SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED: To provide a semiconductor device and its manufacturing method wherein, even if the semiconductor device is large-scaled like a semiconductor for large electric power, silicon separation can be appropriately applied to a substrate. SOLUTION: An insulating film 5 with an opening 4 is formed on a silicon substrate 3 with a diffusion layer 2. A first electrode layer 6 composed of an aluminum alloy film in which a silicon content is equal to or more than a solubility limit at a maximum temperature (about 450°C) applied in a manufacturing process subsequent to a process of forming a metal wiring layer of a semiconductor device 1 is formed on the insulating film 5 so as to be connected to the diffusion layer 2 through the opening 4. Also, a second electrode layer 7 composed of a pure silicon film is formed on the first electrode layer 6, and a third electrode layer 8 composed of a pure aluminum film is formed on the second electrode layer 7, to constitute the semiconductor device 1. Since the silicon of the diffusion layer 2 is not solidified into the first electrode layer 6, and excessive silicon in the first electrode layer 6 is separated on the interface of the second electrode layer 7, silicon separation to the diffusion layer 2 can be largely restrained. COPYRIGHT: (C)2007,JPO&INPIT