METHOD FOR ETCHING, METHOD FOR MANUFACTURING OPTICAL ELEMENT AND OPTICAL ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a method for etching to smoothen the surface of an optical element and to provide a method for manufacturing optical element and an optical element. SOLUTION: A stair-like pattern formed in a resist film 6 is smoothened by isotropic etching and then the pattern is transferred to a quartz glass substrate 5 by anisotropic etching so that a lens in a more smooth form with high accuracy can be manufactured compared to the process using only anisotropic etching. The isotropic etching and anisotropic etching are selected by applying a bias voltage or no voltage on the electrode 8 of an ICP- RIE(induction coupling plasma reactive ion etching) device 1. Thus, the anisotropic etching and isotropic etching can be easily selected and the surface of the lens can be fast formed.