Showerhead design to control stray deposition

A lid for a process chamber, the lid comprising:

• a plate having a first surface and a second surface opposite the first surface, the plate including an axis generally perpendicular to the first surface;
• a seal groove formed in the first surface;
• and
• a showerhead comprising an array of holes extending through the lid plate, each hole of the array of holes extending from an entrance in the first surface to an exit in the second surface, the entrance located radially inward of the seal groove, wherein the showerhead extends radially from the axis 80% or less of a maximum lateral extent of the second surface from the axis.

An assembly, comprising:

• a conduit configured to connect to a first gas source;
• and
• a lid including:
• a plate having:
• a first surface connected to the conduit, wherein a seal member seals an interface between the plate and the conduit;
• a second surface opposite the first surface;
• a recess in the first surface, the recess radially inward of the seal member and centered on an axis that is generally perpendicular to the first surface;
• and
• a showerhead aligned with the recess and the conduit along the axis, and comprising an array of holes extending through the lid plate from the recess to the second surface.