Dual-function wafer backside pressure control and edge purge

Patent metadata

Field	Value
Publication number	US-11923233-B2
Application number	US-202016910540-A
Country	US
Kind code	B2
Filing date	Jun 24, 2020
Priority date	Jun 25, 2019
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

Abstract

Apparatus and methods for providing backside pressure control and edge purge gas to a substrate in a processing chamber. A seal band within a pocket of a substrate support defines an inner pocket region and an outer pocket region. The seal band has a pressure dependent controlled leakage rate so that a backside gas flow to the inner pocket region can diffuse through the seal band to the outer pocket region to create an edge purge while providing backside pressure to the substrate. Processing chambers, methods of processing a substrate and non-transitory computer-readable medium containing instructions to process a substrate are also disclosed.

First claim

What is claimed is:

1. A substrate support pedestal comprising:
a support body having a top surface and a bottom surface defining a thickness;
a pocket formed in the top surface of the support body, the pocket having a bottom surface, a depth and an outer peripheral edge; and
a seal band conforming to a shape of and spaced a distance from the outer peripheral edge of the pocket to form an inner pocket region and an outer pocket region, the seal band having a top surface an inner face and an outer face defining a width, the seal band providing controlled leakage of gases from the inner pocket region through the width of the seal band to the outer pocket region, wherein the seal band property providing controlled leakage of gases comprises one or more of cut outs in the top surface of the seal band, a roughened top surface of the seal band, channels extending through the width of the seal band or a porous material composition, wherein the seal band has a height sufficient so that a wafer supported on the top surface of the seal band is substantially coplanar with the top surface of the support body.

2. The substrate support pedestal of claim 1 , wherein the seal band is spaced from the outer peripheral edge of the pocket by a distance in the range of about 1 to about 2 mm.

3. The substrate support pedestal of claim 1 , wherein the seal band has a height in the range of about 15 μm to about 60 μm.

4. The substrate support pedestal of claim 1 , wherein the support body is an electrostatic chuck comprising electrodes.

5. The substrate support pedestal of claim 1 , wherein the support body comprises heater coils within the thickness of the support body.

6. The substrate support pedestal of claim 1 , further comprising a pedestal shaft extending from the bottom surface of the support body.

7. The substrate support pedestal of claim 6 , wherein the pedestal shaft comprises a gas line extending through the pedestal shaft to an opening in the bottom surface of the inner pocket region of the pocket.

8. The substrate support pedestal of claim 7 , further comprising a flow controller, pressure gauge, pump and feedback circuit connected to the gas line to control a flow of gas through the gas line into the inner pocket region of the pocket.

9. The substrate support pedestals of claim 8 , further comprising a controller configured to control and/or receive information from one or more of the flow controller, pressure gauge, pump or feedback circuit.

10. The substrate support of claim 9 , wherein the flow controller is upstream of and in fluid communication with the gas line, the pressure gauge is downstream of and in fluid communication with the gas line and the pump is downstream of the pressure gauge and in fluid communication with the gas line, and the feedback circuit is configured to measure pressure in the gas line and adjust the flow controller to maintain a uniform pressure within the gas line.

11. A processing chamber comprising:
the substrate support pedestal of claim 10 within the processing chamber defining a reaction space adjacent the top surface of the support body;
a gas distribution assembly directing a flow of gas toward the top surface of the support body; and
a reaction space pressure gauge configured to measure pressure within the reaction space.

12. The processing chamber of claim 11 , wherein the controller is configured to adjust the flow controller to maintain a uniform pressure within the gas line based on readings from the reaction space pressure gauge.

13. The processing chamber of claim 12 , wherein the controller is configured to maintain a positive pressure in the inner pocket region relative to the reaction space.

14. The processing chamber of claim 13 , wherein the pressure in the inner pocket region is sufficient to allow a uniform flow of gas through the seal band to create a pressure in the outer pocket region greater than or equal to pressure in the reaction space.

15. The processing chamber of claim 14 , wherein the support body comprises one or more electrode to act as an electrostatic chuck and the controller is further configured to provide power to the one or more electrode to cause a substrate to be chucked to the top surface of the seal band.

16. The processing chamber of claim 15 , wherein the support body comprises one or more thermal element and the controller is further configured to provide power to the one or more thermal element to control temperature of the support body.

Assignees

• Applied Materials Inc

Inventors

• Aubuchon Joseph
• Ulavi Tejas

Classifications

• H10P72/7611

  characterised by edge profile or support profile · CPC title

• H10P72/722

  Details of electrostatic chucks · CPC title

• H10P72/0441 Primary

  Apparatus for sealing, encapsulating, glassing, decapsulating or the like · CPC title

• H10P72/0402

  Apparatus for fluid treatment (H10P72/0441, H10P72/0448 take precedence) · CPC title

• H10P72/7626 Primary

  characterised by the construction of the shaft · CPC title