High performance multiple stepped quantum well resonant microwave devices

Implemented by low-pressure metal organic chemical vapour deposition and fabricated by simple wet chemical etching, GaAs/In_0.59Ga_0.41As/InAs multiple stepped quantum well resonant interband tunnelling diodes (MSQW RITDs) are demonstrated for the first time. The multiple InAs well layers reduce the thermionic current. In particular, it is shown that the viability of the GaAs/In _0.59Ga_0.41As/InAs MSQW RITD with peak current density reaches over 1.11 kA/cm², valley current density reaches less than 0.46 A/cm², and therefore peak-to-valley ratio (PVCR) up to 2.4times10³ at room temperature. The excellent negative differential resistance characteristics are explained by good confined effect of quantum well and interband tunnelling structure. The largest PVCR achieved is believed to the highest reported value to date for all two-terminal devices