Apparatus and methods for controlling substrate temperature during processing
A substrate support assembly includes a shaft with a platen extending perpendicularly from the shaft at an upper end of the shaft. The shaft includes an electric line and a plurality of coolant conduits. A cooling plate including a coolant channel fluidically coupled to the coolant conduits is mounted to the platen, and extends beyond an outer rim of the platen. A puck assembly including a heater is mounted to the cooling plate. A simultaneous operation of the heater and a flow of coolant through the coolant channel regulates a temperature gradient across the puck assembly during a substrate processing operation.
1 . A substrate support assembly comprising:
a shaft including a plurality of coolant conduits;
a platen extending perpendicularly from the shaft at an upper end of the shaft;
a cooling plate mounted to the platen, the cooling plate including a coolant channel fluidically coupled to the plurality of coolant conduits;
a puck assembly mounted to the cooling plate, and secured thereto by a plurality of first fasteners extending through the cooling plate; and
a clamp ring mounted to an underside of the cooling plate by a plurality of second fasteners, the clamp ring sealingly covering the first fasteners and encircling the platen.
2 . The substrate support assembly of claim 1 , wherein:
the cooling plate includes:
a first portion coupled to the platen; and
a second portion extending beyond an outer rim of the platen;
the coolant channel is fluidically coupled to the plurality of coolant conduits at the first portion; and
the coolant channel extends from the first portion into the second portion.
3 . The substrate support assembly of claim 2 , wherein the coolant channel defines a pathway including a plurality of loops.
4 . The substrate support assembly of claim 1 , further comprising a skirt surrounding an outer rim of the cooling plate.
5 . The substrate support assembly of claim 4 , wherein the skirt includes a lip disposed between the cooling plate and the puck assembly.
6 . The substrate support assembly of claim 5 , wherein the skirt extends to a location at or below a level of the underside of the cooling plate.
7 . The substrate support assembly of claim 4 , wherein an outer diameter of the skirt is substantially equal to an outer diameter of the puck assembly.
8 . The substrate support assembly of claim 4 , wherein the skirt is integrally formed with a puck of the puck assembly.
9 . The substrate support assembly of claim 4 , wherein the clamp ring includes the skirt.
10 . The substrate support assembly of claim 9 , wherein the skirt extends to a location level with a top surface of the cooling plate.
11 . The substrate support assembly of claim 1 , further comprising a thermal choke layer disposed between the puck assembly and the cooling plate.
12 . The substrate support assembly of claim 11 , wherein the thermal choke layer includes a sheet of a material comprising a polymer, a metal, graphene, or any combination thereof.