Etch chamber with dual frequency biasing sources and a single frequency plasma generating source

• US 20040025791A1
• Filed: 01/14/2003
• Published: 02/12/2004
• Est. Priority Date: 08/09/2002
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Hooshdaran, Frank F., Chen, Jin-Yuan, Podlesnik, Dragan V.
• Application Number:
  US10/342,575
• Publication Number:
  US 20040025791A1
• Time in Patent Office: Days
• US Class Current: 118/728
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/32706 Polarising the substrate

Abstract

A method and apparatus for selectively controlling a plasma in a processing chamber during wafer processing. The method includes providing process gasses into the chamber over a wafer to be processed, and providing high frequency RF power to a plasma generating element and igniting the process gases into the plasma. Modulated RF power is coupled to a biasing element, and wafer processing is performed according to a particular processing recipe. The apparatus includes a biasing element disposed in the chamber and adapted to support a wafer, and a plasma generating element disposed over the biasing element and wafer. A first power source is coupled to the plasma generating element, and a second power source is coupled to the biasing element. A third power source is coupled to the biasing element, wherein the second and third power sources provide a modulated signal to the biasing element.

Claims

1. Apparatus for controlling a plasma in a chamber during wafer processing, comprising:

a biasing element disposed in said chamber and adapted to support a wafer;

a plasma generating element disposed over said biasing element;

a first power source coupled to said plasma generating element; and

a second power source coupled to said biasing element that provides a modulated signal to said biasing element.

2. The apparatus of claim 1, wherein said biasing element comprises a substrate support pedestal.

3. The apparatus of claim 2, wherein said biasing element further comprises at least one chucking electrode disposed in said substrate support pedestal.

4. The apparatus of claim 2, wherein said biasing element further comprises a cooling plate formed in said substrate support pedestal.

5. The apparatus of claim 2, wherein said biasing element further comprises a pedestal base plate formed in said substrate support pedestal.

6. The apparatus of claim 1, wherein said plasma generating element further comprises a gas diffuser disposed over said chamber.

7. The apparatus of claim 1, wherein said plasma generating element further comprises coil antennas positioned over a lid, which is disposed over said chamber.

8. The apparatus of claim 1, wherein said first power source provides power in a range between about 0 Watts and about 7500 Watts, at a frequency in a range between about 0 MHz to about 180 MHz.

9. The apparatus of claim 1, wherein said second power source provides modulated pulsed waveforms.

10. The apparatus of claim 9, wherein said modulated pulsed waveforms have a voltage magnitude in a range of about 100 and 7500 volts, and a duty cycle between about 10 and 90 percent.

11. The apparatus of claim 1, wherein said second power source comprises:

an intermediate RF power source coupled to said biasing element; and

a low RF power source coupled to said biasing element.

12. The apparatus of claim 10, wherein:

said low RF power source provides a first RF power signal between about 10 Watts and about 7500 Watts at a frequency between 100 KHz and 6 MHz to said biasing element;

said intermediate RF power source provides a second RF power signal in a range between about 10 Watts and about 7500 Watts at a frequency between 10 MHz and 60 MHz to said biasing element; and

wherein said second RF power signal is modulated by said first RF power signal.

13. The apparatus of claim 12, wherein said first and second RF power signals have frequencies of 2 MHz and 13.56 MHz, respectively.

14. The apparatus of claim 12, wherein said first RF power signal is a waveform selected from the group comprising a sine wave and a square wave.

15. A method for selectively controlling a plasma in a processing chamber during wafer processing, comprising:

providing process gasses into said chamber over a wafer to be processed;

coupling high frequency RF power to a plasma generating element and igniting said process gases into said plasma;

coupling modulated RF power to a biasing element; and

performing said wafer processing according to a particular processing recipe.

16. The method of claim 15, wherein said coupling high frequency RF power step further comprises coupling source power between about 0 Watts and about 7500 Watts, at a frequency of about 0 MHz to about 180 MHz.

17. The method of claim 15, wherein said coupling modulated RF power further comprises:

coupling a first RF power signal in a range between about 10 Watts and about 7500 Watts at a frequency between 100 KHz and 6 MHz to said biasing element; and

coupling a second RF power signal in a range between about 10 Wafts and about 7500 Watts at a frequency between 10 MHz and 60 MHz to said biasing element; and

wherein said second RF power signal is modulated by said first RF power signal.

18. The method of claim 17, wherein said first and second RF power signals have frequencies of 2 MHz and 13.56 MHz, respectively.

19. The method of claim 18, wherein said first RF power signal comprises a sine wave.

20. The method of claim 18, wherein said first RF power signal comprises a square wave, said square wave modulated on said second RF power signal and producing a pulse-like signal.

21. The method of claim 20, wherein said pulse-like signal has a voltage magnitude in a range of about 100 and 7500 volts and a duty cycle between about 10 and 90 percent.

22. The method of claim 15, wherein said wafer processing comprises an etch process or a deposition process.

23. A method for plasma etching a trench in a semiconductor substrate disposed in a chamber, comprising:

providing process gases into the chamber and over the substrate to be etched;

coupling a high frequency RF power signal in a range of about 100 to 7500 Watts, at a frequency in a range of about 40 to 180 MHz, to a plasma generating element and igniting said process gases into a plasma;

coupling a modulated RF power signal in a range of about 10 to 7500 Watts, to a biasing element; and

performing said plasma etching on said substrate.

24. The method of claim 23 wherein the modulated RF power signal comprises a first RF signal in a range of about 10 to 7500 Watts, at a frequency in a range of about 2 KHz to 6 Mhz modulating a second RF signal in a range of about 10 to 7500 Watts, at a frequency in a range of about 10 MHz to 60 MHz.

25. The method of claim 24 wherein the providing process gases step further comprises:

providing between 5 to 2000 sccm of at least one process gas selected from the group consisting of CF₄, Ar, C₄F₈, C₄F₆, C₈F₄, CHF₃, Cl₂, HBr, NF₃, N₂, He, O₂; and

maintaining a pressure in a range of about 2 to 1000 mTorr.