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

• Published in: Journal of crystal growth Vol. 424; pp. 62 - 67
• Main Authors: El Kazzi, S., Smets, Q., Ezzedini, M., Rooyackers, R., Verhulst, A., Douhard, B., Bender, H., Collaert, N., Merckling, C., Heyns, M.M, Thean, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.08.2015
• Subjects: A.1 Characterization; A.1 Tunneling Electronic field; A.3 Molecular Beam Epitaxy; B.1 Antimonides; B.3 Esaki Tunnel diodes; B.1 Antimonides; A.3 Molecular Beam Epitaxy; A.1 Tunneling Electronic field; B.3 Esaki Tunnel diodes; A.1 Characterization
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2015.05.004

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 Sb4 incorporation rather than the As4 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-60mV/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 ×60 factor improvement of BTBT current density for the same electric field with an excellent average Peak-to-Valley Current Ratio (PVCR) of 14. •Influence of MBE growth conditions on GaAsSb composition.•High quality InGaAs(Si)/GaAsSb(Be) diodes for sub-60mV/dec operating devices.•x60 BTBT current density improvement using n+InGaAs/p+GaAsSb compared to n+/p+InGaAs.