Fabrication of submicron deep ultraviolet masks by ion microprojection

Photolithographic masks with submicron resolution have been produced in a one‐step process by 1:10 ion microprojection of a stencil mask pattern into polymethyl methacrylate resist material. In the implanted pattern areas, light transmission is reduced for wavelengths extending into deep ultraviolet (DUV); thus, these patterns can be replicated into UV‐sensitive photoresists using, e.g., excimer laser radiation. In the present ion projection lithography machine a 2.5‐mm‐diam mask was produced using a single 2‐s exposure with 82 keV He+ ions. Replication in poly(butene‐1‐sulfone) resist was performed by single or double shot exposure using a KrF excimer laser (wavelength 248 nm). Resolutions exceeding 800 lp/mm were obtained in the replicated structures.