Negative resist composition and patterning process using the same

A negative resist composition comprising at least:

• (A) a base polymer which is soluble in alkali and which is insolubilized in alkali by an action of an acid;
• and/or a combination of a crosslinking agent and a base polymer which is soluble in alkali and which is reacted with the crosslinking agent by an action of an acid to thereby be insolubilized in alkali;
• (B) an acid generator;
• and
• (C) a nitrogen-containing compound as a basic component;
• wherein the polymer to be used as the base polymer is:
• a polymer, which is obtained by polymerizing two or more kinds of monomers represented by the following general formula (1), or which is obtained by polymerizing a monomer mixture containing one or more kinds of monomers represented by the general formula (1) and one or more kinds of styrene monomers represented by the following general formula (2);
• or a polymer obtained by subjecting the functional groups of the polymerizedly obtained polymer to a further chemical conversion;
• and
• wherein the repeating units derived from the monomers represented by the general formula (1) are included in the obtained polymer at a sum ratio of 50 mole % or more relative to a total amount of all repeating units constituting the obtained polymer:
• (in the formulae,
• X represents (when present in plural, each independently represent):
• a hydroxyl group;
• a tri-hydrocarbon substituted silyloxy group having 3 to 18 carbon atoms;
• a substitutable acyloxy group having 2 to 18 carbon atoms;
• a substitutable oxahydrocarbon group having 1 to 18 carbon atoms;
• a substitutable hydrocarbon group having 1 to 18 carbon atoms;
• a substitutable acyl group having 2 to 18 carbon atoms;
• chlorine;
• bromine;
• iodine;
• a nitro group;
• a cyano group;
• a sulfinyl group;
• a sulfonyl group;
• or an alkyl group having 1 to 6 carbon atoms;
• p is an integer of 0 to 4;
• Y represents (when present in plural, each independently represent):
• a hydroxyl group;
• a trialkylsilyl group having 3 to 18 carbon atoms;
• a substitutable acyloxy group having 2 to 18 carbon atoms;
• a substitutable oxahydrocarbon group having 1 to 18 carbon atoms;
• a substitutable hydrocarbon group having 1 to 18 carbon atoms;
• a substitutable acyl group having 2 to 18 carbon atoms;
• chlorine;
• bromine;
• iodine;
• a nitro group;
• a cyano group;
• a sulfinyl group;
• a sulfonyl group;
• or an alkyl group having 1 to 6 carbon atoms;
• q is an integer of 0 to 3;
• and
• at least one of X and Y is a hydroxyl group, or a substitutional group which is to be converted into a hydroxyl group by a chemical conversion).