Abstract: An imaging system for focusing and deflecting an electron beam comprises, as in prior systems, an evacuated envelope structure having a longitudinal axis and a solenoid for generating a substantially uniform magnetic field within the envelope and along the longitudinal axis thereof. As in prior systems of this type, the envelope includes an electrostatic yoke therein for generating a variable substantially uniform electric field within the envelope to deflect the electron beam along two coordinates of the system. The electric field is orthogonal to the magnetic field. An electron gun within the envelope generates and directs the electron beam through the magnetic and electric field to a target located opposite the electron gun and in a plane perpendicular to the axis of the tube. Unlike prior systems, the electrostatic yoke of the present system comprises a first conductive layer bonded to the interior surface of the envelope, and a second conductive layer overlying the first conductive layer.

Abstract: A method is disclosed for removing a glass backing plate glued to one major surface of a semiconductor wafer having imaging elements formed on the opposed major surface of the wafer. The wafer is disposed in an etch impervious holder having a wafer support surface. The method includes the steps of providing a substantially etch impervious coating on the opposed major surface of the wafer including the imaging elements and a substantially etch impervious layer on the wafer support surface of the holder, then forming a substantially etch impervious, leak-tight seal between the wafer and the holder. The method further includes the steps of etching the glass plate in a suitable etching solution until the glass plate and the glue are dissolved from the one major surface of the wafer, and removing the substantially etch impervious coating on the opposed major surface of the wafer and the substantially etch impervious seal between the wafer and the holder.