Method for manufacturing abrasive grains, composition for chemical mechanical polishing, and method for chemical mechanical polishing
Provided are abrasive grains and a composition for chemical mechanical polishing which are for selectively polishing a silicon nitride film, and which are applicable not only to silicon oxide films but also to amorphous silicon films and polysilicon films. This method for manufacturing abrasive grains includes: a first step of heating a mixture which contains particles having a sulfanyl group (—SH) fixed to the surface thereof via covalent bonds, and which contains a compound having carbon-carbon unsaturated double bonds; and a second step, which is performed after the first step, of further adding a peroxide and carrying out heating.
1 . A method for manufacturing abrasive grains, the method comprising:
a first step of heating a mixture which contains particles having a sulfanyl group (—SH) fixed to a surface thereof via a covalent bond, and which contains a compound having a carbon-carbon unsaturated double bond; and
a second step of further adding a peroxide and carrying out heating after the first step,
wherein a polymer chain is grafted onto a surface of the abrasive grains by a covalent bond via —SO x —, where x is an integer of 0 to 2.
2 . The method for manufacturing abrasive grains according to claim 1 , wherein the mixture in the first step further contains a radical-generating agent.
3 . The method for manufacturing abrasive grains according to claim 1 , wherein an average molecular weight of the compound having a carbon-carbon unsaturated double bond is 100 to 10,000.
4 . The method for manufacturing abrasive grains according to claim 1 , wherein the abrasive grains have a functional group represented by General Formula (1) on a surface thereof,
—SO 3 − M + (1)
(where M + represents a monovalent cation).
5 . The method for manufacturing abrasive grains according to claim 1 , wherein a zeta-potential of the abrasive grains is less than −10 mV in a composition for chemical mechanical polishing containing the abrasive grains.