Laser-assisted chemical vapor deposition of nickel and laser cutting in integrated circuit restructuring

Abstract

Laser-assisted chemical vapor deposition (LCVD) of nickel from Ni(CO)4 has been utilised for the restructuring of integrated circuit (IC) interconnections. Nickel lines were deposited on a SiO2 passivated IC to achieve new local interconnections between integrated circuit structures. Depositions were carried out over the pressure range of 0.2 to 2.2 mbar of pure Ni(CO)4 buffered in 0 to 800 mbar He. Argon ion laser wavelengths of 488 and 514.5 nm, laser power of 50-150 mW and a laser scan speed of 80 μm/s were utilised for the deposition. The morphology and chemical contents of the deposited interconnection microstructures was examined by AFM, optical microscopy and LIMA. The resistivity of the deposited lines was found to be close to the nickel bulk resistivity. The utilisation of Nd: YAG and XeCl excimer lasers in the cutting of Al and Mo conductor lines for integrated circuit modification is also described.