Globalfoundries Inc.

Globalfoundries U.S. Inc.

Oliver M Witnik

Holger S Schuehrer

Frank Koschinsky

Dirk Breuer

Bernd Hintze

Carla Byloos

Disclosed are embodiments of a back end of the line (BEOL) metal structure that includes, within a metal level, a metal via, which has at least eight sides and all interior angles at 135&#xb0; or more, and a metal wire thereon. The metal wire and via include respective portions of a continuous conformal metal layer. A passivation layer coats the top surface of the metal layer. The metal via and the metal wire thereon can be in an upper metal level and can be made of one metal (e.g., aluminum or an aluminum alloy). The upper metal level can be above a lower metal level that similarly includes a metal via and metal wire thereon, but the metal used can be different (e.g., copper) and/or the shape of the via can be different (e.g., four-sided). Also disclosed herein are method embodiments for forming the above-described BEOL metal structure.

Back end of the line metal structure and method

A method includes providing a semiconductor structure. The semiconductor structure includes a substrate having a frontside and a backside, an electrically conductive feature including copper provided at the frontside of the substrate and a low-k interlayer dielectric provided over the electrically conductive feature. A portion of the interlayer dielectric is etched. In the etch process, a surface of the electrically conductive feature is exposed. A degas process is performed, wherein the semiconductor structure is exposed to a first gas, and wherein the semiconductor structure is heated from the backside and from the frontside. A preclean process may be performed. The preclean process may include a first phase wherein the semiconductor structure is exposed to a substantially non-ionized second gas and a second phase wherein the semiconductor structure is exposed to a plasma created from the second gas.

Method including an etching of a portion of an interlayer dielectric in a semiconductor structure, a degas process and a preclean process

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Moritzburg, Germany

Oliver M Witnik