Apparatus and method of detecting the electroless deposition endpoint

• US 7,534,298 B2
• Filed: 09/17/2004
• Issued: 05/19/2009
• Est. Priority Date: 09/19/2003
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Lopatin, Sergey, Birang, Manoocher, Shanmugasundram, Arulkumar, Pancham, Ian A.
• Primary Examiner(s): Lamb; Brenda A
• Application Number:
  US10/944,228
• Publication Number:
  US 20050088647A1
• Time in Patent Office: 1,705 Days
• Field of Search: 118/712, 118/602, 118/679, 118/323, 118320-321, 118697-699, 118/73, 118/52, 427/437, 427/438, 427/443.1
• US Class Current: 118/320
• CPC Class Codes: C23C 18/1651 Two or more layers only obtained by electroless plating
• CPC Class Codes: C23C 18/1667 Radiant energy, e.g. laser
• CPC Class Codes: C23C 18/1675 Process conditions
• CPC Class Codes: G01B 11/0683 measurement during deposition or removal of the layer
• CPC Class Codes: G01N 21/8422 Investigating thin films, e.g. matrix isolation method
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10

Abstract

An apparatus and a method of controlling an electroless deposition process by directing electromagnetic radiation towards the surface of a substrate and detecting the change in intensity of the electromagnetic radiation at one or more wavelengths reflected off features on the surface of the substrate. In one embodiment the detected end of an electroless deposition process step is measured while the substrate is moved relative to the detection mechanism. In another embodiment multiple detection points are used to monitor the state of the deposition process across the surface of the substrate. In one embodiment the detection mechanism is immersed in the electroless deposition fluid on the substrate. In one embodiment a controller is used to monitor, store, and/or control the electroless deposition process by use of stored process values, comparison of data collected at different times, and various calculated time dependent data.

Claims

1. An apparatus for monitoring an electroless deposition process performed on a substrate comprising:

a chamber;

a substrate support disposed in the chamber and having a substrate receiving surface;

an electromagnetic radiation source directed towards the substrate receiving surface;

a detector that detects the intensity of reflected electromagnetic radiation from a surface of the substrate when disposed on the substrate receiving surface during the electroless deposition process;

an emission sensor adapted to measure and compare an output of the electromagnetic radiation source with the reflected electromagnetic radiation collected by the detector;

a fluid source that is adapted to deliver an electroless plating solution to the surface of the substrate when the substrate is disposed on the substrate receiving surface; and

a controller adapted to receive a signal from the detector and a signal from the emission sensor.

2. The apparatus of claim 1, wherein the electromagnetic radiation source emits electromagnetic radiation at wavelengths between about 200 nanometers and about 800 nanometers.

3. The apparatus of claim 1, wherein the electromagnetic radiation source comprises one or more light emitting diodes.

4. The apparatus of claim 1, wherein the detector comprises two or more detectors.

5. The apparatus of claim 1, further comprising a drive mechanism to move the substrate support relative to the detector.

6. An apparatus of claim 5, further comprising a second drive mechanism to move the detector relative to the substrate support.

7. The apparatus of claim 1, wherein the detector is a spectrometer.

8. The apparatus of claim 1, wherein the electroless plating solution comprises a catalytic layer solution, a semi-noble metal solution, a noble metal solution, or a conductive cap layer solution.

9. The apparatus of claim 1, wherein the controller further comprises:

a timer that is adapted to define when a desired period of time has lapsed; and

a rinsing fluid source that is adapted to deliver a rinsing solution to the surface of the substrate after the desired period of time has lapsed.

10. An apparatus for monitoring an electroless deposition process performed on a substrate comprising:

a chamber;

a substrate support disposed in the chamber and having a substrate receiving surface;

an electromagnetic radiation source directed towards the substrate receiving surface;

a detector that detects the intensity of reflected electromagnetic radiation from a surface of the substrate when disposed on the substrate receiving surface during the electroless deposition process;

a controller adapted to receive a signal from the detector and to control the electroless deposition process;

a fiber optic cable which receives the electromagnetic radiation collected from the electromagnetic radiation source;

a mechanical slit that allows the reflected electromagnetic radiation or the electromagnetic radiation from the fiber optic cable to pass to the detector; and

a controller that selectively controls the transmission of the reflected electromagnetic radiation or the electromagnetic radiation from the fiber optic cable to the detector by use of a mechanical actuator that positions the mechanical slit.

