US 12,227,673 B2
Composition and method for silicon nitride CMP
Fernando Hung Low, Aurora, IL (US); Steven Kraft, Plainfield, IL (US); and Roman A. Ivanov, Aurora, IL (US)
Assigned to CMC MATERIALS LLC, Aurora, IL (US)
Filed by Cabot Microelectronics Corporation, Aurora, IL (US)
Filed on Dec. 4, 2018, as Appl. No. 16/208,779.
Prior Publication US 2020/0172761 A1, Jun. 4, 2020
Int. Cl. C09G 1/02 (2006.01); C09K 3/14 (2006.01); H01L 21/3105 (2006.01)
CPC C09G 1/02 (2013.01) [H01L 21/31055 (2013.01); C09K 3/1409 (2013.01)] 5 Claims
 
1. A chemical-mechanical polishing composition for polishing a silicon nitride containing substrate, the polishing composition comprising:
an aqueous carrier;
cationic silica particles dispersed in the aqueous carrier, the cationic silica abrasive particles having a zeta potential of at least 10 mV in the polishing composition;
a polishing additive comprising polyether amine having a weight average molecular weight of about 500 g/mol or less, wherein the polyether amine is of Formula (I):

OG Complex Work Unit Chemistry
wherein R is a C1-C6 alkyl group and x, y, and z independently are integers from 0 to 15, wherein the polishing additive is present in the polishing composition at a concentration in a range from about 0.07 mM to about 0.25 mM; and
wherein the polishing composition has a pH of about 6 to about 8.