Preliminary investigation of the kinetics of post-oxidation anneal induced E′-precursor formation

Detailed knowledge of the underlying defect mechanisms that dominate MOS device reliability is essential for the development of predictive models for semiconductor technology computer-aided-design (TCAD). In this paper, we discuss a preliminary extension our earlier E'-model of hole trap precursor formation in SiO₂. Our results, at least qualitatively, show that a kinetic component can be added to extend the thermodynamics-based E' model of oxide hole trapping. Measurements of the growth of E' precursor density and hole trap precursor density vs. post-oxidation-anneal time reveal that both E' and hole trap density approach saturation values and that the approach to these saturation values is more rapid at higher temperatures. The results indicate strongly that a thermodynamics approach to oxide hole trap precursor modeling is appropriate, i.e., the relevant defect densities approach thermodynamic equilibrium or quasi-equilibrium in reasonable times. Since E' centers are suspected of playing a role in time dependent dielectric breakdown, stress induced leakage currents, and other reliability problems, a process dependent predictive knowledge of E' density could potentially provide information about oxide performance and reliability without the need for extensive testing.