Actinic ray-sensitive or radiation-sensitive resin composition and pattern forming method using the same

An actinic ray-sensitive or radiation-sensitive resin composition, comprising:

• (A) a resin capable of increasing a solubility of the resin (A) in an alkali developer by an action of an acid;
• and
• (C) a resin having at least either a fluorine atom or a silicon atom and containing (c) a repeating unit having at least two or more polarity conversion groups represented by —COO— in the structure represented by formula (KA-1) or (KB-1):
• wherein Zka represents an alkyl group, a cycloalkyl group, an ether group, a hydroxyl group, an amide group, an aryl group, a lactone ring group or an electron-withdrawing group, and when a plurality of Zka's are present, the plurality of Zka's are the same or different;
• each Zka may combine with every other Zka to form a ring;
• nka represents an integer of 0 to 10;
• each of Xkb1 and Xkb2 independently represents an electron-withdrawing group;
• each of nkb and nkb′ independently represents 0 or 1;
• and
• each of Rkb1 to Rkb4 independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an electron-withdrawing group, at least two members of Rkb1, Rkb2 and Xkb1 may combine with each other to form a ring, and at least two members of Rkb3, Rkb4 and Xkb2 may combine with each other to form a ring.