The RIT SMFLs Flash Evaporator has a history of depositing a layer of aluminum with poor electrical and visual characteristics after sinter when deposited on Silicon, suspected to be due to the aluminum spiking into the substrate from a lack of Silicon. This project seeks to characterize this defect by examining the Aluminum films of the Flash Evaporation tool, Thermal Evaporation tool, and DC Sputter tool, both with and without a self-aligned TiSi2 buffer layer. X-ray Photoelectron Spectroscopy (XPS) is used to determine the chemical composition of the layer, Transmission Line Measurements (TLMs) to determine contact resistivity, diodes to electrically detect spikes deeper than a specied threshold, and optical detection to characterize the frequency and geometry of the junction spikes as a function of contact area. A rough film defect was found to occur in every film, independent of deposition method, contact size, and the underlying layer. The defect in these devices was found to likely be Silicon hillocks nucleating above the substrates surface during the sinter, rather than the hypothesized junction spiking.
"Characterization of AlSi and AlSi-TiSi2 Metal-Semiconductor Contacts,"
Journal of the Microelectronic Engineering Conference: Vol. 24:
1, Article 13.
Available at: https://repository.rit.edu/ritamec/vol24/iss1/13