By Topic

Nuclear Science, IEEE Transactions on

Issue 6 • Date Dec. 1977

Filter Results

Displaying Results 1 - 25 of 106
  • Contents

    Publication Year: 1977 , Page(s): 2033 - 2037
    Save to Project icon | Request Permissions | PDF file iconPDF (569 KB)  
    Freely Available from IEEE
  • Williamsburg, Va. July 1977

    Publication Year: 1977 , Page(s): 2038
    Save to Project icon | Request Permissions | PDF file iconPDF (1101 KB)  
    Freely Available from IEEE
  • Summary of 1977 IEEE Annual Conference on Nuclear and Space Radiation Effects

    Publication Year: 1977 , Page(s): 2039
    Save to Project icon | Request Permissions | PDF file iconPDF (105 KB)  
    Freely Available from IEEE
  • IEEE Nuclear and Plasma Sciences Society Radiation Effects Committee

    Publication Year: 1977 , Page(s): 2040
    Save to Project icon | Request Permissions | PDF file iconPDF (117 KB)  
    Freely Available from IEEE
  • Reviewers for this issue

    Publication Year: 1977 , Page(s): 2041
    Save to Project icon | Request Permissions | PDF file iconPDF (108 KB)  
    Freely Available from IEEE
  • Outstanding Paper Award - 1977 IEEE Conference on Nuclear and Space Radiation Effects

    Publication Year: 1977 , Page(s): 2042
    Save to Project icon | Request Permissions | PDF file iconPDF (850 KB)  
    Freely Available from IEEE
  • Radiation Hardening of CMOS Technologies - AN Overview

    Publication Year: 1977 , Page(s): 2043 - 2046
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3101 KB)  

    The current status of four technologies for manufacturing radiation-hardened complementary metal-oxide-semiconductor integrated circuits is presented. The technologies include both aluminum-gate and silicon-gate CMOS structures formed on bulk-silicon and on silicon-on-sapphire (SOS) substrates. The hardness levels achieved on large-scale integrated circuits fabricated in each of these technologies is given. In addition some historical background is included. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Technological Advances in the Manufacture of Radiation-Hardened CMOS Integrated Circuits

    Publication Year: 1977 , Page(s): 2047 - 2050
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (653 KB)  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • CMOS Hardness Assurance through Process Controls and Optimized Design Procedures

    Publication Year: 1977 , Page(s): 2051 - 2055
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1024 KB)  

    Total Dose Hardness Assurance for complimentary MOS integrated circuits is recognized throughout the industry as a difficult problem. Most of the hardness assurance proposals to date have included a large amount of radiation testing on a diffision lot or wafer basis to help guarantee the hardness of a small group of integrated circuits. This, in general, is very expensive, and alternate techniques must be explored. This paper discusses the use of process and device parameter controls along with optimized design procedures for radiation hardness to minimize the need for frequent radiation testing. Total dose data up to 1 × 106 Rads-Si is presented for several metal gate CMOS diffusion lots which demonstrates the reproducibility obtained when these control and design procedures are implemented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Establishment of a Radiation Hardened CMOS Manufacturing Process

    Publication Year: 1977 , Page(s): 2056 - 2059
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (613 KB)  

    A radiation hardened metal gate CMOS IC process, tolerant to doses in excess of 106 rads (Si), has been established by making necessary modifications to a standard process. These modifications are described, a definition of circuit radiation hardness is discussed, and typical electrical performance characteristics as a function of radiation dose are presented. Procedures are described for assuring the hardness of finished product. Operating life test data indicates that the process is inherently reliable. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • SEM Analysis of Ionizing Radiation Effects in Linear Integrated Circuits

    Publication Year: 1977 , Page(s): 2060 - 2065
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1189 KB)  

    A successful diagnostic technique was developed using a scanning electron microscope (SEM) as a precision tool to determine ionization effects in integrated circuits. Previous SEM methods radiated the entire semiconductor chip or major areas. The large area exposure methods do not reveal the exact components which are sensitive to radiation. To locate these sensitive components a new method was developed, which consisted in successively irradiating selected components on the device chip with equal doses of electrons [(10 rad (Si)], while the whole device was subjected to representative bias conditions. A suitable device parameter was measured in situ after each successive irradiation with the beam off. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Important Considerations for SEM Total Dose Testing

