A. Singh et al., REVERSE IV AND C-V CHARACTERISTICS OF SCHOTTKY-BARRIER TYPE DIODES ONZN DOPED INP EPILAYERS GROWN BY METALORGANIC VAPOR-PHASE EPITAXY, Journal of applied physics, 76(4), 1994, pp. 2336-2342
Mesa etched, Au/p-InP Schottky diodes with a thin interface layer [met
al-thin interface layer-semiconductor (MIS) diodes] were fabricated by
evaporation of Au onto a Zn doped epitaxial layer of InP grown by low
pressure metalorganic vapor phase epitaxy, on a highly doped InP subs
trate. The reverse current-voltage (I(r)-V(r)) and 1 MHz capacitance-v
oltage (C-V) characteristics of the Au/p-InP MIS diodes were measured
in the temperature range 220-393 K. The reverse current in the MIS dio
des did not saturate but increased with the increase in the reverse bi
as voltage. The soft I(r)-V(r) characteristics of the epitaxial Au/p-I
nP MIS diodes were very well described by the interface layer thermion
ic emission theory of Wu [J. Appl. Phys. 51, 3786 (1980)] for reverse
bias voltages in the range 0-5 V and over the temperature range 300-39
3 K. In this temperature range, the values of the zero bias barrier he
ight (phi(b0)) obtained from the analysis of the I(r)-V(r)/T character
istic using the self-consistent iterative least square fitting method
of Tseng and Wu [J. Appl. Phys. 61, 299 (1987)] agreed very well with
those obtained from the C-V/T data. The analysis of the I(r)-V(r)/T da
ta provided the values of (7.5+/-1.7) x 10(-3) and (45+/-22) angstrom
for the transmission coefficient and the thickness of the interface la
yer, respectively. The capacitance-frequency (C-f) data for frequencie
s in the range 1 kHz up to 1 MHz and for bias voltages between -0.2 an
d 4.0 V, justify the assumption of voltage independence of the charge
trapped in the states localized at the interface layer, made in the an
alysis of both the I(r)-V(r)/T and C-V/T data.