摘要 |
A process for creating tungsten plugs, to fill high aspect ratio contact holes, has been developed. Narrow seams in the center of a tungsten plug, are protected from the tungsten RIE etch back process, thus avoiding the creation of larger seams or voids. This is accomplished by delaying the tungsten RIE etch back step until formation of an overlying interconnect metallization structure, which will protect the underlying tungsten plug, and seam, during the subsequent tungsten RIE etch back procedure.
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