Showerhead with reduced backside plasma ignition

Patent metadata

Field	Value
Publication number	US-10378108-B2
Application number	US-201615219758-A
Country	US
Kind code	B2
Filing date	Jul 26, 2016
Priority date	Oct 8, 2015
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

Embodiments of the present disclosure relate to a showerhead assembly for use in a processing chamber. The showerhead assembly includes a porous insert disposed in a space defined between a gas distribution plate and a base plate to moderate the corrosive radicals resulting from plasma ignition to reduce particle issues and metal contamination in the chamber. The porous insert is a conductive material, such as metal, used to reduce the gap electrical field strength, or may be a dielectric material such as ceramic, polytetrafluoroethylene, polyamide-imide, or other materials with a low dielectric loss and high electrical field strength under conditions of high frequency and strong electric fields. As such, the electrical breakdown threshold is enhanced. The porous insert may reduce and/or eliminate showerhead backside plasma ignition and may include multiple concentric narrow rings that cover gas holes of the gas distribution plate.

First claim

The invention claimed is:

1. A gas distribution plate, comprising:
a disk-shaped body having a center axis;
a first zone defined in the body, the first zone comprising a first plurality of gas holes extending through the body, the first plurality of gas holes arranged in a circle around the center axis;
a second zone defined in the body and encircling the first zone, the second zone comprising a second plurality of gas holes extending through the body, the second plurality of gas holes arranged in a circle around the center axis;
a plurality of circular gasket seals positioned on the gas distribution plate and positioned concentrically around the center axis and within the first zone and the second zone; and
a first ring shaped porous insert positioned over the first plurality of gas holes, wherein the ring shaped porous insert is positioned between two of the plurality of circular gasket seals.

2. The gas distribution plate of claim 1 , further comprising:
a second ring shaped porous insert covering the second plurality of gas holes.

3. The gas distribution plate of claim 1 , wherein the first ring shaped porous insert is an electrically conductive material.

4. The gas distribution plate of claim 1 , wherein the first ring shaped porous insert has an average pore size of between about 5 micrometers and about 120 micrometers.

5. The gas distribution plate of claim 1 , wherein the first ring shaped porous insert is a dielectric material.

6. The gas distribution plate of claim 1 , wherein the first ring shaped porous insert has a porosity of between about 20% and about 70%.

7. The gas distribution plate of claim 1 , wherein the gas distribution plate comprises a silicon containing material.

8. The gas distribution plate of claim 2 , wherein the second porous insert is an electrically conductive material.

9. The gas distribution plate of claim 2 , wherein the second porous insert is a dielectric material.

10. The gas distribution plate of claim 2 , wherein the second porous insert has an average pore size of between about 5 micrometers and about 120 micrometers.

11. The gas distribution plate of claim 2 , wherein the second porous insert has a porosity of between about 20% and about 70%.

12. A gas distribution plate, comprising:
a disk-shaped body having a center axis;
a first zone defined in the body, the first zone comprising:
a first plurality of gas holes extending through the body and arranged in a first circle around the center axis; and
a second plurality of gas holes extending through the body and arranged in a second circle around the center axis;

a second zone defined in the body and encircling the first zone, the second zone comprising:
a third plurality of gas holes extending through the body and arranged in a third circle around the center axis; and
a fourth plurality of gas holes extending through the body and arranged in a fourth circle around the center axis;

a plurality of circular gasket seals positioned on the gas distribution plate within the first zone and the second zone, wherein the plurality of circular gasket seals are positioned concentrically around the center axis;
a first ring shaped porous insert positioned over the first circle of gas holes of the first plurality of gas holes; and
a second ring shaped porous insert positioned over the second circle of gas holes of the first plurality of gas holes,
wherein each of the ring shaped porous inserts are positioned between two gasket seals of the plurality of circular gasket seals.

13. The gas distribution plate of claim 12 , further comprising:
a third ring shaped porous insert covering the third circle of the third plurality of gas holes of the second zone.

14. The gas distribution plate of claim 12 , wherein the first ring shaped porous insert is an electrically conductive material.

15. The gas distribution plate of claim 12 , wherein the first ring shaped porous insert has an average pore size of between about 5 micrometers and about 120 micrometers.

16. The gas distribution plate of claim 12 , wherein the first ring shaped porous insert is a dielectric material.

17. The gas distribution plate of claim 12 , wherein the first ring shaped porous insert has a porosity of between about 20% and about 70%.

18. The gas distribution plate of claim 12 , wherein the gas distribution plate comprises a silicon containing material.

19. The gas distribution plate of claim 13 , wherein the second porous insert is a conductive material.

20. The gas distribution plate of claim 13 , wherein the second porous insert is a dielectric material.

Assignees

• Applied Materials Inc

Inventors

• Wang Haitao
• Noorbakhsh Hamid
• Zhang Chunlei
• Shoji Sergio Fukuda
• Ramaswamy Kartik
• Smith Roland
• Mays Brad L

Classifications

• C23C16/45565 Primary

  Shower nozzles · CPC title

• H01J37/3244

  Gas supply means · CPC title

• C23C16/4401

  Means for minimising impurities, e.g. dust, moisture or residual gas, in the reaction chamber · CPC title