Steven D Germain

US Patent:

57931925, Aug 11, 1998

Filed:

Jun 28, 1996

Appl. No.:

8/671752

Inventors:

Marc B. Kubly - Fremont CA
Neil Martin Paul Benjamin - Palo Alto CA
Steven Douglas Germain - Fremont CA

Assignee:

Lam Research Corporation - Fremont CA

International Classification:

G05F 304
H01G 2300
B23B 522

US Classification:

323312

Abstract:

A method for clamping a wafer to an electrostatic chuck having a substantially resistive dielectric layer disposed thereon. The method includes the step of providing a build-up voltage having a first polarity to a pole of the electrostatic chuck to cause a potential difference to build up between a first region of the substantially resistive dielectric layer and a second region of the wafer that overlies at least a portion of the first region. This potential difference gives rise to a clamping force to clamp the wafer to the electrostatic chuck. The method further includes the step of terminating the build-up voltage when the clamping force substantially reaches a predefined level. There is further included the step of providing a holding voltage to the pole of the electrostatic chuck to substantially maintain the clamping force at the predefined level. This holding voltage has the first polarity and a magnitude that is lower than a magnitude of the build-up voltage.