Staggered band gap n+In0.5Ga0.5As/p + GaAs0.5Sb0.5 Esaki diode investigations for TFET device predictions

We study in this paper the epitaxial growth and electrical characterization of an n + In0.5Ga0.5As/p+GaAs0.5Sb0.5 Esaki diode lattice matched to (001)-oriented InP substrate. First, the effects of molecular beam epitaxy growth temperature and group-V growth rates on the GaAsxSb1-x composition are characterized by means of X-ray diffraction (XRD). It is found that GaAsxSb1-x lattice constant is mainly determined by the Sb-4 incorporation rather than the As-4 one. After optimization, high quality In0.54Ga0.46As(Si)/GaAs0.52Sb0.48(Be) heterostructure is confirmed by XRD, Transmission electron microscope (TEM) and Secondary Ion Mass Spectroscopy (SIMS) profiles meeting requirements for sub-60 mV/dec operating devices. Esaki tunnel diodes are then fabricated to be used as a prediction of Band-To-Band Tunneling (BTBT) for Tunnel Field-Effect transistors (TFETs). The results are compared to previously reported n +/p + In0.5Ga0.5As homojunction diodes, showing a x 60 factor improvement of BTBT current density for the same electric field with an excellent average Peak-to-Valley Current Ratio (PVCR) of 14. (C) 2015 Elsevier B.V. All rights reserved.

Publication year:2015

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Authors:International

Authors from:Government, Higher Education

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