Electrostatic clamp and a method for manufacturing the same
An electrostatic clamp ( 300 ) and a method for manufacturing the same is disclosed. The electrostatic clamp includes a first layer ( 302 ) having a first ultra-low expansion (ULE) material, a second layer ( 304 ) coupled to the first layer, having a second ULE material, and a third layer ( 306 ), coupled to the second layer, having a third ULE material. The electrostatic clamp further includes a plurality of fluid channels ( 316 ) located between the first layer and the second layer and a composite layer ( 308 ) interposed between the second layer and the third layer. The method for manufacturing the electrostatic clamp includes forming the plurality of fluid channels, disposing the composite layer on the third layer, and coupling the third layer to the second layer. The plurality of fluid channels is configured to carry a thermally conditioned fluid for temperature regulation of a clamped object.
1. A device manufacturing method, the method comprising:
forming a plurality of fluid channels between a first layer and a second layer, the plurality of fluid channels being configured to carry a thermally conditioned fluid;
disposing a composite layer on a third layer, the composite layer comprising alternating conductive layers and insulating layers, wherein the first, second, and third layers comprise a same ultra-low expansion material having a substantially zero coefficient of thermal expansion; and
bonding the third layer to the second layer, wherein the bonding is performed at a temperature above about 350° C.
2. The method of claim 1 , wherein forming the plurality of fluid channels comprises:
forming a plurality of trenches on a top surface of the first layer;
polishing a bottom surface of the second layer;
direct bonding the top surface of the first layer to the bottom surface of the second layer to form a bonded structure of the first layer and the second layer; and
annealing the bonded structure.
3. The method of claim 1 , wherein disposing the composite layer comprises:
disposing a metal layer on a bottom surface of the third layer;
patterning the metal layer;
disposing a dielectric layer on the bottom surface of the third layer and the patterned metal layer; and
patterning the dielectric layer.
4. The method of claim 1 , wherein coupling the third layer to the second layer comprises:
disposing an intermediate layer on the composite layer; and
direct bonding the intermediate layer to a top surface of the second layer.
5. The method of claim 1 , further comprising forming a plurality of burls on a top surface of the third layer, the plurality of burls being configured to receive an object for clamping.
6. The method of claim 5 , wherein forming the plurality of burls comprises:
disposing a polymeric layer on the top surface of the third layer; and
patterning the polymeric layer.
7. The method of claim 1 , wherein the first, second and third ultra-low expansion materials comprise an ultra-low expansion glass.