Isolator apparatus and methods for substrate processing chambers
Aspects of the present disclosure relate generally to isolator devices, components thereof, and methods associated therewith for substrate processing chambers. In one implementation, a substrate processing chamber includes an isolator ring disposed between a pedestal and a pumping liner. The isolator ring includes a first surface that faces the pedestal, the first surface being disposed at a gap from an outer circumferential surface of the pedestal. The isolator ring also includes a second surface that faces the pumping liner and a protrusion that protrudes from the first surface of the isolator ring and towards the outer circumferential surface of the pedestal. The protrusion defines a necked portion of the gap between the pedestal and the isolator ring.
1. A substrate processing chamber, comprising:
a chamber body;
a showerhead having one or more gas openings formed in a lower surface of the showerhead;
a pedestal disposed in the chamber body, the pedestal having a support surface and an outer circumferential surface, the support surface facing the showerhead;
a pumping liner disposed around the pedestal and encircling the pedestal, the pumping liner having a first outer surface that faces the outer circumferential surface of the pedestal and a second outer surface that faces the chamber body; and
an isolator ring disposed between the pedestal and the pumping liner, the isolator ring comprising:
a first surface that faces the pedestal, the first surface being disposed at a gap from the outer circumferential surface of the pedestal,
a second surface that faces the pumping liner, and
a protrusion that protrudes from the first surface of the isolator ring and towards the outer circumferential surface of the pedestal, the protrusion defining a necked portion of the gap between the pedestal and the first surface of the isolator ring, and defining a stepped surface of the isolator ring;
wherein:
the gap between the first surface of the isolator ring and the outer circumferential surface of the pedestal has a first width;
the necked portion between the stepped surface of the isolator ring and the outer circumferential surface of the pedestal has a second width smaller than first width; and
the second width is a ratio of the first width, the ratio within a range of 0.25 to 0.75.
2. The substrate processing chamber of claim 1 , wherein the isolator ring comprises an electrically isolating material.
3. The substrate processing chamber of claim 1 , further comprising a purge gas inlet disposed at a bottom of the chamber body, wherein the isolator ring and the gap are disposed between the purge gas inlet and the showerhead.
4. The substrate processing chamber of claim 3 , wherein the gap is part of a purge gas flow path, and the protrusion defines a flow edge disposed in the purge gas flow path.
5. A substrate processing chamber, comprising:
a chamber body;
a showerhead having one or more gas openings formed in a lower surface of the showerhead;
a pedestal disposed in the chamber body, the pedestal having a support surface and an outer circumferential surface, the support surface facing the showerhead;
a pumping liner disposed around the pedestal and encircling the pedestal, the pumping liner having a first outer surface that faces the outer circumferential surface of the pedestal and a second outer surface that faces the chamber body; and
an isolator ring disposed between the pedestal and the pumping liner, the isolator ring comprising:
a first surface that faces the pedestal, the first surface being disposed at a gap from the outer circumferential surface of the pedestal,
a second surface that faces the pumping liner, and
a protrusion that protrudes from the first surface of the isolator ring and towards the outer circumferential surface of the pedestal, the protrusion defining a necked portion of the gap between the pedestal and the first surface of the isolator ring, and defining a stepped surface of the isolator ring;
wherein:
the gap between the first surface of the isolator ring and the outer circumferential surface of the pedestal has a first width;
the necked portion between the stepped surface of the isolator ring and the outer circumferential surface of the pedestal has a second width smaller than first width; and
the second width is a ratio of the first width, and the ratio is within a range of 0.23 to 0.27.
6. A substrate processing chamber, comprising:
a chamber body;
a showerhead having one or more gas openings formed in a lower surface of the showerhead;
a pedestal disposed in the chamber body, the pedestal having a support surface and an outer circumferential surface, the support surface facing the showerhead;
a pumping liner disposed around the pedestal and encircling the pedestal, the pumping liner having a first outer surface that faces the outer circumferential surface of the pedestal and a second outer surface that faces the chamber body; and
an isolator ring disposed between the pedestal and the pumping liner, the isolator ring comprising:
a first surface that faces the pedestal,
a second surface that faces the pumping liner, and
a tapered upper surface, the tapered upper surface tapering upwards in a direction from the pumping liner and towards the pedestal, and defining an upper edge of the isolator ring, the upper edge of the isolator ring being disposed above the support surface of the pedestal;
wherein:
the upper edge of the isolator ring is disposed at a distance from the lower surface of the showerhead;
the support surface of the pedestal is disposed at a gap from the lower surface of the showerhead; and
the distance is within a range of 50 percent to 100 percent of the gap.
7. The substrate processing chamber of claim 6 , wherein the distance is within a range of 4.0 mm to 7.0 mm.
8. The substrate processing chamber of claim 6 , wherein:
the first surface of the isolator ring that faces the pedestal is disposed at a gap from the outer circumferential surface of the pedestal; and
the isolator ring further comprises a protrusion that protrudes from the first surface of the isolator ring and towards the outer circumferential surface of the pedestal, the protrusion defining a necked portion of the gap between the pedestal and the isolator ring.
9. The substrate processing chamber of claim 8 , wherein:
the protrusion defines a stepped surface of the isolator ring;
the gap between the first surface of the isolator ring and the outer circumferential surface of the pedestal has a first width; and
the necked portion between the stepped surface of the isolator ring and the outer circumferential surface of the pedestal has a second width that is smaller than first width.
10. The substrate processing chamber of claim 9 , wherein the second width is a ratio of the first width, and the ratio is within a range of 0.25 to 0.75.
11. The substrate processing chamber of claim 9 , wherein the second width is a ratio of the first width, and the ratio is within a range of 0.23 to 0.27.
12. The substrate processing chamber of claim 5 , wherein the isolator ring comprises an electrically isolating material.
13. The substrate processing chamber of claim 5 , further comprising a purge gas inlet disposed at a bottom of the chamber body, wherein the isolator ring and the gap are disposed between the purge gas inlet and the showerhead.
14. The substrate processing chamber of claim 13 , wherein the gap is part of a purge gas flow path, and the protrusion defines a flow edge disposed in the purge gas flow path.