System and apparatus for control of sputter deposition process

• US 20040026235A1
• Filed: 05/15/2003
• Published: 02/12/2004
• Est. Priority Date: 05/17/2002
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Films Corp. (Applied Materials Incorporated)
• Inventors: Stowell, Michael W. Jr.
• Granted Patent: US 7,247,221 B2
• Time in Patent Office: Days
• US Class Current: 204/192.12
• CPC Class Codes: C23C 14/35 by application of a magnetic field, e.g. magnetron sputtering C23C14/3457 takes precedence
• CPC Class Codes: H01J 37/3405 Magnetron sputtering

Abstract

A method and apparatus for sputter deposition in which both a pulsed DC power supply and an RF power supply apply power to the target in the sputter deposition equipment. The pulsed DC power supply provides an on cycle where power is applied to the target, and an off cycle, in which a reverse polarity is applied to the target. The application of the reverse polarity has the effect of removing any charge that may have built up on the surface of the target. This reduces the likelihood of arcing occurring on the surface of the target, which can degrade the quality of the film being deposited on the substrate. By applying RF power simultaneously with the pulsed DC power to the target, the ionization efficiency on the target surface is increased. This results in a greater amount of material being removed from the target surface more quickly.

Claims

1. A method of performing magnetron sputter deposition, the method comprising

a) applying power for performing the sputter deposition to at least one target from at least one RF power system comprising at least:

i) an RF power supply having a frequency of at least 1 MHz and not greater than 100 MHZ;

ii) a tuner; and

iii) a DC bias detection circuit; and

b) applying power for performing the sputter deposition to the at least one target from at least one pulsed DC power system comprising at least;

i) a pulsed DC power supply having a frequency of at least 0.1 MHz and not greater than 20 MHz, a duty cycle of at least 0.1% and not greater than 99.9%;

ii) a filter unit; and

iii) a sensor.

2. A method according to claim 1 wherein the pulsed DC power supply reverses the polarity of the voltage supplied to the target during at least a portion of the power application.

3. A method of suppressing arcing on a target during a magnetron sputter deposition process, the method comprising:

a) applying electrical power to the target from a pulsed DC power system comprising at least;

i) a pulsed DC power supply; and

ii) a filter unit;

b) applying electrical power to the target from an RF power system comprising at least;

i) an RF power supply;

ii) a tuner; and

iii) a DC bias detection circuit that monitors the DC voltage at the target;

c) monitoring the electrical power at the target to detect an electrical arc on a surface of the target;

d) shutting down the pulsed DC power supply when an electrical arc is detected on the surface of the target;

e) monitoring the DC voltage at the target by means of the DC bias detection circuit to detect when the pulsed DC power to the target falls below a predefined threshold voltage; and

f) when the DC bias detection circuit detects the reduction in power to the target, sending a signal to the RF power supply to shut down.

4. A method according to claim 3 wherein the pulsed DC power supply reverses the polarity of the voltage supplied to the target during at least a portion of the power application.

5. A method according to claim 3 wherein the pulsed DC power supply has a frequency of at least 0.1 MHz and not greater than 20 MHz.

6. A method according to claim 3 wherein the pulsed DC power supply has a duty cycle of at least 0.1% and not greater than 99.9%.

7. A method according to claim 3 further comprising sending a signal to the pulsed DC power supply to turn back on when a predefined time has elapsed.

8. A method according to claim 3 further comprising sending a signal to the RF power supply to turn back on when the pulsed DC power supply output voltage exceeds a predefined threshold voltage.

9. A method according to claim 3 wherein the threshold voltage is at least 20 volts and not greater than 350 volts.

10. A method according to claim 3 wherein the time from when the electrical arc is detected on the surface of the target until the RF power supply is turned back on is less than 2500 microseconds.

11. A method according to claim 7 further comprising sensing an electrical arc on the target when turning the pulsed DC power supply back on, and shutting down the pulsed DC power supply for a multiple of the predefined time period in response to detecting the electrical arc on the target.

12. A method according to claim 11 further comprising sensing an electrical arc on the target when turning the pulsed DC power supply back on after the multiple of the predefined time period, and shutting down the pulsed DC power supply for a larger multiple of the predefined time period in response to detecting the electrical arc on the target.

13. A method according to claim 11 or 12 further comprising not sensing an electrical arc on the target when turning the pulsed DC power supply back on after some multiple of the predefined time period, and resetting the predefined time period to its original value.

14. A method of suppressing arcing on a target during a magnetron sputter deposition process, the method comprising:

a) applying electrical power to the target from a pulsed DC power system comprising at least;

i) a pulsed DC power supply;

ii) a filter unit; and

iii) a sensor;

b) applying electrical power to the target from an RF power system comprising at least;

i) an RF power supply;

ii) an RF control;

iii) a match network; and

iv) a feedback control mechanism that provides input to the RF power system from the pulsed DC power system;

c) monitoring the electrical power at the target to detect an electrical arc on a surface of the target;

d) shutting down the pulsed DC power supply when an electrical arc is detected on the surface of the target; and

e) sending a signal to the RF power system from the pulsed DC power system when the pulsed DC power supply has been shut down to shut down the RF power supply.

