Method for fabricating a bipolar junction transistor with tunneling current through the gate of a field effect transistor as base current

摘要

A MOSBJT (Metal Oxide Semiconductor Bipolar Junction Transistor) is formed to have both the higher current drive capability of the BJT and the smaller device area of the scaled down MOSFET. The MOSBJT includes a collector region and an emitter region comprised of a semiconductor material with a first type of dopant. A base region is disposed between the collector region and the emitter region, and the base region is comprised of a semiconductor material with a second type of dopant that is opposite of the first type of dopant. Unlike a conventional BJT, a base terminal of the MOSBJT is comprised of a dielectric structure disposed over the base region and comprised of a gate structure disposed over the dielectric structure. Unlike a conventional MOSFET, the dielectric structure of the MOSBJT is relatively thin such that a tunneling current through the dielectric structure results when a turn-on voltage is applied on the gate structure. This tunneling current is a base current of the MOSBJT. Furthermore, unlike a conventional MOSFET, the dielectric structure and the gate structure of the MOSBJT are not disposed over the collector region and the emitter region to prevent tunneling current between the gate structure and the collector and emitter regions.