Hard errors from single heavy ions have been reported in advanced commercial CMOS memories. We examine the physical interactions of ions with MOS gate oxides-charge generation, recombination, transport and trapping. We also consider device and circuit characteristics. We conclude that hard errors from single ions are to be expected, and should not be considered surprising.

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Modified lead titanate of 0.9PbTiO3 −0.1Pb(Mg0.5 W0.5)O3 thin films have been deposited onto Pt-coated Si substrates by pulsed laser deposition. Films were crystallized in situ during deposition or by post-depositional heat treatment (post-annealing). Compositional and structural characterization showed that the phase formation and microstructure of the films were highly sensitive to deposition conditions. Perovskite single phase films were formed in situ at 650 °C, PO2 = 40 Pa as well as by post-annealing amorphous films at 650 °C. In the post-annealing process, the amorphous as-deposited phase was crystallized to perovskite and/or pyrochlore, and the ratio of perovskite to pyrochlore was found to be influenced by the depositional PO2. Depending on the deposition temperature, the grain structures of the crystallized films were columnar or equiaxed. A relatively homogeneous surface morphology was obtained by deposition at a lower pressure (PO2 = 13 Pa). The in situ crystallized films showed variable crystallographic orientation. The more (111) oriented films had the lowest remanent polarizations and the highest coercive fields. A method for preparing randomly oriented films, via a two-step deposition process with intermediate annealing, is believed to give the most consistent results and the best ferroelectric properties at the present level of development.

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Very thin films of lead zirconate titanate (pn? (40/60), 0.26 pn or less, have been prepared on Pt-coated oxidized Si substrates (Pt/IiSiO2/Si) by a sol-gel process. These films were of high density with fine grains of about 0.2 pm and annealed in the range of 6OOO to 700°C in oxygen atmosphere. X-ray diffraction patterns taken on this film showed single-phase perovskite-type structure. Pyroelecmc and P-E hysteresis curve measurements, as well as measurements of the dielectric constant and loss tangent versus temperature and frequency, were performed. The influence of poling treatment on the dielectric and pyroelectric properties was also investigated, as well as dielectric constants and pyroelectric properties, Dielectric constants and pyroelectric coefficients at room temperature were determined as 1300 and 840, and 68.0 and 10.3 nC/cm2. O C for the poled and unpoled PZT films, respectively. The remanent polarization was 37.8 pC/cm2, and a coercive field was 146 kV/ctn at a switching voltage of 16 V peak-to-peak and a frequency of 200 kHz. The remanent polarization and coercive field were found to vary slowly with temperature. The material was also difficult to depole. It is suggested that these films will be suitable for infrared detector applications.