Symmetric RF return path liner

Patent metadata

Field	Value
Publication number	US-9953825-B2
Application number	US-201213683305-A
Country	US
Kind code	B2
Filing date	Nov 21, 2012
Priority date	Nov 24, 2011
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

An apparatus and system for plasma processing a substrate using RF power includes a chamber having walls for housing an electrostatic chuck (ESC) and a top electrode. The top electrode is oriented opposite the ESC to define a processing region. An inner line with a tubular shaped wall is defined within and is spaced apart from the walls of the chamber and is oriented to surround the processing region. The tubular shaped wall extends a height between a top and a bottom. The tubular shaped wall has functional openings for substrate access and facilities access and dummy openings oriented to define symmetry for selected ones of the functional openings. A plurality of straps are connected to the bottom of the tubular shaped wall of the inner liner and are electrically coupled to a ground ring within the chamber to provide an RF power return path during plasma processing.

First claim

What is claimed is:

1. A chamber for plasma processing a substrate using RF power, comprising:
the chamber having walls for housing an electrostatic chuck (ESC) and a top electrode, the top electrode oriented opposite the ESC to define a processing region;
an inner liner having tubular shaped wall defined within the walls of the chamber and spaced apart from the walls of the chamber, the inner liner being oriented to surround the processing region and the tubular shaped wall extending a height between a bottom and a top, the tubular shaped wall having functional openings for substrate access and facilities access, and further including dummy openings oriented symmetrically opposite to selected ones of the functional openings so as to define symmetry for the selected ones of the functional openings, wherein the dummy openings are filled using insulating material plugs;
a plurality of straps connected to the bottom of the tubular shaped wall of the inner liner, the plurality of straps further being electrically coupled to a ground ring within the chamber to provide an RF power return path to ground during the plasma processing, the ground ring configured to surround the ESC having a substrate support, the ground ring disposed at a level that is below the substrate support;
a dummy via defined to extend downward from the bottom of the tubular shaped wall of the inner liner and oriented on a side that is symmetrically opposite to a side of the tubular shaped wall of the inner liner that includes a via, wherein the dummy via is filled using an insulating material plug, the dummy via and the via are oriented below one or more of the plurality of straps that are connected to the bottom of the inner liner, wherein the via provides an opening that is used to route facility connections for the chamber and the dummy via is used to provide a structural symmetry inside the chamber;
an edge ring configured to surround the substrate support of the ESC; and
a dielectric ring disposed over the ground ring, such that a space between the dielectric ring and the tubular shaped wall of the inner liner remains for gas flow conductance, the plurality of straps are distributed uniformly around and between the bottom portion of the tubular shaped wall of the inner liner and the ground ring with symmetric spacing defined there-between for facilitating said gas flow conductance.

2. The apparatus of claim 1 , wherein the number of straps is selected from any one of a group of 13 straps, a group of 14 straps, and a group of 20 straps.

3. The apparatus of claim 2 , wherein the number of straps is selected from a group of 13 pairs of straps or a group of 14 pairs of straps, wherein the pairs of straps have symmetric inter-strap spacing defined there-between.

4. The apparatus of claim 1 , wherein the plurality of straps are made of copper.

5. The apparatus of claim 4 , wherein the plurality of straps are coated with an insulating material.

6. The apparatus of claim 5 , wherein the insulating material is anyone from a group consisting of Rhodorsil, Kapton, perfluoroalkoxy polymer resin (PFA), and Polyimide/Polyamide-imide.

7. The apparatus of claim 1 , wherein the dummy openings include dummy port openings, and dummy door openings.

8. The apparatus of claim 1 , wherein the insulating material is quartz.

9. A system for plasma processing a substrate using radio frequency (RF) power, comprising:
a chamber having walls for housing an electrostatic chuck (ESC) and a top electrode, the top electrode oriented opposite the ESC to define a processing region;
an inner liner having tubular shaped wall defined within the walls of the chamber and spaced apart from the walls of the chamber, the inner liner being oriented to surround the processing region and the tubular shaped wall extending a height between a bottom and a top, the tubular shaped wall having functional openings for substrate access and facilities access, and further including dummy openings oriented to define symmetry for selected ones of the functional openings, wherein the dummy openings are filled using insulating material plugs;
a plurality of straps connected to bottom portion of the tubular shaped wall of the inner liner at one end and electrically coupled to a ground ring within the chamber at an opposite end to provide RF power return path to ground during the plasma processing, the ground ring disposed to surround the ESC having a substrate support, the ground ring is disposed at a level that is below the substrate support;
a dummy via defined to extend downward from the bottom of the tubular shaped wall of the inner liner and oriented on a side that is opposite to a side of the tubular shaped wall of the inner liner that includes a via, the dummy via is filled using an insulating material plug, the dummy via and the via are oriented below one or more of the plurality of straps that are connected to the bottom of the inner liner, wherein the via is used to route facility connections for the chamber and the dummy via is used to provide a structural symmetry inside the chamber;
an edge ring disposed to surround the substrate support of the ESC;
a dielectric ring is disposed adjacent to the edge ring and configured to surround the edge ring, the dielectric ring is spaced apart from the tubular shaped wall of the inner liner, the ground ring defined below the dielectric ring;
a quartz ring is defined adjacent to the ground ring, such that the quartz ring is between at least a portion of the ground ring and the ESC;
the plurality of straps are distributed uniformly around the bottom portion of the tubular shaped wall of the inner liner and oriented between the bottom portion of the tubular shaped wall and the ground ring with symmetric spacing defined there-between for facilitating gas flow conductance;
an RF power source coupled to the electrostatic chuck for providing RF power to the processing region; and
a process gas source connected to the top electrode for supplying process gas to the processing region.

10. The system of claim 9 , wherein the RF power source further includes,
a first RF power source and a second RF power source, wherein the first RF power source is configured to provide low frequency RF power of about 2 MHz and the second RF power source is configured to provide high frequency RF power of about 27 MHz.

11. The system of claim 9 , further includes,
a first RF power source and a second RF power source, wherein the first RF power source is configured to provide low frequency RF power of about 2 MHz and the second RF power source is configured to provide high frequency RF power of about 60 MHz.

12. The system of claim 9 , further includes a plurality of control knobs to adjust processing attributes of gas plasma generated within the plasma processing region of the plasma chamber from the process gas supplied by the top electrode.

13. The system of claim 9 , wherein the number of straps is selected from any one of a group of 13 straps, a group of 14 straps, or a group of 20 straps.

14. The system of claim 9 , wherein the number of straps is selected from a group of 13 pairs of straps or a group of 14 pairs of straps, wherein the pairs of straps have symmetric inter-strap spacing defined there-between.

15. The system of claim 9 , wherein the dummy openings include dummy port openings, and dummy door openings, wherein the insulating material is quartz.

Assignees

• Lam Res Corp

Inventors

• Carman David
• Taylor Travis
• Ramdutt Devin

Classifications

• H10P72/72

  using electrostatic chucks · CPC title

• H10P95/00 Primary

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• H01J37/32091 Primary

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

• H01J37/32477

  characterised by the means for protecting vessels or internal parts, e.g. coatings · CPC title

• H01L21/02 Primary

  Electricity · mapped topic