Syntheses of Base-Soluble Si Polymers and Their Application to Resists

Three kinds of Si-polymers, which have Si in the main chain and are soluble in basic aqueous solutions, were synthesized. The first one is polysiloxane with a phenol group directly bonded to Si(Polymer(I)). The second one is polysilane substituted with a phenol group(polysilane(II)). The third one, polysilanes substituted with carboxylic acids-(polysilane(III)s) were synthesized from polysilane(II) and carboxylic acid anhydrides Polysilane(II) and polysilane(III)s were soluble in polar solvents such as alcohols, acetonitrile and basic aqueous solutions, however, they were insoluble in non-polar solvents such as toluene and hexane. On photolysis, the polysilane(II) and the polysilane(III)s behaved almost the same as alkylpolysilanes, except for polysilane(III)s with a chloride group which accelerated the photolysis. The polysilane(II) showed blue shifts in solvents making the stronger hydrogen bonding with phenol groups. The blue shift was also seen on cooling. Thermal stability of the polysilane(II) was the same as that of methylphenylpolysilane, however, the polysilane(III)s were