Method for Fabricating Multilevel Interconnection Structures using Differential Delamination Energies between Metal and Silicon Oxide Thin Films

Abstract

A method for fabricating multilevel interconnection structures using differential delamination energies (adhesion strength) between metal and silicon oxide thin films has been developed. When the selectivity of the delamination energies between the metal and the silicon oxide thin films sets on the wiring, the silicon oxide thin film can be released on the low delaminaion energy area and can be held on the high delamination energy area by using ultrasonic waves. The delamination energies are calculated by using a molecular dynamics simulation. The delamination energies between chromium, titanium, and nickel and silicon oxide thin films are larger than those of copper and gold thin films. The chromium, titanium, and nickel are applied as an adhesion layer with silicon oxide, and the copper and gold are applied as a release layer from silicon oxide. The results are applied to the process for fabricating the multilevel interconnection structures, and the release and the adhesive areas of silicon oxide thin film can be fabricated on the wiring by adding ultrasonic waves. With this method, the lower wrings and the contact areas of the multilevel interconnection structures can be easily fabricated.