Summary: Current­voltage characteristics of
cubic Al(Ga)N/GaN double barrier structures on 3C­SiC
C. Mietze*, K. Lischka, and D. J. As
Department of Physics, University of Paderborn, Warburger Str. 100, 33098 Paderborn, Germany
Received 8 July 2011, revised 4 November 2011, accepted 4 November 2011
Published online 27 December 2011
Keywords cubic nitrides, molecular beam epitaxy, negative differential resistance, resonant tunnelling diodes
* Corresponding author: e-mail cmietze@mail.upb.de, Phone: þ49 5251 60 5828, Fax: þ49 5251 60 5843
Resonant tunnelling diodes of cubic Al(Ga)N/GaN were grown
by plasma assisted molecular beam epitaxy on 3C-SiC (001).
We observe a pronounced negative differential resistance at
about 1.2 V with a peak-to-valley ratio (PVR) of 1.3 to 2.7 at
room temperature. Experimental data is in good agreement with
calculated I­V curves showing only asmall deviation of 0.3 Vof
the resonance peak voltage. We find a decrease of the PVR
when the I­V characteristic is measured repeatedly with short
time intervals between the voltage-cycles. However, the I­V
characteristics can be recovered fully when the diodes are
illuminated by UV-light indicating charge trapping in our
devices. Mesa structures are prepared by reactive ion etching.

Source: As, Donat Josef - Department Physik, Universität Paderborn

Collections: Materials Science; Physics