OPTICAL SYSTEM FOR CRYSTALLIZATION APPARATUS

摘要

PURPOSE: An optical system for a crystallization apparatus is provided to enable a large area LCD fabrication by growing a uniform crystal having an equal grain size by performing a projection exposure as to micro stripe patterns by a projection optical system and by scanning gradually them. CONSTITUTION: The optical system makes an amorphous silicon thin film as a silicon thin film crystallized by an exposure of a micro stripe pattern using an eximer laser as a light source. The system includes the first lens-the tenth lens arranged along an optical axis from the eximer laser. The first lens(300) is a both convex lens, and the second lens(310) is a convex concave lens convex toward the light source, and the third lens(320) is a convex concave lens convex toward the light source, and the fourth lens(330) is a both concave lens. The fifth lens(340) is a both convex lens, and the sixth lens(350) is a concave convex lens concave toward the light source and the seventh lens(360) is a convex concave lens convex toward the light source. The eighth lens(370) is a both convex lens, the ninth lens(380) is a convex concave lens convex toward the light source, and the tenth lens(390) is a both convex lens. At least one of the ten lenses includes a CaF2 to improve an efficiency of a light intensity and to reduce a color aberration. The system further includes an optical component(200) made with a birefringent material to control a depth of focus of a light transmitted the tenth lens.