Diffusivity and Solubility of Si in the Al Metallization of Integrated Circuits

Si was diffused along the evaporated Al layer of an integrated-circuit structure at temperatures between 360 and 560 °C, and the resulting concentration profile analyzed by electron microprobe. The Si solubility was found to agree with literature values for Si in wrought Al. The Si diffusivity was found to be substantially enhanced, however, probably due to a high density of imperfections in the evaporated Al film. Our measured diffusivities indicate an activation energy EA ~= 0. 8 eV, about 40% less than the value for Si in wrought Al

Precipitation of Si from the Al metallization of integrated circuits

The Al metallization of integrated circuits is known to dissolve 1/2% or more Si, but the ultimate location of this Si has been uncertain. An electron microprobe operated at low beam energy so as to penetrate only the upper portion of the metallization was used to follow the movement of dissolved Si on cooling after the "forming" heat treatment. Dissolved Si substantially less than a diffusion length from the substrate was found to regrow there; elsewhere the Si forms precipitates in the Al matrix, preferentially near the free surface of the Al

Solid-phase epitaxial growth of Si mesas from Al metallization

Si epitaxial growth from solution in solid Al onto crystal Si substrates was studied by scanning electron microscopy. Growth in reentrant corners of the substrate was found to be favored over growth onto a flat surface. For this reason, the smaller-diameter oxide cuts used in integrated-circuit fabrication, in which no portion of the exposed substrate Si is far from a reentrant corner, are favored sites for growth. Si growth readily fills in such oxide cuts forming mesa structures potentially useful in device construction. The probable cause for such preferential growth was indicated in pressure experiments which show that regions in the solid Al under relatively less compression are favored locations for growth

Features extraction for quality assessment of aerial image segmentation, in

We present a new evaluation methodology and a feature extraction scheme for segmentation algorithms in the context of photo-interpretation. The novelty of the proposed methodology is that subjective evaluation marks are involved in the determination of the feature subspace. In fact, our aim is to determine features in alignment with the perception of photo-interpreters, alternatively called psychovisual features. The proposed methodology was applied to the detection of building targets in aerial images. More specifically we considered the delineation of polygonal buildings in semiurban areas on IKONOS images (1 meter resolution). We determined from the images, concurrently, various objective performance measures and collected votes of a jury of evaluators. The methodology to find the concordance between objective features and subjective marks was the canonical analysis of tables.