Charlesby s gel formation theory

The relationship between sensitivity and component ratio in copolymer negative resists was studied theoretically on the basis of Charlesby s gel formation theory. The formulas for sensitivity as a function of component weight ratio are derived for a nonchain reaction and for a chain reaction, respectively. Copolymer sensitivities for any component ratio can be estimated numerically using the derived formulas, from the data on sensitivities for homopolymers composed of individual constituent monomers in the copolymer. The calculated results are in good agreement with the experimental data reported. 

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