Monitoring plasma ion implantation systems for fault detection and process control

• US 20080026133A1
• Filed: 06/02/2004
• Published: 01/31/2008
• Est. Priority Date: 06/02/2004
• Status: Active Grant

• Current Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated), Freudenberg-Nok General Partnership (Freudenberg & Company KG)
• Original Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated)
• Inventors: Ko, Sung-Cheon, Koo, Bon Woong, Godet, Ludovic, Fang, Ziwei, Distaso, Daniel, Scheuer, Jay T., Winder, Edmund J.
• Granted Patent: US 7,878,145 B2
• Time in Patent Office: Days
• US Class Current: 427/8
• CPC Class Codes: H01J 37/32412 Plasma immersion ion implantation

Abstract

A plasma ion implantation system includes a process chamber, a source for producing a plasma in the process chamber, a platen for holding a substrate in the process chamber and a pulse source for generating implant pulses for accelerating ions from the plasma into the substrate. In one aspect, the system includes a plasma monitor configured to measure ion mass and energy in the process chamber and an analyzer configured to determine an operating condition of the system in response to the measured mass and energy. In another aspect, the system includes a data acquisition unit configured to acquire samples of the implant pulses and analyzer configured to determine an operating condition of the system based on the acquired samples.

Claims

1. Plasma ion implantation apparatus comprising:

a process chamber;

a platen located in said process chamber for supporting a substrate;

an anode spaced from said platen in said process chamber;

a process gas source coupled to said process chamber, wherein a plasma containing ions of the process gas is produced in a plasma discharge region between said anode and said platen;

a pulse source for applying implant pulses between said platen and said anode for accelerating ions from the plasma into the substrate; and

a plasma monitor configured to measure mass and energy of ions in said process chamber, wherein the measured ion mass and energy are indicative of an operating condition of the plasma ion implantation apparatus.

2. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor comprises an ion mass and energy analyzer.

3. Plasma ion implantation apparatus as defined in claim 1, wherein an entrance of the plasma monitor is located in the anode.

4. Plasma ion implantation apparatus as defined in claim 1, wherein an entrance of the plasma monitor is located in the platen.

5. Plasma ion implantation apparatus as defined in claim 1, wherein an entrance of the plasma monitor is located adjacent to a substrate support surface of the platen.

6. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor is configured and positioned to analyze ions in the plasma discharge region.

7. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor is configured and positioned to analyze ions accelerated from the plasma discharge region to the substrate.

8. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor is configured to determine ion mass and energy during a selected time interval relative to said implant pulses.

9. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor is configured to determine ion mass and energy during an acquisition time interval.

10. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor is configured to perform a time-averaged measurement of ion mass and energy.

11. Plasma ion implantation apparatus as defined in claim 1, further comprising an analysis unit for determining an operating condition of the plasma ion implantation apparatus in response to the measured ion mass and energy, and a controller for controlling a parameter of the plasma ion implantation apparatus in response to the determined operating condition.

12. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor is configured for scanning measurement with respect to ion mass.

13. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor is configured for scanning measurement with respect to ion energy.

14. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor communicates with the process chamber through an entrance orifice.

15. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor is configured to measure ion mass and energy in a predetermined time interval during each of said pulses.

16. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor is configured to measure ion mass and energy in a predetermined time interval after each of said pulses.

17. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor measures a distribution of ion masses in said process chamber.

18. Plasma ion implantation apparatus as defined in claim 1, wherein the plasma monitor measures a distribution of ion energies in said process chamber.

19. Plasma ion implantation apparatus comprising:

a process chamber;

a platen located in said process chamber for supporting a substrate;

an anode spaced from said platen in said process chamber;

a process gas source coupled to said process chamber, wherein a plasma containing ions of the process gas is produced in a plasma discharge region between said anode and said platen;

a pulse source for applying implant pulses between said platen and said anode for accelerating ions from the plasma into the substrate; and

a data acquisition unit configured to acquire samples of said implant pulses, wherein the acquired samples are indicative of an operating condition of the plasma ion implantation apparatus.

