RESONANT TUNNELING TRANSISTOR UTILIZING UPPER RESONANCE

摘要

A three-terminal device which exploits the resonant tunneling of carriers is disclosed, with resonant tunneling through higher energy levels in a central quantum well for high speed operation. The new type of unipolar transistor has a base region consisting of the quantum well with reduced base resistance. The second highest subband is used for electron tunneling, thereby reserving the lower subband for a high electron carrier density which lowers the base resistance. The base is undoped to reduce impurity scattering. In a preferred embodiment the double-barrier structure is Ga1-y' Aly' As-Ga1-xAlxAs-GaAs-Ga1-xAlyAs-Ga1-yAlyAs. Alternative embodiments of the invention make use of other III-V or II-VI materials, such as InGaAs-GaAs-GaAlAs (with InGaAs as the well), or HgTe-CdTe. Since the lowest level is always populated, the GaAs well will be conductive, making it feasible to modulate the base region.