    Publication Year: 1977 , Page(s): 2066 - 2070
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (844 KB)  

    The kilovolt electron beam utilized in a scanning electron microscope has been of interest as a tool for total dose screening of semiconductor devices for hardness assurance because of its convenience and because devices can be selectively irradiated directly at the wafer level. A number of factors such as the depth-dose distribution of kilovolt electrons, the dose-rate, uniformity of exposure, and device biasing must be considered when applying this technique. This paper is devoted to these and other aspects of SEM total dose testing. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Application of Operational Amplifiers to Hardened Systems

    Publication Year: 1977 , Page(s): 2071 - 2078
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1353 KB)  

    Methods are described for evaluating neutron damage in the types of operational amplifiers that are typically used in modern tactical systems. Critical electrical parameters are discussed, and the internal current sources are identified as important control parameters for hardness assurance. These current sources are more important than internal transistor gain in determining internal operating margins of many linear circuit types. Damage factor variability is compared with digital devices, and potential hardness assurance approaches are discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Hard Off-the-Shelf SG1524 Pulse Width Modulator

    Publication Year: 1977 , Page(s): 2079 - 2083
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (726 KB)  

    Samples from three lots of SG 1524 pulse width modulators and from four manufacturers of LM139 quad comparators were irradiated in cobalt-60 to determine total dose effects. Within the context of our INTELSAT V circuit designs, the SG1524 demonstrated a damage threshold of about 0.8 Mrad, which was an order of magnitude more radiation hardness than the best LM139. The source of this hardness may be partially due to lower betas and some manufacturing processes which have previously been shown to be effective in hardening LM108's. The variation in LM139 hardness needs further investigation. The SG1524 contains an oscillator, regulator, comparator, error amplifier, on-off control, and other important functions necessary to spacecraft power conversion equipment. A dc/dc converter designed around the SG1524 has the same power consumption as one designed around the LM139; but, because fewer parts are required, the overall weight is less and the circuit reliability is higher. Changes in the electrical parameters of both parts were examined as a function of the logarithm of the total radiation dose between exposures ranging from 0.02 to 1.0 Mrad. Degradation comparisons were based on the upper 95 percent confidence limit around a least-squares fit to a second-degree polynomial. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hardness Assurance Implications of Variables in Junction Burnout

    Publication Year: 1977 , Page(s): 2084 - 2087
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (863 KB)  

    The electrical energy to cause junction damage varies between device types and between units of a single type. Thermal diffusion models are used to establish the dependence of damage energy on device parameters, taking into account factors that stabilize and destabilize the current density profile. Candidate hardness assurance screens can be deduced from the results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Radiation-Induced Increase of Mobile Sodium in MOS Capacitors

    Publication Year: 1977 , Page(s): 2088 - 2092
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1381 KB)  

    MOS capacitors fabricated from commercially-grown gate and field oxides were examined for sodium ion concentrations before and after radiation using the high-temperature voltage ramp technique. The gate oxides were found to have much lower sodium ion concentrations than the field oxides. Mobile sodium levels at 295°C in both gate and field oxides increased as a result of exposure to 1 MRad (SiO2) Co60 gamma radiation. During prolonged exposure to the high-temperature ramp, a further increase in the amount of mobile sodium was detected. A temperature-bias stress experiment on irradiated and unirradiated type 4007 integrated circuits showed much larger numbers of failures in irradiated devices which had received temperature-bias stress compared with those which received stress only or radiation only. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Parameter Sensitivities for Hardness Assurance: Displacement Effects in Bipolar Transistors

    Publication Year: 1977 , Page(s): 2093 - 2096
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (600 KB)  

    A model of the dependence of displacement damage in bipolar transistors on material parameters can be used to predict worst-case displacement damage constants for transistors. Many real-device complexities, such as parasitic capacitances, some emitter-crowding effects, unknown base grading, can be eliminated by a worst-case approach. The resulting worst-case damage constant for a 2N914 transistor is near the value extrapolated from statistical test data. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Gamma-Induced Voltage Breakdown Anomaly in a Schottky Diode

