Wafer probe for measuring plasma and surface characteristics in plasma processing environments

• US 20050011611A1
• Filed: 08/17/2004
• Published: 01/20/2005
• Est. Priority Date: 07/12/2002
• Status: Abandoned Application

• Current Assignee: KLA-Tencor Corporation (KLA Corporation)
• Original Assignee: KLA-Tencor Corporation (KLA Corporation)
• Inventors: Carter, Daniel C., Mahoney, Leonard J., Roberts, Steven J., Roche, Gregory A.
• Application Number:
  US10/920,138
• Publication Number:
  US 20050011611A1
• Time in Patent Office: Days
• US Class Current: 156/345.240
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring

Abstract

There is provided by this invention a wafer probe for measuring plasma and surface characteristics in plasma processing environment that utilizes integrated sensors on a wafer substrate. A microprocessor mounted on the substrate receives input signals from the integrated sensors to process, store, and transmit the data. A wireless communication transceiver receives the data from the microprocessor and transmits information outside of the plasma processing system to a computer that collects the data during plasma processing. The integrated sensors may be dual floating Langmuir probes, temperature measuring devices, resonant beam gas sensors, optical emission sensors, or other sensors of plasma or surface properties. There is also provided a self-contained power source that utilizes the plasma for power that is comprised of a topographically dependent charging device or a charging structure that utilizes stacked capacitors.

Claims

1. An apparatus for obtaining measurements in a plasma processing system comprising:

a) a substrate;

b) an optical emission sensor disposed on the substrate to obtain measurements of the plasma in the plasma processing system; and

c) a wireless communication transceiver mounted on the substrate disposed to transmit sensor measurement data from the substrate outside the plasma processing system.

2. The apparatus of claim 1 wherein the optical emission sensor is a photo diode.

3. The apparatus of claim 1, further comprising a first band-pass filter disposed upon the optical emission sensor.

4. The apparatus of claim 3, further comprising a second optical emission sensor disposed on the substrate, and a second band-pass filter disposed upon the second optical emission sensor.

5. The apparatus of claim 4 wherein the first band-pass filter transmits a spectral band of a processing gas species, and the second band-pass filter transmits a spectral band of a neutral gas species.

6. The apparatus of claim 1 wherein the optical emission sensor is a photo diode array.

7. The apparatus of claim 6, further comprising a gradient optical filter disposed upon the photo diode array.

8. The apparatus of claim 1, further comprising a dual floating Langmuir probe sensor.

9. The apparatus of claim 1, further comprising a topographically dependant charging sensor.

10. The apparatus of claim 1, further comprising a differential surface charge sensor.

11. The apparatus of claim 1, further comprising a temperature measuring sensor.

12. The apparatus of claim 1, further comprising a self contained power source.

13. The apparatus of claim 1 wherein the substrate is a silicon wafer.

14. The apparatus of claim 1, further comprising electronics for processing sensor measurements disposed upon the primary substrate and interconnected to the optical emission sensor.

15. The apparatus of claim 14, wherein the electronics for processing sensor measurements are optically interconnected to the optical emission sensor.

16. The apparatus of claim 1 wherein the optical emission sensor is disposed to obtain measurements of triggering events in a pulsed plasma processing system.

17. The apparatus of claim 16, further comprising one or more additional sensors for obtaining measurements of the plasma, and wherein the one or more additional sensors obtain measurements in response to the triggering events.

18. A method of measuring properties of a plasma processing environment comprising the steps of:

a) providing a measurement probe comprising a substrate, a first optical emission sensor disposed on the substrate to obtain measurements of the plasma in a plasma processing system, and a wireless communication transceiver mounted on the substrate disposed to transmit sensor measurement data from the substrate outside the plasma processing system;

b) disposing the measurement probe into the plasma processing system; and

c) collecting data relating to plasma properties in the plasma processing system using the measurement probe.

19. The method of claim 18 wherein the first optical emission sensor is a photo diode.

20. The method of claim 18 wherein the first optical emission sensor is a photo diode array.

21. The method of claim 18 wherein the measurement probe further comprises a first band-pass filter disposed upon the first optical emission sensor.

22. The method of claim 21 wherein the measurement probe further comprises a second optical emission sensor disposed on the substrate, and a second band-pass filter disposed upon the second optical emission sensor.

23. The method of claim 22 wherein the first band-pass filter transmits a spectral band of a processing gas species, and the second band-pass filter transmits a spectral band of a neutral gas species.

24. The method of claim 23, further comprising the step of quantifying the amount of the processing gas species by comparing measurements from the first optical emission sensor to measurements from the second optical emission sensor.

25. The method of claim 18 further comprising the step of measuring a triggering event using the first optical emission sensor.

26. The method of claim 25 wherein data relating to plasma properties in the plasma processing system are collected in response to the triggering event.