MULTILAYER-FORM METAL COATING SYSTEM OF SILICON SEMICONDUCTOR DEVICE

摘要

PURPOSE: To form a stable low-resistance electrical contact on silicon by successively forming amorphous tungsten and silicon on a layer that is made of titanium and metal silicide on the surface of a contact region in a silicon substrate and a layer that is made of aluminum and aluminum alloy on it. CONSTITUTION: A three-layer metal covering pattern is arranged on a silicon oxide covering 20. The metal covering pattern is partially in contact with a silicon surface part 12' being exposed in a gap 22. The second part is in contact with the silicon surface part 12' being exposed in a gap 24. The three-layer metal covering pattern contains a first layer or a lower layer 26 made of titanium. Amorphous tungsten and silicon, second layer or an intermediate layer 28 is arranged on the titanium layer 26. A thick layer 30 made of aluminum alloy is arranged on the amorphous tungsten and silicon layer 28. The titanium layer 26 forms a low-resistance contact for both of silicon and amorphous tungsten and the silicon layer.