    Publication Year: 1977 , Page(s): 2097 - 2098
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1819 KB)  

    In a routine evaluation of an electrically identical Schottky diode made by two manufacturers, it was discovered that the diode by one manufacturer was unexpectedly sensitive to gamma radiation. In brief, the breakdown voltage of the diode was reduced by more than 20 percent after a dose of 1 × 105 rads. Subsequent investigations of this anomaly showed that the behavior resulted from the fact that the diode metallization extended significantly beyond the guard ring over the oxide forming a parasitic MOS device. The parasitic device is large and is formed by a thick, "unhardened" oxide. The radiation effects properties of this device are therefore similar to those of an unhardened MOS device formed with a field oxide. It is the charge accumulation in this thick oxide which significantly alters the diode properties following exposure to gamma radiation. The problem is easily eliminated by reducing the metallization size so that it does not extend significantly over the thick oxide, thereby eliminating formation of the parasitic MOS device. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Radiation Hardened Field Oxide

    Publication Year: 1977 , Page(s): 2099 - 2101
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (437 KB)  

    This paper describes the results of a radiation-tolerant field oxide development compatible with both MOS and bipolar technologies. Data is presented which illustrates that nonguardbanded devices utilizing conventional field oxide structures cannot be expected to survive an ionizing radiation dose above approximately 5 × 104 rads (Si) due to inversion of p-type silicon surfaces under metallized areas. The radiation hardened oxide was evaluated with both aluminum and polycrystalline silicon gate MOS structures which conclusively demonstrates that this oxide eliminates the field inversion problem for radiation levels in excess of 106 rads (Si). View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Chemical and Structural Aspects of the Irradiation Behavior of SiO2 Films on Silicon

    Publication Year: 1977 , Page(s): 2102 - 2107
    Cited by:  Papers (24)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1147 KB)  

    Similarly to vitreous silica, irradiation of Sio2 films on silicon releases bond strain by creating network defects and a small increase in density and a decrease in polarizability. In contrast, the density of quartz crystal decreases and its polarizability increases during irradiation. These effects are due to the basic trend of maximizing ¿-bonding and minimizing bond strain in the Si-O network. From the irradiation-generated electron-hole pairs, the holes are trapped in narrow and localized ¿-bands at ~0.4 eV above the SiO2 valence band while the electrons move rather freely. This hole trapping is an intrinsic property of the Si-O bond. Hole trapping also occurs at the Si/SiO2 interface where interface states are generated. It is suggested that this process involves breaking surface Si-H bonds. Results obtained with various analytical techniques demonstrate that hydrogen present in various forms in the oxide film plays a crucial and complex role in the irradiation behavior of Si/SiO2 interface structures. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Experimental Observations of the Chemistry of the SiO2/Si Interface

    Publication Year: 1977 , Page(s): 2108 - 2112
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2279 KB)  

    Changes in silicon surface preparation prior to thermal oxidation are shown to leave a signature by altering the final SiO2/Si interface structure. Surface analytical techniques, including XPS, static SIMS, ion milling, and newly developed wet-chemical profiling procedures are used to obtain detailed information on the chemical structure of the interface. The oxides are shown to be essentially SiO2 down to a narrow transitional interface layer (3-7 Å). A number of discrete chemical species are observed in this interface layer, including different silicon bonds (e.g., C-, OH-, H-) and a range of oxidation states of silicon (0 ¿ +4). The effect of surface preparation and the observed chemical species are correlated with oxide growth rate, surface-state density, and flatband shifts after irradiation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Field- and Time-Dependent Radiation Effects at the SiO2/Si Interface of Hardened MOS Capacitors

    Publication Year: 1977 , Page(s): 2113 - 2118
    Cited by:  Papers (68)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1889 KB)  

