Component of a substrate support assembly producing localized magnetic fields

Patent metadata

Field	Value
Publication number	US-10388493-B2
Application number	US-201113234473-A
Country	US
Kind code	B2
Filing date	Sep 16, 2011
Priority date	Sep 16, 2011
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

A component of a substrate support assembly such as a substrate support or edge ring includes a plurality of current loops incorporated in the substrate support and/or the edge ring. The current loops are laterally spaced apart and extend less than halfway around the substrate support or edge ring with each of the current loops being operable to induce a localized DC magnetic field of field strength less than 20 Gauss above a substrate supported on the substrate support during plasma processing of the substrate. When supplied with DC power, the current loops generate localized DC magnetic fields over the semiconductor substrate so as to locally affect the plasma and compensate for non-uniformity in plasma processing across the substrate.

First claim

What is claimed is:

1. A component of a substrate support assembly useful for supporting individual semiconductor substrates undergoing plasma processing, the component comprising:
an electrostatic chuck for supporting a semiconductor substrate during plasma processing thereof or an edge ring which surrounds the semiconductor substrate, wherein the electrostatic chuck includes an embedded electrode receiving a first voltage to electrostatically attract the semiconductor substrate to the substrate support assembly; and
a plurality of current loops incorporated in the electrostatic chuck or the edge ring, the plurality of current loops being laterally spaced apart and extending less than halfway around the electrostatic chuck or edge ring, each of the plurality of current loops being a wire formed into a loop;
one or more DC power sources electrically connected to the plurality of current loops; and
a controller configured to:
supply the first voltage to the embedded electrode;
supply a DC current to the plurality of current loops from the one or more DC power sources, the DC current directly supplied to the plurality of current loops being separate from and in addition to the first voltage supplied to the embedded electrode; and
control the one or more DC power sources such that each of the plurality of current loops is independently operable and generates a localized DC magnetic field above the semiconductor substrate supported on the electrostatic chuck when the DC current is applied to a current loop of the plurality of current loops during plasma processing of the semiconductor substrate to adjust or correct the plasma processing of the semiconductor substrate
wherein the localized DC magnetic field generated by the plurality of current loops does not generate plasma.

2. The component of claim 1 , wherein the electrostatic chuck includes a baseplate, a thermal insulating layer above the baseplate, and a ceramic plate with the embedded electrode above the thermal insulating layer; and the plurality of current loops are embedded in the baseplate or the ceramic plate such that the plurality of current loops lie substantially in a plane parallel to an upper surface of the semiconductor substrate.

3. The component of claim 1 , wherein the plurality of current loops are embedded in the edge ring such that the plurality of current loops lie substantially in a plane parallel to an upper surface of the semiconductor substrate.

4. The component of claim 1 , wherein the plurality of current loops includes up to 200 current loops that have the same size and a circular shape and that are embedded in the electrostatic chuck or the edge ring.

5. The component of claim 1 , wherein each of the plurality of current loops has a circular, semi-circular, oval, semi-oval, square, rectangular, trapezoidal, triangular or polygonal shape.

6. The component of claim 1 , wherein the wire has a diameter of between about 0.5-10 mm.

7. The component of claim 1 , wherein a periphery of each current loop of the plurality of current loops is laterally offset from a periphery of an adjacent current loop of the plurality of current loops.

8. A plasma processing chamber incorporating the component of claim 1 , wherein the electrostatic chuck includes a heater layer having a plurality of heaters laterally distributed across the electrostatic chuck and operable to tune a spatial temperature profile for critical dimension (CD) control, the plurality of current loops including at least 9 current loops distributed laterally across the electrostatic chuck and operable to compensate for local non-uniformity in processing on the semiconductor substrate.

9. The plasma processing chamber of claim 8 , wherein the plasma processing chamber is a plasma etching chamber.

10. The plasma processing chamber of claim 8 , wherein the controller is configured to control the one or more DC power sources such that the one or more DC power sources supply the DC current to the plurality of current loops at the same time or different times with the same or different levels of the DC current, and wherein the DC current flows in the plurality of current loops in the same direction or different directions.

11. A method of controlling and/or adjusting a magnetic field pattern during plasma processing of the semiconductor substrate undergoing processing in the plasma processing chamber of claim 8 , comprising:
a) supporting the semiconductor substrate on the electrostatic chuck;
b) plasma processing the semiconductor substrate; and
c) supplying at least one of the plurality of current loops with the DC current to generate the localized DC magnetic field in a region above the semiconductor substrate so as to compensate for local non-uniformity in processing.

12. The method of claim 11 , further comprising supplying the plurality of current loops with different amounts of the DC current, with the DC current travelling in a clockwise direction in each of the plurality of current loops.

13. The method of claim 11 , further comprising supplying the plurality of current loops with different amounts of the DC current, with the DC current travelling in different directions in some of the plurality of current loops.

14. The method of claim 11 , wherein each of the plurality of current loops generates the localized DC magnetic field above the semiconductor substrate with a field strength of less than 1 Gauss.

15. The method of claim 14 , wherein the field strength is less than 20 Gauss or less than 0.5 Gauss.

16. The method of claim 11 , wherein the plurality of current loops includes at least two current loops, and wherein the electrostatic chuck is surrounded by an edge ring having the at least two current loops, with each of the at least two current loops arranged on an opposite side of the edge ring.

17. The method of claim 16 , wherein the plurality of current loops includes at least four current loops; wherein the edge ring has the at least four current loops, with each of the at least four current loops arranged diametrically opposite to another one of the at least four current loops; and wherein each of the at least four current loops has a circular, semi-circular, oval, semi-oval, square, rectangular, trapezoidal, triangular or polygonal shape.

18. The method of claim 11 , wherein the plasma processing is plasma etching and further comprising, after steps a) and b) and prior to step c):
removing the semiconductor substrate from the plasma processing chamber;
detecting an etch-rate non-uniformity in an etch-rate pattern on the semiconductor substrate; and
modifying step c) so as to compensate for film thickness induced etch-rate non-uniformity, etch chamber induced etch-rate non-uniformity or plasma induced etch-rate non-uniformity.

19. The method of claim 11 , wherein the DC current is supplied from the one or more DC power sources comprising a multiplexed power scheme.

20. The method of claim 11 , wherein the electrostatic chuck is adapted to support the semiconductor substrate having a diameter of at least about 200 mm, at least about 300 mm or at least about 450 mm.

Assignees

• Singh Harmeet
• Gaff Keith
• Richardson Brett
• Lee Sung
• Lam Res Corp

Inventors

• Singh Harmeet
• Gaff Keith
• Richardson Brett
• Lee Sung

Classifications

• H10P72/0421

  for drying etching · CPC title

• H10P50/283

  by chemical means · CPC title

• H01F7/20

  without armatures (cores H01F3/00; coils H01F5/00 {; shaping metal by applying magnetic forces B21D26/14; electromagnets specially adapted for NMR applications G01R33/381}) · CPC title

• H01J37/32669 Primary

  Particular magnets or magnet arrangements for controlling the discharge · CPC title

• H01J37/32715

  Workpiece holder · CPC title