15. A method according to claim 14 wherein the pulsed DC power supply reverses the polarity of the voltage supplied to the target during at least a portion of the power application.

16. A method according to claim 14 wherein the pulsed DC power supply has a frequency of at least 0.1 MHz and not greater than 20 MHz.

17. A method according to claim 14 wherein the pulsed DC power supply has a duty cycle of at least 0.1% and not greater than 99.9%.

18. A method according to claim 14 wherein the RF power supply has a frequency of at least 1 MHz and not greater than 100 MHZ

19. A method according to claim 14 further comprising sending a signal to the pulsed DC power supply to turn back on when a predefined time has elapsed.

20. A method according to claim 19 further comprising sending a signal to the RF power supply by means of the feedback control mechanism to turn back on when the pulsed DC power supply has been turned back on.

21. A method according to claim 14 wherein a time for from when the pulsed DC power to the target falls below the predefined threshold until the RF power supply is shut down is less than 250 microseconds.

22. A method according to claim 14 further comprising sensing an electrical arc on the target when turning the pulsed DC power supply back on, and shutting down the pulsed DC power supply for a multiple of the predefined time period in response to detecting the electrical arc on the target.

23. A method according to claim 22 further comprising sensing an electrical arc on the target when turning the pulsed DC power supply back on after the multiple of the predefined time period, and shutting down the pulsed DC power supply for a larger multiple of the predefined time period in response to detecting the electrical arc on the target.

24. A method according to claim 22 or 23 further comprising not sensing an electrical arc on the target when turning the pulsed DC power supply back on after some multiple of the predefined time period, and resetting the predefined time period to its original value.

25. A method according to claim 14 wherein the filter unit blocks RF feedback from the pulsed DC power supply.

26. A method according to claim 14 wherein the match network blocks DC feedback from the RF power supply.

27. An apparatus for suppressing arcs on a target in a vacuum sputter deposition system, the apparatus comprising:

a) a pulsed DC power system comprising at least;

i) a pulsed DC power supply;

ii) a filter unit; and

iii) a sensor

b) an RF power system comprising at least;

i) an RF power supply;

ii) a tuner; and

iii) a DC bias detection circuit;

c) a target that is electrically connected to the pulsed DC power system and the RF power system;

d) the sensor in the pulsed DC power system monitoring a surface of the target mechanism to detect an electrical arc, sending a signal to the pulsed DC power supply to shut down when an electrical arc is detected on the surface of the target; and

e) a DC bias detection circuit for detecting when the pulsed DC power to the target falls below a predefined threshold and sending a signal to the RF power supply to shut down.

28. An apparatus according to claim 27 wherein the pulsed DC power supply reverses the polarity of the voltage supplied to the target during at least a portion of the power application.

29. An apparatus according to claim 27 wherein the pulsed DC power supply has a frequency of at least 0.1 MHz and not greater than 20 MHz.

30. An apparatus according to claim 27 wherein the pulsed DC power supply has a duty cycle of at least 0.1% and not greater than 99.9%.

31. An apparatus according to claim 27 wherein the RF power supply has a frequency of at least 1 MHz and not greater than 100 MHZ

32. An apparatus according to claim 27 wherein the pulsed DC power supply has a duty cycle of at least 10% and not greater than 20% and a frequency of at least 0.25 MHz and not greater than 0.6 MHz.

33. An apparatus according to claim 27 wherein the pulsed DC power supply has a duty cycle of at least 20% and not greater than 45% and a frequency of at least 0.75 MHz and not greater than 1.25 MHz.

34. An apparatus according to claim 27 wherein the pulsed DC-power supply has a duty cycle of at least 45% and not greater than 70% and a frequency of at least 2.5 MHz and not greater than 4 MHz.

35. An apparatus according to claim 27 wherein the RF power system is electrically connected to the target by means of a feed located in a central portion of the target and the pulsed DC power system is electrically connected to the target by means of a feed located near an end of the target.

36. An apparatus according to claim 27 further comprising a mounting plate to which the target is attached, the RF power system being electrically connected to the target by means of a feed located in a central portion of the target mounting plate and the pulsed DC power system being electrically connected to the target by means of a feed located near an end of the target mounting plate.

37. An apparatus according to claim 27 wherein a signal is sent by the sensor to the pulsed DC power supply to turn back on when a predefined time has elapsed.

38. An apparatus according to claim 37 wherein after the pulsed DC power supply has turned back on, a signal is sent to the RF power supply by to turn back on.

39. An apparatus according to claim 37 wherein the sensor further comprises means for detecting an electrical arc on the target when turning the pulsed DC power supply back on, and shutting down the pulsed DC power supply for a multiple of the predefined time period in response to detecting the electrical arc on the target.

40. An apparatus according to claim 39 wherein the sensor further comprises means for sensing an electrical arc on the target when turning the pulsed DC power supply back on after the multiple of the predefined time period, and shutting down the pulsed DC power supply for a larger multiple of the predefined time period in response to detecting the electrical arc on the target.

