| 摘要 |
PURPOSE:To prevent the disconnection of metal layer as an upper side wiring from happening by a method wherein a high melting point metal layer and its silicide layer are formed on Si in contact holes so as to flatten the contact holes. CONSTITUTION:An infield oxide film 2, a gate electrode 4a made of poly Si film, a lower side wiring 4b, a source layer 7a, a drain layer 7b and a PSG film 6 are formed on an Si substrate 1. Then contact holes 8a-8c are opened to expose Si on the bottom of respective contact hole. Firstly a high melting point metal, e.g. Mo film 9 is formed in the holes 8a-8c wherein MoSi2 films 10a- 10c are further formed. Secondly Mo films 11a-11c are selectively formed in the holes 8a-8c only providing the Mo films 11a-11c with the same thickness as that of the PSG film 6 to almost flatten the holes 8a-8c. Later an Al film 12 is formed as an upper side wiring. Through these procedures, the film 12 so far formed may not cause any step difference at all preventing the upper layer from being disconnected. |
