SYSTEMS AND METHODS FOR HOMOGENOUS INTERMIXING OF PRECURSORS IN ALLOY ATOMIC LAYER DEPOSITION

A showerhead includes a plurality of plenums and a plurality of through holes positioned in the plurality of plenums. The plenums are stacked in a sequential order in an axial direction perpendicular to a semiconductor substrate. The plenums extend radially fully across the semiconductor substrate. The plenums are disjoint from each other and are configured to respectively supply a first metal precursor, a second metal precursor, and a reactant via the respective plenums without intermixing the first metal precursor, the second metal precursor, and the reactant in the plenums. The through holes of the respective plenums are arranged in a radial direction, which is perpendicular to the axial direction, in the same sequential order as the sequential order of the plenums. The through holes of the plenums open along a flat surface at a bottom of the showerhead. The flat surface extends radially fully across the bottom of the showerhead.