Fabrication of a High-Performance RTD on InP Substrate

InGaAs/AlAs RTD material structure on InP substrate is designed and grown by molecular beam epitaxy.A device with good negative differential resistance characteristics and a higher resistive cutoff frequency is fabricated using mesa isolation,metal lift-off,wet chemical etch,and air bridge technologies.The forward bias peak-to-valley current ratio (PVCR) and reverse bias PVCR are about 17.5 and 28,respectively.The peak current density is 56kA/cm2,and the data fitting resistive cutoff frequency using an RNC circuit model is 82.8GHz.The experiment lays a foundation for the design and fabrication of high-performance RTD and monolithic integration circuits of RTD and other high speed and high frequency three terminal devices.