The Field of a Line Charge Near the Tip of a Dielectric Wedge

Lewis and Wasserstrom 1 have calculated the strength of the field singularity at the tip of a dielectric wedge in the configuration shown in Fig. 1. In particular, with a wedge permittivity e x greater than the permittivity t> of the surrounding medium and a conductor angle /3 = 7r (the "overhanging electrode"), they found that the tip field was singular for all wedge angles a greater than t/2. From this analysis, it was concluded that semiconductor devices with undercut edges (a