High power electrostatic chuck with features preventing he hole light-up/arcing

A spark suppression apparatus for a wafer backside cooling line in an electrostatic chuck in a plasma processing chamber, the spark suppression apparatus comprising a dielectric multilumen plug in the wafer backside cooling line, wherein the dielectric multilumen plug has a plurality of lumens, wherein the wafer backside cooling line has a first portion on a first side of the dielectric multilumen plug and a second portion on a second side of the dielectric multilumen plug, and wherein the lumens of the plurality of lumens are not placed along a direct line of sight between the first portion of the wafer backside cooling line and the second portion of the wafer backside cooling line, wherein the dielectric multilumen plug is T-shaped, and wherein the dielectric multilumen plug is mounted in a T-shaped cavity, and wherein the dielectric multilumen plug does not extend to a bottom of the T-shaped cavity.