Modeling Microdefects Formation in Crystalline Silicon: The Roles of Point Defects and Oxygen

Most microelectronic devices are fabricated on single crystalline silicon substrates that are grown from the melt by the Czochralski crystal growth method. There is an ever increas-ing demand for control of size and density of microdefects in the silicon for control of quality and uniformity of the fabricated microelectronic devices. This thesis is aimed at developing a fundamental understanding of the mechanisms for formation of such micro-defects through the development of models, theoretical analysis and large-scale simula-tion. Two major problems have been addressed. First, following the work of T. Sinno [150] and T. Mori [108], models have been developed for the transport, reaction and aggregation of native point defects — self-interstitials (I’s) and vacancies (V’s) — in crys-talline silicon, so as to explain the dynamics of void formation (aggregation of V’s) and stacking faults (aggregation of I’s). Second, the model of point defect and cluster dynam-ics has been extended to include oxygen, the most common impurity in silicon, and to model oxide precipitation, an important step in silicon wafer preparation and device pro-cessing