Monomer, polymer, chemically amplified resist composition, and pattern forming process

A monomer having the formula (A):

• wherein n1 is 1, 2 or 3, n2 is 0, 1 or 2,
• RA is hydrogen, fluorine, methyl or trifluoromethyl,
• XL1 is a single bond, optionally substituted phenylene group or optionally substituted naphthylene group,
• XL2 is a single bond or C1-C40 hydrocarbylene group which may contain a heteroatom,
• LA and LB are each independently a single bond, ether bond, ester bond, amide bond, carbonate bond or carbamate bond,
• LC is a single bond, carbonyl group or ester bond,
• R1 is halogen, nitro, cyano, hydroxy, carboxy, or a C1-C20 hydrocarbyl group, C1-C20 hydrocarbyloxy group or C1-C20 hydrocarbylthio group, which may contain a heteroatom;
• when n2=2, two R1 may be identical or different, and
• R2 is a C1-C20 hydrocarbyl group which may contain a heteroatom.