Kishore Lavu from 4770 Harwood Rd, San Jose, CA 95124, age 47

Krypton Sputtering Of Low Resistivity Tungsten
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US Patent:

8216933, Jul 10, 2012
Filed:

Aug 31, 2010
Appl. No.:

12/872522
Inventors:

Wei D. Wang - San Jose CA, US
Srinivas Gandikota - Santa Clara CA, US
Kishore Lavu - Santa Clara CA, US
Assignee:

Applied Materials, Inc. - Santa Clara CA
International Classification:

H01L 21/02
US Classification:

438628, 438635, 438684, 438721, 438722, 257E21169, 257E21526, 257E21565, 257E21598, 257E23161
Abstract:

A method of depositing a bilayer of tungsten over tungsten nitride by a plasma sputtering process in which krypton is used as the sputter working gas during the tungsten deposition. Argon may be used as the sputtering working gas during the reactive sputtering deposition of tungsten nitride. The beneficial effect of reduction of tungsten resistivity is increased when the thickness of the tungsten layer is less than 50 nm and further increased when less than 35 nm. The method may be used in forming a gate stack including a polysilicon layer over a gate oxide layer over a silicon gate region of a MOS transistor in which the tungsten nitride acts as a barrier. A plasma sputter chamber in which the invention may be practiced includes gas sources of krypton, argon, and nitrogen.

Krypton Sputtering Of Thin Tungsten Layer For Integrated Circuits
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US Patent:

20090053882, Feb 26, 2009
Filed:

Aug 20, 2007
Appl. No.:

11/841205
Inventors:

WEI D. WANG - San Jose CA, US
Srinivas Gandikota - Santa Clara CA, US
Kishore Lavu - Santa Clara CA, US
Assignee:

Applied Material, Inc. - Santa Clara CA
International Classification:

H01L 21/3205
C23C 16/00
US Classification:

438592, 118723 R, 257E21294
Abstract:

A method of depositing a bilayer of tungsten over tungsten nitride by a plasma sputtering process in which krypton is used as the sputter working gas during the tungsten deposition. Argon may be used as the sputtering working gas during the reactive sputtering deposition of tungsten nitride. The beneficial effect of reduction of tungsten resistivity is increased when the thickness of the tungsten layer is less than 50 nm and further increased when less than 35 nm. The method may be used in forming a gate stack including a polysilicon layer over a gate oxide layer over a silicon gate region of a MOS transistor in which the tungsten nitride acts as a barrier. A plasma sputter chamber in which the invention may be practiced includes gas sources of krypton, argon, and nitrogen.