The basic principles common to all eMET systems are shown in Fig. 4. Electrons are extracted at gun-level first pass through a multielectrode stack, which acts as a condenser and generates a broad, homogeneous beam of ca. 25 mm in diameter. This electron beam then impinges perpendicularly onto a programmable aperture plate system (APS), where (262,144) micrometer-sized beams are formed (cf. 256 k-APS). Additionally, each beam can be deflected individually by CMOS-controlled microdeflectors. All beams (deflected and undeflected) then enter the projection optics of the system where they get accelerated from 5 to 50 keV beam energy in an electrostatic multielectrode lens and demagnified by a magnetic lens system located at the bottom of the optical column. Only undeflected beams make it to the substrate level. Deflected beams are filtered out at a stopping aperture plate in the projection optics. All eMET systems are designed to print 82-μm-wide stripes on-the-fly, i.e., the substrate is continuously moving at constant velocity underneath the column while beams are switched on and off according to the data fed into the APS via the eMET data path. In this write mode, IMS’s proprietary writing strategy provides an inherent redundancy of up to . This high redundancy level averages out the effects of individual defective beams and thereby allows ignoring up to 100 (statistically distributed) defective beams. Furthermore, the operability of APS units is monitored in situ on a weekly basis by measurements that give information on the precise position of all defective beams. This information can be used to further reduce the impact of defective beams via online correction in the eMET data path. This inherent property of the eMET writing strategy coupled with the online correction capability drastically reduces the technical risk associated with the most critical element of this new technology and speaks for the suitability of IMS’s MB solution for high-volume manufacturing (HVM).