TTLアライメントを用いたエキシマレーザ露光装置

概要

論文の詳細を見る
A new excimer laser stepper at 248 nm wavelength has been developed. The numerical aperture and the field size of an all quartz 5X reduction lens are 0.4 and 15 mm square, respectively. A key feature of the system is a through-the-lens alignment system using an optical heterodyne method operating with a 633 nm He-Ne laser. The problem of the large focal plane difference between exposure and alignment wavelength has been solved by a new alignment system using two symmetrical grating marks on the reticle and a checkerboard grating mark on the wafer. Moreover, a wafer leveling mechanism and a yaw compensating mechanism have been adopted in order to realize precise positioning of the wafer stage. Exposure experiments have proved that the resolution is O.35 μm and overlay accuracy is better than O.1 μm. The results show that the stepper is suitable for developing 0.4 μm devices.
社団法人精密工学会の論文
1993-08-05