Internal Faraday shield having distributed chevron patterns and correlated positioning relative to external inner and outer TCP coil

Patent metadata

Field	Value
Publication number	US-9490106-B2
Application number	US-201113198683-A
Country	US
Kind code	B2
Filing date	Aug 4, 2011
Priority date	Apr 28, 2011
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

Plasma processing chambers having internal Faraday shields with defined groove configurations, are defined. In one example, the chamber includes an electrostatic chuck for receiving a substrate and a dielectric window connected to a top portion of the chamber, where the dielectric window disposed over the electrostatic chuck. Also included is a Faraday shield disposed inside of the chamber and defined between the electrostatic chuck and the dielectric window. The Faraday shield includes an inner zone having an inner radius range, a middle zone having a middle radius range, an outer zone having an outer radius range, where the inner zone is adjacent to the middle zone, and the middle zone being adjacent to the outer zone. Further defining the Faraday shield is a first set of radial slots (A) extending through the inner zone, the middle zone, and the outer zone, a second set of radial slots (C) extending through only the outer zone; and a third set of radial slots (B) extending through the middle zone and outer zone. In this configuration, the first, second and third radial slots are arranged radially around the Faraday shield in a repeating pattern of slots A, C, B, and C.

First claim

What is claimed is:

1. A plasma processing chamber, comprising:
an electrostatic chuck for receiving a substrate;
a chamber liner surrounding the electrostatic chuck and coupled to a wall of the plasma processing chamber, the wall of the processing chamber being electrically connected to ground;
an upper liner coupled to the chamber liner and being electrically connected to ground via the chamber liner and the wall of the processing chamber, the upper liner has a tapered profile that is gradually thinning along a downward direction that is toward the chamber liner, the tapered profile provides an angle that is away from a center of the chamber;
a Faraday shield having an outer edge that is configured for support on a lowered upper surface of the upper liner, the lowered upper surface including O-rings that provide electrical conduction for the Faraday shield to ground;
a dielectric window placed over the outer edge of the Faraday shield, wherein other than the outer edge where the dielectric window is placed over, a space is defined separating the Faraday shield from the dielectric window, and the dielectric window is disposed at a top portion of the chamber, the dielectric window being oriented above the electrostatic chuck, wherein the Faraday shield is disposed inside of the chamber and under the dielectric window so as to be defined between the electrostatic chuck and the dielectric window, the Faraday shield includes,
(a) an inner zone having an inner radius range that surrounds a center hole that bounds an inner edge;
(b) a middle zone having a middle radius range;
(c) an outer zone having an outer radius range, the inner zone being adjacent to the middle zone, and the middle zone being adjacent to the outer zone;
(d) a first set of radial slots (A) extending through the inner zone, the middle zone, and the outer zone;
(e) a second set of radial slots (C) extending through only the outer zone; and
(f) a third set of radial slots (B) extending through the middle zone and outer zone, wherein the first, second and third sets of radial slots are consecutively arranged radially around the Faraday shield in a repeating pattern of slots A, C, B, and C, the outer edge of the Faraday shield surrounds the outer zone, such that the repeating pattern of slots A, C, B, C do not extend into the outer edge and the first set of radial slots A do not extend into the inner edge;
transformer coupled plasma (TCP) coils disposed over the dielectric window, the TCP coils includes an inner coil and an outer coil, each of the inner coil and outer coil has a flat coil distribution with a circular winding, wherein,
the outer coil is disposed over the dielectric window and is oriented over the outer zone of the Faraday shield that includes consecutively repeating slots A, C, B, and C to define an open area under the outer coil in the outer zone to provide passage for magnetic flux generated by the outer coil that is coupled to an RF generator; and
the inner coil is disposed over the dielectric window and is at least partially oriented over the middle and inner zones of the Faraday shield that include consecutively repeating slots A and B,
wherein the inner coil and outer coil, as correlated to the sets of radial slots, are connected to a tuning circuit, the turning circuit being configured adjust magnetic flux imparted through either or both of the outer zone and middle zone of the Faraday shield.

2. The plasma processing chamber as recited in claim 1 , wherein each one of the slots A, B, and C are defined from a chevron shaped groove.