41. An apparatus according to claim 39 or 40 wherein the sensor further comprises means for sensing an electrical arc is not occurring on the target when turning the pulsed DC power supply back on after some multiple of the predefined time period, and resetting the predefined time period to its original value.

42. An apparatus in accordance with claim 27 wherein the operating pressure in the vacuum sputter deposition system chamber is maintained between 1.0×

10−

3 Torr and 10×

10−

3 Torr.

43. An apparatus in accordance with claim 27 wherein the magnetic field maintained on the target surface in the vacuum sputter deposition chamber is less than 600 oersted.

44. An apparatus for suppressing arcs on a target in a vacuum sputter deposition system, the apparatus comprising:

a) a pulsed DC power system comprising at least;

i) a pulsed DC power supply;

ii) a filter unit; and

iii) a sensor

b) an RF power system comprising at least;

i) an RF power supply;

ii) an RF control; and

iii) a match network;

c) a target that is electrically connected to the pulsed DC power system and the RF power system;

d) the sensor in the pulsed DC power system monitoring a surface of the target mechanism to detect an electrical arc on a surface of the target mechanism and sending a signal to the pulsed DC power supply to shut down when an electrical arc is detected on the surface of the target; and

e) a feedback control mechanism capable of detecting a shut down of the pulsed DC power supply and sending a signal to the RF power supply to shut down.

45. An apparatus according to claim 44 wherein the pulsed DC power supply reverses the polarity of the voltage supplied to the target during at least a portion of the power application.

46. An apparatus according to claim 44 wherein the pulsed DC power supply has a frequency of at least 0.1 MHz and not greater than 20 MHz.

47. An apparatus according to claim 44 wherein the pulsed DC power supply has a duty cycle of at least 0.1% and not greater than 99.9%.

48. An apparatus according to claim 44 wherein the RF power supply has a frequency of at least 1 MHz and not greater than 100 MHZ

49. An apparatus according to claim 44 wherein the pulsed DC power supply has a duty cycle of at least 10% and not greater than 20% and a frequency of at least 0.25 MHz and not greater than 0.6 MHz.

50. An apparatus according to claim 44 wherein the pulsed DC power supply has a duty cycle of at least 20% and not greater than 45% and a frequency of at least 0.75 MHz and not greater than 1.25 MHz.

51. An apparatus according to claim 44 wherein the pulsed DC power supply has a duty cycle of at least 45% and not greater than 70% and a frequency of at least 2.5 MHz and not greater than 4 MHz.

52. An apparatus according to claim 44 wherein the RF power system is electrically connected to the target by means of a feed located in a central portion of the target and the pulsed DC power system is electrically connected to the target by means of a feed located near an end of the target.

53. An apparatus according to claim 44 wherein the RF power system is electrically connected to a feed located near an end of the target by means of the filter unit of the pulsed DC power system, and the pulsed DC power system is electrically connected to the feed located at the end of the target.

54. An apparatus according to claim 44 further comprising a mounting plate to which the target is attached, the RF power system being electrically connected to the target by means of a feed located in a central portion of the target mounting plate and the pulsed DC power system being electrically connected to the target by means of a feed located near an end of the target mounting plate.

55. An apparatus according to claim 44 further comprising a mounting plate to which the target is attached, the RF power system being electrically connected to the target by means of a feed located near an end of the mounting by means of the filter unit of the pulsed DC power system, and the pulsed DC power system being electrically connected to the target by means of a feed located near an end of the target mounting plate.

56. An apparatus according to claim 44 wherein a signal is sent by the sensor to the pulsed DC power supply to turn back on when a predefined time has elapsed.

57. An apparatus according to claim 44 wherein after the pulsed DC power supply has turned back on, a signal is sent to the RF power supply by the control mechanism to turn back on.

58. An apparatus according to claim 56 wherein the sensor further comprises means for detecting an electrical arc on the target when turning the pulsed DC power supply back on, and shutting down the pulsed DC power supply for a multiple of the predefined time period in response to detecting the electrical arc on the target.

59. An apparatus according to claim 58 wherein the sensor further comprises means for sensing an electrical arc on the target when turning the pulsed DC power supply back on after the multiple of the predefined time period, and shutting down the pulsed DC power supply for a greater multiple of the predefined time period in response to detecting the electrical arc on the target.

60. An apparatus according to claim 58 or 59 wherein the sensor further comprises means for sensing an electrical arc is not occurring on the target when turning the pulsed DC power supply back on after some multiple of the predefined time period, and resetting the predefined time period to its original value.

61. An apparatus according to claim 44 wherein the filter unit blocks RF feedback from the pulsed DC power supply.

62. A method according to claim 44 wherein the match network blocks DC feedback from the RF power supply.

63. An apparatus in accordance with claim 44 wherein the operating pressure in the vacuum sputter deposition system chamber is maintained between about 1.0×

10−

3 Torr and 10×

10−

3 Torr.

64. An apparatus in accordance with claim 44 wherein the magnetic field maintained on the target surface in the vacuum sputter deposition chamber is less than 600 oersted.