Verfahren zur Herstellung dreidimensional gekrümmter Oberflächen, Verfahren zur Herstellung eines Oberflächenprofils, das einer Linse entspricht und Profil einer Linse

摘要

PCT No. PCT/EP94/01307 Sec. 371 Date Dec. 28, 1994 Sec. 102(e) Date Dec. 28, 1994 PCT Filed Apr. 26, 1994 PCT Pub. No. WO94/25881 PCT Pub. Date Nov. 10, 1994In a stepped lens with a Fresnel surface structure produced by lithography and a process for fabricating same, the high potential exposure speed of high-speed electron-beam exposure systems which work with variable rectangular beam cross sections is converted in such a way that stepped Fresnel type lenses can be fabricated with high efficiency and, in so doing, the required amounts of data is reduced. According to the invention, radiation dose distributions which correspond to cylindrical lenses are exposed one upon the other, at least one of the radiation dose distributions corresponding to a Fresnel type cylindrical lens. Lens structures with any desired lens curvature, from radially spherical to elliptical, can be efficiently produced by lithography by the disclosed process.