Abstract: An integrated circuit including a plurality of active devices each including a thermionic cathode or a cold cathode, an anode, and a grid element, all coplanarly disposed on an insulating substrate in a vacuum. A plurality of electrostatic lens elements also are exposed on the substrate to produce electric fields that control the trajectories of electrons emitted by the cathodes to prevent the electrons from migrating to and charging up exposed portions of the substrate and the inner surface of the vacuum envelope and thereby preventing such charge buildup from altering the electrical characteristics of the active devices.