The present disclosure describes a compound slot, and systems and methods of forming the compound slot. An example of a compound slot includes a wafer, where the compound slot includes a trench along a long axis of the compound slot and on a top surface of the wafer, where the trench passes through an initial portion of a total depth of the wafer. A number of openings pass through a remaining portion of the total depth of the wafer, where at least a retained portion of a bottom of the trench is present around a perimeter of each of the number of openings.