LOGIC-CIRCUITS USING RESONANT-TUNNELING HOT-ELECTRON TRANSISTORS (RHETS)

A full adder and a 1/2 frequency divider using resonant-tunneling hot-electron transistors (RHET's) have been proposed and demonstrated. These circuits make the best use of negative differential conductance, a feature of RHET's, and contain much fewer transistors than used in conventional circuits. They were fabricated using self-aligned InGaAs RHET's and WSiN thin-film resistors on a single chip. The RHET's have an i-InGaAlAs/i-InGaAs collector barrier that improves the current gain at low collector-base voltages. Circuit operation was confirmed at 77 K with a supply voltage of 3 V.