Taiwan Semiconductor Manufacturing Company Limited
Self aligned via and method for fabricating the same

Abstract:

A self aligned via and a method for fabricated a semiconductor device using a double-trench constrained self alignment process to form the via. The method includes forming a first trench and depositing a first metal into the first trench. Afterwards, the process includes depositing a dielectric layer over the first metal such that a top surface of the dielectric layer is at substantially the same level as the top surface of the first trench. Next, a second trench is formed and a via is formed by etching the portion of the dielectric layer exposed by the overlapping region between the first trench and the second trench. The via exposes a portion of the first metal and a second metal is deposited into the second trench such that the second metal is electrically coupled to the first metal.