Exposure device

Abstract

Abstract PURPOSE:To make an alignment of reticle and wafer of LSI accurate and easy with excellent productivity by a method wherein a part of multiple diffractive beams diffracted by the first grating on a reticle are passed through an air filter and then projected on the second grating on a substrate to detect the intensity of the diffractive beams diffracted by the second grating. CONSTITUTION:A reticle 14 is inserted into an optical path to load a wafer 18. The reticle 14 and the wafer 18 are roughly aligned with each other in advance. Next the first grating 10 of reticle 14 is illuminated with the light from a light source 11. Multiple diffractive beams 22 are diffracted from the first grating 10 on reticle 14 and led to the first lens system 15 so that an air filter 16 may be arranged to selectively pass the + or - primary beams only. The + or - primary beams are passed through the second lens system 17 to form interference fringes near the wafer 18 through a contractive projection optical system 19. Finally the diffractive beams diffracted by the second grating 21 are detected by a photodetector 23 to make an alignment of the wafer 18 and the reticle 14 with high precision.

Inventors

• 👤 Noboru Nomura
• 👤 登 野村
• 👤 Kazuhiro Yamashita
• 👤 一博 山下

Bibliographic Details