Plasma processing with enhanced charge neutralization and process control

• US 8,926,850 B2
• Filed: 12/07/2012
• Issued: 01/06/2015
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated)
• Original Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated)
• Inventors: Singh, Vikram, Miller, Timothy J., Lindsay, Bernard G.
• Primary Examiner(s): Norton, Nadine
• Assistant Examiner(s): GATES, BRADFORD M
• Application Number:
  US13/708,412
• Publication Number:
  US 20130092529A1
• Time in Patent Office: 760 Days
• Field of Search: None
• US Class Current: 216/67
• CPC Class Codes: C23C 14/345 using substrate bias
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/32165 Plural frequencies
• CPC Class Codes: H01J 37/32412 Plasma immersion ion implantation
• CPC Class Codes: H01L 21/32136 using plasmas

Abstract

Plasma processing with enhanced charge neutralization and process control is disclosed. In accordance with one exemplary embodiment, the plasma processing may be achieved as a method of plasma processing a substrate. The method may comprise providing the substrate proximate a plasma source; applying to the plasma source a first RF power level during a first period and a second RF power level during a second period, the first and second RF power levels being greater than zero RF power level, wherein the second RF power level is greater than the first RF power level; generating with the plasma source a first plasma during the first period and a second plasma during the second period; and applying to the substrate a first bias voltage during the first period and a second bias voltage during the second period, wherein the first voltage has more negative potential than the second voltage.

Claims

1. A method of plasma processing a substrate, the method comprising:

providing the substrate proximate a plasma source;

applying to the plasma source a first RF power level during a first period and a second RF power level during a second period, the first and second RF power levels being greater than zero RF power level, wherein the second RF power level is greater than the first RF power level;

generating with the plasma source a first plasma during the first period and a second plasma during the second period;

applying to the substrate a first bias voltage during the first period and a second bias voltage during the second period, wherein the first bias voltage has more negative potential than the second bias voltage; and

applying to the plasma source a third RF power level during a third period, wherein the third RF power level is less than the first RF power level; and

applying to the substrate the second bias voltage during the third period.

2. The method according to claim 1, the method further comprising:

striking the plasma to generate the first plasma during the first period.

3. The method according to claim 1, further comprising:

etching the substrate during at least one of the first and second periods.

4. The method according to claim 1, further comprising:

depositing a material during at least one of the first and second periods.

5. The method according to claim 1, wherein at least one of the first and the second power levels are substantially constant during respective ones of the first and the second periods.

6. The method according to claim 1, further comprising:

directing ions from in the first plasma toward the substrate during the first period; and

directing electrons from the second plasma toward the substrate during the second period.

7. The method according to claim 1, wherein the plasma source comprises:

at least one of a planar coil RF antenna and a helical coil RF antenna; and

a RF power supply electrically coupled to at least one of the planar coil RF antenna and the helical coil RF antenna.

8. The method according to claim 1, wherein the plasma source comprises:

at least one of a planar coil RF antenna and a helical coil RF antenna; and

a RF power supply electrically coupled to one of the planar coil RF antenna and the helical coil RF antenna, the other one of the planar coil RF antenna and the helical coil RF antenna being a parasitic antenna.

9. The method according to claim 1, wherein the plasma source comprises:

a planar coil RF antenna and a helical coil RF antenna; and

a RF power supply electrically coupled to the planar coil RF antenna and the helical coil RF antenna.

10. The method according to claim 9, further comprising:

applying the first RF power level to the one of the planar coil RF antenna and the helical coil RF antenna of the plasma source during the first period; and

applying the second RF power level to the other one of the planar coil RF antenna and the helical coil RF antenna of the plasma source during the second period.

11. The method according to claim 1, wherein the second period immediately follows the first period.

12. The method according to claim 1, wherein the first bias voltage is negative bias voltage and the second bias voltage is ground bias voltage.

13. The method according to claim 1, wherein the first bias voltage is negative bias voltage and the second bias voltage is positive bias voltage.

14. A method of plasma processing a substrate, the method comprising:

applying to a plasma source a first power level during a first period and generating a first plasma containing first ions;

applying to the plasma source a second power level during a second period and generating a second plasma containing second ions, the second power level being greater than the first power level;

applying to the plasma source a third power level during a third period, the third power level being less than the first power level;

applying to the substrate a second bias voltage during the third period

directing, during the first period, the first ions from the first plasma toward the substrate and accumulating charges in the substrate; and

decreasing, during the second period, the charge accumulated in the substrate.

15. The method according to claim 14, the method further comprising:

striking the plasma to generate the first plasma during the first period while applying to the plasma source the first power level.

16. The method according to claim 14, the method further comprising:

etching the substrate during the first period.

17. The method according to claim 14, the method further comprising:

depositing a material during the first period.

18. The method according to 14, the method further comprising:

implanting ions from the plasma into the substrate during the first period.

19. The method according to claim 14, wherein the plasma source comprises:

a planar coil RF antenna and a helical coil RF antenna; and

a RF power supply electrically coupled to the planar coil RF antenna and the helical coil RF antenna.

20. The method according to claim 19, further comprising:

applying the first power level to the one of the planar coil RF antenna and the helical coil RF antenna of the plasma source during the first period; and

applying the second power level to the other one of the planar coil RF antenna and the helical coil RF antenna of the plasma source during the second period.