By Targeted News Service
ALEXANDRIA, Va., Sept. 13 -- Varian Semiconductor Equipment Associates, Gloucester, Mass., has been assigned a patent (8,531,814) developed by five co-inventors for a "removal of charge between a substrate and an electrostatic clamp." The co-inventors are Dale K. Stone, Lynnfield, Mass., Lyudmila Stone, Lynnfield, Mass., Klaus Petry, Merrimac, Mass., David E. Suuronen, Newburyport, Mass., and Julian G. Blake, Gloucester, Mass.
The abstract of the patent published by the U.S. Patent and Trademark Office states: "An electrostatic clamp, which more effectively removes built up charge from a substrate prior to and during removal, is disclosed. Currently, the lift pins and ground pins are the only mechanisms used to remove charge from the substrate after implantation. The present discloses describes a clamp having one of more additional low resistance paths to ground. These additional conduits allow built up charge to be dissipated prior to and during the removal of the substrate from the clamp. By providing sufficient charge drainage from the backside surface of the substrate 114, the problem whereby the substrate sticks to the clamp can be reduced. This results in a corresponding reduction in substrate breakage."
The patent application was filed on April 14, 2010 (12/759,990). The full-text of the patent can be found at http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8,531,814.PN.&OS=PN/8,531,814&RS=PN/8,531,814
Written by Kusum Sangma; edited by Anand Kumar.