Experimental identification of nitrogen-vacancy complexes in nitrogen implanted silicon

Nitrogen implantation is commonly used in multigate oxide thickness process ing for mixed signal complementary metal-oxide-semiconductor and System on a Chip technologies. Current experiments and diffusion models indicate that upon annealing, implanted nitrogen diffuses towards the surface. The mecha nism proposed for nitrogen diffusion is the formation of nitrogen-vacancy c omplexes in silicon, as indicated by ab initio studies by J. S. Nelson, P. A. Schultz, and A. F. Wright [Appl. Phys. Lett. 73, 247 (1998)]. However, t o date, there does not exist any experimental evidence of nitrogen-vacancy formation in silicon. This letter provides experimental evidence through po sitron annihilation spectroscopy that nitrogen-vacancy complexes indeed for m in nitrogen implanted silicon, and compares the experimental results to t he ab initio studies, providing qualitative support for the same. (C) 2001 American Institute of Physics.