Passive power distribution for multiple electrode inductive plasma source

• US 8,742,669 B2
• Filed: 11/19/2012
• Issued: 06/03/2014
• Est. Priority Date: 02/02/2009
• Status: Active Grant

• Current Assignee: AES Global Holdings Pte Ltd. (Advanced Energy Industries, Inc. (China))
• Original Assignee: Advanced Energy Industries Incorporated
• Inventors: Carter, Daniel, Brouk, Victor
• Primary Examiner(s): Le, Tung X
• Application Number:
  US13/681,258
• Publication Number:
  US 20130320853A1
• Time in Patent Office: 561 Days
• Field of Search: 315/111.21, 315/111.41, 315/111.51, 315/111.71
• US Class Current: 315/111.51
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32183 Matching circuits
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence

Abstract

Systems, methods, and Apparatus for controlling the spatial distribution of a plasma in a processing chamber are disclosed. An exemplary system includes a primary inductor disposed to excite the plasma when power is actively applied to the primary inductor; at least one secondary inductor located in proximity to the primary inductor such that substantially all current that passes through the secondary inductor results from mutual inductance through the plasma with the primary inductor. In addition, at least one terminating element is coupled to the at least one secondary inductor, the at least one terminating element affecting the current through the at least one secondary inductor so as to affect the spatial distribution of the plasma.

Claims

1. A method for controlling a spatial distribution of plasma in a processing chamber that includes a primary inductor and N secondary inductors, comprising:

exciting the plasma in the processing chamber with the primary inductor;

inductively coupling the primary inductor to each of N secondary inductors through the plasma, wherein N is equal to or greater than one; and

terminating each of the N secondary inductors such that substantially all current that passes through each of the N secondary inductors results from mutual inductance through the plasma with the primary inductor, the current through each of the N secondary inductors affecting the spatial distribution of the plasma.

2. The method of claim 1, wherein terminating each of the N secondary inductors includes passively terminating each of the N secondary inductors.

3. The method of claim 1, including regulating current through the N secondary inductors so as to regulate the spatial distribution of the plasma.

4. The method of claim 3, wherein terminating includes terminating each of the N secondary inductors with an impedance-adjustable termination element, and regulating current through the N secondary inductors includes regulating the current by adjusting an impedance of each of the impedance-adjustable termination elements.

5. The method of claim 4, including:

sensing at least one parameter indicative of plasma density in regions proximal to the N secondary inductors, and adjusting the impedance of the impedance-adjustable termination elements responsive to the sensing.

6. The method of claim 5, including sensing current in each of the N secondary inductors, and adjusting the impedance of the impedance-adjustable termination elements by adjusting a capacitance of the impedance-adjustable termination elements.

7. A system for controlling a spatial distribution of plasma in a processing chamber that includes a primary inductor and N secondary inductors, comprising:

means for exciting the plasma in the processing chamber with the primary inductor;

means for inductively coupling the primary inductor to each of N secondary inductors through the plasma, wherein N is equal to or greater than one; and

means for terminating each of the N secondary inductors such that substantially all current that passes through each of the N secondary inductors results from mutual inductance through the plasma with the primary inductor, the current through each of the N secondary inductors affecting the spatial distribution of the plasma.

8. The system of claim 7, wherein the means for terminating each of the N secondary inductors includes means for passively terminating each of the N secondary inductors.

9. The system of claim 7, including means for regulating current through the N secondary inductors so as to regulate the spatial distribution of the plasma.

10. The system of claim 9, wherein the means for terminating includes means for terminating each of the N secondary inductors with an impedance-adjustable termination element, and the means for regulating current through the N secondary inductors includes means for adjusting an impedance of each of the impedance-adjustable termination elements.

11. The system of claim 10, including:

means for sensing at least one parameter indicative of plasma density in regions proximal to the N secondary inductors, and means for adjusting the impedance of the impedance-adjustable termination elements responsive to the sensing.

12. The system of claim 11, including means for sensing current in each of the N secondary inductors, and means for adjusting a capacitance of the impedance-adjustable termination elements.