| 摘要 |
PURPOSE: A method for fabricating a metal interconnection of a semiconductor device is provided to increase electromigration(EM) lifetime caused by a reservoir effect, by reducing contact resistance of the metal interconnection and by preventing a misalignment in a photolithography process. CONSTITUTION: A stack structure composed of the first interlayer dielectric(33), an etch barrier layer(35) and the second interlayer dielectric(37) is formed on a semiconductor substrate(31). The stack structure is etched to form a metal interconnection contact hole by using a metal interconnection contact mask as an etch mask. The first diffusion barrier layer pattern(41) and a tungsten plug(43) are formed to fill the metal interconnection contact hole. A photoresist layer pattern exposing a portion reserved for the metal interconnection(50) is formed on the resultant structure. The second interlayer dielectric is etched to form a trench exposing the tungsten plug and the first diffusion barrier layer pattern while the photoresist layer pattern is used as an etch mask and the etch barrier layer is used as an etch barrier. The photoresist layer pattern is removed. The second diffusion barrier layer and a metal layer connected to the tungsten plug and the first diffusion barrier layer pattern are formed. The metal layer and the second diffusion barrier layer are planarized by a chemical mechanical polishing(CMP) process to form a metal interconnection and the second diffusion barrier layer pattern(48) which are filled in the trench.
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