Pedestals and showerheads including dual plenum and baffle arrangements

A pedestal comprising:

• a support shaft comprising a supply channel configured to receive a process fluid;
• and
• a body comprising a plurality of layers configured to receive the process fluid from the supply channel and distribute the process fluid across the body and direct the process fluid from the pedestal at a substrate being processed, the body comprising
• a distribution layer comprising
• a first plenum, and
• a plurality of channels extending radially from the supply channel to the first plenum and supplying the process fluid from the supply channel to the first plenum,
• a baffle layer comprising a first plurality of passages extending from the first plenum to a second plenum, and
• a cross-drill layer comprising a second plurality of passages and the second plenum,
• wherein the first plenum, the first plurality of passages, and the second plenum are configured to at least one of i) trap particles, and ii) increase flow rate uniformity of the process fluid to the second plurality of passages.