PRETREATMENT METHOD, OPTICAL ELEMENT, EXPOSURE DEVICE, DEVICE MANUFACTURING METHOD, AND DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a pretreatment method by which the adhesive properties and the tight fitting properties of the surface of a calcium fluoride are enhanced, and an optical element, an exposure device, a device manufacturing method, and a device. SOLUTION: The pretreatment method comprises the step to make a caustic alkali solution and a hydrochloric and solution act upon a calcium fluoride substrate sequentially after irradiating the surface of the substrate with a beam and the step to form an adhesive layer on the substrate.