System and method for controlling process end-point utilizing legacy end-point system

• US 7,873,052 B2
• Filed: 04/16/2007
• Issued: 01/18/2011
• Est. Priority Date: 04/16/2007
• Status: Active Grant

• Current Assignee: Pivotal Systems Corporation
• Original Assignee: Pivotal Systems Corporation
• Inventors: Monkowski, Joseph Raymond, Chung, Sherk, Lozic, Tomislav, Wong, Geoffrey Rodney
• Primary Examiner(s): Vu; Thong H
• Application Number:
  US11/787,654
• Publication Number:
  US 20080253377A1
• Time in Patent Office: 1,373 Days
• Field of Search: 700/175, 702/34, 156/345
• US Class Current: 370/395.3
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/32963 End-point detection
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32

Abstract

Embodiments in accordance with the present invention allow a second end-point determination (EPD) system to actively control the end-pointing of a semiconductor process chamber, by leveraging a legacy EPD system that is already integrated with the chamber. In one embodiment, the second EPD system controls a shutter that regulates the amount of light transmitted between a plasma light source and an optical emission spectroscopy (OES) sensor of the legacy OES EPD system. In this embodiment, the legacy OES EPD system is pre-configured to call end-point when an artificial end-point condition occurs, i.e. the intensity of light falls below a pre-set threshold. When the second EPD system determines an actual end-point condition has been reached, it closes the shutter which, causes the light intensity being read by the OES sensor to fall below the pre-set threshold. This in turn triggers an end-point command to the chamber from the legacy OES EPD system.

Claims

1. A method comprising:

providing a first end-point determination (EPD) system of a processing tool;

monitoring a process in the processing tool using a second EPD system; and

creating an artificial end-point condition using the second EPD system that causes the first EPD system to determine that an end-point of the process run on the processing tool has been reached, whereby the first EPD system sends an end-point command to the processing tool.

2. A method according to claim 1 further comprising configuring the first EPD system to recognize the artificial end-point condition as an end-point.

3. A method according to claim 1 wherein the second EPD system creates the artificial end-point condition upon determining that the process has reached the end-point.

4. A method according to claim 3 wherein the first EPD system notifies the processing tool that the end-point has been reached.

9. A method according to claim 1 wherein the first EPD system determines the end-point based on a measurement selected from an optical signal measurement, a radio frequency measurement, a residual gas analysis (RGA) measurement, or an interferometer measurement.

5. A method according to claim l wherein the first EPD system determines the end-point based upon measurements from an optical emissions spectroscopy (OES) sensor.

6. A method according to claim 5 wherein the first EPD system determines the end-point when an intensity of light being measured by the OES sensor crosses a threshold.

7. A method according to claim 6 wherein the artificial end-point condition is created by controlling a shutter to regulate an intensity of light received by the OES sensor.

8. A method according to claim 6 wherein the artificial end-point condition is created by controlling a light source to regulate an intensity of light received by the OES sensor.

10. An apparatus comprising:

an input port configured to receive a signal; and

circuitry in communication with the input port and configured to receive the signal, and in response to output a second signal corresponding to an artificial condition that results in a first end-point determination (EPD)device determining that a process end-point has been reached, whereby the first EPD device sends an end-point command to a processing tool.

11. An apparatus according to claim 10 wherein the circuitry is configured to receive the signal from another EPD device.

12. An apparatus according to claim 10 wherein the circuitry comprises a capacitor.

13. An apparatus according to claim 10 wherein the circuitry comprises a processor.

14. An apparatus according to claim 10 wherein the circuitry is configured to receive power from a power supply and to amplify the received power to generate the second signal.

15. A system comprising:

a first end-point determination (EPD) system;

a second EPD system in communication with a chamber of a processing tool;

an apparatus configured to receive a first signal from the second EPD system indicating that a process occurring in the chamber has reached an actual end-point condition, and in response to create an artificial end-point condition which the first EPD system recognizes as an end-point of the process, whereby the first EPD system sends an end-point command to the processing tool.

16. A system according to claim 15 wherein the apparatus is configured to output a second signal in response to receipt of the first signal, the apparatus further comprising a device configured to communicate with the first EPD system in response to receipt of the second signal.

17. A system according to claim 16 wherein the device comprises one of a mechanical shutter, a liquid crystal device, a filter, or a light source configured to regulate an amount of light communicated to the first EPD system.

18. A system according to claim 15 wherein first EPD system comprises an Optical Emission Spectroscopy (OES) sensor.

19. A system according to claim 15 wherein first EPD system includes at least one of an optical sensor, a radio frequency sensor, a residual gas analysis (RGA) sensor, or an interferometer.