Abstract

An energy efficient optical system is essential for excimer laser ablation, due to the excimer laser's higher photon cost compared to other lasers. Our highly energy-efficient KrF excimer laser ablation apparatus has already been reported.^1,2 For this system, a mask pattern reduction projection method was chosen. Figure 1 shows a simplified block diagram. The distinctive features of this optical system are the illuminating source with multiple irradiation, and the synchronous scanning mechanism. The mask and the imaging lens play very important roles in the realizing these technologies. The dielectric multi-layer coated mask and the imaging lens developed for this system are described below.

© 1995 IEEE