Sulfonic acid ester containing polymers for organic solvent based dual-tone photoresists

A method comprising the steps of:

• (a) preparing a chemically amplified photoresist composition comprising an organic acid developable photoresist polymer, the polymer comprising an acid-labile sulfonate-ester moiety in the range of 1-50 wt %, a casting solvent, and optionally a photoacid generator (PAG);
• (b) applying the resist composition of step (a) to a substrate to form a resist film;
• (c) optionally, baking the resist film (PAB);
• (d) exposing the resist film to radiation;
• (e) optionally, baking the resist film (PEB);
• (f) developing the resist film with an organic solvent to expose a pattern etched onto the resist film;
• and
• (g) optionally rinsing the resist film with water or an organic solvent.