METHOD AND APPARATUS FOR MONITORING AND CONTROL OF SUCK BACK LEVEL IN A PHOTORESIST DISPENSE SYSTEM

• US 20080035666A1
• Filed: 03/26/2007
• Published: 02/14/2008
• Est. Priority Date: 08/11/2006
• Status: Active Grant

• Current Assignee: Screen Semiconductor Solutions Co., Ltd. (SCREEN Holdings Co., Ltd.)
• Original Assignee: SOKUDO Co., Ltd. (SCREEN Holdings Co., Ltd.)
• Inventors: Porras, Erica R., Ramanan, Natarajan
• Granted Patent: US 7,935,948 B2
• Time in Patent Office: Days
• US Class Current: 222/1
• 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

An apparatus for monitoring a position of a semiconductor process fluid interface in a dispense nozzle includes an extended optical source adapted to provide an optical beam propagating along an optical path. The optical beam is characterized by a path width measured in a first direction aligned with a dispense direction. The apparatus also includes an optical detector coupled to the optical path and adapted to detect at least a portion of the optical beam and a dispense nozzle disposed along the optical path at a location between the extended optical source and the optical detector. The apparatus further includes a nozzle positioning member coupled to the dispense nozzle and adapted to translate the dispense nozzle in the first direction.

Claims

1. An apparatus for monitoring a position of a semiconductor process fluid interface in a dispense nozzle, the apparatus comprising:

an extended optical source adapted to provide an optical beam propagating along an optical path, wherein the optical beam is characterized by a path width measured in a first direction aligned with a dispense direction;

an optical detector coupled to the optical path and adapted to detect at least a portion of the optical beam;

a dispense nozzle disposed along the optical path at a location between the extended optical source and the optical detector; and

a nozzle positioning member coupled to the dispense nozzle and adapted to translate the dispense nozzle in the first direction.

2. The apparatus of claim 1 wherein the nozzle positioning member is further adapted to translate the dispense nozzle in a second direction and a third direction, wherein the second direction and the third direction are orthogonal to the first direction.

3. The apparatus of claim 1 wherein the nozzle positioning member is adapted to translate the dispense nozzle such that a first portion of the optical beam impinges on the dispense nozzle and a second portion of the optical beam is free from impingement on the dispense nozzle.

4. The apparatus of claim 1 wherein the dispense nozzle is characterized by a proximal portion adjacent a proximal end of the dispense nozzle and a distal portion adjacent a distal end of the dispense nozzle.

5. The apparatus of claim 4 wherein the nozzle positioning member is adapted to translate the dispense nozzle such that the proximal portion of the dispense nozzle is disposed along the optical path, the distal portion of the dispense nozzle is disposed along the optical path, and a portion of the optical beam propagates to the optical detector without impingement on the dispense nozzle.

6. The apparatus of claim 4 wherein the nozzle positioning member is adapted to translate the dispense nozzle such that the proximal portion of the dispense nozzle extends a first distance into the optical path, the distal portion of the dispense nozzle extends a second distance into the optical path, wherein a sum of the first distance and the second distance being less than the path width.

7. The apparatus of claim 1 wherein the extended optical source comprises a linear array of optical emitters.

8. The apparatus of claim 1 wherein the optical detector comprises a linear array of optical detectors.

9. The apparatus of claim 8 wherein the linear array of optical detectors is characterized by a dimension measured along the linear array substantially equal to the path width of the optical beam.

10. A method of providing a predetermined fluid level of a dispense fluid in a dispense nozzle of a semiconductor process module, the method comprising:

a) providing an optical beam propagating along an optical path, wherein the optical beam is provided by an optical source;

b) positioning the dispense nozzle along the optical path at a first location between the optical source and an optical detector coupled to the optical path, the first location being characterized by a first position measured along a first direction aligned with a dispense direction such that the optical beam impinges on the dispense nozzle;

c) establishing a first fluid level recessed a first distance from a tip of the dispense nozzle;

d) measuring a first optical signal utilizing the optical detector;

e) establishing a second fluid level recessed a second distance from the tip of the dispense nozzle, wherein the second distance is greater than the first distance;

f) measuring a second optical signal utilizing the optical detector; and

g) repeating steps (e) and (f) until a meniscus of the dispense fluid is associated with the predetermined fluid level.

11. The method of claim 10 wherein establishing the first fluid level comprises operating a valve coupled to the dispense nozzle.

12. The method of claim 10 wherein positioning the dispense nozzle comprises aligning the dispense nozzle such that a first portion of the optical beam impinges on the dispense nozzle and a second portion of the optical beam is free from impingement on the dispense nozzle.

13. The method of claim 10 wherein the optical source comprises a linear array of optical emitters.

14. A system for controlling a semiconductor process fluid dispense operation, the system comprising:

an extended optical source adapted to provide an optical beam propagating along an optical path, wherein the optical beam is characterized by a path width measured in a first direction aligned with a dispense direction;

an optical detector coupled to the optical path and adapted to detect at least a portion of the optical beam and to provide an optical signal;

a dispense nozzle disposed along the optical path at a location between the extended optical source and the optical detector, wherein the dispense nozzle is adapted to support the semiconductor process fluid;

a suck back valve coupled to the dispense nozzle and adapted to modify a position of a semiconductor process fluid interface in the dispense nozzle; and

a processor coupled to the optical detector and the suck back valve, wherein the processor is adapted to adjust the position of the semiconductor process fluid interface in response to the optical signal provided by the optical detector.

15. The system of claim 14 wherein the dispense nozzle is characterized by a proximal portion adjacent to a proximal end of the dispense nozzle and a distal portion adjacent to a distal end of the dispense nozzle.

16. The system of claim 15 wherein the processor comprises:

an input adapted to receive a first optical signal;

a comparator adapted to compare the first optical signal to a baseline optical signal; and

an output adapted to provide;

a first signal to the suck back valve if the optical signal is less than a baseline signal, and

a second signal to the suck back valve if the optical signal is greater than the baseline signal.

17. The system of claim 16 wherein the first signal is associated with the position of the semiconductor process fluid interface being less than a predetermined distance from the distal end of the nozzle.

18. The system of claim 17 wherein the second signal is associated with the position of the semiconductor process fluid interface being greater than a predetermined distance from the distal end of the nozzle.

19. The system of claim 18 wherein the predetermined distance ranges from about 1 mm to about 2 mm.

20. The system of claim 14 wherein the dispense nozzle is disposed along the optical path such that a first portion of the optical beam impinges on the dispense nozzle and a second portion of the optical beam is free from impingement on the dispense nozzle.