Microwave performance of pseudomorphic resonant-tunnelling hot electron transistors at 77 K

Describes the first 77 K microwave measurements for resonant-tunnelling hot electron transistors (RHETs) fabricated using GaInAs/AlInAs pseudomorphic heterostructures. A collector current peak-to-valley ratio of 10 is obtained with a peak collector current density of 2*10⁵ A/cm². A current gain cut-off frequency f_T of 63 GHz and a maximum oscillation frequency f_max of 44 GHz are measured at 77 K with an emitter current density of 1.1*10⁵ A/cm².