THIN FILM MULTILAYER OXYGEN DIFFUSION BARRIER CONSISTING OF ALUMINUM ON HIGH-MELTING-POINT METAL

摘要

PROBLEM TO BE SOLVED: To cause a semiconductor base layer to work as an oxygen diffusion barrier for protecting the semiconductor base layer from oxidation, by allowing a metallic layer of a high melting point and an aluminum layer stuck onto it to form an aluminum oxide layer on the surface of aluminum. SOLUTION: An aluminum film 16 is stuck onto a metallic layer of a high melting point 18 and the layer 18 is stuck onto a substrate 20 to constitute an oxygen diffusion barrier. As soon as the aluminum film 16 stuck in the middle of annealing at high temperature is exposed to atmosphere, Al2 O3 thin layer is formed. During annealing at the high temperature, metal Al reacts with Ta at the temperature higher than 400 deg.C to form the intermetallic compound of a high melting point (not lower than 1000 deg.C). Thereby, a diffusion barrier protecting the semiconductor base layer form oxidation is easily formed.