A high reliability Metal-Insulator-Metal capacitor integrated into a 0.18 ym CMOS foundry technology using Copper interconnects is discussed. Integration solutions specific to Copper processing are described and process yield and reliability results are presented on 0.72 fF/pm2 capacitors. Performance and reliability metrics are shown to be comparable to those formed on Aluminum technologies.

We report on a new colour-switching effect of photoluminescing spark-processed silicon which was prepared in pure oxygen. Whereas as-prepared specimens display an orange PL peaking at 655 nm (1.89 eV), the PL changes to a more intense blue emission centred at 475 nm (2.61 eV) when the sample is subjected to a lower pressure. The same blue PL band is observed after heat treatments up to 350 • C. Moreover, at annealing temperatures above 400 • C a third radiative transition emerges in the infrared and eventually dominates the spectrum. A model is suggested that links ozone molecules, generated during spark-processing and incorporated into the sp-matrix, to the orange PL band. The results of heat treatments and temperature-dependent PL measurements allow for the relationship of the 2.61 eV band to oxygen deficiency centres, created by out-driven ozone molecules. The IR band is discussed in the light of luminescing properties of porous silicon and silicon oxides. The experiments demonstrate that the UV/blue (3.25 eV) and green (2.36 eV) PL bands for Si spark-processed in air cannot be related to radiative transitions in silicon oxides.

Radiative and compositional properties of spark-processed silicon are studied by photoluminescence and x-ray photoelectron spectroscopy measurements. Spark processing of silicon is performed in different atmospheres composed of nitrogen and oxygen. As a result of the process, room-temperature radiative transitions occur at 2.35 eV and vary in intensity over five orders of magnitude depending on the N 2 /O 2 ratio. After processing in pure nitrogen or pure oxygen, however, the green photoluminescence ͑PL͒ is wiped out and weak blue ͑2.7 eV͒ or orange ͑1.9 eV͒ PL bands, respectively, are discernable. The temperature-dependent features of the 2.35 eV emission are characterized by an intensity increase in conjunction with a red shift of the peak position at lowered temperatures. A cross-sectional study reveals that the green PL is mainly generated in a near-surface layer having a chemical composition close to SiO 2 and a nitrogen concentration below 1 at. %. Nearly no PL was observed from a deeper SiO 2 layer enriched by silicon clusters and with an increased density of nitrogen ͑up to 7 at. %͒. The findings do not support a quantum-dot-related PL mechanism in spark-processed silicon. It is proposed that nitrogen additions reduce the density of nonradiative centers introduced by silicon dangling bonds.

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