Multi-zone gasket for substrate support assembly
A gasket for a substrate support assembly may have a top surface having a surface area and a plurality of zones that together define the surface area of the top surface. The plurality of zones may comprise at least a) a first zone comprising a first stack of gasket layers, the first zone having a first average thermal conductivity in a first direction, and b) a second zone comprising one or more gasket layers, the second zone having a second average thermal conductivity in the first direction.
1. A gasket comprising:
a top surface having a surface area; and
a plurality of zones that together define the surface area of the top surface, the plurality of zones comprising:
a first zone comprising a first stack of gasket layers, the first zone having a first average thermal conductivity in a first direction; and
a second zone comprising one or more gasket layers, the second zone having a second average thermal conductivity in the first direction;
wherein at least one of:
a) the first stack of gasket layers comprises a first number of gasket layers and the one or more gasket layers in the second zone comprises a second number of gasket layers that differs from the first number of gasket layers;
b) at least one gasket layer in the first stack of gasket layers comprises a first material that is not present in the one or more gasket layers in the second zone; or
c) the one or more gasket layers in the second zone comprises a second stack of gasket layers, wherein one or more gasket layers in the first stack of gasket layers has a third thermal conductivity in a second direction that is different from a fourth thermal conductivity of a corresponding gasket layer in the second stack of gasket layers in the second direction, and wherein the second direction is orthogonal to the first direction.
2. The gasket of claim 1 , wherein the first stack of gasket layers comprises the first number of gasket layers and the one or more gasket layers in the second zone comprises the second number of gasket layers that differs from the first number of gasket layers.
3. The gasket of claim 1 , wherein at least one gasket layer in the first stack of gasket layers comprises the first material that is not present in the one or more gasket layers in the second zone.
4. The gasket of claim 1 , wherein the plurality of zones further comprises at least one of:
a third zone having a third average thermal conductivity in the first direction; or
a fourth zone having a fourth average thermal conductivity in the first direction.
5. The gasket of claim 1 , wherein the gasket has a thickness of about 0.2-2.0 mm, and wherein the first stack of gasket layers approximately has the thickness of 0.2-2.0 mm.
6. The gasket of claim 1 , wherein the first direction is orthogonal to the surface area.
7. The gasket of claim 1 , wherein the first zone is approximately concentric with the second zone.
8. The gasket of claim 1 , wherein at least one of a top gasket layer or a bottom gasket layer of the first stack of gasket layers comprises grafoil.
9. The gasket of claim 8 , wherein one or more intermediate gasket layers of the first stack of gasket layers comprises at least one of a metal, polyimide, silicone, rubber or a fluoropolymer.
10. The gasket of claim 1 , wherein the one or more gasket layers in the second zone comprises the second stack of gasket layers, wherein one or more gasket layers in the first stack of gasket layers has the third thermal conductivity in the second direction that is different from the fourth thermal conductivity of the corresponding gasket layer in the second stack of gasket layers in the second direction, and wherein the second direction is orthogonal to the first direction.
11. The gasket of claim 1 , wherein the second zone comprises a single gasket layer comprising grafoil.
12. A substrate support assembly comprising:
a puck comprising a plurality of heating zones, wherein each of the plurality of heating zones comprises one or more heating elements;
a gasket, wherein a top surface of the gasket contacts the puck, the gasket comprising a plurality of zones that approximately align with the plurality of heating zones, the plurality of zones comprising:
a first zone comprising a first stack of gasket layers, the first zone having a first average thermal conductivity in a first direction; and
a second zone comprising one or more gasket layers, the second zone having a second average thermal conductivity in the first direction; and
a cooling plate, wherein a bottom surface of the gasket contacts the cooling plate.
13. The substrate support assembly of claim 12 , wherein the gasket is compressed between the puck and the cooling plate, wherein the first direction is orthogonal to the top surface, and wherein the gasket has a thickness of approximately 0.2-2.0 mm.
14. The substrate support assembly of claim 12 , wherein the one or more heating elements of each the plurality of heating zones has a power rating, wherein the first average thermal conductivity causes the one or more heating elements of a first heating zone of the plurality of heating zones to maintain a supported substrate at a target temperature while staying within 20-80% of the power rating, and wherein the second average thermal conductivity causes the one or more heating elements of a second heating zone of the plurality of heating zones to maintain the target temperature or an alternate target temperature while staying within 20-80% of the power rating.
15. The substrate support assembly of claim 12 , wherein the first stack of gasket layers comprises a first number of gasket layers and the one or more gasket layers in the second zone comprises a second number of gasket layers that differs from the first number of gasket layers.
16. The substrate support assembly of claim 12 , wherein one or more gasket layers in the first stack of gasket layers comprises a first material that is not present in the one or more gasket layers in the second zone.
17. The substrate support assembly of claim 12 , wherein at least one of a top gasket layer or a bottom gasket layer of the first stack of gasket layers comprises grafoil and has a thermal conductivity of approximately 100-1200 Watts per meter Kelvin in a second direction that is orthogonal to the first direction.
18. The substrate support assembly of claim 12 , wherein one or more intermediate gasket layers of the first stack of gasket layers comprises at least one of a metal, polyimide, silicone, rubber or a fluoropolymer.
19. The substrate support assembly of claim 12 , wherein the one or more gasket layers in the second zone comprises a second stack of gasket layers, wherein one or more gasket layers in the first stack of gasket layers has a third thermal conductivity in a second direction that is different from a fourth thermal conductivity of a corresponding gasket layer in the second stack of gasket layers in the second direction, wherein the second direction is orthogonal to the first direction.
20. A substrate support assembly comprising:
an electrostatic puck comprising:
an electrically insulative upper puck plate comprising one or more heating elements and one or more electrodes to electrostatically secure a substrate;
a lower puck plate bonded to the electrically insulative upper puck plate by a first metal bond; and
an electrically insulative backing plate bonded to the lower puck plate by a second metal bond;
a cooling plate coupled to the electrostatic puck; and
a gasket compressed between the electrostatic puck and the cooling plate, the gasket comprising a plurality of zones, wherein a first zone of the plurality of zones comprises a first stack of gasket layers and has a first average thermal conductivity in a first direction, and wherein a second zone of the plurality of zones comprises one or more gasket layers and has a second average thermal conductivity in the first direction.