Techniques herein provide an etch-based planarization technique. An initial film is deposited on a substrate. Deposition of this initial film results in a non-planar film because of differences in area density of underlying structures (for example, open areas compared to closely spaced trenches). Etch processes are executed that use a reverse lag RIE process to planarize the initial film, and then another coat of the film material can be deposited, resulting in a planar surface. Such techniques can planarized substrates without using chemical mechanical polishing (CMP).

Techniques herein provide an etch-based planarization technique. An initial film is deposited on a substrate. Deposition of this initial film results in a non-planar film because of differences in area density of underlying structures (for example, open areas compared to closely spaced trenches). Etch processes are executed that use a reverse lag RIE process to planarize the initial film, and then another coat of the film material can be deposited, resulting in a planar surface. Such techniques can planarized substrates without using chemical mechanical polishing (CMP).

A method of manufacturing an IC, comprising providing a substrate having a first side and a second opposite side, forming a STI opening in the first side of the substrate and forming a partial TSV opening in the first side of the substrate and extending the partial TSV opening. The extended partial TSV opening is deeper into the substrate than the STI opening. The method also comprises filling the STI opening with a first solid material and filling the extended partial TSV opening with a second solid material. Neither the STI opening, the partial TSV opening, nor the extended partial TSV opening penetrate an outer surface of the second side of the substrate. At least either: the STI opening and the partial TSV opening are formed simultaneously, or, the STI opening and the extended partial TSV opening are filled simultaneously.