The Formation Of Electroplating Molds By Reactive Ion Etching

Polyimide, polymethylmethacrylate (PMMA) and polyester-based polymers were investigated as potential electroplating mold materials. They showed high tensile stress (/spl equiv/10/sup 8/ dyne/cm/sup 2/) after heat treatment at temperatures /spl ges/ 200/spl deg/C. Conventional reactive ion etching techniques together with a trilevel masking scheme was used to delineate the polymer layers. The etch mask used was either spin-on glass or aluminum, and the etch gas was oxygen. With proper power density and etch gas pressure, aspect ratios >5 were obtained. Compatibility issues between RIE and the etch mask materials, as well as between RIE and the plating base materials are discussed.