Treatment liquid and substrate treatment method

A treatment liquid for a semiconductor device, comprising:

• water;
• a removing agent;
• and
• a resin,
• wherein the resin has a first repeating unit having at least one selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and a quaternary ammonium cation, and a second repeating unit different from the first repeating unit, and
• the second repeating unit comprises a sulfonyl group, or a repeating unit represented by Formula (2a),
• in Formula (2a), A21, A22, and A23 each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or -L2-X21,
• where X21 represents a hydrophilic group selected from the group consisting of a carboxy group, an alkoxy group, a polyoxyalkylene group, an amide group, a carbamoyl group, a nitrile group, a sulfonamide group, and a sulfamoyl group,
• L2 represents a divalent linking group, and
• in a case where two or more X21's or two or more L2's are present, the two or more X21's or two or more L2's may be the same or different from each other.