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Charge Collection Studies on Integrated Circuit Test Structures using Heavy-Ion Microbeams and MEDICI Simulation Calculations

Description: Ion induced charge collection dynamics within Integrated Circuits (ICs) is important due to the presence of ionizing radiation in the IC environment. As the charge signals defining data states are reduced by voltage and area scaling, the semiconductor device will naturally have a higher susceptibility to ionizing radiation induced effects. The ionizing radiation can lead to the undesired generation and migration of charge within an IC. This can alter, for example, the memory state of a bit, and thereby produce what is called a "soft" error, or Single Event Upset (SEU). Therefore, the response of ICs to natural radiation is of great concern for the reliability of future devices. Immunity to soft errors is listed as a requirement in the 1997 National Technology Roadmap for Semiconductors prepared by the Semiconductor Industry Association in the United States. To design more robust devices, it is essential to create and test accurate models of induced charge collection and transport in semiconductor devices. A heavy ion microbeam produced by an accelerator is an ideal tool to study charge collection processes in ICs and to locate the weak nodes and structures for improvement through hardening design. In this dissertation, the Ion Beam Induced Charge Collection (IBICC) technique is utilized to simulate recoil effects of ions in ICs. These silicon or light ion recoils are usually produced by the elastic scattering or inelastic reactions between cosmic neutrons or protons and the lattice atoms in ICs. Specially designed test structures were experimentally studied, using microbeams produced at Sandia National Laboratories. A new technique, Diffusion Time Resolved IBICC, is first proposed in this work to measure the average arrival time of the diffused charge, which can be related to the first moment (or the average time) of the arrival carrier density at the junction. A 2D device simulation ...
Date: May 2000
Creator: Guo, Baonian
Partner: UNT Libraries

Proceedings of the Workshop on the Interface Between Radiation Chemistry and Radiation Physics; Held at Argonne National Laboratory, September 9-10, 1982

Description: This conference evolved out of an idea that originated Department of Energy contractor's meeting in Gettysburg to have a conference devoted to topics of interest to both radiation chemists and physicists in radiation research. Radiation chemists tend to operate in a time domain where chemical reactions can be observed and to deduce values from that data. Meanwhile, physicists naturally focus considerable attention on initial energy deposition events and perform calculations which should predict the same initial yields. Contributed papers and remarks have been grouped according to broad subjects.
Date: March 1983
Creator: Argonne National Laboratory
Partner: UNT Libraries Government Documents Department

Approximations of Gamma Cross Sections for Fast Nuclear Reactors

Description: The report shows a method to approximate a P₁ scattering solution for the flux in a fast reactor, using an isotropic, but not a diagonal-transport-approximation scattering matrix. Presented are flux errors relative to a P₁ solution for different levels of transport approximation in an EBR-II type of core surrounded by a stainless steel reflector. Problems associated with the use of the method are also presented.
Date: 1978?
Creator: Grimm, K. N. & Meneghetti, D.
Partner: UNT Libraries Government Documents Department

Effects of Radionuclide Decay on Waste Glass Behavior : a Critical Review

Description: This paper is an extension of a chapter in an earlier report that provides an updated review on the status of radiation damage problems in nuclear waste glasses. This report will focus on radiation effects on vitrified borosilicate nuclear waste glasses under conditions expected in the proposed Yucca mountain repository. Radiation effects on high-level waste glasses and their surrounding repository environment are important considerations for radionuclide immobilization because of the potential to alter the glass stability and thereby influence the radionuclide retentive properties of this waste form. The influence of radionuclide decay on vitrified nuclear waste may be manifested by several changes, including volume, stored energy, structure, microstructure, mechanical properties, and phase separation. Radiation may also affect the composition of aqueous fluids and atmospheric gases in relatively close proximity to the waste form. What is important to the radionuclide retentive properties of the repository is how these radiation effects collectively or individually influence the durability and radionuclide release from the glass in the event of liquid water contact.
Date: December 1993
Creator: Wronkiewicz, David J.
Partner: UNT Libraries Government Documents Department

Comparative Nuclear Effects of Biomedical Interest

Description: Report containing environmental consequences of nuclear explosions with a primary focus on early effects such as exposure to blasts and radiation. Includes definitions of terms, the progression of an explosion, and graphs depicting the relationship between the effects of blasts and the distance of material from Ground Zero.
Date: September 1960
Creator: White, Clayton S.; Bowen, I. Gerald; Richmond, Donald R. & Corsbie, R. L.
Partner: UNT Libraries Government Documents Department