Authors: R Bernasconi A Molazemhosseini M Cervati S Armini L Magagnin
Publish Date: 2016/07/01
Volume: 45, Issue: 10, Pages: 5449-5455
Abstract
Allwet electroless metallization of throughsilicon vias TSVs with a width of 5 μm and a 110 aspect ratio was carried out Immersion in a n2aminoethyl 3aminopropyltrimethoxysilane AEAPTMS selfassembled monolayer SAM was used to enhance the adhesion between the metal film and substrate Contact angle variation and atomic force microscopy were used to verify the formation of a SAM layer A PdCl2 solution was later used to activate the silanized substrates exploiting the affinity of the –NH3 functional group of AEAPTMS to palladium A nickelphosphorusboron electroless bath was employed to deposit the first barrier layer onto silicon The NiPB growth rate was evaluated on flat silicon wafers while the structure of the coating obtained was investigated via glow discharge optical emission spectroscopy Crosssectional scanning electron microscope observations were carried out on metallized TSVs to characterize the NiPB seed the Cu seed layer deposited with a second electroless step and the Cu superfilling obtained with a commercial solution Complete filling of TSV was achieved
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