  The two-component approach to the one-dimensional Dirac equation is applied
to the Woods-Saxon potential. The scattering and bound state solutions are
derived and the conditions for a transmission resonance (when the transmission
coefficient is unity) and supercriticality (when the particle bound state is at
E=-m) are then derived. The square potential limit is discussed. The recent
result that a finite-range symmetric potential barrier will have a transmission
resonance of zero-momentum when the corresponding well supports a half-bound
state at E=-m is demonstrated.
