HIGH THERMAL CONDUCTIVITY WAFER SUPPORT PEDESTAL DEVICE
A support pedestal device for an electrostatic chuck includes a base housing defining an internal cavity, and a base insert disposed proximate the internal cavity of the base housing. A fluid pathway is formed in the internal cavity and includes a plurality of linear-parallel cooling channels separated by corresponding plurality of linear-parallel cooling fins, a fluid supply channel, and a fluid return channel. A cooling fluid flows through the fluid supply channel, through the plurality of linear-parallel cooling channels, and back through the fluid return channel to cool the support pedestal device.
1 . A support pedestal device for an electrostatic chuck comprising:
a base housing defining an internal cavity;
a base insert disposed within the internal cavity of the base housing; and
at least one fluid pathway disposed within the internal cavity, the fluid pathway defining:
a plurality of linear-parallel cooling channels separated by a corresponding plurality of linear-parallel cooling fins;
a fluid supply channel; and
a fluid return channel,
wherein a cooling fluid is able to flow through the fluid pathway by passing through the fluid supply channel, through the plurality of linear-parallel cooling channels, and back through the fluid return channel to cool the support pedestal device.
2 . The support pedestal device according to claim 1 , wherein the linear-parallel cooling fins are a part of the base insert.
3 . The support pedestal device according to claim 1 , wherein the linear-parallel cooling fins are a part of the base housing.
4 . The support pedestal device according to claim 1 , wherein a first fluid pathway is formed in the base insert and a second fluid pathway is formed in the base housing, wherein each fluid pathway defines a plurality of linear-parallel cooling channels separated by a corresponding plurality of linear-parallel cooling fins, a fluid supply channel, and a fluid return channel, wherein the linear-parallel cooling fins are a part of the base housing and the base insert.
5 . The support pedestal device according to claim 1 , wherein the base housing and the base insert are separate components.
6 . The support pedestal device according to claim 1 further comprising a plurality of electrode feed-throughs extending through the base housing and the base insert.
7 . The support pedestal device according to claim 6 further comprising a plurality of spacers disposed within recesses formed in either the base housing or the base insert, wherein the electrode feed-throughs extend through the spacers.
8 . The support pedestal device according to claim 1 , wherein the fluid supply channel extends radially from a central portion, in a direction parallel to the cooling channels, and then bi-circumferentially around an outer periphery of the fluid pathway.
9 . The support pedestal device according to claim 1 , wherein the fluid return channel extends bi-circumferentially and then radially to a central portion, in a direction parallel to the cooling channels of the fluid pathway.
10 . The support pedestal device according to claim 1 , wherein a fluid inlet and a fluid outlet are formed around a peripheral area of the support pedestal device
11 . The support pedestal device according to claim 1 , wherein the base insert comprises a lower radial flange defining an outer face that abuts an inner side surface of the internal cavity of the base housing.
12 . The support pedestal device according to claim 1 , wherein the plurality of cooling channels define the same cross-sectional area.
13 . The support pedestal device according to claim 12 , wherein the cooling channels define an aspect ratio of about 10:1.
14 . The support pedestal device according to claim 1 , wherein the device defines a thermal resistance of 0.000171° C./w or less.
15 . The support pedestal device according to claim 1 , wherein an interface between the base housing and the base insert is planar.
16 . The support pedestal device according to claim 1 , wherein the linear-parallel cooling fins define a spacing and geometry to provide zones of different thermal conductivity across the support pedestal device.
17 . A support pedestal device for an electrostatic chuck comprising:
a plurality of linear-parallel cooling channels separated by a corresponding plurality of linear-parallel cooling fins;
a fluid supply channel; and
a fluid return channel,
wherein a cooling fluid flows through the fluid supply channel, through the plurality of linear-parallel cooling channels, and back through the fluid return channel to cool the support pedestal device.
18 . The support pedestal device according to claim 17 , wherein the cooling channels and the fluid supply and return channels are internal to the support pedestal device.
19 . A method of improving thermal conductivity and reducing thermal mass of a wafer support pedestal comprising:
directing a cooling fluid through a fluid supply channel to a central portion of the wafer support pedestal;
directing the cooling fluid outward radially;
directing the cooling fluid bi-circumferentially;
directing the cooling fluid through linear-parallel cooling channels;
directing the cooling fluid bi-circumferentially; and
directing the cooing fluid inward radially through a fluid return channel to the central portion of the wafer support pedestal.
20 . The method according to claim 19 , wherein the cooling fluid is a two-phase fluid.