A radiation-sensitive resin composition, comprising:
- a base resin comprising a structure unit having an acid-dissociable group;
- a radiation-sensitive acid generator;
- an acid diffusion controlling agent which is an onium salt compound capable of being degraded and losing acid diffusion controlling properties by an exposure;
- and
- a solvent;
- wherein the radiation-sensitive acid generator comprises a compound represented by formula (2), a compound represented by formula (3), and optionally a compound represented by formula (1), provided that the compound represented by the formula (1) and the compound represented by the formula (3) within the scope of the compound represented by the formula (2) are excluded:
- wherein in the formulae (1) to (3),
- R1 and R3 are each independently a group having a cyclic structure, and R2 is an alicyclic hydrocarbon group or an alicyclic group in which a carbon ring atom of an alicyclic hydrocarbon group is replaced with a hetero atom;
- X11, X12, X21, X22, X31 and X32 are each independently a hydrogen atom, a fluorine atom, or a fluorinated hydrocarbon group, provided that at least one of X11 or X12 is not a hydrogen atom, at least one of X21 or X22 is not a hydrogen atom, and at least one of X31 or X32 is not a hydrogen atom;
- A11, A12, A21, A22, A31 and A32 are each independently a hydrogen atom, or a hydrocarbon group having a carbon number of 1 to 20;
- m1, m2 and m3 are each independently an integer of 0 to 5;
- n1, n2 and n3 are each independently an integer of 1 to 4;
- G is a single bond, or a divalent linking group;
- and
- Z1+, Z2+ and Z3+ are each independently a monovalent onium cation,
- wherein the radiation-sensitive resin composition does not comprise a ketone-based solvent, and
- the radiation-sensitive resin composition does not comprise a monovalent onium cation other than an onium cation represented by formula (X-1), an onium cation represented by formula (X-3), an onium cation represented by formula (X-4), or an onium cation represented by formula (X-5):
- wherein in the formula (X-1),
- k1, k2 and k3 are each independently an integer of 0 to 5, and
- Ra1, Ra2 and Ra3 are each independently, at each occurrence, a substituted or unsubstituted, straight or branched chain alkyl group, alkoxy group or alkoxy carbonyloxy group having a carbon number of 1 to 12;
- a substituted or unsubstituted, monocyclic or polycyclic cycloalkyl group having a carbon number of 3 to 12;
- a substituted or unsubstituted aromatic hydrocarbon group having a carbon number of 6 to 12;
- a hydroxy group, —OSO2—RP, —SO2—RQ or —S—RT;
- or a ring structure obtained by combining two or more thereof, wherein RP, RQ and RT are each independently, at each occurrence, a substituted or unsubstituted, straight or branched chain alkyl group having a carbon number of 1 to 12;
- a substituted or unsubstituted alicyclic hydrocarbon group having a carbon number of 5 to 25;
- and a substituted or unsubstituted aromatic hydrocarbon group having a carbon number of 6 to 12,
- in the formula (X-3),
- Rc1, Rc2 and Rc3 are each independently a substituted or unsubstituted, straight or branched chain alkyl group having a carbon number of 1 to 12;
- or a substituted or unsubstituted aromatic hydrocarbon group having a carbon number of 6 to 12,
- in the above formula (X-4),
- k6 and k7 are each independently an integer of 0 to 5, and
- Rd1 and Rd2 are each independently, at each occurrence, a substituted or unsubstituted, straight or branched chain alkyl group, alkoxy group or alkoxycarbonyl group having a carbon number of 1 to 12;
- a substituted or unsubstituted aromatic hydrocarbon group having a carbon number of 6 to 12;
- a halogen atom;
- a halogenated alkyl group having a carbon number of 1 to 4;
- a nitro group;
- or a ring structure obtained by combining two or more thereof, and
- in the above formula (X-5),
- k8 and k9 are each independently an integer of 0 to 4, and
- Re1 and Re2 are each independently, at each occurrence, a halogen atom;
- a substituted or unsubstituted straight or branched chain alkyl group having a carbon number of 1 to 12;
- or
- a substituted or unsubstituted aromatic hydrocarbon group having a carbon number of 6 to 12,
- wherein a CDU property of the radiation-sensitive resin composition is 3.1 nm or less,
- wherein the CDU property is obtained by:
- forming a hole resist pattern by exposing to an electron beam in an amount of an optimum exposed amount (Eop);
- measuring hole diameters of the hole resist pattern at 16 points within a square 400 nm;
- calculating an average value of the hole diameters;
- and
- measuring the average values at five hundred of arbitrary points and determining a 3σ value from a distribution of the average values as the CDU properties (nm), and
- wherein the Eop is obtained by:
- applying the radiation-sensitive resin composition to a substrate conducting a heating at 90° C. for 60 seconds, and then conducting a cooling at 23° C. for 30 seconds to form a resist film having a film thickness of 50 nm;
- exposing the resist film to an electron beam through a mask for forming a pattern having 40 nm line and space;
- conducting heating at 120° C. for 60 seconds:
- developing with 2.38% by mass of aqueous TMAH solution at 23° C. for 30 seconds;
- and
- determining an amount of the exposure as the Eop, when width of the formed line was 40 nm.