Polymer radiation insolubilization

A large number of polymeric materials have been developed over the past two decades which are photochemically reactive. In many cases, such polymers are initially soluble in organic solvents prior to exposure with insolubilization accompanying ultraviolet radiation. This often presents a problem in practical applications where handling of organic solvents is objectionable or expensive. A need exists to develop functional polymers which are both water soluble and photochemically labile. 

The G values (chemical events/100 ev absorbed) are also indications of the tendency of a polymer to degrade or insolubilize under any form of radiation in excess of bond energies. In Table XI, a compilation of the G values is noted along with the expended energy for each bond broken or formed. In the case of... 

To be useful in lithography, a polymer should be capable of being almost completely insolubilized by radiation. That is, s should approach something less than 0.05 as D becomes large. In terms of equation 5, this is a condition of s + s /2 = G(s)/2(Gx) < 0.2736 (6)... 

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