Semiconductor structures and methods of forming them

Abstract

The invention discloses a structure and a forming method thereof. A manganese oxide layer is deposited on a substrate including at least one layer of dielectric material as a hard mask layer. An optional silicon oxide layer can be formed over the manganese oxide layer. Optional silicon oxide and manganese oxide layers can be etched using a patterned photoresist layer. An anisotropic etching process is used to etch the dielectric material layer within the substrate. The dielectric material layer may include silicon oxide and / or silicon nitride, and the manganese oxide layer may serve as an effective etch mask that minimizes hard mask corrosion and widening of the etch trench. The manganese oxide layer can be used as an etch mask for substrate bonding processes.

Description

technical field [0001] The present disclosure relates to methods of forming trenches using manganese oxide hardmask layers and structures formed therefrom. Background technique [0002] The hard mask etch limits the parameters of the anisotropic etch process, particularly the depth of trenches that can be formed by the anisotropic etch process. Erosion of the hard mask is particularly problematic if the material being etched is a dielectric material. For example, hard masks comprising silicon oxide tend to be etched at a substantial rate when etching silicon oxide containing materials such as organosilicate glass (OSG) and doped silicate glass. The hard mask etch can result in widening of the upper portion of the trench, thus causing the formation of a tapered trench. Furthermore, when such tapered trenches are filled with a conductive material, for example, to form a through-substrate via (TSV) structure, the formed conductive structure includes a tapered portion where th...

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Problems solved by technology

Hard mask etch can cause widening of the upper part of the trench, thus causing the formation of tapered trenches

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