| 摘要 |
PURPOSE:To enable alignment of a mask which has a minute pattern of submicron region and a wafer in high precision by detecting the relative positioning error of the mask and the wafer scanning the mask or the wafer by a separate electro-optic electron beam respectively. CONSTITUTION:An electron beam 2 from an electron gun 1 is deflected by a deflecting electrode 5 through a condenser lens 3 and an objective lens 4 and scanning by the electron beam is carried out in cylinders A, B respectively. A reflected electron is generated from a reference mark 8a and the mark Ma of a mask M in the cylinder A and from a reference mark 8b and the mark Wb of a wafer W in the cylinder B. The reflected electron is detected by a detector 9a or 9b respectively. Consequently, the X direction positioning error of the mask M and the wafer W can be detected considering the reference distance between the reference marks 8a and 8b. |