20. Plasma ion implantation apparatus as defined in claim 19, wherein the data acquisition unit is configured to perform high speed sampling of at least one of a voltage waveform and a current waveform of each of said implant pulses.

21. Plasma ion implantation apparatus as defined in claim 19, further comprising a dose measurement device for providing an electrical signal representative of ion current implanted into the substrate, wherein the data acquisition unit is configured to perform high speed sampling of the electrical signal produced by the dose measurement device.

22. Plasma ion implantation apparatus as defined in claim 19, wherein the data acquisition unit is configured to monitor operation of the plasma ion implantation apparatus.

23. Plasma ion implantation apparatus as defined in claim 19, further comprising an analysis unit for determining an operating condition of the plasma ion implantation apparatus in response to the acquired waveforms, and a controller for controlling a parameter of the plasma ion implantation apparatus in response to the determined operating condition.

24. Plasma ion implantation apparatus as defined in claim 19, wherein the data acquisition unit is configured to acquire multiple samples of each of said implant pulses.

25. Plasma ion implantation apparatus as defined in claim 19, wherein the data acquisition unit is configured to acquire samples indicative of a rise time of each of said implant pulses.

26. Plasma ion implantation apparatus as defined in claim 19, wherein the data acquisition unit is configured to acquire samples indicative of a fall time of each of said implant pulses.

27. Plasma ion implantation apparatus as defined in claim 19, wherein the data acquisition unit is configured to acquire samples indicative of an overshoot of each of said implant pulses.

28. Plasma ion implantation apparatus as defined in claim 19, wherein the data acquisition unit is configured to acquire samples indicative of an amplitude of each of said implant pulses.

29. Plasma ion implantation apparatus as defined in claim 19, wherein the data acquisition unit is configured to acquire samples indicative of variations in said implant pulses.

30. Plasma ion implantation apparatus as defined in claim 19, wherein the data acquisition unit is configured to acquire samples of said implant pulses during an acquisition time interval.

31. A method for plasma ion implantation of a substrate, comprising:

providing a plasma ion implantation system including a process chamber, a source for producing a plasma in the process chamber, a platen for holding a substrate in the process chamber and a pulse source for generating implant pulses for accelerating ions from the plasma into the substrate;

acquiring measurements of mass and energy of ions in said process chamber; and

determining an operating condition of the plasma ion implantation system based on the acquired measurements of ion mass and energy.

32. A method as defined in claim 31, wherein acquiring measurements of ion mass and energy comprises acquiring measurements of ions in a plasma discharge region in said process chamber.

33. A method as defined in claim 31, wherein acquiring measurements of ion mass and energy comprises acquiring measurements of ions accelerated from the plasma toward the platen.

34. A method as defined in claim 31, wherein acquiring measurements of ion mass and energy comprises acquiring measurements of ion mass and energy during a selected time interval relative to said implant pulses.

35. A method as defined in claim 31, further comprising controlling a parameter of the plasma ion implantation system in response to the determined operating condition.

36. A method for plasma ion implantation of a substrate, comprising:

providing a plasma ion implantation system including a process chamber, a source for producing a plasma in the process chamber, a platen for holding a substrate in the process chamber and a pulse source for generating implant pulses for accelerating ions from the plasma into the substrate;

acquiring samples of said implant pulses; and

determining an operating condition of the plasma ion implantation system based on the acquired samples.

37. A method as defined in claim 36, wherein acquiring samples of said implant pulses comprises performing high speed sampling of at least one of a voltage waveform and a current waveform of each of said implant pulses.

38. A method as defined in claim 36, further comprising controlling a parameter of the plasma ion implantation system in response to the determined operating condition.

39. A method as defined in claim 36, wherein acquiring samples of said implant pulses comprises acquiring samples during an acquisition time interval.