3. The plasma processing chamber as recited in claim 2 , wherein the chevron shaped groove does not include a line of sight between respective sides of the Faraday shield.

4. The plasma processing chamber of claim 1 , wherein the space is between 0.3 mm and 1.5 mm.

5. The plasma processing chamber of claim 1 , wherein the inner zone has 25 of said first set of radial slots (A), the middle zone has 50 of said first set of radial slots (A) and said second set of radial slots (B), and the outer zone has 100 of said first set of radial slots (A), said second set of radial slots (B), and said third set of radial slots (C).

6. A plasma processing system, comprising:
a chamber including a lower liner and an upper liner with a tapered structure, the upper liner being grounded;
an electrostatic chuck for receiving a substrate;
a Faraday shield having an outer edge that is configured for support on a lowered upper surface of the upper liner, wherein O-rings are provided between the lowered upper surface of the upper liner and the outer edge of the Faraday shield;
a dielectric window disposed over the Faraday shield and supported on the outer edge of the Faraday shield, wherein other than the outer edge where the dielectric window is disposed over, a space separating the Faraday shield from the dielectric window is set to be between 0.3 mm and 1.5 mm, and the Faraday shield is inside the chamber facing the electrostatic chuck, the Faraday shield being electrically grounded by contact with the upper liner and further facilitated via the O-rings, the Faraday shield includes,
(a) an inner zone having an inner radius range that surrounds a center hole that bounds an inner edge;
(b) a middle zone having a middle radius range;
(c) an outer zone having an outer radius range, the inner zone being adjacent to the middle zone, and the middle zone being adjacent to the outer zone;
(d) a first set of radial slots (A) extending through the inner zone, the middle zone, and the outer zone;
(e) a second set of radial slots (C) extending through only the outer zone; and
(f) a third set of radial slots (B) extending through the middle zone and outer zone, wherein the first, second and third sets of radial slots are consecutively arranged radially around the Faraday shield in a repeating pattern of slots A, C, B, C the outer edge of the Faraday shield surrounds the outer zone, such that the repeating pattern of slots A, C, B, C do not extend into the outer edge and the first set of radial slots A do not extend into the inner edge;
transformer coupled plasma (TCP) coils disposed over the dielectric window, the TCP coils includes an inner coil and an outer coil, each of the inner coil and outer coil has a flat coil distribution with a circular winding, wherein,
the outer coil is oriented over the outer zone of the Faraday shield that includes consecutively repeating slots A, C, B, C to define an open area under the outer coil in the outer zone to provide passage for magnetic flux generated by the outer coil that is coupled to an RF generator; and
the inner coil is oriented over the middle and inner zones of the Faraday shield that include consecutively repeating slots A, B;
wherein the inner zone has 25 of said first set of radial slots (A), the middle zone has 50 of said first set of radial slots (A) and said second set of radial slots (B), and the outer zone has 100 of said first set of radial slots (A), said second set of radial slots (B), and said third set of radial slots (C);
wherein the inner coil and outer coil are connected to a tuning circuit, the turning circuit being configured adjust magnetic flux imparted through either or both of the outer zone and middle zone of the Faraday shield.

7. The plasma processing system of claim 6 , wherein each one of the slots A, B, and C are defined from a chevron shaped groove.

8. The plasma processing system of claim 7 , wherein the chevron shaped groove does not include a line of sight between respective sides of the Faraday shield.

9. The plasma processing system of claim 6 , wherein the Faraday shield is made of stainless steel, or is made of stainless steel having a passivation c

Assignees

• Drewery John
• Long Maolin
• Paterson Alex
• Lam Res Corp

Inventors

• Drewery John
• Long Maolin
• Paterson Alex

Classifications

• H10P50/242

  of Group IV materials · CPC title

• H01J37/32651 Primary

  Shields, e.g. dark space shields, Faraday shields · CPC title

• H01J37/321

  the radio frequency energy being inductively coupled to the plasma · CPC title

• H01J37/32633

  Baffles · CPC title

• C23F1/00 Primary

  Etching metallic material by chemical means (manufacture of printing surfaces B41C; manufacture of printed circuits H05K) · CPC title