Information medium master manufacturing method information medium stamper manufacturing method information medium master manufacturing apparatus and information medium stamper manufacturing apparatus

摘要

An information medium master manufacturing method forms a latent image by emitting an exposing beam onto a photoresist layer formed on a light absorbing layer, then develops the latent image to expose a part of the light absorbing layer from the photoresist layer, dry etches the light absorbing layer using the photoresist layer as a mask to form concave parts in the light absorbing layer, and removes the remaining photoresist layer from the light absorbing layer to manufacture a master in which a protrusion/depression pattern is formed. The light absorbing layer is formed of a resin material such that the selection ratio of the etching rate of the photoresist layer to the etching rate of the light absorbing layer is 0.5 or above during the dry etching. By doing so, it is possible to ensure that the photoresist layer used as a mask remains even when the formation of concave parts of a desired depth is completed, so that problems such as rounding or shallow formation of the groove shapes of the concave parts can be avoided and it is possible to manufacture an information medium master with a sharp protrusion/depression pattern.