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.