LED-BASED PHOTOLITHOGRAPHIC ILLUMINATOR WITH HIGH COLLECTION EFFICIENCY

摘要

Provided is a LED-based photolithographic illuminator with high collection efficiency. The illuminator uses an LED array. Each LED comprises an LED die and a heat sink. The LED die is imaged on the input terminal of a homogenizer rod to actually cover an input terminal without including a heat sink part that does not emit light from the LED. A micro lens array for imaging the LED die is used. The collection efficiency of the illuminator exceeds 50% and illumination uniformity is about +/- 2% in the output terminal of a homogenizer.