Suppression of boron penetration in BF2+-implanted poly-Si gate

Abstract

In this paper, a comprehensive study of gate engineering to suppress the penetration of boron in p-type metaloxide-semiconductor held-effect transistor (MOSFET) with the p(+)-poly-Si-gate is reported. Four types of poly-Si gate structure, two types of gate dielectrics were investigated to suppress the boron penetration. Among the different gate structures, the stacked amorphous silicon structure was found to be the most effective way to retard the boron penetration. N2O oxide exhibited a better retarding of the boron diffusion as compared with the O-2 oxide. It was found that a combination of stacked amorphous silicon with N2O oxide is the most effective way to suppress the boron penetration. Thermal stability, oxide integrity, and D-it of this sample are superior to all the other samples.