The Whitaker Corporation

Paulette Rita Noonan

Timothy Edward Boles

Joel Lee Goodrich

James Tajadod

Brian Rizzi

A voltage controlled oscillator includes a varactor (201) and a transistor (202) and a ground via (203), of epitaxially grown silicon that is etched to provide respective pedestals embodying the varactor (201) and the transistor (202) and the ground via (203), an L-C resonator circuit, the varactor (201) and an inductor providing a tank circuit that changes the frequency of the L-C resonator circuit, and that shifts the average frequency of the oscillator to that of an input voltage to the collector of the transistor (202).

Heterolithic voltage controlled oscillator

A method of fabricating a bipolar junction transistor having emitter line spacings on the order of approximately 0.25 microns or less is disclosed. Windows are opened in the silicon dioxide layer for the emitter collector and base fabrication. A layer of silicon nitride is disposed on top of the layer of silicon dioxide having been deposited over he entire surface containing approximately 0.5 width line features at he emitter, base and collector sites. Silicon nitride is deposited by low pressure chemical vapor deposition (LPCVD). The deposited nitride film is etched using a standard reactive ion etching technique, removing the silicon nitride from the horizontal surfaces of the oxide without removing the nitride from the sidewalls of the etched opening at the emitter, base and collector sites. The result of the RIE etching is that the thickness of the film on the horizontal surfaces is removed without removal of the nitride from the sidewalls of the etched pattern. The resulting spacer produces the window of the original features at the emitter, base and collector by a dimension of approximately 2X the thickness of the deposited silicon nitride.

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Dracut, MA, United States of America

Paulette Rita Noonan