A system (100) to form a dielectric layer on a substrate from a plasma of dielectric precursors is described. The system (100) may include a deposition chamber (201 ), a substrate stage in the deposition chamber (201 ) to hold the substrate, and a remote plasma generating system coupled to the deposition chamber (201 ), where the plasma generating system is used to generate a dielectric precursor having one or more reactive radicals. The system (100) may also include a precursor distribution system (700) comprising dual-channel showerhead (700) positioned above the substrate stage. The showerhead (700) may have a faceplate (802) with a first set of openings (804) through which the reactive radical precursor enters the deposition chamber (201 ), and a second set of openings (806) through which a second dielectric precursor enters the deposition chamber (201 ). An in-situ plasma generating system may als be included to generate the plasma in the deposition chamber (201 ) from the dielectric precursors supplied to the deposition chambe (201)
