Superlattice base hot-electron transistors

Summary form only given. The authors discuss the transport dynamics of carriers in hot-electron transistor structures with superlattices incorporated in the base. The devices consist of a low doping (n=4*10¹⁷ cm^-3) electron injector and a 100-AA Al_0.3Ga_0.7As tunnel barrier that serve as the emitter. Adjacent to this is grown a heavily doped base region (n=2*10¹⁸ cm^-3) consisting of a finite number of periods ( approximately=6) of GaAs/Al_0.3Ga_0.7As superlattice. Finally, on the opposite side of the base, an electron spectrometer consisting of a graded triangle barrier and a collector contact is incorporated. The three-terminal device allows independent control of the injection energy of electrons into the superlattice and simultaneous study of the electron distribution after they have traversed the superlattice using the analyzer characteristic. The author have studied samples with two sorts of superlattice in the base: those in which superlattice minibands are well formed and those in which the possibility of band transport is intentionally precluded.