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and the solvent not having a hydroxyl group is usually from 1/99 to 99/1, preferably from 10/90 to 90/10, more preferably from 20/80 to 60/40. 

The solvent having a hydroxyl group is preferably an alky› lene glycol monoalkyl ether, and the solvent not having a hydroxyl group is preferably an alkylene glycol monoalkyl ether carboxylate. 

The amount used of the solvent based on the entire amount of the composition of the present invention may be appropri› ately adjusted according to the desired film thickness or the like, but in general, the amount used is adjusted such that the entire solid content concentration of the composition becomes from 0.5 to 5 mass%, preferably from 0.8 to 3 mass %, more preferably from 0.8 to 2 mass %, still more prefer› ably from 0.8 to 1.5 mass %. 

[ 6] Other Additives 

Other than the above-described components, the composi› tion of the invention may appropriately contain an onium carboxylate, a dissolution inhibiting compound having a molecular weight of3,000 or less described, for example, in Proceeding ofSPIE, 2724, 355 (1996), a dye, a plasticizer, a photosensitizer, a light absorber, an antioxidant and the like. Also, in the case of using EUV as the exposure light source, the composition may contain an additive capable of absorbing out-of-band light. Examples of the out-of-band light absorber include the aromatic compounds described in U.S. Patent Application Publication No. 2006/0223000. 

The present invention is described below by referring to Examples, but the present invention should not be construed as being limited thereto. 

Poly(p-hydroxystyrene) (VP-2500, produced by Nippon Soda Co., Ltd.) (30 g) as a polyhydroxystyrene compound was dissolved in 120 g of PGMEA (propylene glycol monom› ethyl ether acetate). To this solution, 10.40 g of2-cyclohexy- 

## Synthesis of Polymer Compound (R-11) 

## EXAMPLES 

## Synthesis Example 1 

!ethyl vinyl ether as a vinyl ether compound and 1 .45 g of 2 mass % comphorsulfonic acid (PGMEA solution) were added thereto, and the mixture was stirred at room tempera› ture for 2 hours. Furthermore, 1.05 g of 10 mass% triethy› lamine (PGMEA solution) was added and after stirring for a while, the reaction solution was transferred to a separating funnel containing 165 mL of ethyl acetate. The organic layer was washed with 200 mL of distilled water three times, and ethyl acetate was removed in an evaporator. The obtained reaction solution was added dropwise to 2 L of hexane, and the supernatant was removed. The obtained product was dis› solved in 95 g of PGMEA, and the low-boiling-point solvent was removed under reduced pressure conditions to obtain 132.3 g of a PGMEA solution (28.3 mass %) of Polymer Compound (R-11 ). 

With respect to Polymer Compound (R-11 ), the molar ratio of respective repeating units was determined using $^{1 }$H-NMR and $^{13}$C-NMR. Also, the mass average molecular weight (Mw) in terms of polystyrene and the polydispersity (Mw/ Mn) were determined using GPC (solvent: THF). The results are shown in Table 1 below 

In Table 1, the molar ratio of respective repeating units (corresponding to repeating units starting from the left) is shown in the column of"Compositional Ratio", and the mass average molecular weight in terms of polystyrene as mea› sured using GPC (solvent: THF) is shown in the colunm of "Mw". Also, the polydispersity Mw/Mn is shown in the col- unm of"Polydispersity". 

In Table 1, Polymer Compounds (R-8), (R-10) and (R-17) were synthesized by the same method as in the synthesis example of Polymer Compound (R-11) except for differing in the acetalizing agent. 

Polymer Compound (R-12) was synthesized by obtaining a precursor of Polymer Compound (R-12) by a known radical polymerization method using p-acetoxystyrene and cyclo› hexyl acrylate and thereafter, introducing an acetal protective group by the same operation as in Polymer Compound (R-11) except for differing in the acetalizing agent. 

Polymer-XI was synthesized by a known radical polymer› ization method using p-acetoxystyrene and tert-butyl meth› acrylate. 

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