Contact printing as second exposure of double exposure attenuated phase shift mask process

摘要

Utilizing contact printing as the second exposure within a double exposure attenuated phase shift mask (APSM) fabrication process is disclosed. The process defines the shift pattern within the attenuated layer of the APSM using a first exposure, such as electron beam (e-beam) writing. The attenuated layer may be MoSi, MoSiO, and so on. The process then defines the border pattern within the opaque layer of the APSM using a second exposure. The second exposure employs contact printing, utilizing a contact exposure mask. The contact printing process may align the contact exposure mask over the wafer on which the APSM is fabricated utilizing a camera and an image storage system storing an image of this wafer.