Published online by Cambridge University Press: 28 February 2011
Highly selective metal and alloy deposition with simultaneous silicide formation - on semiconductor substrates immersed in commercial electroplating solutions has been investigated via pulse laser irradiation without masking procedures and external electric current.
Specimens of 5i and GaAs substrates, immersed in gold and in palladiumnickel electroplating solutions, were irradiated by a Qswitch YAG pulse laser perpendicular to their surfaces at predesired local zones. The gold, palladium and nickel deposits thus obtained were subsequently examined and characterised by SEM, TEM, AES, ESCA and RBS.
Deposit thickness ranged from a few hundred angstroms to several micrometers, depending primarily on the laser irradiation energy. The elemental Gold deposit exhibited Schottky barrier contacts with the GaAs and Si substrates. Palladium and nickel silicides obtained on n-type silicon substrates likewise exhibited Schottky behavior contracts.