Base-amplifying silicone resins generating aliphatic secondary amines autocatalytically: synthesis, characterization and application to positive-working photoresists

New base-sensitive silicone resins bearing base-amplifying units that autocatalytically transform into aliphatic primary or secondary amino groups were designed and synthesized. Photogenerated amines from photobase generators by 254 nm light irradiation triggered a base-catalysed autocatalytic reaction, referred to as a base proliferation reaction, during post-exposure baking at 100 °C. This gave a positive-working developable photoresist with a 2 wt% lactic acid aqueous solution. A photosensitivity of 0.3 mJ cm⁻² was achieved, and 3 × 3 μm line-and-space patterns were successfully fabricated using a 0.7 μm thick film of the polymer.