A Permeable-Base Switching Device Using Stacked Layers of Silicon, Silicon Dioxide, and Silicon-Rich Silicon Dioxide

Abstract

A novel permeable-base device that is a type of solid-state analog to the vacuum tube has been constructed using stacked layers of silicon, silicon dioxide, and silicon-rich silicon dioxide. The base or grid, which is formed from thin patterned polycrystalline silicon with degenerate doping, is separated from a single-crystal silicon substrate that acts as the collector or anode by a layer of silicon dioxide The emitter or cathode is formed on top of the base using a stack of slicon dioxide, silicon-rich silicon dioxide, and degenerately doped polcrys-talline silicon (known as an electron injector structure). Currenl flow from the emitter to the base and collector is modulated by the elcctric fields created in the silicon dioxide layers by the voltages applied 1o the various terminals. This unipolar device, which has only electrons carrying the current, is shown to be capable of operation over a wide range of voltages and gains depending on design. Copyright © 1987 by The Institute of Electrical and Electronics Engineers, Inc.