Ultrafast circuits and systems using quantum devices

In this paper, we discuss circuit design methodologies and simulation techniques for ultrafast digital systems using resonant tunneling devices. State of the art circuit techniques and process technologies are limited by the incremental performance improvement offered by device scaling. To achieve an order of magnitude improvement in circuit performance, it is necessary to develop technologies that are not solely dependent on device scaling for performance enhancement. Quantum effect devices use a radically different tunneling transport mechanism which allows picosecond device switching speeds and hence quantum circuit technology is a promising emerging alternative VLSI circuit technology. In a concentrated effort in the area of ultrafast circuit design using resonant tunneling devices, at the University of Michigan, we have developed circuit theory, logic families, architectural techniques, and CAD tools for the design of high performance circuit systems using quantum effect resonant tunneling diodes (RTDs) in conjunction with hetero-junction bipolar transistors (HBTs), high electron mobility transistors (HEMTs) and CMOS devices.