Upper layer film forming composition and method of forming photoresist pattern
An upper layer film forming composition for forming an upper layer film on the surface of a photoresist film includes (A) a resin dissolvable in a developer for the photoresist film and (B) a compound having a sulfonic acid residue group, the composition forming an upper layer film with a receding contact angle to water of 70° or more. The upper layer film forming composition of the present invention can form an upper layer film which has a sufficient transparency and is stably maintained without eluting the components into a medium without being intermixed with a photoresist film, can form a resist pattern with high resolution while effectively suppressing a defect, and can suppress a blob defect.
1. A method of forming a photoresist pattern comprising:
a step of forming a photoresist film by applying a photoresist to a substrate;
a step of forming an upper layer film on the photoresist film; and
a step of forming a resist pattern by irradiating the photoresist film and the upper layer film with radiation via water through a mask having a specific pattern, and developing the resist pattern,
wherein the step of forming an upper layer film is carried out using an supper layer film forming composition comprising:
(A) a resin dissolvable in a developer for the photoresist film; and
(B) a compound shown by the following formula (2),
wherein R 6 individually represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alicyclic alkyl group having 3 to 10 carbon atoms or a derivative thereof, a hydroxyl group, a carboxyl group, an alkyl ether group, an alkyloxycarbonyl group, or an alkylcarbonyloxy group; Z represents a linear, branched or alicyclic hydrocarbon having 4 to 12 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon; m is 0 to 4;
and n is 1 to 4,
wherein the resin (A) has at least one repeating unit selected from repeating units shown by the following formulas (I-1), (I-2), and (I-3),
wherein R 1 represents a hydrogen atom, a methyl group, or a trifluoromethyl group, R 2 , R 3 , and R 4 represent a single bond or a divalent organic group, R 5 represents a linear or branched alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted by a fluorine atom or an alicyclic alkyl group having 3 to 10 carbon atoms, and R 1x represents a linear or branched alkyl group having 1 to 3 carbon atoms in which at least one hydrogen atom is substituted by a fluorine atom,
wherein an amount of the compound (B) is 3 parts by mass or less for 100 parts by mass of the resin (A).
2. The method according to claim 1 , wherein the photoresist is a radiation-sensitive resin composition comprising (a) a resin containing an acid-dissociable group and (b) an acid generator, the resin (a) containing a repeating unit having an acid-dissociable group in an amount of 30 to 60 mol % of the total amount of the resin (a).
3. The method according to claim 1 , wherein Z in the formula (2) showing the compound (B) is a group derived from an aromatic hydrocarbon.