Point Defects, Diffusion and Gettering in Silicon

Abstract

The status of our knowledge on intrinsic point defects and diffusion mechanisms is reviewed. Special attention is given to the question of the possible role of carbon in influencing effective diffusivities of intrinsic point defects and the resulting consequences for the values of vacancy and self-interstitial thermal equilibrium concentrations and diffusivities. It is pointed out that we might have to deal with the unfortunate situation that the effective diffusivities of intrinsic point defects might be influenced already by a carbon concentration which is below the detection limit and therefore not amenable to measurement and control. Whereas dopant diffusion processes have been modeled and simulated for a long time the first attempts to quantitatively simulate various gettering processes have just started as will be described in the paper. Finally, the subject of microcrack formation in hydrogen implanted silicon will be dealt with as used for the so-called "smart-cut" process for fabricating silicon-on-insulator (SOI) substrates with thin and uniform silicon layers by wafer bonding. Presently no quantitative treatment of this fascinating hydrogen agglomeration phenomenon is available.

A Selective Review of the Quantification of Defect Dynamics in Growing Czochralski Silicon Crystals

“…The accuracy of the model predictions is strongly dependent on the accuracy of the parameters describing the key properties of the point defects. Various studies have reported the acceptable parameters describing the defect dynamics. ,,,,− In this section, a few results obtained by solving the described equations using the properties of the point defects reported by Kulkarni et al are discussed …”

The agglomeration dynamics of self-interstitials in growing Czochralski silicon crystals

“…Various sets of the properties of the point defects have been reported [24,44,[48][49][50][51][52]. In this study, the properties reported by Kulkarni et al [44] are used.…”

Procesos de extracción de impurezas contaminantes y aplicación a estructuras de células solares

“…Si bien han sido muchos los pasos dados en la clarificación del fenómeno, aún quedan muchos aspectos oscuros para los cuales se ofi-ecen argumentos cualitativos o intuitivos no suficientemente contrastados. Diversos factores contribuyen a la dificultad de establecer un modelo definitivo como son el hecho de que intervengan especies sobre cuyos parámetros también hay discrepancia (como es el caso de los valores de difusividad y solubilidad de autointersticiales y vacantes [96]), o la gran cantidad de variables que están enjuego durante el proceso (condiciones en que éste se realiza, "historia previa" de las muestras, impurezas contaminantes presentes y sus mecanismos de difusión, segregación e interacción entre sí o con otras especies -oxígeno, carbono, defectos de red,...-, etc. ).…”