Systems, apparatuses, and methods related to semiconductor structure formation are described. An example method may include patterning a working surface of a semiconductor wafer. The method may further include performing a vapor etch on a first dielectric material at the working surface to recess the first dielectric material to a first intended depth of an opening relative to the working surface and to expose a second dielectric material on a sidewall of the opening. The method may further include performing a wet etch on the second dielectric material to recess the second dielectric material to the intended depth.