Search

We describe proton induced bulk damage observed in 90 nm process SDRAM. The degradation of the data retention ability was evaluated. The effect due to the difference of process technology and memory cell structure was discussed. The result indicates that the value of the capacitance of the storage capacitor and the volume of the depletion region are key parameters concerning the failures caused by bulk damage. Index Terms--Bulk damage, 90 nm, protons, retention time, SDRAM.

Charge collection efficiency (CCE) generated in a 6H-SiC [p.sup.+]n diode by impact of heavy ions was evaluated by the transient ion beam induced current (TIBIC) technique. Numerical analysis by using technology computer aided design (TCAD) concludes that the Auger recombination process reduces CCE. Comparing experimentally measured CCEs with calculated ones revealed that the ambipolar Auger coefficient of about 3 x [10.sup.-29][cm.sup.6]/s. Index Terms--6H-SiC diode, auger recombination, CCE, PHD, TCAD, TIBIC system.

Single Event Transient (SET) current is one of the most interesting issues for understanding and predicting Single Event Effects (SEEs) in real space environments. Since space radiation consists of high energy heavy ions, estimation of the energy dependence of SET currents is required. In order to estimate this effect, we have developed the Transient Ion Beam Induced Current (TIBIC) system combined with collimated high energy ion beams accelerated by AVF Cyclotron. We have demonstrated the function of TIBIC developed here. Using the newly developed TIBIC system and the Technology Computer Aided Design (TCAD) simulator, the influence of ion energy on SET currents is estimated. Index Terms--Collimated beam, single event transient (SET) current, transient ion beam induced current (TIBIC).

We designed logic cells hardened for SEUs/SETs using hardness-by-design (HBD) methodology with OKI's 0.15 [micro]m Fully Depleted CMOS/SOI commercial process and these cells were evaluated with sample devices. Our previous work demonstrated that SET-free inverters could be successfully applied as SEU-immune latches. In this work, the logic cells were optimized for SEU/SET immunity up to an LET of 64 MeV/(mg/[cm.sup.2]), demonstrating that the process was suitable for space applications with a little penalty. Index Terms--Commercial process, fully depleted CMOS/SOI, hardness-by-design, SET, SEU.

The characteristic nondestructive single-event latchup (SEL) phenomena, 'local' and 'pseudo' SELs, were identified in complex digital Large Scale Integrations (LSIs) by using a photo-emission microscope. Usually, SELs are detected as an abrupt increase of power supply current. However, it was experimentally demonstrated that the simple method could not give sufficient information to determine if it is a destructive or a nondestructive phenomenon. If the observed SELs can be confirmed as a nondestructive phenomenon with a certain confidence level, a simple circumvention technique can be effectively employed and the chance to utilize attractive commercial devices will be greatly enhanced. The SEL test method to identify this type of LSI was discussed and a new procedure was proposed. Index Terms--Non-destructive, photo-emission microscope, single-event latchup (SEL), system-on-a-chip (SoC).

A description of the new capacitive transimpedance amplifier (CTIA) that can be operated at 2K is presented. The performance of this CTIA fulfills the requirements for the far-infrared array detectors onboard ASTRO-F, Japanese infrared astronomical satellite to be launched in 2005.

A new failure mode that is attributable to the bulk damage caused by single protons has been reported in 256-Mbit SDRAMs. The refresh rate required to retain memorized data was measured as a typical parameter to detect the effect. We performed the proton irradiation test and discussed results regarding the influence of this failure. Index Terms--Bulk damage, protons, radiation, retention time, sunchronous dynamic random access memory (SDRAM).

The optical spectral response of Si pin photodiodes was examined after gamma and electron irradiation. We observed both a significant decrease in the peak optical response and peak position with increasing total dose. This effect was successfully explained by modeling the degradation of the minority carrier diffusion length in the base region. The diffusion length damage factor was estimated in the context of the nonionization energy loss (NIEL). A close agreement was found between the observed degradation behavior and that predicted by NIEL. Index Terms--Equivalent displacement damage dose, minority carrier diffusion length, nonionizing energy loss (NIEL), optical spectral response, pin photodiode.

We report on the temperature dependence of the heavy-ion transient-ion beam induced current response of Si epilayer devices from 80 to 300 K. The measurements were performed on a heavy-ion microbeam in conjunction with the new transient-ion beam induced current system developed at the Japan Atomic Energy Research Institute. Furthermore, we perform a detailed comparison with technology computer-aided design (TCAD) simulations and discuss the results in terms of TCAD modeling, experimental procedure, and the implications for temperature-related single-event upset modeling. Index Terms--MeV heavy-ion microbeam, single-event phenomena (SEP), technology computer-aided design (TCAD) simulation, transient current, transient IBIC.

Research is presented describing the study and fabrication characterization of high temperature superconducting multilayered film junctions of manganite.

Carrier transport in hydrogenated amorphous silicon was studied using the modulated photoconductivity method.

The development of 70 MW class superconducting generators as a national project of Japan is described. The program began in 1988 while the manufacturing of the slow response excitation type rotor was finished by the early part of 1996. A performance test of the rotor was performed in the factory by 1997. Factory test results of the cryogenic and electrical performances of the rotor are described.