Backside gas leakby for bevel deposition reduction

Patent metadata

Field	Value
Publication number	US-11495483-B2
Application number	US-202017071595-A
Country	US
Kind code	B2
Filing date	Oct 15, 2020
Priority date	Oct 15, 2020
Publication date	Nov 8, 2022
Grant date	Nov 8, 2022

Abstract

Exemplary substrate support assemblies include an electrostatic chuck body defining a substrate platform. The substrate platform may be characterized by an upper surface. The platform may define a purge aperture. The platform may include a plurality of mesas that are disposed in an inner region of the upper surface. Each of the mesas may protrude upward from the upper surface. The platform may include a sealing band that extends upward from the upper surface in a circumferential pattern and partially encircles the inner region of the upper surface. Top surfaces of the mesas and sealing band may form a support surface for a substrate. The sealing band may define a number of gaps. The assemblies may include a support stem coupled with the electrostatic chuck body, a heater embedded within the electrostatic chuck body, and a backside gas source that is coupled with the purge aperture of the support surface.

First claim

What is claimed is:

1. A substrate support assembly, comprising:
an electrostatic chuck body defining a substrate platform, wherein:
the substrate platform is characterized by an upper surface, the substrate platform defining a purge aperture; and
the substrate platform comprises:
a plurality of mesas that are disposed in an inner region of the upper surface, wherein each of the plurality of mesas protrudes upward from the upper surface; and
a sealing band that extends upward from the upper surface in a circumferential pattern and partially encircles the inner region of the upper surface, wherein:
top surfaces of the plurality of mesas and the sealing band form a support surface for a substrate;
the sealing band defines a number of gaps;
the sealing band is characterized by a plurality of protruding segments that define a support seat for an outer periphery of a substrate, wherein adjacent pairs of the plurality of protruding segments are separated by a respective one of the number of gaps; and
a size of each of the plurality of segments and a size of each of the number of gaps are substantially equal;

a support stem coupled with the electrostatic chuck body;
a heater embedded within the electrostatic chuck body; and

a backside gas source that is coupled with the purge aperture of the support surface.

2. The substrate support assembly of claim 1 , wherein:
the top surfaces of the plurality of mesas and the sealing band are the same height.

3. The substrate support assembly of claim 1 , wherein:
the gaps are provided at regular angular intervals about the sealing band.

4. The substrate support assembly of claim 1 , wherein:
the support stem defines a fluid lumen that extends between and couples the backside gas source and the aperture.

5. The substrate support assembly of claim 1 , wherein:
the plurality of mesas are uniformly arranged about the inner region of the upper surface.

6. The substrate support assembly of claim 1 , wherein:
the sealing band is positioned on the substrate platform so as to define a support seat for an outer periphery of a substrate; and
a portion of the sealing band and a portion of each gap extends radially outward from an outermost edge of the support seat.

7. The substrate support assembly of claim 1 , wherein:
the sealing band is characterized by a generally circular shape that is interrupted by the number of gaps.

8. The substrate support assembly of claim 1 , wherein:
the backside gas source delivers a reactive purge gas.

9. The substrate support assembly of claim 8 , wherein:
the reactive purge gas comprises O 2 .

10. The substrate support assembly of claim 1 , wherein:
a peripheral edge of the sealing band and a portion of each of the number of gaps extend radially outward of a peripheral edge of a substrate seated on the sealing band.

11. A substrate support assembly, comprising:
electrostatic chuck body defining a substrate platform, wherein:
the substrate platform is characterized by an upper surface, the substrate platform defining a single purge aperture; and
the substrate platform comprises:
a plurality of mesas that are disposed in an inner region of the upper surface, wherein each of the plurality of mesas protrudes upward from the upper surface; and
a sealing band that extends upward from the upper surface in a circumferential pattern and partially encircles the inner region of the upper surface, wherein:
the sealing band is characterized by a plurality of protruding segments that define a support seat for an outer periphery of a substrate;
adjacent pairs of the plurality of protruding segments are separated by one of a plurality of gaps; and
a size of each of the plurality of segments and a size of each of the plurality of gaps are substantially equal;

a support stem coupled with the electrostatic chuck body; and

a backside gas source that is coupled with the purge aperture of the support surface.

12. The substrate support assembly of claim 11 , wherein:
the gaps are provided at regular angular intervals about the sealing band.

13. The substrate support assembly of claim 11 , wherein:
the support stem defines a fluid lumen that extends between and couples the backside gas source and the aperture.

14. The substrate support assembly of claim 11 , wherein:
the plurality of mesas are uniformly arranged about the inner region of the upper surface.

15. The substrate support assembly of claim 11 , wherein:
the backside gas source delivers a reactive purge gas.

16. The substrate support assembly of claim 11 , wherein:
a peripheral edge of the sealing band and a portion of each of the plurality of gaps extend radially outward of a peripheral edge of a substrate seated on the sealing band.

17. A method of processing a semiconductor substrate, comprising:
clamping a semiconductor substrate to a support surface of a substrate platform using a chucking voltage, wherein:
the substrate platform is characterized by an upper surface and defines a single purge aperture; and
the substrate platform comprises:
a plurality of mesas that are disposed in an inner region of the upper surface, wherein each of the plurality of mesas protrudes upward from the upper surface; and
a sealing band that extends upward from the upper surface in a circumferential pattern and partially encircles the inner region of the upper surface, wherein:
the support surface is formed from top surfaces of the plurality of mesas and the sealing band;
the sealing band defines a number of gaps separating a number of protruding segments; and
a size of each of the number of protruding segments and a size of each of the number of gaps are substantially equal; and

flowing a reactive purge gas to an underside of the semiconductor substrate and through the number of gaps.

18. The method of processing a semiconductor substrate of claim 17 , wherein:
the reactive purge gas comprises 02.

19. The method of processing a semiconductor substrate of claim 17 , wherein:
at least a portion of each gap and each protruding segment of the sealing band extends outward beyond an outer periphery of the semiconductor substrate.

20. The method of processing a semiconductor substrate of claim 17 , wherein:
a peripheral edge of the sealing band and a portion of each of the number of gaps extend radially outward of a peripheral edge of the semiconductor substrate.

Assignees

• Applied Materials Inc

Inventors

• Parimi Venkata Sharat Chandra
• Kedlaya Diwakar

Classifications

• H10P72/0404

  for general liquid treatment, e.g. etching followed by cleaning · CPC title

• H10P72/722 Primary

  Details of electrostatic chucks · CPC title

• H10P72/7611

  characterised by edge profile or support profile · CPC title

• H10P72/72

  using electrostatic chucks · CPC title

• H10P72/0432

  mainly by conduction · CPC title