Polishing of electrostatic substrate support geometries

Patent metadata

Field	Value
Publication number	US-10654147-B2
Application number	US-201815886574-A
Country	US
Kind code	B2
Filing date	Feb 1, 2018
Priority date	Oct 17, 2017
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

Methods of polishing a patterned surface of an electrostatic chucking (ESC) substrate support to be used in plasma assisted or plasma enhanced semiconductor manufacturing chambers are provided herein. In particular, embodiments described herein, provide polishing methods that round and debur the edges of elevated features and remove dielectric material from the non-substrate contacting surfaces of a patterned substrate support to reduce defectivity associated therewith.

First claim

The invention claimed is:

1. A method of polishing a substrate support, comprising:
rotating a polishing platen having a polishing pad mounted thereon;
applying a polishing fluid to the polishing pad;
urging a patterned surface of the substrate support against the polishing pad with a polishing downforce, wherein the patterned surface of the substrate support comprises a plurality of protrusions extending from one or more recessed surfaces, and wherein a substrate contacting surface area of the patterned surface is less than about 20% of a non-device side surface area of a substrate to be disposed on the substrate support; and
polishing the patterned surface of the substrate support, comprising:
removing a first thickness of material from a plurality of protrusions at substrate facing surfaces thereof; and
removing a second thickness of material from one or more sides of the plurality of protrusions, wherein the second thickness is about the same or more than the first thickness.

2. The method of claim 1 , wherein each of the plurality of protrusions have a height of between about 3 μm and about 50 μm.

3. The method of claim 2 , wherein the patterned surface of the substrate support is formed of a dielectric material.

4. The method of claim 3 , wherein the plurality of protrusions have a mean diameter between about 500 μm and about 5 mm.

5. The method of claim 4 , wherein polishing the patterned surface includes smoothing one or more recessed surfaces thereof to a surface roughness less than about 0.2 μm Ra.

6. The method of claim 4 , wherein a substrate contacting surface area of the patterned surface is less than about 10% of a non-device side surface area of a substrate to be disposed on the substrate support.

7. The method of claim 4 , wherein the patterned surface further comprises a plurality of inner sealing bands, each one coaxially disposed about an opening formed in the dielectric material of the substrate support.

8. The method of claim 7 , wherein the patterned surface of the substrate support is formed by bead blasting a surface of the dielectric material thereof.

9. The method of claim 3 , wherein the dielectric material is selected from the group consisting of aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), titanium oxide (TiO), titanium nitride (TiN), yttrium oxide (Y 2 O 3 ), and combinations thereof.

10. The method of claim 9 , wherein the first thickness is between about 0.5 μm and about 4 μm.

11. The method of claim 3 , wherein the patterned surface of the substrate support further comprises one or more outer sealing bands concentrically disposed on the substrate support and at least one of the one or more outer sealing bands is proximate to an outer circumference of the patterned surface.

12. The method of claim 1 , wherein the polishing pad comprises a urethane impregnated felt material having a nap length of more than about 300 μm.

13. The method of claim 1 , wherein the polishing pad has a pore volume of more than about 50%.

14. A method of polishing a patterned surface of a substrate support, comprising:
rotating a polishing platen having a polishing pad mounted thereon;
applying a polishing fluid to the polishing pad, the polishing fluid comprising diamond abrasives having an average diameter of less than about 10 μm;
urging the patterned surface of the substrate support against the polishing pad with a polishing downforce, wherein:
the patterned surface of the substrate support comprises a plurality of elevated features extending from one or more recessed surfaces,
a surface area of the plurality of elevated features defining a substrate contacting surface is less than about 20% of a non-device side surface area of a substrate to be disposed on the substrate support,
the patterned surface is formed of a dielectric material selected from the group consisting of aluminum oxide (Al2O3), aluminum nitride (AlN), titanium oxide (TiO), titanium nitride (TiN), yttrium oxide (Y2O3), and combinations thereof,
the plurality of elevated features further comprises a plurality of inner sealing bands, one of each of the inner sealing bands coaxially disposed about an opening formed in the dielectric material of the substrate support; and

polishing the patterned surface of the substrate support to remove more than about 0.5 μm of material from the substrate contacting surfaces of the elevated features.

15. A method of polishing a patterned surface of a substrate support, comprising:
rotating a polishing platen having a polishing pad mounted thereon;
applying a polishing fluid to the polishing pad, the polishing fluid comprising diamond abrasives having an average diameter of less than about 10 μm;
urging the patterned surface of the substrate support against the polishing pad with a polishing downforce, wherein the patterned surface of the substrate support comprises a plurality of elevated features extending from one or more recessed surfaces thereof, and wherein a surface area of the plurality of elevated features defining a substrate contacting surface is formed is less than about 20% of a non-device side surface area of a substrate to be disposed on the substrate support; and
polishing the patterned surface of the substrate support to remove more than about 0.5 μm of material from the substrate contacting surfaces of the elevated features, wherein the plurality of elevated features comprise a plurality of protrusions having a mean diameter between about 500 μm and about 5 mm and one or more outer sealing bands concentrically disposed on the substrate support, wherein at least one of the one or more outer sealing bands is proximate to an outer circumference of the patterned surface, and wherein polishing the patterned surface of the substrate support further comprises removing more than about 0.5 μm of material form the sides of the elevated features.

16. The method of claim 15 , wherein polishing the patterned surface includes smoothing the one or more recessed surfaces thereof to a roughness less than about 0.2 μm Ra.

17. A method of polishing a patterned surface of a substrate support, comprising:
rotating a polishing platen having a polishing pad mounted thereon;
applying a polishing fluid to the polishing pad, the polishing fluid comprising diamond abrasives having an average diameter of less than about 10 μm;
urging the patterned surface of the substrate support against the polishing pad with a polishing downforce, wherein the patterned surface of the substrate support comprises a plurality of cylindrical protrusions extending from one or more recessed surfaces thereof,
wherein a surface area of the substrate contacting areas of the plurality of cylindrical protrusions is less than about 20% of a non-device side surface area of a substrate to be disposed on the substrate support,
wherein the plurality of cylindrical protrusions have a mean diameter of between 500 μm and about 5 mm,
and wherein the patterned surface is formed of a dielectric material selected from the group consisting of aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), titanium oxide (TiO), titanium nitride (TiN), yttrium oxide (Y 2 O 3 ), and combinations thereof; and
polishing the patterned surface of the substrate support to remove more than about 0.5 μm of dielectric material from the surfaces of the plurality of cylindrical protrusions to form the substrate contacting surfaces and more than about 0.1 μm of dielectric material from the one or more recessed surfaces.

Assignees

• Applied Materials Inc

Inventors

• Boyd Jr Wendell Glenn
• He Jim Zhongyi

Classifications

• H01J2237/3321

  CVD [Chemical Vapor Deposition] · CPC title

• B24B37/105

  the workpieces or work carriers being actively moved by a drive, e.g. in a combined rotary and translatory movement · CPC title

• B24B37/14 Primary

  characterised by the composition or properties of the plate materials · CPC title

• H01J37/32715

  Workpiece holder · CPC title

• B24B37/044

  characterised by the composition of the lapping agent · CPC title