Experiment shows that the reverse short channel effect (RSCE) in nMOS devices is critically impacted by the inclusion of nitrogen in the gate oxide. A higher concentration of nitrogen results in a lessened RSCE, i.e. more threshold voltage rolloff for smaller gate lengths. We propose that the additional nitrogen reduces the interstitial recombination rate at the interface, resulting in a smaller interstitial flux and therefore less transient enhanced diffusion (TED) of boron to that interface. To test this hypothesis, we simulate boron redistribution in one and two dimensional MOS capacitor structures, as well as full nMOS devices. We then present simulations calibrated to a 0.2 pim technology currently in production.