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SOI structures are becoming progressively thinner as device dimensions are scaled down. Although thinner layers of Si and SiO/sub 2/ can be made directly by (a) reducing the dose and energy of oxygen ions in the SIMOX process, and (b) using lower H/sup +/ implant energy in the SmartCut/sup TM/ wafer (Bruel, 1995), there are limits to how thin Si films can be made in that way. Therefore, direct thinning methods are often used to obtain the final thickness of Si on the buried oxide (BOX) layer. Sacrificial oxidation is frequently used, a process in which oxidation consumes Si and the oxide is removed by wet etching in a HF solution. Direct wet etching of Si is not used since the etch rates are not as well controlled as oxidation rates, and significant roughening of the surface may occur. In this paper, we discuss application of a conventional SC1 surface cleaning procedure for adjusting silicon film thickness. We also note that silicon removal during cleaning steps must be taken into account when processing thin SOI films.

A 1296-port MEMS transparent optical crossconnect with 5.1dB/spl plusmn/1.1dB insertion loss at 1550 nm is reported. Measured worst-case optical crosstalk in a fabric was n38 dB and nominal switching rise/fall times were 5 ms. A 2.07 petabit/s switch capacity was verified upon cross-connecting a forty-channel by 40 Gb/s DWDM data stream through a prototype fabric.

The microstructure of narrow metal conductors in the electrical interconnections on IC chips has often been identified as of major importance in the reliability of these devices. The stresses and stress gradients that develop in the conductors as a result of thermal expansion differences in the materials and of electromigration at high current densities are believed to be strongly dependent on the details of the grain structure. The present work discusses new techniques based on microbeam x-ray diffraction (MBXRD) that have enabled measurement not only of the microstructure of totally encapsulated conductors but also of the local stresses in them on a micron and submicron scale. White x-rays from the Advanced Light Source were focused to a micron spot size by Kirkpatrick-Baez mirrors. The sample was stepped under the micro-beam and Laue images obtained at each sample location using a CCD area detector. Microstructure and local strain were deduced from these images. Cu lines with widths ranging from 0.8 [.proportional]m to 5 [.proportional]m and thickness of 1 [.proportional]m were investigated. Comparisons are made between the capabilities of MBXRD and the well established techniques of broad beam XRD, electron back scatter diffraction (EBSD) and focused ion beam imagining (FIB).

The microstructure of 0.8.µm, A1(0.5% Cu) lines has been measured both before and after post-pattern annealing in nitrogen at various times and temperatures. Grain boundary inclinations in single grain segments of lines were determined from Focused Ion Beam (FIB) images of two surfaces of the lines. The statistical distributions of inclination angles before and after annealing reveal the tendency for boundaries to rotate to reduce their area. In these experiments the rotation stagnates with the normals to the grain boundaries having a distribution of inclinations with a FWHM of about 33 degrees around the line direction.

Etude de la variation de la distribution en energie des ions issus d'une source d'ions de metal liquide d'or en fonction des conditions d'ecoulement hydrodynamique imposees par l'etat de surface de la pointe

We have studied the changes in the energy distribution of the Au++3 and Au+2 species from Au liquid metal ion sources (LMIS) with increasing current. The distributions are single peaked at low currents but develop secondary maxima at higher currents. We evaluate the feasibility of several mechanisms that have been proposed in order to explain such changes and find them unsatisfactory. We propose two alternative models which may be effective. We have also studied the angular intensity and the energy distributions of the above species as well as those of the Au++ species as a function of angle of emission. These results further emphasize the complexity of the processes by which these species are created, and which, as yet, are not well understood.