Two-sided mask for patterning of materials with electromagnetic radiation

摘要

A mask and a fabrication method therefor that incorporates a patterned radiation blocking layer such as a second patterned high-reflectivity dielectric coating on the back surface of the mask which also includes a first patterned reflective coating on the front. This second high-reflective dielectric coating referred to as a premask, eliminates most of the laser energy directed onto the mask that leads only to substrate heating without effecting the laser energy transmitted through the open area of the mask. The open areas of the premask are sufficiently larger than those in the mask so not to interfere with the illumination geometry (i.e. forms a greater angle than the illumination numerical aperture).