HIGH-PERFORMANCE CONTACT FORMATION IN LSI CIRCUIT RESTRUCTURING USING VISIBLE PULSE LASER-INDUCED ABLATION AND CVD

The formation of a superior electrical contact for a directly written W line and Al interconnection, covered with an insulator, has been substantially improved in LSI circuit restructuring technology, using ablation and CVD with visible pulse lasers. Single shot visible pulse irradiation can make a contact hole reproducibly by evaporating the thin upper layer of an underlying Al interconnection with a simultaneous blowout of the covering insulator. Sequential steps in the contact hole filling have been carried out by high repetition visible pulse laser induced pyrolytic W CVD. The peak temperature during the hole filling has to be controlled below 450°C, to get good electrical contact quality. The obtained contact resistance through a 1.5 μm diameter contact hole was less than about 0.3 Ω. © 1990.