By Targeted News Service
ALEXANDRIA, Va., Aug. 26 -- International Business Machines, Armonk, N.Y., has been assigned a patent (8,513,081) developed by four co-inventors for a "carbon implant for workfunction adjustment in replacement gate transistor." The co-inventors are Dechao Guo, Fishkill, N.Y., Shu-Jen Han, Cortlandt Manor, N.Y., Keith Kwong HonWong, Wappingers Falls, N.Y., and Jun Yuan, Fishkill, N.Y.
The abstract of the patent published by the U.S. Patent and Trademark Office states: " A method includes providing a wafer that has a semiconductor layer having an insulator layer disposed on the semiconductor layer. The insulator layer has openings made therein to expose a surface of the semiconductor layer, where each opening corresponds to a location of what will become a transistor channel in the semiconductor layer disposed beneath a gate stack. The method further includes depositing a high dielectric constant gate insulator layer so as to cover the exposed surface of the semiconductor layer and sidewalls of the insulator layer; depositing a gate metal layer that overlies the high dielectric constant gate insulator layer; and implanting Carbon through the gate metal layer and the underlying high dielectric constant gate insulator layer so as to form in an upper portion of the semiconductor layer a Carbon-implanted region having a concentration of Carbon selected to establish a voltage threshold of the transistor."
The patent application was filed on Oct. 13, 2011 (13/272,349). 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=8,513,081.PN.&OS=PN/8,513,081&RS=PN/8,513,081
Written by Kusum Sangma; edited by Anand Kumar.