Importance

Loading Importance Indicators...

Abstract

A method of forming contact plugs in a semiconductor device employing multiple steps of a selective polishing technique is provided. This method selectively removes an interlayer insulating film and a conductive layer, thereby providing layers polished with a CMP process improved planarity and uniformity. The method includes forming an interlayer insulating film over a semiconductor substrate having a plurality of diffusion regions and conductive layers. The interlayer insulating film has an uneven upper surface as deposited, following the contours produced by underlying structures formed on the semiconductor substrate. A contact hole is opened through the interlayer insulating film to expose an upper surface of a conductive layer or a semiconductor substrate in the first region. A second conductive layer is deposited over the resulting structure. The key step of the present invention is then accomplished by performing a plurality of selective polishing steps on the resulting structure.

Loading the Abstract Image...

First Claim