Ring Silicon Ring Descriptions The silicon ring mounted around wafer on ESC serves to maintain a uniform plasma density and etching rate View more information Specifications Properties Value Material Single Crystal Silicon Out diameter 480mm ~ 240mm Resistivity(Ω.㎝) Low Res. (< 0.02) / Middle Res. (1~4) / High Res. (60~90)) Surface condition Polishing, Lapping, Grinding Surface Flatness < 5㎛ Machining precision < 10㎛ Quality Chipping, Scratch, Crack free, Contamination, Stain free