Metal-containing onium salt compound, photodegradable base, resist composition, and method for manufacturing device using said resist composition

A metal-containing onium salt compound represented by the following Formula (1),

• (R13M-Ar1—Y+R2)nX− (1)
• wherein in the above Formula (1):
• each of R1 and R2 is independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 5 to 20 carbon atoms, where a part or all of hydrogen atoms of the alkyl group and the aryl group may be substituted;
• Ar1 is an arylene group having 5 to 20 carbon atoms, where a part or all of hydrogen atoms of the arylene group may be substituted;
• the alkyl group may contain a hetero atom-containing group instead of at least one methylene group thereof, and the aryl group and the arylene group may contain a hetero atom instead of at least one carbon atom in ring structure thereof;
• M is;
• Y is any one selected from the group consisting of an iodine atom, a sulfur atom, a selenium atom and a tellurium atom;
• n is 1 when Y is the iodine atom, and n is 2 when Y is any one selected from the group consisting of the sulfur atom, the selenium atom and the tellurium atom;
• any two or more of Ar1 and two R2 may be bonded to each other to form a ring structure with Y bonded thereto, and the ring structure may contain a hetero atom;
• and
• X− is an anion.