Amplification Type Positive Resist Composition

Title Chemical Amplification Type Positive Resist Composition 

Preparation of Poly(2-Ethyl-2-Adamantyl Methacrylate-co-p-Acetoxystyrene) 

A reaction flask was charged with 2-ethyl-2-adamantyl methacrylate (0.24 mol), p-acetoxystyrene (0.56 mol), and isopropanol (279 g) and then heated to 75°C. This mixture was next treated with dimethyl-2,2 -azobis(2-methylpropionate) (0.048 mol) dissolved in isopropanol (22.11 g), stirred 20 minutes, and finally refluxed for 

12 hours. The solution was diluted with acetone and then precipitated in methanol 250 g of the copolymer were isolated. 

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Chemical amplification type positive resist compositions provided in Table 1 were prepared by Takemoto [4] and were suitable for excimer laser lithography using ArF and KrF lasers. 

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