A COMPARISON OF ONE, 2, AND 3 BAND CALCULATIONS OF CONTACT RESISTANCE FOR A GAAS OHMIC CONTACT USING THE WENTZEL-KRAMERS-BRILLOUIN APPROXIMATION AND A NUMERICAL-SOLUTION TO THE SCHRODINGER-EQUATION

We explore the different contact resistances obtained by using a one, two, and three band Wentzel-Kramers-Brillouin (WKB) calculation of the tunneling probability for majority carriers in an ohmic contact to n-type GaAs. The depletion approximation is used resulting in a parabolic potential. Finally, the calculations are repeated using a numerical solution to the wave equation in the depletion region of the semiconductor instead of employing WKB. It will be seen that the WKB approximation leads to contact resistances that are approximately twice as large as those numerically calculated from the wave equation.