Interface reaction between Ir films and relaxed SiGe MBE layers by rapid thermal annealing

• Published in: Journal of crystal growth 1995-12, Vol.157 (1), p.236-241
• Main Authors: Curello, G., Gwilliam, R., Harry, M., Reeson, K.J., Sealy, B.J., Rodriguez, T., Almendra, A.
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Diffusion; interface formation; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Metals. Metallurgy; Physics; Solid surfaces and solid-solid interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/0022-0248(95)00410-6

The thermal evolution of Ir p-Si x Ge 1 − x interface reactions was investigated for the first time for the potential application in far infrared image sensors. A 20 nm iridium film was deposited in vacuum by electron beam evaporation onto p-Si 0.75Ge 0.25 fully relaxed MBE grown layers. Rapid thermal annealing in the temperature range of 500–1000°C have been performed. Cross-sectional transmission electron microscopy (XTEM) and Rutherford backscattering spectrometry (RBS) have been used in characterizing the reacted layers. The morphology of the interface at the early stages of the reaction has been shown to be very dependent on the annealing temperature. For the annealing times investigated it was found that Ir reacts mainly with Si to form silicides, while the Ge is expelled from the reacted layer and piles up at the silicide SiGe interface. The effect of a double step annealing on the redistribution of the elements in the reacted layer is also described.