Resonant Tunneling Device Logic Circuits

Preface This report is a summary of the activities in the field of resonant tunneling device circuit design. (GMUD) during the first year of the Microelectronics Advanced Research Initiative projects ANSWERS (Autonomous Nanoelectronic Systems with Extended Replication and Signalling) and LOCOM (Logic Circuits with Reduced Complexity based on Devices with Higher Functionality). As part of the ANSWERS work-package the principal task of UNIDO is to investigate novel logic circuit architectures for resonant tunneling devices, to perform circuit simulations, and to specify the electrical device parameters. The basic device configuration is a monolithically integrated resonant tunneling diode heterostruc-ture field-effect transistor (RTD-HFET). This device and the demonstrator circuits are fabricated by the LOCOM partner GMUD. The report is structured as follows: section 1 describes the current state of nano-scale circuit design and analyzes in which way architecture related aspects have to be considered in the early phase of this emerging technology. Topic of section 2 is a clocked RTD-HFET Boolean logic family. Based on the experimental results of a programmable NAND/NOR logic gate a concept for the implementation of linear threshold gates is derived. In section 3 this approach is applied to the design of two full adders with a reduced logic depth and a parallel ripple carry adder utilizing the enhanced computational capabilities of threshold logic gates. According to the work-plan of both projects, the specification of the device parameters and the experimental results of the NAND/NOR logic gates are deliverables no.1 and no.2 of LOCOM and deliverable no.4 of ANSWERS, respectively.