Figure 4.

Atomic force microscopy was used to measure the flatness of the planarized apertures coated with 10 nm of SiO₂ following chemical mechanical polishing and atomic layer deposition. (A) Eight apertures are shown, each with a height <3 nm above the surrounding film. (B) A 3D rendering of a single aperture and (C) line scans over nine different apertures show the film roughness as compared to the protrusions of the SiO₂-filled apertures.