Ti/Au/n-GaAs planar Schottky diode with a moderately Si-doped matching sublayer

Microelectronic Engineering. 2018. Vol. 195. P. 26–31.

Shurakov A., Mikhalev P., Михайлов Д. М., Mityashkin V., Tretyakov I., Kardakova A., Belikov I., Kaurova N., Voronov B., Vasil’evskii I., Goltsman G.

In this paper we report on the results of the study of the Ti/Au
/ n-GaAs planar Schottky diodes (PSD) intended for the wideband detection of
terahertz radiation. The two types of the PSD devices were compared having
either the dual n/n+ silicon dopant profle or the triple one with a moderately
doped matching sublayer inserted. All the diodes demonstrated no noticeable
temperature dependence of ideality factors and barrier heights, whose values
covered the ranges of 1.2{1.5 and 0.75{0.85 eV, respectively. We observed
the lowering of the at band barrier height of 80 meV after introducing the
matching sublayer into the GaAs sandwich. For both the devices types, the
series resistance value as low as 20 Ohm was obtained. The measurements of
the input frequency bandwidth within the range of 400{480 GHz were performed.
The diodes demonstrated quite consistent frequency response regardless the type
of the silicon dopant profle chosen, the cuto frequency value of 655 GHz
was evaluated. We also calculated the AC current density distribution within
the layered structures similar to those being experimentally studied. It was
demonstrated that insertion of the moderately Si-doped matching sublayer might
be benefcial for implementation of a PSD intended for the operation within the
'super-THz' range.

Keywords: Planar Schottky diode, Matching sublayer, Terahertz frequencies, Input bandwidth