Bistable switching in supercritical n+-n-n+GaAs transferred electron devices

Bistable switching in supercritically doped n⁺-n-n⁺GaAs transferred electron devices (TED's) is investigated experimentally and interpreted in computer simulations, for which details of the computer program are given. Three switching modes all leading to stable anode domains are discussed, namely: 1) cathode-triggered traveling domain; 2) cathode-triggered accumulation layer; 3) anode-triggered domain. Relative current drops up to 40 percent, and switching times down to 60 ps are obtained in low-duty-cycle pulsed experiments with threshold currents around 400 mA. Optimum device parameters are shown to be as follows: 1) doping in the 3-4 × 10¹⁵cm^-3range; 2) length around 6 µm; 3) doping gradients below 20 percent; 4) high-quality interfaces.