US 2007/0072121 Al  20  Mar. 29, 2007  -continued  B-80  B-81  B-82  B-83  [0100]  The content of the compound (B) is from 5 to 20  mass  %, preferably from 6 to 18 mass %, more preferably  from 7 to 16 mass %, based on the entire solid content of the  photosensitive composition. The content is 5 mass  % or  more in view of sensitivity or line edge roughness and 20  mass % or less in view of resolving power, pattern profile  and film quality. One of the compound (B) may be used, or  two or more species thereof may be mixed and used. For  example, a compound capable of generating an arylsulfonic  acid upon irradiation with actinic rays or radiation and a  compound capable of generating an alkylsulfonic acid upon  irradiation with actinic rays or radiation may be used in  combination as the compound (B).  [0101]  The compound (B) can be synthesized by a known  method such as synthesis method described in JP-A-2002- 27806. (Compound (C) capable of generating a carboxylic  acid upon irradiation with actinic rays or radiation)  [0102]  In the positive resist composition of the present  invention, a compound capable of generating a carboxylic  acid upon irradiation with actinic rays or radiation (some› times referred to as a "compound (C)" or a "carboxylic acid  generator") may be used in combination with the sulfonic  acid generator (compound (B)).  [0103]  The carboxylic acid generator is preferably a com› pound represented by the following formula (C):  wherein R$_{21 }$ to R$_{23 }$ each independently represents an alkyl  group, a cycloalkyl group, an alkenyl group or an aryl group,  R$_{24 }$represents a hydrogen atom, an alkyl group, a cycloalkyl  group, an alkenyl group or an aryl group, Z represents a  sulfur atom or an iodine atom, and p is 1 when Z is a sulfur  atom, and  O  when Z is an iodine atom.  [0104]  In formula  (C), R$_{21 }$ to R$_{23 }$ each independently  represents an alkyl group, a cycloalkyl group, an alkenyl  group or an aryl group, and these groups each may have a  substituent.  [0105]  Examples of the substituent which the alkyl group,  cycloalkyl group and alkenyl group each may have include  a halogen atom (e.g., chlorine, bromine, fluorine), an aryl  (C)  R21  R22-i+  I  (R23)p 