Rapid crystallization and equally rapid revitrification of amorphous chalcogenide films exposed to short laser pulses has been observed. A model is developed in which both the speed reversibility are attributed large enhancement rate under influence photon flux.

We present electron diffraction data from amorphous silicon which cannot be reconciled with the intensity profiles derived small-crystallite models based on diamond structure. Our patterns do reveal a pronounced low-angle scattering anneals out progressive heating and is indicative of actual void spaces, or regions distinctly deficient density, in films. These may responsible for recent observations Brodsky Title surface states within bulk Si.

Medium and high-energy x-ray diffraction has been used to study the atomic structure of pure amorphous Si prepared by MeV implantation into crystalline silicon. Both as-implanted annealed samples were studied. The inelastically scattered x rays removed fitting energy spectrum for rays. scattering factor silicon, previously known reliably up 20 ${\mathrm{\AA{}}}^{\mathrm{\ensuremath{-}}1}$, extended 55 ${\mathrm{\AA{}}}^{\mathrm{\ensuremath{-}}1}$. radial distribution function Si, before...

We report what is to our knowledge the first simultaneous measurement of two-photon absorption coefficient and free-carrier cross section above bandgap in a semiconductor. This also observation 1 μm radiation single-crystal Si at room temperature regime where stepwise process involving indirect followed by usually dominant. A critical pulsewidth (and fluence) established below above) which cannot be neglected. Pulses that range from 4 100 ps duration are then used isolate...

We have used two-photon absorption, self-defocusing, and optically-induced melting in GaAs to limit 1 μm picosecond pulsed radiation. The contribution the limiting action from each of these mechanisms is discussed demonstrated. Additionally, we measure a absorption coefficient 26 cm/GW, which good agreement with smallest values reported literature. A pulse-width study nonlinear was conducted isolate effects two-photon-generated free-carrier absorption. Results indicate that, even though...

Selected analog devices were tested for heavy-ion-induced single event upset (SEU). The results of these tests are presented, likely mechanisms discussed, and standards the characterization upsets suggested. OP-15 operational amplifier, which was found to be susceptible SEU in laboratory, has also experienced space. Possible strategies mitigating occurrence SEUs space discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

We show that the thresholds for picosecond (psec) laser pulse-induced latchup and energetic particle-induced are well correlated over a range of bulk CMOS test structures designed to be susceptible latchup. The spatial length latchup-sensitive node covers values commonly occur in devices. accuracy this correlation implies laser-induced can used hardness assurance and, under proper conditions, an accurate predictor threshold linear energy transfer (LET) most

We present an x-ray diffraction study of $\mathrm{Y}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}\ensuremath{\delta}}$ single crystals. High-resolution scans reveal two orthorhombic phases with different lattice constants but a common orientation indicating phase separation into $\ensuremath{\delta}\ensuremath{\approx}0.0 \mathrm{and} 0.3$. Thermal expansions the unit-cell parameters both measured between 10 and 300 K were fit using quasiharmonic approximation giving...

Generally good agreement is obtained between the single-event output voltage transient waveforms by exposing individual circuit elements of a bipolar comparator and operational amplifier to an ion microbeam, pulsed laser beam, simulations using SPICE. The achieved adjusting amounts charge deposited or injected in SPICE simulations. implications for radiation hardness assurance are discussed.

A single crystal of ${\mathrm{Fe}}_{0.53}$${\mathrm{Cr}}_{0.47}$, quenched to 300 K after an anneal above the \ensuremath{\sigma}-phase boundary, was studied at three x-ray energies: 5.969, 7.092, and 7.6 keV (where contrast \ensuremath{\sim}0). With our analyzer detector we were able remove Compton resonant Raman scattering experimentally leave solely diffuse from concentration fluctuations atomic displacements. Using 7.6-keV data determine combined pure static thermal scattering, other two...

We demonstrate a new silicon picosecond nonlinear-optical energy regulator for 1-microm radiation. The device has high transmission low input energies and clamps the output at constant value. attribute this optical Zener action to nonlinear refraction absorption induced in by intense pulses.

A scanning electron diffraction attachment providing for energy analysis of the scattered electrons has been constructed use in conjunction with a J.E.M. 6AS microscope. This permits direct recording diffracted intensities as function angle an accuracy ±0.1%. The can be operated to exclude all but elastically electrons, or, alternatively, detect measurable amount loss. electrostatic analyzer cutoff better than 1.1 eV out 100 keV. angular resolution instrument is presently 2.2×10−4 rad,...

The single event upset (SEU) sensitivity of certain types linear microcircuits is strongly affected by bias conditions. For these devices, a model mechanism and method for SEU control have been suggested.

A variation of the excite-and-probe technique is used to measure picosecond evolution laser-induced transient gratings that are produced in germanium by direct absorption 35-psec optical pulses at 1.06 \ensuremath{\mu}m. Grating lifetimes determined for peak excitation levels between 1.8 mJ/${\mathrm{cm}}^{2}$ (\ensuremath{\sim} 50 MW/${\mathrm{cm}}^{2}$) and 36 1 GW/${\mathrm{cm}}^{2}$), four grating spacings, two sample temperatures, 295 135 K. For lower fluence, a linear...

Radiation-induced edge-leakage current in minimum geometry n-channel MOSFETs from five submicron technologies is examined as a function of dose rate. Under worst-case bias, degradation transistors the TSMC 0.35-, 0.25-, and 0.18-/spl mu/m processes more severe following low-dose-rate irradiation than high-dose-rate anneal. The leakage anneals with an activation energy /spl sim/1.0 eV, which suggests that charge trapping field oxide associated shallow defects such E'/sub delta// centers. A...

X-ray data were collected on films of ${\mathrm{Al}}_{0.72}$${\mathrm{Mn}}_{0.22}$${\mathrm{Si}}_{0.06}$ sputtered NaCl at 45, 150, and 230 \ifmmode^\circ\else\textdegree\fi{}C. The 45 \ifmmode^\circ\else\textdegree\fi{}C show a typical metallic-glass structure factor, $S(Q)$, while the is quasicrystalline plus Al. A combined particle-size phason strain broadening was applied to normalized reduced $S(Q)$ for film bring it essentially into coincidence with amorphous (45...

X-ray diffraction of ${\mathrm{La}}_{1.8}$${\mathrm{Ba}}_{0.2}$${\mathrm{CuO}}_{4\mathrm{\ensuremath{-}}\mathrm{y}}$ reveals two macroscopically segregated tetragonal (${\mathrm{K}}_{2}$${\mathrm{NiF}}_{4}$-type) phases nearly identical lattice parameter. Many peaks show additional broadening upon cooling. This is consistent with a spontaneous monoclinic distortion, an onset temperature \ensuremath{\approxeq}150 K, and possibly relevant to the superconducting properties. Small single...