SEMICONDUCTOR DEVICE MANUFACTURING METHOD AND THE SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To provide a semiconductor device that can reduce the amount of warpage and on-resistance of a back electrode that is formed on the rear-face side of a silicon substrate, and to provide a method of manufacturing the device. SOLUTION: A semiconductor device has a front electrode 6 on the front face side of a silicon substrate 2 and a p-type impurity diffusion layer and a back electrode 7 abutted thereagainst on the rear face side. A longitudinal-type semiconductor element is provided so as to allow current flow between the front electrode 6 and the back electrode 7. A silicon single-crystal face is exposed, by performing wet-etching of the front face of the p-type impurity diffusion layer. The back electrode 7 is formed at the rear face of the silicon substrate 2, whose temperature is 120°C or lower. A metal layer whose work function is 4.5 eV or greater is arranged on the face that abuts against, at least with the silicon single-crystal face in the back electrode 7. By having a junction surface formed such that the silicon single-crystal face is brought into contact with the metal layer whose work function is 4.5 eV or greater, the resistance of an ohmic contact is well-preserved without performing heat treatment. COPYRIGHT: (C)2011,JPO&INPIT