CMP POLISHING LIQUID AND POLISHING METHOD
An aspect of the present disclosure provides a CMP polishing liquid for polishing polysilicon, the CMP polishing liquid containing: abrasive grains; and a cationic polymer, in which the cationic polymer includes at least one selected from the group consisting of a polymer A having a main chain containing a nitrogen atom and a carbon atom and a hydroxyl group bonded to the carbon atom and an allylamine polymer B. Another aspect of the present disclosure provides a polishing method including a step of polishing a material to be polished by using this CMP polishing liquid.
1 . A CMP polishing liquid for polishing polysilicon, the CMP polishing liquid comprising:
abrasive grains; and a cationic polymer, wherein
the cationic polymer includes at least one selected from the group consisting of a polymer A and an allylamine polymer B, and
the polymer A has a main chain containing a nitrogen atom and a carbon atom and a hydroxyl group bonded to the carbon atom.
2 . The CMP polishing liquid according to claim 1 , wherein the cationic polymer includes the polymer A.
3 . The CMP polishing liquid according to claim 2 , wherein the polymer A has a plurality of kinds of structure units each having the main chain.
4 . The CMP polishing liquid according to claim 2 , wherein the polymer A includes a reaction product of a raw material containing at least dimethylamine and epichlorohydrin.
5 . The CMP polishing liquid according to claim 2 , wherein the polymer A includes a reaction product of a raw material containing at least dimethylamine, ammonia, and epichlorohydrin.
6 . The CMP polishing liquid according to claim 2 , wherein a weight average molecular weight of the polymer A is 5000 to 1500000.
7 . The CMP polishing liquid according to claim 2 , wherein a content of the polymer A is 0.001 to 0.1 parts by mass with respect to 100 parts by mass of the CMP polishing liquid.
8 . The CMP polishing liquid according to claim 1 , wherein the cationic polymer includes the allylamine polymer B.
9 . The CMP polishing liquid according to claim 8 , wherein the allylamine polymer B includes a polymer having a diallyldialkylammonium salt as a monomer unit.
10 . The CMP polishing liquid according to claim 8 , wherein a content of the polymer B is 0.001 to 0.01 parts by mass with respect to 100 parts by mass of the CMP polishing liquid.
11 . The CMP polishing liquid according to claim 1 , wherein the abrasive grains contain a cerium-based compound.
12 . The CMP polishing liquid according to claim 11 , wherein the cerium-based compound includes cerium oxide.
13 . The CMP polishing liquid according to claim 1 , wherein the abrasive grains do not contain a hydroxide.
14 . The CMP polishing liquid according to claim 1 , wherein a content of the abrasive grains is 0.1 to 2 parts by mass with respect to 100 parts by mass of the CMP polishing liquid.
15 . The CMP polishing liquid according to claim 1 , wherein a pH is 7.0 or less.
16 . The CMP polishing liquid according to claim 1 , wherein a pH is 2.0 to 5.0.
17 . A polishing method comprising a step of polishing a material to be polished by using the CMP polishing liquid according to claim 1 .
18 . The polishing method according to claim 17 , wherein the material to be polished contains polysilicon.
19 . The CMP polishing liquid according to claim 2 , wherein a weight average molecular weight of the polymer A is 30000 or more.
20 . The CMP polishing liquid according to claim 8 , wherein a weight average molecular weight of the polymer B is 30000 or more.