Accession Number : ADA332500

Title :   Ultra-Dense, Ultra-Fast Computing Components: Multiple-Value Logic Circuits with Resonant Tunneling Bipolar Transistors

Descriptive Note : Final progress report 17 Aug 93-31 Jul 96

Corporate Author : SANDERS LOCKHEED MARTIN CO NASHUA NH

Personal Author(s) : Rogers, Thomas J. ; Yanka, Robert W.

PDF Url : ADA332500

Report Date : SEP 1997

Pagination or Media Count : 42

Abstract : The objective of the program was to develop multiple value logic for a 2:1 reduction in circuit complexity and a 2:1 increase in circuit speed. The approach was to achieve modulo-4 arithmetic in circuits based on resonant tunneling bipolar transistors. Because the multiple value functionality is integrated into the individual devices within the circuits, reductions in circuit complexity and propagation delays may be realized that might not otherwise be achieved. MBE and GSMBE were used to grown epitaxial structures that included AlGaAs-GaAs and InGaP-GaAs heterojunction bipolar transistors integrated with multiple barrier AlAs-GaAs-InGaAs resonant tunnel diodes. Collaborations were with Scientific Research Associates and the University of Michigan for device and circuit design, and with Georgia Tech for device characterization. Three RTD designs were demonstrated with peak to valley rations of 6 at 300K. An RTBT was fabricated that exhibited a bandwidth of 30 GHz. In addition, a novel epitaxial structure was proposed for a 'collector-up' RTBT configuration that will greatly simplify the processing involved in monolithic integration of RTD's and HBT's in multi-valued circuits. Finally, two multi-valued circuits were designed, simulated and tested in hybrid form. These were a 4-step counter and a 4:1 multiple valued multiplexer. Both functioned as designed. The counter, executed with only three transistors and one RTD, would have required more than three transistors to implement with binary CMOS logic circuitry.

Descriptors :   *LOGIC CIRCUITS, *BIPOLAR TRANSISTORS, VELOCITY, PROPAGATION, STRUCTURES, EPITAXIAL GROWTH, INTEGRATION, RESONANCE, DELAY, CIRCUITS, MONOLITHIC STRUCTURES(ELECTRONICS), TUNNELING, MULTIPLEXING, LOGIC, RATIONS, VALLEYS, TRANSISTORS, GEORGIA.

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE