Patent ID: 7158305

Claim:
The method of providing patterning illumination in an exposure system, characterized by the following steps: Step 1) Providing a high-intensity radiation beam in a tight focus; Step 2) Passing such radiation beam through a small entry aperture in an aperture plate, such aperture plate having a mirrored back surround, such aperture providing opening into an entry chamber with internal mirrorization and having a rear closure with an exit gap significantly greater in area than said entry aperture Step 3) Passing a significant portion of such radiation beam through such exit gap to a homogenization section extending away from such chamber toward a utilization station having the characteristic of accepting for utilization only a portion of the radiation applied, and reflecting another portion of the radiation applied, such reflection going all the way back through homogenizer and entry chamber to be re-reflected by the mirrorized surround of such entry aperture with only an insignificant fraction of such reflection passing out such entry aperture because of a wider focus encompassing such entry aperture surround; and Step 4 ) Providing for a portion of the radiation beam not passing through such exit gap to strike a mirrorized surround about such exit gap, for re-reflecting back to the entry aperture surround and chamber walls for additional homogenization and recycling.