  For the relativistic tunneling effect described using Dirac's equation, in
[Phys. Rev. A 70, 052112 (2004)] the authors presented the deduction of a
general result that allows for the determination of the phase time (group
delay) as the sum of the particle dwell time inside a potential barrier and of
the self-interference delay associated with the incident and reflected wave
functions interaction. In this article, a mathematical model is derived through
a construction analogous to the proposal mentioned above, but based on an
alternative representation for Dirac's equation. This representation is similar
to the one introduced in [Found. Phys. 45, 1586 (2015)]. Thus, from the
application of this model in the study of the tunneling effect in the absence
of an external magnetic field, the influence of spin on the tunneling times is
described. More specifically, the tunneling time is obtained as the sum of the
dwell times inside the potential barrier for particles with spin up and spin
down and the self-interaction time associated with the incident and reflected
wave functions for particles with spin up.
