Articles written in Bulletin of Materials Science

• Probing of the influence of bilayer geometry, substrate temperature and post-deposition annealing on Si and Cr thin film interdiffusion through Raman spectroscopy

Cr and Si thin films were sequentially deposited on fused silica substrates by electron beam evaporation. Two bilayer film geometries, one with Cr thin film at the bottom and the other with it on top of the Si thin film, were investigated. The thin films were deposited at 200, 400 and 500°C followed by annealing in vacuum. Thereafter, the bilayer films were post-deposition annealed at temperatures between 600 and 800°C in 50°C steps. Raman spectroscopy studies showed that the interdiffusion process resulted in the crystallization of the as-deposited amorphous Si films. The temperature at which the crystallization occurred was geometry dependent, being lower when the Si film was at the top and at higher substrate temperature in the reverse case. The onset of crystallization temperature and the extent of crystallization of Si were determined by investigating the Raman spectra of the films recorded after post-annealing at each temperature. In addition to crystalline Si, the formation of CrSi$_2$ and Cr$_2$O$_3$ was also detected. Thus, under favourable conditions the crystallization of Si is not silicide mediated. Bilayers with Cr on top and deposited at 400°C, the onset of crystallization occurred at 700°C with a maximum crystallization fraction of 67%. In contrast, in the case of metal at the bottom geometry and deposited at 500°C, the onset of crystallization occurred at a lower temperature of 600°C. Significantly, the presence of silicides was detected in the Cr (top)/Si (bottom) geometry and there was absence of silicides inthe reverse geometry. This study provides new insights into the behaviour of metal–Si interfaces with implications for semiconductor devices and solar cells.

• # Bulletin of Materials Science

Volume 46, 2023
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Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020