Indium phosphide heterojunction bipolar transistors (HBTs) find applications in very wide-band digital and mixed-signal integrated circuits (ICs). Devices fabricated in high-yield process flows at 500 nm feature size obtain 450 GHz cutoff frequencies and 5 V breakdown and enable high yield fabrication of integrated circuits having more than 3000 transistors. Laboratory devices at 250 nm feature size obtain 755 GHz . We describe device and circuit bandwidth limits associated with HBTs, develop scaling roadmaps for HBTs having lithographic minimum feature sizes between 512 and 64 nm, and identify key technological challenges in realizing 480-GHz digital ICs and 1000-GHz amplifiers. Key features of manufacturable self-aligned dielectric sidewall processes are described in detail.

In the above titled paper (ibid., vol. 96, no. 2, pp. 271-286, Feb 08), there are errors. Corrections are presented here.

The inherent bistability and picosecond time-scale switching of the resonant tunneling diode (RTD) provides an ideal element for the design of digital circuits and analog signal quantizers in the 10-100 GHz domain. New differential RTD-based circuits for quantizers and a first-order sigma-delta modulator capable of operating at 10 GHz and beyond are introduced.