Methods and apparatus for applying periodic voltage using direct current

• US 9,039,871 B2
• Filed: 05/10/2011
• Issued: 05/26/2015
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: AES Global Holdings Pte Ltd. (Advanced Energy Industries, Inc. (China))
• Original Assignee: Advanced Energy Industries Incorporated
• Inventors: Nauman, Kenneth E., Finley, Kenneth, Larson, Skip B., Pelleymounter, Doug
• Primary Examiner(s): MCDONALD, RODNEY GLENN
• Application Number:
  US13/104,942
• Publication Number:
  US 20110248633A1
• Time in Patent Office: 1,477 Days
• Field of Search: 204/192.12, 204/298.08
• US Class Current: 204/192.12
• CPC Class Codes: C23C 14/3485 using pulsed power to the target
• CPC Class Codes: C23C 14/3492 Variation of parameters during sputtering
• CPC Class Codes: C23C 14/54 Controlling or regulating the coating process
• CPC Class Codes: C23C 14/542 Controlling the film thickness or evaporation rate
• CPC Class Codes: C23C 14/548 Controlling the composition
• CPC Class Codes: C23C 14/564 Means for minimising impurities in the coating chamber such as dust, moisture, residual gases
• CPC Class Codes: H01J 37/34 operating with cathodic sputtering H01J37/36 takes precedence ; methods of cathodic sputtering C23C14/34
• CPC Class Codes: H01J 37/3417 Arrangements
• CPC Class Codes: H01J 37/3429 Plural materials
• CPC Class Codes: H01J 37/3438 Electrodes other than cathode
• CPC Class Codes: H01J 37/3444 Associated circuits
• CPC Class Codes: H01J 37/3467 Pulsed operation, e.g. HIPIMS
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence
• CPC Class Codes: H05H 2242/22 DC, AC or pulsed generators

Abstract

Methods and apparatus for applying pulsed DC power to a plasma processing chamber are disclosed. In some implementations, frequency of the applied power is varied to achieve desired processing effects such as deposition rate, arc rate, and film characteristics. In addition, a method and apparatus are disclosed that utilize a relatively high potential during a reverse-potential portion of a particular cycle to mitigate possible nodule formation on the target. The relative durations of the reverse-potential portion, a sputtering portion, and a recovery portion of the cycle are adjustable to effectuate desired processing effects.

Claims

1. A method for applying pulsed DC power to a plasma processing chamber, the method comprising:

applying a negative potential to a cathode during a sputtering portion of a particular cycle of the pulsed DC power for a first time duration, the negative potential having a magnitude, whereby the application of the negative potential effectuates sputtering;

applying, during a reverse-potential portion of the particular cycle, a positive potential to the cathode for a second time duration that is less than the first time duration, a magnitude of the positive potential is the same as the magnitude of the negative potential; and

applying, during a recovery portion of the particular cycle, a recovery potential for a third time duration that has a magnitude that is less than the magnitude of the negative potential and is less than the magnitude of the positive potential;

wherein

the sum of the second and third time durations is less than the first time duration;

the sum of the second and third time durations is less than ten percent of the particular cycle; and

the second duration is less than ten percent of the particular cycle and at least one microsecond.

2. The method of claim 1 wherein the second duration is less than 10 microseconds.

3. A power supply comprising:

a power control component in communication a direct current power source and configured to direct the power to at least one electrode with an alternating polarity according to processor readable instructions; and

a non-transitory, tangible computer readable storage medium, encoded with the processor readable instructions to perform a method for applying power, the method comprising;

applying a negative potential to a cathode during a sputtering portion of a particular cycle of the pulsed DC power for a first time duration, the negative potential having a magnitude, whereby the application of the negative potential effectuates sputtering;

applying, during a reverse-potential portion of the particular cycle, a positive potential to the cathode for a second time duration that is less than the first time duration, a magnitude of the positive potential is the same as the magnitude of the negative potential; and

applying, during a recovery portion of the particular cycle, a recovery potential for a third time duration that has a magnitude that is less than the magnitude of the negative potential and is less than the magnitude of the positive potential;

wherein

the sum of the second and third time durations is less than the first time duration;

the sum of the second and third time durations is less than ten percent of the particular cycle; and

the second duration is less than ten percent of the particular cycle and at least one microsecond.

4. The power supply of claim 3, wherein the second duration is less than 10 microseconds.