Time-dependent diffusivity of boron in silicon oxide and oxynitride

Abstract

The diffusivities of boron in silicon oxide and oxynitride have been determined from secondary ion mass spectroscopy measurements of annealed metal-oxide-silicon structures. The results clearly show a decrease in diffusivity with increasing anneal time which is approximately exponential in form. This effect implies a similar time dependence in the concentration of a secondary species, such as hydrogen, or a defect within the dielectric, which promotes diffusion even in a nominally pure oxide.