Wafer contact surface protrusion profile with improved particle performance

An electrostatic chuck comprising:

• an electrode in a ceramic base;
• and
• a surface layer of the electrostatic chuck activated by a voltage in the electrode to form an electric charge that electrostatically clamps a substrate to the electrostatic chuck;
• wherein
• the surface layer of the electrostatic chuck comprises a plurality of protrusions, the protrusions comprising a composition whose morphology is columnar or granular, and whose microstructure is crystalline or amorphous, the protrusions extending to an average height H above the surface layer surrounding the protrusions, the protrusions supporting the substrate upon the protrusions during electrostatic clamping of the substrate;
• a cross section of the protrusions has a structure characterized by a non-arcuate plateau shaped top surface, an edge surface, and a side surface;
• wherein the non-arcuate plateau shaped top surface of the protrusions has a length L in microns that is characterized by a flatness parameter Δ in microns, the top surface having a surface roughness Ra of 1 micron or less and a value of (Δ*100)/L that is less than ±0.01;
• the edge surface of the protrusion is between the top surface and the side surface of the protrusion and has an edge surface profile that lies on or within a quadrant or portion thereof of an ellipse, the minor axis Y of the ellipse intersecting a portion of the top surface of the protrusion wherein the value of (Δ*100)/L is equal to or greater than ±0.01, and the minor axis apex of the ellipse lying along the top surface of the protrusion, the value of Y/2 is 0.5 microns or less;
• the major axis X of the ellipse is substantially parallel to the top surface or surface layer of the protrusion and the value of X/2 is between 25 microns and 250 microns;
• and
• the side surface of the protrusions connects the edge surface and the surface layer of the electrostatic chuck.