No abstract

Impurities in a GaAs layer that had been amorphized by ion implantation were observed to precipitate upon annealing. Photoluminescence spectra indicated that the resulting high electrical resistivity could be attributed to the formation of neutral impurity complexes rather than a compensation mechanism. Impurities studied were implanted Si and Se. Transmission electron microscopy and x-ray microanalysis were used to identify impurity precipitates and related stacking fault tetrahedra. These results correlate with similar examples of poor activation for impurities in GaAs grown by low-temperature molecular beam epitaxy.

Thin films of aluminum alloyed with copper, silicon, or titanium have been conventionally used as interconnection materials in integrated circuits to reduce hillock growth, electromigration, and junction spiking. The interconnection resistivity of these homogeneous alloys is, however, too high for maximum performance integrated circuits. In this work, hillock growth, resistivity, and stress were investigated for aluminum alloyed with samarium (Al-1 wt. % Sm) as an alternative interconnection material. The results indicated that Al–Sm metallization exhibits very favorable properties, namely, low resistivity and good thermal stability including hillock growth resistance, for potential integrated circuit applications. Other property measurements and process and material compatibility studies are, however, desired prior to its application.

Gallium focused ion beam (FIB) milling is the method of choice to prepare cross sections of selected features from microelectronic devices for transmission electron microscope (TEM) imaging and analysis. The FIB milling technique is unsurpassed in producing an ultra-thin cross section accurately located through the feature of interest. While much effort has been invested in the development and refinement of Ga+ FIB techniques and instrumentation, there are problems due to the physics of the ion-solid interaction. The problem of surface amorphization limits the quality of the TEM samples and its significance increases as the feature size and the specimen thickness decrease.In Ga+ FIB milling of silicon, the amorphous damage layer consists of amorphous Si doped with implanted Ga. This damage layer is caused by ions that strike the surface of the silicon and are subsequently scattered laterally as a result of collisions with the Si atoms.

The preferred orientation of MnS inclusions in hot-rolled steel was studied by electron diffraction.Specimens of resulfudzed steel were examined after casting and after hot rolling to true strains of 0.5, 1.0 and 1.5. After rolling, the orientations of the inclusions tended toward an ideal (100) {001 }.Only a moderate correlation between the final inclusion shape and orientation was found.