Patent ID: 8357613
Filing Date: 2013-01-22
Classification: H01L

Abstract:
1. A method of fabricating a semiconductor device, comprising: depositing tungsten on an insulating layer in which a contact hole is formed by chemical vapor deposition (CVD); performing chemical mechanical planarization (CMP) on the tungsten to expose the insulating layer and form a tungsten contact plug; performing rapid thermal oxidation (RTO) on the tungsten contact plug in an oxygen atmosphere such that the tungsten expands volumetrically into tungsten oxide, after performing the RTO, removing a part of the tungsten oxide that has volumetrically expanded upward from a surface of the insulating layer by buffing CMP, wherein removing a part of the tungsten oxide includes flattening a surface of the tungsten oxide to be at a same level as the surface of the insulating layer; and after the buffing CMP, reducing the tungsten oxide and transforming the tungsten oxide to metallic tungsten by performing rapid thermal hydrogenation (RTH) or rapid thermal ammoniation (RTNH) on the contact plug in a hydrogen or ammonia atmosphere.