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This paper reports on the effects of oxidation-induced stress on the generation current in pn-junction and gated diodes. It is observed that even in the regime where no extended defects are present, the generation current is a strong function of the compressive stress in the substrate. Experimental results are presented revealing an order of magnitude increase in generation current for stress changes of a few 100 MPa's. A stress-induced bandgap narrowing model that describes the relationship between the oxidation-induced stress and the generation current in MOS devices is proposed and experimentally verified. Using this model, we have calculated the stress-induced generation current in scaled shallow trench isolated (STI) devices due to reoxidation after STI formation. As the device pitch is reduced a large increase in stress and leakage current is observed, consistent with the experimental data.

Summary form only given. Crystals of KDP and DKDP with dimensions of 41/spl times/41/spl times/1 cm/sup 3/ will be used as Pockels cell and harmonic conversion elements in the world's largest laser system, the National Ignition Facility (NIF). Determining the optical performance of these crystals under NIF-like conditions and understanding the connection between optical performance and internal defect structure has been a crucial part of the effort to build this facility. The crystals must exhibit a high degree of optical homogeneity, low anomalous birefringence, low absorption, uniform phase matching and high laser damage threshold at the 1st, 2nd and 3rd harmonics of Nd:YAG in order to meet the NIF goals for conversion efficiency, energy on target and beam focusability. Here we review the results of extensive spectroscopy, interferometry, polarimetry, X-ray topography, phase matching homogeneity and laser-induced damage measurements on full-scale and/or sub-scale crystals.

With the continuing reduction of device dimensions, the impact of the isolation process on device performance becomes increasingly important. A major concern when scaling LOCOS and shallow trench isolation structures (STI) is the build-up of localized stress near the isolation edge, often leading to dislocation formation and altering device characteristics. In this paper, we show for the first time that even when no dislocations are formed, a reduction in isolation pitch can severely degrade the device characteristics, due to the presence of high localized stresses. A stress-induced bandgap narrowing model is proposed and succesfully applied to explain the observed behavior.

Single crystals of the in situ composite TaSi2-Si are candidates for wide bandpass monochromators and analyzers for x-ray experiments. Two large crystals (32 × 39 × 7 mm3 and 32 x 39 x 30 mm3) were studied in detail using 115 keV synchrotron radiation at the BESSRC beamline at the APS. For transmission geometry, the Si(111) reflection and 39 mm crystal thickness, rocking curve widths of 95 arc sec with reflectivities of 50% were measured over the entire crystal. Turning the crystal to an angle of 45° to the incident beam and translating it through the beam allowed investigation of the influence of crystal thickness on diffracted intensity. For sample thicknesses ranging between 5 mm and 12.5 mm, the full width at half maximum (FWHM) of the rocking curve increased linearly from 29 arc sec to 53 arc sec. The greatest gain in integrated intensity was obtained for 8-9 mm thickness where FWHM = 40 arc sec. If this crystal were used as a monochromator for synchrotron radiation, it would provide 40 times more intensity than a perfect silicon crystal and an energy bandwidth of 1 keV at 115 keV photon energy. With the increase of the rocking curve FWHM, a plateau across the peak maximum developed; its width increased from 5 arc sec to 25 arc sec when the crystal thickness increased from 5 mm to 12.5 mm, respectively. This plateau allows these crystals to be used as analyzer crystals in diffraction experiments, i.e., as very narrow slits to suppress background. A plateau width of about 5-20 arc sec for the analyzer crystal is needed to insure that the entire intensity scattered from a sample is delivered to the detector. The simple expedient of changing the crystal thickness alters the plateau width of the analyzer crystal and tunes its acceptance to the needs of the sample under study.