A fluorescent and diffracted X-ray spectrometer with an X-ray sub-micron beam was developed for the analysis of stress, crystal structure, and contamination in micro-regions of ULSIs. A fine glass capillary with a parabolic cross-sectional inner wall surface was made to form a micro X-ray beam. A micro-focus X-ray generator with a membrane-type target was also developed for use with the capillary. The equipment was used to analyze the crystal phases of Ti silicide fine lines and the strains in Al interconnections.
The resistance of Ti-silicide lines increases the line width narrows under about 0.5 μrn. This is because of the growth of crystal phases of TiSi2(C49) and TiSi(B27) with high resistivity ﹛60 to 100 μΩ-cm).
Hillocks of Al grow at line edges when Al layers are compressed by Si substrates and surrounding insulating layers. On the other hand, when the Al is extended by these layers, voids form in the AI lines.