Cobalt's unique physico-chemical properties, including wear resistance and electrical resistivity, make it ideal for several different components within integrated circuits.
The connections between different components of an integrated circuit (IC) are called contacts.
Within these connections copper is generally used. The thickness and length of the connection causes gate resistance. Silicides such as CoSi2 can be used to reduce this resistance. The use of a cobalt silicide has the advantage of low resistance, good process compatibility (high duration of high temperatures) and little electro-migration (displacement of a substance by the electric current).
Cobalt is also used in metal leads (a length of wire or a metal pad that comes from a device). Gold is commonly used for marking mechanical electrical contacts. By co-depositing the gold with 15% cobalt, the wear-resistance properties of the metal lead are greatly increased. When an electrical current passes through the IC cycling occurs, the friction produced can cause the IC to fail, the addition of cobalt prevents this.
Lastly, cobalt is used in the packaging of ICs. Cobalt can be used in printing circuit board materials (PCB). PCBs usually consist of an insulating support surrounded by layers of electrically resistive materials which are attached to highly conductive materials.
Cobalt antimony, cobalt boron, cobalt geranium, cobalt indium, cobalt-molybdenum, cobalt phosphorous, cobalt rhenium, cobalt ruthenium, cobalt tungsten and cobalt vanadium can all be used as resistive materials.