Anchoring inserts, electrode assemblies, and plasma processing chambers

A silicon-based showerhead electrode comprising a backside, a frontside, a plurality of showerhead passages, a plurality of backside recesses, and a plurality of backside inserts, wherein:

• the plurality of showerhead passages extend from the backside of the silicon-based showerhead electrode to the frontside of the silicon-based showerhead electrode;
• the plurality of backside recesses are formed in the backside of the silicon-based showerhead electrode, the backside recesses leaving a thickness of silicon-based electrode material between the recess and the frontside of the silicon-based showerhead electrode;
• the backside inserts are positioned in the backside recesses along the backside of the silicon-based showerhead electrode;
• the backside inserts comprise a threaded outside diameter, a threaded inside diameter, and a tool engaging portion formed in the threaded inside diameter;
• the tool engaging portion of the backside insert comprises a plurality of torque-receiving slots arranged about an axis of rotation of the backside insert;
• and
• the torque-receiving slots are arranged to avoid on-axis rotation of the backside insert via opposing pairs of torque receiving slots wherein the silicon-based electrode material comprises single crystal silicon.

A silicon-based showerhead electrode comprising a backside, a frontside, a plurality of showerhead passages, a plurality of backside recesses, and a plurality of backside inserts, wherein:

• the plurality of showerhead passages extend from the backside of the silicon-based showerhead electrode to the frontside of the silicon-based showerhead electrode;
• the plurality of backside recesses are formed in the backside of the silicon-based showerhead electrode, the backside recesses leaving a thickness of silicon-based electrode material between the recess and the frontside of the silicon-based showerhead electrode;
• the backside inserts are positioned in the backside recesses along the backside of the silicon-based showerhead electrode;
• the backside inserts comprise a threaded outside diameter, a threaded inside diameter, and a tool engaging portion formed in the threaded inside diameter;
• the tool engaging portion of the backside insert comprises n torque-receiving slots arranged about an axis of rotation of the backside insert as n(n−1)/2 opposing pairs of torque receiving slots;
• the torque-receiving slots are arranged to avoid on-axis rotation of the backside insert via each of the n(n−1)/2 opposing pairs of torque receiving slots, define a progressively non-constrictive cross sectional profile along a direction parallel to the axis of rotation of the backside insert, and comprise apex-free side walls that extend parallel to the axis of rotation wherein the silicon-based electrode material comprises single crystal silicon.