Sunday, May 06, 2012

US Patent 8169768 - Electrostatic chuck including CNTs

Electrostatic chucks are used for holding wafers in place during semiconductor manufacturing processes. One defect in conventional electrostatic chucks is that they can warp and contaminate the wafers. This patent from KLA-Tencor teaches using carbon nanotube filled polymers as a material for forming electrostatic chucks to alleviate this problem. Claim 1 reads:

1. An electrostatic chuck for retaining a substrate, comprising:

a clamping surface for receiving the substrate, and formed of a hard polymeric material filled with carbon nanotubes,

electrodes disposed beneath the clamping surface for inducing localized electrostatic charges in the substrate and thereby retaining the substrate against the clamping surface, and

a base for supporting the clamping surface and the electrodes.