Abstract: Methods of forming deep trenches in substrates are described. A method includes providing a substrate with a patterned film disposed thereon, the patterned film including a trench having a first width and a pair of sidewalls, the trench exposing the top surface of the substrate. The method also includes forming a material layer over the patterned film and conformal with the trench. The method also includes etching the material layer to form sidewall spacers along the pair of sidewalls of the trench, the sidewall spacers reducing the first width of the trench to a second width. The method also includes etching the substrate to form a deep trench in the substrate, the deep trench undercutting at least a portion of the sidewall spacers.

Abstract: Methods of filling deep trenches in substrates are described. A method includes providing a substrate with a deep trench formed therein. The method also includes forming a dielectric layer conformal with the substrate and the deep trench. The method also includes, with the entire portion of the dielectric layer conformal with the deep trench exposed, removing at least a portion, but not all, of the dielectric layer at the top of the deep trench with a relatively low bias plasma etch process.

Abstract: Methods of forming deep trenches in substrates are described. A method includes providing a substrate with a patterned film disposed thereon, the patterned film including a trench having a first width and a pair of sidewalls, the trench exposing the top surface of the substrate. The method also includes forming a material layer over the patterned film and conformal with the trench. The method also includes etching the material layer to form sidewall spacers along the pair of sidewalls of the trench, the sidewall spacers reducing the first width of the trench to a second width. The method also includes etching the substrate to form a deep trench in the substrate, the deep trench undercutting at least a portion of the sidewall spacers.