METHOD FOR FORMING TWO LAYERS ON SILICON SUBSTRATE AND METHOD FOR FORMING PACKING MATERIAL FOR CONTACT REGION ON SILICON SUBSTRATE

摘要

PURPOSE: To obtain a low contact resistivity without significant sacrifice of integrity at contact joint by forming a refractory metal nitride layer on a silicon substrate and forming a quasi-novel metal silicide layer thereon. CONSTITUTION: A refractory metal 11 is deposited on a silicon substrate 10 and a quasi-novel metal layer 12 is formed thereon. Preferably, the refractory metal 11 is composed of titanium and the quasi-novel metal layer 12 is composed of cobalt. First time annealing is then performed in an environment of nitrogen or ammonia and followed by cobalt etching and titanium etching. Subsequently, second time annealing is performed in same environment, thus forming two layers of titanium nitride/cobalt silicide. This structure is advantageous in contact resistivity and enhances integrity at a joint.