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Thickness and temperature‐dependent study of Co/Si interface
Author(s) -
Kumar Anil,
Brajpuriya Ranjeet,
Singh Priti
Publication year - 2018
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.6488
Subject(s) - materials science , annealing (glass) , nanocrystalline material , transmission electron microscopy , raman spectroscopy , thin film , amorphous solid , analytical chemistry (journal) , electron beam physical vapor deposition , chemical vapor deposition , silicon , crystallography , nanotechnology , composite material , optics , chemistry , optoelectronics , physics , chromatography
Thin films of cobalt (10, 40, and 100 nm) are deposited on Si substrate by electron beam physical vapor deposition technique. After deposition, 4 pieces from each of the wafers of silicon substrate were cut and annealed at a temperature of 200°C, 300°C, and 400°C for 2 hours each, separately. X‐ray diffraction, atomic force microscopy, and transmission electron microscopy (TEM) are used to study the structural and morphological characteristics of the deposited films. To obtain TEM images, Co films are deposited on Cu grids; so far, no such types of TEM images of Co films are reported. Structural studies confirm nanocrystalline nature with hexagonal close packed structure of the deposited Co film at lower thickness, while at higher thickness, film structure transforms to amorphous with lower surface roughness value. The particle sizes in all the cases are in the range of 3 to 5 nm. Micro‐Raman spectroscopy is also used to study the phase formation and chemical composition as a function of thickness and temperature. The results confirm that the grown films are of good quality and free from any impurity. Studies show the silicide formation at the interface during deposition. The appearance of new band at 1550 cm −1 as a result of annealing indicates the structural transformation from CoSi to CoSi 2 , which further enhances at higher annealing temperatures.