Lift pin for substrate processing
A lift pin is provided for manipulating a substrate above a support surface of a substrate support and uniformly transferring heat from the substrate support to the substrate. The lift pin includes a pin shaft. The pin shaft includes a cross-section having at least three equal edges and round corners configured alternatively. A pin head is an end portion of the pin shaft, wherein the pin head has a convex support surface larger than the cross-section of the pin shaft. A flat portion is disposed on a central area of the convex support surface for directly contacting the substrate.
1. A lift pin for manipulating a substrate above a support surface of a substrate support, the lift pin comprising:
a pin shaft comprising a cross-section having at least three equal edges and round corners configured alternatively, wherein the round corners are part of a circular circumference;
a pin head being an end portion of the pin shaft, wherein the pin head has a convex support surface larger than the cross-section of the pin shaft; and
a flat portion disposed on a central area of the convex support surface for directly contacting the substrate.
2. The lift pin of claim 1 , wherein the cross-section of the pin shaft is an equilateral triangle with three round corners.
3. The lift pin of claim 1 , wherein the flat portion is smaller than the cross-section of the pin shaft.
4. The lift pin of claim 1 , wherein when the flat portion is in contact with the substrate, an angle between the convex support surface and a bottom surface of the substrate is about 5 degrees.
5. The lift pin of claim 1 , wherein the flat portion is a circular area.
6. The lift pin of claim 1 , wherein the convex support surface is a circular area.
7. The lift pin of claim 1 , wherein the pin shaft comprises alumina.
8. A substrate support assembly for manipulating a substrate above thereof, the substrate support assembly comprising:
a lift pin assembly having a plurality of lift pins, wherein each lift pin comprises:
a pin shaft comprising a cross-section having at least three equal edges and round corners configured alternatively, wherein the round corners are part of a circular circumference;
a pin head being an end portion of the pin shaft, wherein the pin head has a convex support surface larger than the cross-section of the pin shaft;
a flat portion disposed on a central area of the convex support surface for directly contacting the substrate; and
a substrate support, having a plurality of pin holes through which the plurality of lift pins are movable for manipulating the substrate.
9. The substrate support assembly of claim 8 , wherein the pin shaft comprises alumina.
10. The substrate support assembly of claim 8 , wherein the substrate support comprises ceramic materials.
11. The substrate support assembly of claim 8 , wherein the cross-section of the pin shaft is an equilateral triangle with three round corners.
12. The substrate support assembly of claim 8 , wherein the flat portion is smaller than the cross-section of the pin shaft.
13. The substrate support assembly of claim 8 , wherein when the flat portion is in contact with the substrate, an angle between the convex support surface and a bottom surface of the substrate is about 5 degrees.
14. The substrate support assembly of claim 8 , wherein the flat portion is a circular area.
15. The substrate support assembly of claim 8 , wherein the convex support surface is a circular area.
16. The substrate support assembly of claim 8 , wherein the lift pin assembly comprises at least three lift pins.