Oxide thickness effect on boron diffusion in thin oxide p⁺ Si gate technology

Based on a network defect model for the diffusion of B in SiO2, we propose that B diffuses via a peroxy linkage defect whose concentration in the oxide changes under different processing conditions. We show that as the gate oxide is scaled below 80 Å in thickness, additional chemical processes act to increase B diffusivity and decrease its activation energy, both as a function of the distance from the Si/SiO2 interface. For a 15 Å oxide, the B diffusivity at 900°C would increase by a factor of 24 relative to diffusion in a 100 Å oxide.

Duke Scholars

Author Richard B. Fair Electrical and Computer Engineering