Creation of vias and trenches with different depths

摘要

Embodiments of the invention provide a method of creating vias and trenches with different length. The method includes depositing a plurality of dielectric layers on top of a semiconductor structure with the plurality of dielectric layers being separated by at least one etch-stop layer; creating multiple openings from a top surface of the plurality of dielectric layers down into the plurality of dielectric layers by a non-selective etching process, wherein at least one of the multiple openings has a depth below the etch-step layer; and continuing etching the multiple openings by a selective etching process until one or more openings of the multiple openings that are above the etch-stop layer reach and expose the etch-stop layer. Semiconductor structures made thereby are also provided.

主权项

1. A semiconductor device comprising:
a semiconductor structure; a plurality of dielectric layers on top of said semiconductor structure and being separated by at least a first etch-stop layer; a second etch-stop layer underneath said first etch-stop layer and being separated from said first etch-stop layer; at least a first via, inside said plurality of dielectric layers, having a height crossing at least two of said plurality of dielectric layers and a depth below said first etch-stop layer; a second via having a height crossing at least two of said plurality of dielectric layers and a depth below said second etch-stop layer; and one or more trenches, inside said plurality of dielectric layers, whose depth are defined by said first etch-stop layer, wherein said second via has a uniform width that is wider than that of said first via, and a depth deeper than that of said first via.