Heat shield assemblies for minimizing heat radiation to pump of process chamber

1 . A heat shield assembly for a processing chamber, comprising:

a first shield comprising a circular plate;

a second shield coupled to the first shield and in a parallel configuration with the first shield, wherein the second shield has an outer diameter greater than an outer diameter of the first shield and the second shield includes a central opening having a diameter smaller than an outer diameter of the first shield; and

a third shield coupled to and in a parallel configuration with the second shield, wherein an outer diameter of the third shield is greater than the diameter of the central opening of the second shield, and wherein a central opening of the third shield is smaller than the central opening of the second shield.

2 . The heat shield assembly of claim 1 , wherein the first shield has a concave shape.

3 . The heat shield assembly of claim 1 , further comprising an annular mounting flange disposed in a parallel configuration with the first shield and coupled to the first shield via a support member extending from a central axis of the annular mounting flange.

4 . The heat shield assembly of claim 3 , wherein the annular mounting flange includes a fluid passage.

5 . The heat shield assembly of claim 3 , wherein the central opening of the third shield is sized to accommodate the support member such that a flow path extends from around the outer diameter of the first shield, through the central opening of the second shield, and around the outer diameter of the third shield.

6 . The heat shield assembly of claim 1 , further comprising a plurality of first spacers disposed between the first shield and the second shield, and a plurality of second spacers disposed between the second shield and the third shield.

7 . The heat shield assembly of claim 1 , wherein the first shield, the second shield, and the third shield are all coupled to a mounting bracket disposed between the first shield and the third shield and in the central opening of the second shield.

8 . The heat shield assembly of claim 1 , further comprising:

an annular mounting flange disposed in a parallel configuration with the first shield and coupled to the first shield via a support member extending from a central axis of the annular mounting flange;

a plurality of first spacers disposed between the first shield and the second shield, wherein the first shield is coupled to the second shield via fasteners that extend through the plurality of first spacers; and

plurality of second spacers disposed between the second shield and the third shield.

9 . The heat shield assembly of claim 1 , wherein the first shield, the second shield, and the third shield are made of a material with an emissivity of about 0.2 or less.

10 . A heat shield assembly for a processing chamber, comprising:

a plurality of shields arranged in a parallel configuration, wherein a first shield of the plurality of shields comprises a circular plate, wherein a second shield of the plurality of shields has an outer diameter greater than an outer diameter of the first shield and the second shield includes a central opening having a diameter smaller than an outer diameter of the first shield; and

a bracket, wherein the bracket is coupled to a central region of the first shield and a peripheral region of the second shield.

11 . The heat shield assembly of claim 10 , further comprising a third shield of the plurality of shields, wherein the third shield is disposed farther from the second shield than from the first shield.

12 . The heat shield assembly of claim 11 , wherein the third shield is made of two parts that, when coupled together, form a central opening of the third shield to accommodate a support member.

13 . The heat shield assembly of claim 10 , wherein the first shield has a concave shape with an outer edge of the first shield extending away from the second shield.

14 . The heat shield assembly of claim 10 , wherein at least one of:

the first shield and the second shield are coupled to a mounting bracket, or

the first shield is directly coupled to the second shield along an outer peripheral region of the first shield via a plurality of fasteners.

15 . A processing chamber, comprising:

a chamber body defining an interior volume therein, wherein the chamber body includes a pump port configured for coupling the chamber body to a pump;

a substrate support disposed in the interior volume and configured to support a substrate; and

a heat shield assembly disposed in the interior volume proximate the pump port and substantially covering the pump port, the heat shield assembly comprising:

a plurality of shields arranged in a parallel configuration, wherein a first shield of the plurality of shields comprises a circular plate, wherein a second shield of the plurality of shields has an outer diameter greater than an outer diameter of the first shield and the second shield includes a central opening having a diameter smaller than an outer diameter of the first shield, and wherein a third shield of the plurality of shields is a plate that has an outer diameter greater than a diameter of the central opening of the second shield.

16 . The processing chamber of claim 15 , wherein the heat shield assembly defines a flow path around an outer edge of the first shield and through the central opening of the second shield and around the outer diameter of the third shield to the pump port.

17 . The processing chamber of claim 15 , further comprising a cryogenic pump coupled to the pump port.

18 . The processing chamber of claim 15 , wherein the third shield is disposed in the pump port, and wherein the first shield is disposed outside of the pump port.

19 . The processing chamber of claim 15 , wherein the pump port includes a tab, and wherein the heat shield assembly is coupled to the pump port via the tab.

20 . The processing chamber of claim 15 , wherein the heat shield assembly further comprises an annular mounting flange coupled to the chamber body.