Logic circuits using resonant-tunneling hot electron transistors (RHETs)

A full adder and 1/2 frequency divider using resonant-tunneling hot electron transistors (RHETs) have been proposed and demonstrated. These circuits make the best use of negative differential conductance, a feature of RHETs, and contain fewer transistors than used in conventional circuits. The RHETs were fabricated using self-aligned InGaAs RHETs and WSiN thin-film resistors on a single chip. The RHETs 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.<>