11. An apparatus for monitoring an electroless deposition process performed on a substrate comprising:

a chamber;

a substrate support disposed in the chamber and having a substrate receiving surface;

an electromagnetic radiation source directed towards the substrate receiving surface;

a detector that detects the intensity of reflected electromagnetic radiation from a surface of the substrate when disposed on the substrate receiving surface during the electroless deposition process;

a controller adapted to receive a signal from the detector and to control the electroless deposition process;

a memory attached to the controller to stored the signal data; and

a control device wherein the controller device is used to control the electroless deposition process based on commands from the controller based on the comparison of the signal data and a process value.

12. An apparatus for monitoring an electroless deposition process performed on a substrate comprising:

a chamber;

a substrate support disposed in the chamber and having a substrate receiving surface;

an electromagnetic radiation source directed towards the substrate receiving surface;

a detector that detects the intensity of the reflected electromagnetic radiation from a surface of the substrate when disposed on the substrate receiving surface during the electroless deposition process;

a second detector that detects the intensity of the electromagnetic radiation from the electromagnetic radiation source;

a controller adapted to receive a signal from the detector and a signal from the second detector and to control the electroless deposition process; and

a fiber optic cable that receives the electromagnetic radiation collected from the electromagnetic radiation source and transmits the signal to the second detector.

13. The apparatus of claim 12, wherein the detector is a spectrometer.

14. The apparatus of claim 12, wherein the electromagnetic radiation source emits electromagnetic radiation at wavelengths between about 200 nanometers and about 800 nanometers.

15. The apparatus of claim 12, wherein the detector comprises two or more detectors.

16. The apparatus of claim 12, further comprising a drive mechanism to can move the substrate support relative to the detector.

17. An apparatus of claim 16, further comprising a second drive mechanism to move the detector relative to the substrate support.

18. The apparatus of claim 12, wherein the second detector is a spectrometer.

19. The apparatus of claim 12, wherein the electromagnetic radiation source is one or more light emitting diodes.

20. An apparatus for monitoring an electroless deposition process performed on a substrate comprising:

a chamber;

a substrate support disposed in the chamber and having a substrate receiving surface;

a electromagnetic radiation source directed towards the substrate receiving surface;

a detector that detects the intensity of the reflected electromagnetic radiation from a surface of the substrate when disposed on the substrate receiving surface during the electroless deposition process;

a fluid source that is adapted to deliver an electroless plating solution to the surface of the substrate when it is disposed on the substrate receiving surface; and

a controller adapted to receive a signal from the detector, and is adapted to start a timer when the detected intensity of the reflected electromagnetic radiation reaches a desired value and end an electroless process step when the timer has reached a desired value.

21. The apparatus of claim 20, wherein the electroless plating solution comprises a catalytic layer solution, a semi-noble metal solution, a noble metal solution, or a conductive cap layer solution.

22. The apparatus of claim 20, wherein electromagnetic radiation source further comprises one or more light emitting diodes.

23. The apparatus of claim 20, further comprising a rinsing fluid source that is adapted to deliver a rinsing solution to the surface of the substrate.

24. An apparatus for monitoring an electroless deposition process performed on a substrate comprising:

a chamber;

a substrate support disposed in the chamber and having a substrate receiving surface;

a electromagnetic radiation source comprising one or more light emitting diodes directed towards the substrate receiving surface;

a detector that detects the intensity of the reflected electromagnetic radiation from a surface of the substrate when disposed on the substrate receiving surface during the electroless deposition process;

a controller adapted to receive a signal from the detector and processes the signals to determine an initiation of the electroless deposition process; and

a second detector that detects the intensity of the electromagnetic radiation from the electromagnetic radiation source.

25. A system for monitoring an electroless deposition process performed on a substrate comprising:

a chamber;

a substrate support mounted in the chamber and having a substrate receiving surface;

an electromagnetic radiation source directed towards the substrate receiving surface;

a detector that detects the intensity of the reflected electromagnetic radiation from a surface of the substrate when disposed on the substrate receiving surface during the electroless deposition process;

a controller adapted to receive a signal from the detector and to control the electroless deposition process; and

a memory, coupled to the controller, the memory comprising a computer-readable medium having a computer-readable program embodied therein for directing the operation of the electroless deposition system, the computer-readable program comprising;

computer instructions to control the electroless deposition system to;

i. start processing;

ii. collect and store into the memory the intensity of the reflected electromagnetic radiation data during the electroless deposition process;

iii. compare the stored data with the collected data, then subsequently;

iv. stop the electroless deposition process when the collected data exceeds a threshold value.

