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wash away particles. After exposure, a step of rinsing (post-soaking) may be introduced to remove any water remaining on the film after exposure. 

In the pattern forming process, an alkaline aqueous solu- tion, typically an aqueous solution of 0.1 to 5 wt %, more preferably 2 to 3 wt% TMAH is often used as the developer. The negative tone development technique using an organic solvent instead is also applicable wherein the unexposed region is developed and dissolved in the organic solvent. 

In the organic solvent development, the organic solvent used as the developer is preferably selected from 2-oc› tanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-hep› tanone, 2-hexanone, 3-hexanone, diisobutyl ketone, meth- ylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, isopentyl acetate, butenyl acetate, phenyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, methyl lactate, ethyl lac› tate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzo› ate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, and 2-phenylethyl acetate. These organic solvents may be used alone or in admixture of two or more. 

Examples and Comparative Examples are given below by way of illustration and not by way of limitation. The 40 abbreviation "pbw" is parts by weight. For all polymers, Mw and Mn are determined by GPC versus polystyrene stan› dards using THF solvent. Monomer 1 used herein is iden› tified below. 45 

## EXAMPLE 

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1) Synthesis of Polymers 

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Under nitrogen atmosphere, a solution was prepared by dissolving 25.2 g of Monomer 1, 4.80 g of 3-hydroxyada› mantyl methacrylate, 20.0 g of 1-isopropylcyclopentyl methacrylate, and 3.29 g of dimethyl 2,2’-azobisisobutyrate in 70 g of PGMEA. Under nitrogen atmosphere, the solution was added dropwise over 4 hours to 23 g of PGMEA while stirring at 80° C. After the completion of dropwise addition, stirring was continued at 80° C. for 2 hours. The reaction solution was cooled to room temperature and added drop› wise to 800 g of methanol. The thus precipitated solid was collected by filtration and vacuum dried at 50° C. for 20 hours, obtaining Polymer 1 in white powder solid form. Amount 38.8 g, yield 78%. 

## Synthesis Examples 2 to 8 and Comparative Synthesis Examples 1 to 8 

Synthesis of Polymers 2 to 8 and Comparative Polymers 1 to 8 

Polymers 2 to 8 and Comparative Polymers 1 to 8 were synthesized by the same procedure as in Synthesis Example 1 aside from changing the type and amount of monomers. 

## Synthesis Example 1 

