Development of a Deep Ultraviolet Positive-Tone Photoresist from the Sustainable Building Block Cyrene

The advancements in micro- and nanofabrication of semiconductor devices have led to a growing demand for innovative molecules to enhance photolithographic imaging materials. However, intensified production demands placed on deep ultraviolet (DUV) positive-tone chemically amplified resists, especially those based on polymethacrylates with alicyclic pendant groups, face increasing environmental challenges (e.g., nonsustainable monomer feedstocks). Disclosed herein is the synthesis of a series of methacrylic monomers and homopolymers derived from derivatives of the sustainable chemical building block dihydrolevoglucosenone (Cyrene, DLGO), obtained from renewable cellulose feedstocks. Poly( n -BuMDLGO) showed photoacid lability that modified the solubility upon treatment with basic developing solutions. This feature enabled photopatterning using both DUV (contact mask) and electron beam lithography.