4  US 8,637,222 B2  3  The bridge margin is indicated by a maximum size allow› ing a pattern to be separated when irradiated with an exposure  dose exceeding the exposure dose at which the objective  pattern size is obtained. A pattern is stably separated and  formed even in an overexposed region, so that production of  a bridge defect giving rise to wiring breakage at the wiring  formation can be prevented and reduction of the yield can be  suppressed.  The collapse margin is indicated by a minimum size allow› ing a pattern to be held when irradiated with an exposure dose  less than the exposure dose at which the objective pattern size  is obtained. A pattern can be held without collapsing even in  a region having a small exposure dose, so that a pattern with  a small exposure dose compared to a dense pattern, such as  isolated pattern, can be stably formed.  In the production of a semiconductor device or the like,  formation of various patterns such as line, trench and hole is  required and therefore, it is important to satisfy both the  bridge margin and the collapse margin.  As a result of intensive studies, the present inventors have  found that the above-described object can be attained by  performing pattern exposure of a crosslinkable negative  chemical-amplification resist and then developing the unex› posed area with a developer containing an organic solvent.  That is, the present invention is as follows.  1.  A resist pattern forming method comprising, in the fol› lowing order, (1) a step of forming a film by using a negative  chemical-amplification resist composition capable of under› going negative conversion by a crosslinking reaction, (2) a  step of exposing the film, and ( 4) a step of developing the  exposed film by using a developer containing an organic  solvent.  2. The resist pattern forming method as described in 1  above, wherein the organic solvent contained in the developer  is one or more kinds of solvents selected from the group  consisting of an ester-based solvent, a ketone-based solvent,  an alcohol-based solvent, an amide-based solvent, an ether› based solvent and a hydrocarbon-based solvent.  3. The resist pattern forming method as described in 1 or 2  above, wherein the organic solvent contained in the developer  is one or more kinds of solvents selected from the group  consisting of an alkylene glycol monoalkyl ether carboxy› late-based solvent, an alkylene glycol monoalkyl ether-based  solvent, an alkyl carboxylate-based solvent and an alkyl  ketone-based solvent.  4. The resist pattern forming method as described in any  one of 1 to 3 above, wherein the organic solvent contained in  the developer is one or more kinds of solvents selected from 50  the group consisting of propylene glycol monomethyl ether,  propylene glycol monomethyl ether acetate, methyl isobutyl  ketone, methyl amyl ketone, cyclopentanone, cyclohex› anone, ethyl lactate and butyl acetate.  5. The resist pattern forming method as described in any  one of 1 to 3 above, wherein the organic solvent contained in  the developer is one or more kinds or solvents selected from  the group consisting of an ester-based solvent containing no  hydroxyl group in the molecule, a ketone-based solvent con› taining no hydroxyl group in the molecule, and an ether-based  solvent containing no hydroxyl group in the molecule.  6. The resist pattern forming method as described in any  one of 1 to 5 above, further comprising: (5) a step of perform› ing a rinsing treatment by using a rinsing solution containing  an organic solvent after ( 4) the developing step.  7. The resist pattern forming method as described in 6  above, wherein the organic solvent contained in the rinsing  solution is one or more kinds of solvents selected from the  group consisting of a monohydric alcohol-based solvent and  a hydrocarbon-based solvent.  8. The resist pattern forming method as described in any  one of 1 to 7 above, further comprising: (3) a baking step  between the exposing step (2) and the developing step (4).  9. The resist pattern forming method as described in any  one of 1 to 8 above, wherein the exposure in the exposing step  (2) is performed by an electron beam or EUV light.  10. The resist pattern forming method as described in any  one of 1 to 9 above, which is used for fabrication of a semi› conductor microcircuit.  11. The resist pattern forming method as described in any  one of 1 to 10, wherein the percentage of water content in the  developer is 10 mass% or less.  12. The resist pattern forming method as described in any  one of 1 to 11 above, wherein the negative chemical-ampli› fication resist composition comprises: (A) a resin, (B) a  crosslinking agent capable of crosslinking the resin (A) by the  action of an acid, and (C) a compound capable of generating  an acid upon irradiation with an actinic ray or radiation.  13. The resist pattern forming method as described in 12  above, wherein the resin (A) is a resin containing a repeating  unit represented by formula (1):  (1)  wherein  A represents a hydrogen atom, an alkyl group, a cycloalkyl  group, a halogen atom or a cyano group,  R  represents a halogen atom, an alkyl group, a cycloalkyl  group, an aryl group, an alkenyl group, an aralkyl group, an  alkoxy group, an alkylcarbonyloxy group or an alkylsulfony› loxy group, and when a plurality of R’s are present, each R  may be the same as or different from every other R and they  may combine with each other to form a ring,  a represents an integer of 1 to 3, and  b represents an integer of0 to (3-a).  14. The resist pattern forming method as described in 12 or  13 above, wherein the crosslinking agent (B) is a phenol  compound.  15. The resist pattern forming method as described in 14  above, wherein the crosslinking agent (B) is a phenol com- pound having two or more benzene rings in the molecule.  16. The resist pattern forming method as described in any  one of 12 to 15 above, wherein the content of the crosslinking  agent (B) in the negative chemical-amplification resist com› position is from 3 to 65 mass % based on the entire solid  content of the resist composition.  1 7. The resist pattern forming method as described in any  one of 12 to 16 above, wherein the compound (C) is a com› pound capable of generating at least any one acid of a sulfonic  acid, a bis(alkylsulfonyl)imide and a tris(alkylsulfonyl)me- thide upon irradiation with an actinic ray or radiation.  18. A developer for use in the resist pattern forming method  described in any one of 1 to 17 above. 