Papers by Keyword: Intrinsic Point Defects (IPD)

Abstract: The use of Rapid Thermal Processing to install lattice vacancy profiles into silicon wafers for the purpose of forming a template for the nucleation and ideal control of oxygen precipitation has become an important materials engineering tool for the microelectronics industry. This paper reviews the principles of the technique and the precise materials/defect engineering that it engenders. It furthermore discusses what has been learned regarding the elusive properties of the intrinsic point defects in silicon through studies of the distributions of vacancies created by use of the technique. Also discussed are recent discoveries about the critical role of the other intrinsic point defect, the self-interstitial and the development of oxygen precipitates and their distributions post-nucleation and the critical importance of what has become to be called the “ninja transformation” in the switching-on of gettering efficiency of oxygen precipitate systems.

Abstract: The features of microdefect formation during dislocation-free Si single crystals are considered in connection with the specific thermal CZ growing conditions. For this purpose the thermal crystal growth histories are calculated by means of a global thermal mathematical model and then on their basis the intrinsic point defect recombination and microdefect formation are modeled numerically. Difficulty of such integrated approach is explained by of the complicated and conjugated thermal modeling and a presence of various temperature zones in growing single crystal, answering to various defect formation mechanisms.

Abstract: A probing of the atomic environment of positron in Cz-Si single crystal heat-treated at T=600C and T=450C has been performed by one-dimensional angular correlation of annihilation radiation (ACAR). It has been established that positrons get trapped by the oxygen-related complexes. The penetration of positrons into the core region of surrounding atoms results in emission of the elementally specific high-momentum annihilation radiation. The processes of expelling of positron from ion cores and its penetration into the core region are regulated by the potential barrier (to be considered as the Coulomb’s one as a first approximation). The characteristic electron-positron ion radius and the probabilities of correlated events of the highmomentum annihilation are due to the chemical nature of the ion cores of atoms involved in the composition of the oxygen-related complexes. The interpretation of the results is based on the notion of the positron localization in the field of negative effective charge resulted from comparatively high electron affinity of the oxygen impurity atom. The presence of a free volume (perhaps, a vacancy) as well as the carbon atom in the microstructure of the oxygen-related positron-sensitive thermal defects is briefly discussed.