A 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