Conformal deposition of polymer thin-films in high aspect ratio 3D structures

Published : 28 May 2018

The deposition of thin films on challenging high aspect ratio structures are of key importance in many different areas of microelectronics and nano-technologies. For polymer thin films, filament-assisted CVD techniques (such as iCVD) have emerged recently as promising method for the conformal deposition of insulating thin films in 3D structures. However, it is still not clear if this CVD method can allow conformal coating inside porous and 3D substrates with acceptable growth rates and what are the limits of utilization. The work proposed here aims to study polymer thin film deposition by iCVD in high aspect ratio 3D structures in order to identify the parameters governing the deposition speed and the accessible degree of conformality. The works will be performed on high aspect ratio Through Silicon Vias and on various porous substrates. The candidate will be in charge of thin films deposition on a 200 mm tool and of the material characterization. The thin films will be characterized using physicochemical analyses (FTIR, X-Ray Reflectometry, Ellipsometry, Porosimetry, Contact angle, AFM). More in depth characterizations (using Electronic Microscopy, ToF-SIMS) will be carried out to study the deposition in 3D structures.

The main objective of the work will be to identify the key parameters that play a role in the conformal deposition inside 3D structures and porous substrates as a function of the feature shape and size. The work will be done in the LETI/DTSi division. The material deposition and characterizations will be performed in the LETI clean room in close collaboration with an industrial partner. Part of the work will be done in collaboration with experts of materials characterization (CEA nanocharacterization platform), and specialists in charge of 3D integration.

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