Micrel, Incorporated

Robert William Bechdolt

Jayasimha Prasad

Ronald Lloyd Schlupp

Jay Albert Shideler

Thomas S Wong

Phi Thai

A logic gate is described that has an N-type region, which may be an N-well or N-tub, forming a cathode of one or more Schottky diodes and a collector of an NPN bipolar transistor. Accordingly, the Schottly diodes and transistor do not need to be isolated from one another, resulting in a very compact logic gate. The logic gate forms a portion of a NAND function in one embodiment. One or more Schottky diodes between the collector and base of the bipolar transistor act as a clamp to prevent the transistor from saturating. The clamp diodes can also be used to adjust the output voltage of the gate to ensure downstream transistors can be fully turned off.

Integrated Schottky transistor logic configuration

Embodiments of a bipolar transistor are disclosed, along with methods for making the transistor. An exemplary transistor includes a collector region in a semiconductor substrate, a base layer overlying the collector region and bound by a field oxide layer, a dielectric isolation layer overlying the base layer, and an emitter structure overlying the dielectric isolation layer and contacting the base layer through a central aperture in the dielectric layer. The transistor may be a heterojunction bipolar transistor with the base layer formed of a selectively grown silicon germanium alloy. A dielectric spacer may be formed adjacent the emitter structure and over a portion of the base layer.

Growing community of inventors

San Jose, CA, United States of America

Robert William Bechdolt