Si. Kim et al., TEMPERATURE-DEPENDENT ELECTRICAL-PROPERTIES OF HEAVILY CARBON-DOPED GAAS GROWN BY LOW-PRESSURE METALORGANIC CHEMICAL-VAPOR-DEPOSITION, Solid state communications, 93(11), 1995, pp. 939-942
The temperature dependence of the electrical properties of heavily car
bon (C)-doped GaAs has been analyzed by Van der Pauw-Hall measurements
. All samples were grown by low-pressure metalorganic chemical vapor d
eposition (MOCVD). At low temperature range (T < 100 K) the mobility c
urves were almost flat, however, at high temperature range (T > 100 K)
the mobility values were decreased due to lattice phonon scattering.
With decreasing the temperature, the carrier concentration was nearly
the same, and even at low temperature range the carrier concentration
was not frozen out. The resistivity increased at high temperature due
to decreased mobility, but it did not increase in the low temperature
range. All these electrical properties proved the degenerate conductio
n of heavily C-doped GaAs. The temperature dependence of mobility was
analyzed using a simple analytical equation in the strongly degenerate
limit and with constant effective mass. There was no compensation in
the C-doped GaAs epilayer with p = 4.25 x 10(19) cm(-3), however there
was some compensation (theta = N-d/N-a = 0.02) in the epilayer with p
= 1.01 x 10(20) cm(-3). Thus it is suggested that heavily C-doped GaA
s grown by low-pressure MOCVD exhibits a little or no compensation in
the epilayers, and our simple analysis can explain the temperature dep
endence of Hall mobility of heavily C-doped GaAs epilayer very well.