Abstract: Additively manufactured showerheads for semiconductor processing operations are disclosed that may have various features enabled by the use of such manufacturing techniques. In some implementations, such showerheads may have multiple independent flow paths featuring transverse passages arranged to form a rhombic lattice pattern and gas distribution ports and/or riser passages that are located at various intersections between such transverse passages. Such showerheads may also include features that improve their manufacturability while providing desired gas flow performance. For example, the cross-sections of the transverse passages may be designed such that they are generally triangular or pentagonal in shape, which may allow for more efficient use of available material volume within the showerhead for the purposes of providing gas flow passages while also providing geometries that take into account the limitations of typical additive manufacturing processes that may be used.