Enhanced polymeric lithography resists via sequential infiltration synthesis

Etch resistance of two commonly used lithography resists is increased significantly by sequential infiltration synthesis (SIS). Exposing films to trimethyl-aluminum and water with long dosage times infiltrates the bulk of the film with alumina, which renders them dramatically more resistant to plasma etching with no degradation to the patterns. Enhanced etch resistance eliminates the need for an intermediate hard mask and the concomitant costs and pattern fidelity losses. Moreover, by allowing for thinner resist films, this approach can improve the final pattern resolution.