Quantum chemical calculations were employed to get insight into the mechanisms involved in plasma-induced nitridation of gate oxide that will suppress boron penetration. The roles played by the nitrogen cations and atoms were explored. It was shown that B interaction with siloxane rings that contain incorporated nitrogen yielded a larger energy gain than rings without nitrogen. This explains the chemical nature of the nitrogen-induced barrier effect. Monte Carlo simulations were used to simulate the necessary energy of incident N₂ cations to produce the bond cleavage down to a particular depth in the amorphous SiO₂ layer. A combination of the HPEM and PCMC codes were used to simulate nitrogen atomic and cation fluxes and their energy distributions at the wafer surface. Combining simulated cation fluxes and their energy distributions at the wafer surface. Combining simulated cation energies with PROMIS Monte Carlo simulation results make it possible to derive the plasma process parameters that will permit a desired level of nitridation to be reached.

Date Published: 1 September 1999
PDF: 10 pages
Proc. SPIE 3881, Microelectronic Device Technology III, (1 September 1999); doi: 10.1117/12.360558

Published in SPIE Proceedings Vol. 3881:
Microelectronic Device Technology III
David Burnett; Toshiaki Tsuchiya, Editor(s)