Defect Generation In Silicon Research Articles

Point defect reactions in silicon studiedin situby high flux electron irradiation in high voltage transmission electron microscope

AbstractResults are presented of in situ studies of 1 MeV electron irradiation induced {113} defect generation in silicon containing different types and concentrations of extrinsic point defects. A semiquantitative model is developed describing the influence of interfaces and stress fields and of extrinsic point defects on the {113} defect generation in silicon during irradiation. The theoretical results obtained are correlated with experimental data obtained on silicon uniformly doped with boron and phosphorus and with observations obtained by irradiating cross-sectional samples of wafers with highly doped surface layers. It is shown that in situ irradiation in a high voltage electron microscope is a powerful tool for studying local point defect reactions in silicon.MST/3446

On the influence of extrinsic point defects on irradiation-induced point-defect distributions in silicon

A semi-quantitave model describing the influence of interfaces and stress fields on {113}-defect generation in silicon during 1-MeV electron irradiation, is further developed to take into account also the role of extrinsic point defects. It is shown that the observed distribution of {113}-defects in high-flux electron-irradiated silicon and its dependence on irradiation temperature and dopant concentration can be understood by taking into account not only the influence of the surfaces and interfaces as sinks for intrinsic point defects but also the thermal stability of the bulk sinks for intrinsic point defects. In heavily doped silicon the bulk sinks are related with pairing reactions of the dopant atoms with the generated intrinsic point defects or related with enhanced recombination of vacancies and self-interstitials at extrinsic point defects. The obtained theoretical results are correlated with published experimental data on boron-and phosphorus-doped silicon and are illustrated with observations obtained by irradiating cross-section transmission electron microscopy samples of wafers with highly doped surface layers.

On the influence of interfaces and localised stress fields on irradiation-induced point-defect distributions in silicon

High-flux 1-MeV electron irradiation in a high voltage transmission electron microscope is used to study the influence of interfaces and localised stress fields on {113}-defect generation in silicon. A semi-quantitative model is presented to explain the observations, suggesting that the silicon oxide/silicon interface is a stronger sink for self-interstitials than for vacancies. It is shown that the position and the height of the maximum of the {113}-defect density strongly depends on the strength of the interface as a vacancy sink and that compressive straining of the silicon substrate slows down the diffusion of vacancies towards the interface.

In-situ HVEM study of the influence of localised strain, interfaces, and extrinsic point defects on {113}-defect generation in silicon

Results are presented of an in-situ study of 1 MeV electron irradiation induced {113}-defect generation in silicon containing different types and concentration profiles of extrinsic point defects and/or locally strained areas. It is shown that most of the observations can be explained semi-quantitatively on the basis of known point defect reactions. The results suggest that in-situ electron irradiation might be a powerful tool to study local sinks for point defects in integrated circuit structures. Die Erzeugung von Defekten des {113}-Typs in Silizium während der in-situ Bestrahlung mit Elektronen der Energie 1 MeV wird untersucht. Das Silizium enthält verschiedene Typen und Konzentrationsprofile von extrinsischen Punktdefekten und/oder Zonen mit lokalen Verzerrungen. Die Mehrzahl der Beobachtungen kann semiquantitativ durch bekannte Punktdefektreaktionen erklärt werden. Die Ergebnisse zeigen, daß die in-situ Elektronenbestrahlung eine sehr leistungsstarke Technik ist, um lokale Senken für Punktdefekte in integrierten Bauelementen zu untersuchen.

In-situ HVEM study of dopant dependent (113)-defect generation in silicon during 1-MeV electron irradiation.

By high flux, high energy electron irradiation in the temperature range between 200 and 900K lattice defects with (113) habit planes are generated in silicon. The required experimental conditions to form (113)-defects can easily be obtained by electron irradiation of thin silicon foils in a high voltage transmission electron microscope (HVEM). In this communication, results are presented of an in-situ study of the effect of dopant concentration profiles on the (113)-defect generation in silicon, using 1-MeV electron irradiation in a HVEM. The (113)-defect nucleation and growth is studied as a function of the irradiation conditions and of the dopant type and concentration profile. The observation are interpreted on the basis of well-known point defect reactions and are correlated with data obtained on electron irradiated, homogeneously doped silicon by Fedina and Aseev (1990).

Dopant and Strain Dependence of Extended Defect Generation in Silicon by 1-MeV Electron Irradiation

ABSTRACTResults are presented of an in-situ study of 1-MeV electron irradiation induced {113}-defect generation in silicon with boron, phosphorus or arsenic doped surface layers. By 1-MeV electron irradiation in a high voltage transmission electron microscope, {113}-defects are dorni-nandy formed in areas with a well defined dopant concentration range which depends on the tjpe of dopant atom, the irradiation temperature and fluence and the sample thickness. The observations for samples with boron and phosphorus concentration profiles are compared with published data on electron irradiation induced ( 113}-defect formation in uniformly doped silicon. In the present paper first results on heavily arsenic doped silicon are presented. It is shown that ihe observed dopant dependence of the {113}-defect generation can be understood on the basis of known point defect reactions. A few irradiation experiments are also performed on a local isolation structure illustrating for the first time the influence of localised tensile and compressive strain fields on {113} -defect nucleation.

In Situ HVEM Study of Dopant Dependent Defect Generation in Silicon during 1 MeV Electron Irradiation

In Situ HVEM Study of Dopant Dependent Defect Generation in Silicon during 1 MeV Electron Irradiation

Defect generation in silicon

Defects can be generated in silicon during device processing. It is shown that the quality of the finish on the edges and reverse side of the wafer are important in determining the defect density of the crystal after processing. Wafers with defect densities of the order of 102 per sq cm before processing, have had defect densities of the order of 106 per sq cm after processing if the work damage was not removed from the back side of the wafers, and defect densities of the order of 102 per sq cm if the work damage had been removed from the back side. Chips on the edges of the wafers are shown to lead to slip lines of dislocations propagating in toward the center of the wafer. This generation of defects during thermal processing appears to be related to a stress-relief mechanism taking place at elevated temperatures. The thermally generated defects have been observed to lower the lifetime in bulk silicon and to cause increases in the leakage current of individual diodes in integrated circuits.