The temperature dependence of the DC base and collector currents in silicon bipolar transistors

Detailed measurements have been made of the base and collector-current characteristics of both n-p-n and p-n-p silicon transistors as a function of temperature. The collector current shows ideal behavior over the temperature range -60 to 150°C in that
I_{C} \infin \exp (eV_{BE}/kT)
. On the other hand, the base current is nonideal:
I_{B} \infin \exp (eV_{BE}/nkT)
, where
n > 1.0
. The nonideality of I
B
is the main source of the temperature dependence of
h_{FE} = I_{C}/I_{B}
. There is no evidence for bandgap narrowing in the devices we have investigated. The temperature dependence of the collector current is given by
I_{C} \infin T_{m} \exp (-e E_{g0}/kT) \exp (eV_{BE}/kT)
, where
m = 1.4
or 1.7 for n-p-n or p-n-p devices, respectively.
E_{g0} = 1.19 \pm 0.01
eV. This result is consistent with the findings of others. The base current is a complicated function of temperature due to the presence of nonideal components.