A study of tin-containing block copolymers

The controlled synthesis of poly(styrene-block-trimethylstannylstyrene) has been accomplished. Thin films of the polymer were successfully oriented perpendicular to the substrate through use of neutral top and bottom coats to produce well-formed lamellae with the classical finger print pattern. Preliminary blanket etch studies show that the inclusion of tin into the block copolymer provides very high etch contrast for selective removal of the styrene block in both oxygen and fluorine plasma conditions. The etch rate of the tin polymer is significantly slower than that of thermal oxide under the conditions studied. Future work will be directed toward the synthesis of a sample with smaller pitch and to a study of the potential for use of organotin polymers for the patterning of fused silica imprint templates.