26. The apparatus of claim 25, wherein the threshold value data is stored in the memory.

27. The apparatus of claim 25, wherein the electromagnetic radiation source emits electromagnetic radiation at wavelengths between about 200 nanometers and about 800 nanometers.

28. The apparatus of claim 25, wherein the electromagnetic radiation source is one or more light emitting diodes.

29. The apparatus of claim 25, wherein the detector comprises two or more detectors.

30. The apparatus of claim 25, further comprising a drive mechanism to can move the substrate support relative to the detector.

31. An apparatus of claim 30, further comprising a second drive mechanism to move the detector relative to the substrate support.

32. The apparatus of claim 25, wherein the detector is a spectrometer.

33. The apparatus of claim 25, further comprising a second detector that detects the intensity of the electromagnetic radiation from the electromagnetic radiation source.

34. An apparatus for monitoring an electroless deposition process performed on a substrate comprising:

a chamber;

a substrate support disposed in the chamber and having a substrate receiving surface;

the substrate having a detection feature on a surface, wherein the substrate is disposed on the substrate receiving surface of the substrate support;

an electromagnetic radiation source directed towards the surface of the substrate;

a detector that detects the intensity of reflected electromagnetic radiation from the detection feature during the electroless deposition process, wherein the detection feature comprises two or more metallic features disposed on the surface of the substrate;

an emission sensor adapted to measure and compare an output of the electromagnetic radiation source with the reflected electromagnetic radiation collected by the detector;

a fluid source that is adapted to deliver an electroless plating solution to the surface of the substrate when the substrate is disposed on the substrate receiving surface; and

a controller adapted to receive a signal from the detector and a signal from the emission sensor, and to control the electroless deposition process.

35. The apparatus of claim 34, wherein the electromagnetic radiation source emits electromagnetic radiation at wavelengths between about 200 nanometers and about 800 nanometers.

36. The apparatus of claim 34, wherein the detection feature is shaped to interact with the electromagnetic radiation reflected from the detection feature as the electroless deposition process progresses.

37. The apparatus of claim 34, wherein the electromagnetic radiation source comprises one or more light emitting diodes.

38. The apparatus of claim 34, wherein the detector comprises two or more detectors.

39. The apparatus of claim 34, further comprising a drive mechanism to move the substrate support relative to the detector.

40. An apparatus of claim 39, further comprising a second drive mechanism to move the detector relative to the substrate support.

41. The apparatus of claim 34, wherein the detector is a spectrometer.

42. The apparatus of claim 34, wherein the detection feature is an array of features spaced between about 100 nanometers and about 100 micrometers apart.

43. The apparatus of claim 34, wherein the electroless plating solution comprises a catalytic layer solution, a semi-noble metal solution, a noble metal solution, or a conductive cap layer solution.

44. An apparatus for monitoring an electroless deposition process performed on a substrate comprising:

a chamber;

a substrate support disposed in the chamber and having a substrate receiving surface;

a electromagnetic radiation source directed towards the substrate receiving surface;

a detector that detects the intensity of the reflected electromagnetic radiation from a surface of the substrate when disposed on the substrate receiving surface during the electroless deposition process;

a fluid source that is adapted to deliver an electroless plating solution to the surface of the substrate when it is disposed on the substrate receiving surface;

a motor coupled to the substrate support, wherein the motor is adapted to rotate the substrate receiving surface; and

a controller adapted to receive a signal from the detector, wherein the controller is adapted to control the rotation of the substrate receiving surface after the detected intensity of the reflected electromagnetic radiation from the surface of the substrate reaches a desired value.

45. The apparatus of claim 44 wherein the electroless plating solution comprises a catalytic layer solution, a semi-noble metal solution, a noble metal solution, or a conductive cap layer solution.

46. The apparatus of claim 44, further comprising a rinsing fluid source that is adapted to deliver a rinsing solution to the surface of the substrate.