Spatial integration of direct band-to-band tunneling currents in general device structures

A simplified integration technique for direct band-to-band tunneling current calculation in semiconductor devices of 1- or 2-D general device structures is described. The integration, along part of the depletion region, is of a tunneling generation function which depends on the local electric field. The simplified integration scheme relies on Kane´s parabolic shaped gap barrier which accurately applies to such narrow-bandgap semiconductors as InSb and Hg_1-xCd_xTe. Tunneling current and zero bias resistance calculations in 1-D Hg_1-xCd_xTe p-n junctions using the proposed technique are presented. The extension of the technique to 2-D potential structures is demonstrated by modeling peripheral surface tunneling currents. The results compare well with measured reverse breakdown currents of InSb gate-controlled diodes