Integration of EBDW of one entire metal layer as substitution for optical lithography in 220 nm node microcontrollers

Abstract

Electron beam direct write (EBDW) with a variable shaped beam writer can be applied for very low volume applications like prototyping and personalization. Together with Infineon Technologies, the Center of Competence E-Beam Lithography of Qimonda in Dresden has demonstrated the integration of an E-Beam written back end of line metal layer into a productive 220nm node microcontroller fabrication process. For this purpose an electron beam lithography unit process was developed, and all necessary steps like data prep, proximity correction, alignment and overlay processes and etching processes were reviewed. Several test wafers have been completed in fabrication and measured electrically. At first go, full electrical functionality with a yield >70% could be demonstrated.