a thickness of a stream of the process solution poured through the process solution pouring nozzle and time for which the process solution is poured represented by the image data.

13. The wet processing system according to claim 1 further comprising a suck back valve for retracting the process solution into an end part of each of the process solution pouring nozzles, and a coating operation control means that gives a process solution supply start signal to the process solution supply unit;

wherein the decision means calculates a pouring speed at which the process solution is poured on the basis of a distance by which the process solution has been retracted behind the tip of the process solution pouring nozzle by the agency of the suck back valve, and time between a time the coating operation control means provided the process solution supply start signal and a time image data representing the process solution at the tip of the process solution pouring nozzle is obtained.

14. The wet processing system according to claim 1, wherein the drip preventing operation includes the steps of returning the process solution pouring nozzles back to the nozzle bath and discharging the process solution through each of the process solution pouring nozzles into the nozzle bath.

15. The wet processing system according to claim 14, wherein the control means execute the drip preventing operation after completing pouring the process solution onto the substrate held by the substrate holding device when an image of a globule of the process solution is obtained during a nozzle carrying operation for carrying the process solution pouring nozzles to the position for pouring the process solution to pour the process solution onto the surface of the substrate.

16. The wet processing system according to claim 14, wherein the control means execute the drip preventing operation before starting pouring the process solution onto a substrate held by the substrate holding device when an image of a globule of the process solution is obtained during a nozzle carrying operation for carrying the process solution pouring nozzles to the position for pouring the process solution to pour the process solution onto the surface of the substrate.

17. The wet processing system according to claim 14, wherein plural wet processing devices each having the cup and the substrate holding device are arranged laterally in a line in a common box, and the plural wet processing devices share the process solution pouring nozzles and the nozzle carrying mechanism, and

intermediate baths are disposed each between the adjacent ones of the wet processing devices arranged in the box to move the process solution pouring nozzles thereto and to make the process solution pouring nozzles execute the drip preventing operation thereon.

18. The wet processing system according to claim 1, wherein the drip preventing operation stops carrying a succeeding substrate into the wet processing system.

19. The wet processing system according to claim 1 further comprising a warning means for giving a warning to the effect that the globule of the process solution is in the drippy or dripping state when it is decided by the decision means that the globule of the process solution is in the drippy or dripping state.

20. The wet processing system according to claim 19 further comprising counters respectively combined with the process solution pouring nozzles to count frequencies of globules of the process solution in the drippy state occurred in the process solution pouring nozzles;

wherein the warning means gives a warning to the effect that the process solution is drippy or dripping when the frequency of drippy or dripping globules occurred in any one of the process solution pouring nozzles is greater than a predetermined frequency.

21. The wet processing system according to claim 1, wherein plural wet processing devices each having the cup and the substrate holding device are arranged laterally in a line in a common box, and the plural wet processing devices share the process solution pouring nozzles and the nozzle carrying mechanism.