Described processing chambers may include a chamber housing at least partially defining an interior region of the semiconductor processing chamber. The chambers may include a pedestal. The chambers may include a first showerhead positioned between the lid and the processing region, and may include a faceplate positioned between the first showerhead and the processing region. The chambers may also include a second showerhead positioned within the chamber between the faceplate and the processing region of the semiconductor processing chamber. The second showerhead may include at least two plates coupled together to define a volume between the at least two plates. The at least two plates may at least partially define channels through the second showerhead, and each channel may be characterized by a first diameter at a first end of the channel and may be characterized by a plurality of ports at a second end of the channel.