Surface recombination velocity of highly doped n-type silicon

New experimental data for the minority-carrier surface recombination velocity of n-type silicon, S-p, are reported. The data, obtained from photoconductance decay measurements of the recombination currents corresponding to different phosphorus diffusions, include oxide-passivated, unpassivated and metal-coated surfaces. For the passivated case, S-p increases linearly with surface dopant density, N-D, for dopant densities higher than 1X10(18) cm(-3), while for unpassivated (bare) and for metal-coated silicon S-p remains essentially constant, at about 2X10(5) cm/s and 3X10(6) cm/s, respectively. The experiments also allow for a determination of the apparent energy bandgap narrowing as a function of dopant density, Delta E(g)(app) = 14 meV [ln(N-D/1.4X10(17) cm(-3))]. These surface recombination velocity and Delta E(g)(app) data form, together with the dependences of minority-carrier lifetime, tau(p), and mobility, mu(p), used in the analysis, a consistent set of parameters that fully characterize highly doped n-type silicon. (C) 1995 American Institute of Physics.