abstract |
A circuit pattern, a reticle alignment mark, a bar code, and a discrimination mark which are formed on a glass plate of a photo mask is constituted of a photo sensitive and photo attenuative material containing a fine particle material and a binder. Discrimination of the photo mask is performed by irradiating predetermined discrimination light on the discrimination mark or the bar code. Alignment of the photo mask by an aligner is performed by irradiating predetermined detection light on the reticle alignment mark. In an exposure process, the pattern on the photo mask is transferred onto a semiconductor wafer by using exposure light having a wavelength different from that of the discrimination light or that of the detection light. |