US 2019/0196326 Al  48  Jun.27,2019  Carboxylic Acid Onium Salt  Other Additives  Application  Pattern Forming Method  Preparation Method  [0478]  (ii) an exposure step of exposing the resist film; and  [0477]  (i) a resist film forming step of forming a resist film  by using the actinic ray-sensitive or radiation-sensitive resin  composition;  [0476]  The pattern forming method according to the  embodiment of the present invention includes:  [0470]  In view of resolving power improvement, with the  composition according to the embodiment of the present  invention, it is preferable to form a resist film having a film  thickness of 90 nm or less and preferably having a film  thickness of 85 nm or less. In a case where coatability and  film formability are improved by setting the concentration of  the solid. content in the composition to an appropriate range  [0475]  The present invention also relates to a pattern  forming method using the actinic ray-sensitive or radiation› sensitive resin composition. Subsequently, the pattern form› ing method according to the embodiment of the present  invention is described. Together with the description of the  pattern forming method, the resist film according to the  embodiment of the present invention is described.  [0469]  Specific examples of alicyclic or aliphatic com› pounds having a carboxy group include a carboxylic acid  derivative that has a steroid structure such as cholic acid,  deoxycholic acid, and lithocholic acid, an adamamanecar› boxylic  acid derivative,  adamantanedicarboxylic  acid,  cyclohexanecarboxylic acid, and cyclohexane dicarboxylic  acid.  [0474]  The composition according to the embodiment of  the present invention relates to an actinic ray-sensitive or  radiation-sensitive resin composition of which properties  change in reaction to the irradiation with an actinic ray or  radiation. More specifically, the present invention relates to  an actinic ray-sensitive or radiation-sensitive resin compo› sition used in a step of manufacturing a semiconductor such  as an IC, the manufacturing of a circuit board such as a  liquid crystal and a thermal head, the manufacturing of a  mold structure for imprinting, a photofabrication step, a  lithographic printing plate, and an acid curable composition.  [0467]  In the composition according to the embodiment of  the present invention, if necessary, an acid proliferation  agent, a dye, a plasticizer, a photosensitizer, a light absorber,  an alkali-soluble resin, a dissolution inhibitor, a compound  (for example, a phenol compound having a molecular  weight of 1,000 or lower, alicyclic or aliphatic compound  having a carboxy group) that promotes solubility in the  developer, and the like can be further contained.  [0468]  The phenol compound having a molecular weight  of 1000 or less can be easily synthesized by those skilled in  the art, for example, with reference to methods disclosed in  JP! 992-122938A  (JP-H04-122938A),  JP1990-028531A  (JP-H02-028531A),  U.S.  Pat.  No.  4,916,210A,  and  EP219294B.  [0473]  The composition according to the embodiment of  the present invention can be used by dissolving the above  components in a predetermined organic solvent, preferably  the mixed solvent, performing filter filtration, and applying  on a predetermined support (substrate). The pore size of the  filter used in the filter filtration is 0.1  µm or lower, more  preferably 0.05 µm  or lower, and even more preferably 0.03  µm or lower, and preferably made of polytetrafluoroethyl› ene, polyethylene, or nylon. In the filter filtration, for  example, as disclosed in JP2002-062667 A, cyclical filtration  may be performed, or filtration may be performed by con› necting plural kinds of filters in series or in parallel. In  addition, the composition may be filtrated a plurality of  times. Before or after the filter filtration, a deaeration  treatment or the like may be performed on the composition.  [0466]  In a case where the composition according to the  embodiment of the present invention contains carboxylic  acid onium salt, the content thereof is generally 0.1 to 20  mass%, preferably 0.5 to 10 mass%, and more preferably  1 to 7 mass % with respect to the total solid content of the  composition.  [0465]  These carboxylic acid onium salts can be synthe› sized by reacting sulfonium hydroxide, iodonium hydroxide,  ammonium hydroxide, and carboxylic acid with silver oxide  in an appropriate solvent.  [0464]  The composition according to the embodiment of  the present invention may or may not contain carboxylic  acid onium salt. Examples of the carboxylic acid onium salt  include salts disclosed in paragraphs <0605> and <0606> of  US2008/0187860A.  [0472]  The concentration of the solid content is a mass  percentage of a mass of the other resist components exclud› ing the solvent with respect to the total mass of the com› position.  [0471]  The concentration of the solid content of the com› position according to the embodiment of the present inven› tion is generally 1.0 to 10 mass%, preferably 2.0 to 5.7 mass  %, and more preferably 2.0 to 5.3 mass %. By causing the  solid content concentration to be in the above range, the  substrate can be uniformly coated with the resist solution,  and also an excellent resist pattern can be formed by LWR.  Although the reason is unclear, it is considered that, by  setting the concentration of the solid content to 10 mass %  or less and preferably 5.7 mass% or less, the aggregation of  the material, particularly, the acid generator in the resist  solution is suppressed, and as a result, a uniform resist film  can be formed.  such that the composition has an appropriate viscosity, the  film thickness can be obtained.  [0462]  In a case where the composition according to the  embodiment of the present invention contains a surfactant,  the used amount of the surfactant is preferably 0.0001 to 2  mass% and more preferably in the range of0.0005 to 1 mass  % with respect to the total solid content of the composition.  [0463]  Meanwhile, in a case where the addition amount of  the surfactant is 10 ppm or lower with respect to the total  amount (except for the solvent) of the composition, the  uneven distribution properties of the surface of the hydro› phobic resin increase, and accordingly, the resist film surface  can become more hydrophobic, and thus it is possible to  improve water followability in a case of immersion expo› sure. 