Brian Andrew Schell

Hydrosiloxane-modified styrene-diene block copolymer resists

Block copolymers are a class of polymers deserving of more investigation by the resist community. We are investigating styrene-hydrosiloxane modified diene block copolymers which have good properties for use as negative tone, electron sensitive resists. Resolution better than 0.1 micrometers , sensitivity of 30 (mu) C/cm2 and contrast of 2.8 have been demonstrated using a poly(styrene)-pentamethyldisiloxane modified poly(isoprene) block copolymer (PS-b-PDPI). Used in a bilayer resist scheme, PS-b-PDPI has an oxygen RIE selectivity ratio of 42 with respect to poly(imide). A poly(styrene)-heptamethyltrisiloxane modified poly(butadiene) block copolymer (PS-b-HTPB) has an oxygen RIE selectivity ratio of 54 with respect to poly(imide). In a bilayer resist system, using PS-b-PDPI as the imageable layer, patterns of 0.3 micrometers wide lines and 1.5 micrometers wide spaces have been transferred through a 1.2 micrometers thick poly(imide) planarizing layer.