Extended Focal Depth Optical Microlithography
Original Publication Date: 1989-Jun-01
Included in the Prior Art Database: 2005-Jan-28
It is proposed to improve the operation of optical lithography tools used in semiconductor manufacturing operations so as to minimize the defocus effect caused by the vertical topography on the wafers. The proposal suggests that the wafer be moved through the focus to lessen the defocus effects. This will serve to compensate for the shallow depth of focus of the tool and the resulting problem of image size variation.