    The field and temperature dependence of the interface-state density as a function of time following pulsed e-beam irradiation, and the dose dependence of the interface-state density following steady state Co60 irradiation were examined in MOS capacitors with both hardened dry and wet (pyrogenic) gate oxides. From the results of the pulsed e-beam experiment, we show that in the wet oxide the electric field affects the time scale for the buildup of interface states as well as the final or saturation value of interface states at late times (~105 s), but that in the dry oxide there is no marked field dependence. For the wet oxide, we observed that temperature affects only the time scale for the buildup of interface states. From total-dose Co60 measurements, we report a power law dependence on dose, D0.65, for both wet and dry oxide capacitors. The buildup of interface states in the wet-oxide capacitors is considerably larger than in the dry. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Leakage Current Phenomena in Irradiated SOS Devices

    Publication Year: 1977 , Page(s): 2119 - 2127
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1967 KB)  

    A detailed study of ionizing radiation effects on SOS devices has been performed with emphasis placed on determining the mechanisms of back-channel leakage current phenomena. Behavior for n-channel transistors fabricated with both wet and dry gate oxides is compared and differences in radiation response are attributed to a larger density of hole traps in the sapphire for dry-oxide devices. It is observed that reduction of radiation-induced leakage current to very near its preirradiation value can be readily accomplished by continuing to irradiate a device under a condition of zero drain bias. Studies with low-energy electrons (6 - 45 keV) from a scanning electron microscope reveal that energy must be deposited in the sapphire in order to increase the leakage current and that energy deposition in the sapphire bulk is unimportant in terms of leakage current production. For the present devices, the region which is effective in producing such current extends into the sapphire a distance on the order of 2 ¿m from the Si-Al2O3 interface. If hole traps are spatially distributed, then the dominant mechanism for reducing leakage current is shown to be injection of electrons from Si into Al2O3 where they neutralize trapped holes. A model for radiation-induced production and reduction of leakage current in SOS devices is described. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Avalanche Injection of Holes into SiO2

    Publication Year: 1977 , Page(s): 2128 - 2134
    Cited by:  Papers (32)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1561 KB)  

    Avalanche injection techniques are used to provide hole currents through MOS capacitors and study the trapping of holes in the oxide layer. Although radiation is not in any way involved in these experiments, the trapped positive charge and surface states resulting from hole injection are similar to those obtained using radiation. The processing and oxide thickness dependence of hole trapping phenomena are also investigated. Prolonged post-oxidation annealing treatments are shown to lead to enhanced hole trapping in "hardened" oxides. Hole trapping cross-sections between 10-13 and 10-14 cm2 and trap densities between 1012 - 1013 cm-2 are measured depending on the processing conditions. The effective charge density is studied over the range of oxide thickness between 200 Å and 600 Å as a function of post-oxidation anneal in these "hardened" oxides. While the effective charge density is only weakly dependent on oxide thickness in unannealed oxides, in annealed oxides it exhibits a strong linear dependence of trapping on oxide thickness. The dependence on post-oxidation anneal time and ambient are also discussed. These results indicate a strong similarity between hole trapping induced by avalanche injection and by radiation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Low Temperature Radiation Response of Al2O3 Gate Insulators

    Publication Year: 1977 , Page(s): 2135 - 2139
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1077 KB)  

    The response of Al2O3 MIS capacitors to steady state (Co60) and pulsed high-energy (13-MeV e-) ionizing radiation was measured at 297 and 80 K as a function of applied bias and dose. The radiation sensitivity of the Al2O3 at 80 K was found to be little altered from its room temperature value and was significantly reduced from that of comparable SiO2 gate insulator materials measured under similar conditions. Experimental evidence suggests that the primary mechanism for the superior performance of Al2O3 at 80 K is rapid transport of most of the radiation generated carriers out of the oxide layer. The injection of electrons into the Al2O3 under bias stress was also measured at 297 and 80 K, and was found to be drastically slowed at the lower temperature. As a consequence of its superior performance under irradiation at 80 K, Al2O3 may be an attractive alternative to SiO2 gate insulator materials in critical low temperature applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

IEEE Transactions on Nuclear Science focuses on all aspects of the theory and applications of nuclear science and engineering, including instrumentation for the detection and measurement of ionizing radiation; particle accelerators and their controls; nuclear medicine and its application; effects of radiation on materials, components, and systems; reactor instrumentation and controls; and measurement of radiation in space.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Paul Dressendorfer
11509 Paseo del Oso NE
Albuquerque, NM  87111  USA