Electrostatic chuck assembly having a dielectric filler
Embodiments include an electrostatic chuck assembly having an electrostatic chuck mounted on an insulator. The electrostatic chuck and insulator may be within a chamber volume of a process chamber. In an embodiment, a ground shield surrounds the electrostatic chuck and the insulator, and a gap between the ground shield and the electrostatic chuck provides an environment at risk for electric field emission. A dielectric filler can be placed within the gap to reduce a likelihood of electric field emission. The dielectric filler can have a flexible outer surface that covers or attaches to the electrostatic chuck, or an interface between the electrostatic chuck and the insulator Other embodiments are also described and claimed.
1. An electrostatic chuck assembly, comprising:
a support member including a ceramic layer on an electrostatic chuck on an insulator, wherein the electrostatic chuck includes a chuck sidewall, and the ceramic layer has a top surface;
a ground shield extending around the support member, wherein the ground shield is electrically grounded, and wherein the ground shield includes a shield sidewall facing the chuck sidewall; and
a dielectric filler between the chuck sidewall and the shield sidewall, wherein the dielectric filler includes a flexible outer surface on the chuck sidewall, and wherein the dielectric filler has a top surface below the top surface of the ceramic layer of the support member.
2. The electrostatic chuck assembly of claim 1 , wherein the top surface of the dielectric filler is below a bottom surface of the ceramic layer of the support member.
3. The electrostatic chuck assembly of claim 1 , wherein the flexible outer surface is attached to the chuck sidewall.
4. The electrostatic chuck assembly of claim 2 , wherein the flexible outer surface includes a surface portion on the shield sidewall.
5. The electrostatic chuck assembly of claim 1 , wherein the chuck sidewall has a lower edge, wherein the insulator has an insulator sidewall having an upper edge, and wherein the flexible outer surface covers the lower edge and the upper edge.
6. The electrostatic chuck assembly of claim 5 , wherein one or more of the lower edge or the upper edge is a transitional edge.
7. The electrostatic chuck assembly of claim 1 , wherein the dielectric filler includes an encapsulation layer surrounding a core.
8. The electrostatic chuck assembly of claim 7 , wherein the core is polytetrafluoroethylene, and wherein the encapsulation layer is a chemical vapor deposited poly(p-xylylene) polymer.
9. The electrostatic chuck assembly of claim 1 , further comprising a protective cap extending from the ground shield to the ceramic layer over the dielectric filler.