Barrier scattering in field theory removal of Klein paradox

The Feynman method of the Green function in quantum electrodynamics is modified to treat scattering problems with a one-dimensional potential. The Green function is constructed from the solutions of the Klein-Gordon (Dirac) equation. The absence of a Klein paradox in a field theoretical treatment is demonstrated. Pair production by the one dimensional potential is considered and the Sauter type potential is used to illustrate general results.