Metallization is the fabrication step in which proper interconnection of circuit elements is made. For

VLSI, metallization applications can be divided into three groups; gate for MOSFET, contacts, and interconnects.

Aluminum is popular metal used to interconnect IC's, both to make ohmic contact to the devices and this to the bonding pads on the chip's edge. Aluminum adheres well to both silicon and silicon dioxide, cab be easily vacuum deposited (since it has low boiling point), and has high conductivity.

The other important metals are copper, tungsten, and gold. Gold is generally used fir GaAs technologies.

Three dimensional network of interconnection is given the name multilevel connection. It has the advance of reduced interconnection lengths, enhanced performance due to reduced RC time constant, higher package densities and more design flexibility.