Patent ID: 9142438
Filing Date: 2015-09-22
Classification: H01L

Abstract:
1. A method of clamping and declamping a wafer from a platen, comprising: placing said wafer on said platen, said platen comprising an electrode for clamping said wafer onto said platen, while said electrode is biased at an initial voltage; applying a first voltage to said electrode of the platen to electrostatically clamp said wafer to said platen, said first voltage greater than said initial voltage; applying a second voltage to said electrode directly after application of said first voltage, said second voltage less than said first voltage and greater than said initial voltage; applying a third voltage to said electrode directly after application of said second voltage, wherein said third voltage is less than said second voltage and greater than said initial voltage; applying a fourth voltage to said electrode directly after application of said third voltage, wherein said fourth voltage is greater than said third voltage and less than said first voltage; and applying a fifth voltage to said electrode directly after application of said fourth voltage, wherein said fifth voltage is less than said fourth voltage and greater than said initial voltage, wherein said wafer is removed after application of said fifth voltage.