Impact of the interaction between nitrogen implant and NO anneal on narrow-width transistors

This study reports a new behavior in narrow-width transistors resulting from the interaction of oxides grown with nitrogen implant with the nitridation associated with growing other oxides. Nitric oxide (NO) annealing of 28-A oxides grown on nitrogen-implanted silicon results in the decrease of NMOS threshold voltage and in the increase (absolute value) of PMOS threshold with decreasing width. This effect arises from the positive charge from NO anneal interacting with the parasitic transistor associated with the shallow trench isolation edge recess. The parasitic impact becomes more pronounced for narrower widths due to higher effect of recess on total transistor width.