A high voltage-gain GaAs vertical field-effect transistor with an InGaAs/GaAs planar-doped barrier launcher

摘要

A high voltage-gain GaAs vertical field-effect transistor (VFET) with an InGaAs-GaAs pseudomorphic planar-doped barrier (PDB) launcher is described. The pseudomorphic structure, which includes a small amount of indium in the launcher, was grown by molecular beam epitaxy (MBE). Fabricated transistors, with good pinch-off characteristics (gate threshold voltage of -1.6 V), have exhibited DC open-drain voltage gains of up to 50 at 77 K. This high voltage gain results from the combination of high transconductances and low output conductances. The former are attributed to velocity enhancement by hot-electron injection, and the latter are attributed to the suppression of electron spillover by energy band discontinuity at the heterointerface between the launcher and the channel.