Three-terminal Si-based negative differential resistance circuit element with adjustable peak-to-valley current ratios using a monolithic vertical integration

Abstract

Si-based resonant bipolar transistors are demonstrated by the monolithic vertical integration of Si-based resonant interband tunnel diodes atop the emitter of Si/SiGe heterojunction bipolar transistors (HBTs) on a silicon substrate. In the common emitter configuration, IC versus VCE shows negative differential resistance characteristics. The resulting characteristics are adjustable peak-to-valley current ratios, including infinite and negative values, and tailorable peak current densities by the control of the HBT base current under room temperature operation. With the integrated RITD-HBT combination, latching properties which are the key operating principle for high-speed mixed-signal, memory, and logic circuitry, are experimentally demonstrated.