Embodiments of process kits for use in substrate processing chambers are provided herein. In some embodiments, a process kit for use in a substrate processing chamber includes an annular electrode configured to surround an electrostatic chuck, wherein the annular electrode includes an upper portion bonded to a lower portion and an annular channel disposed at an interface between the upper portion and the lower portion; wherein the annular electrode includes a first channel extending from a lower surface of the lower portion to the annular channel and a second channel extending from the lower surface of the lower portion to the annular channel; wherein the annular electrode is configured to flow a coolant from the first channel to the second channel via the annular channel to cool the annular electrode; and wherein the annular electrode includes at least one of a dielectric coating or a ceramic cap to reduce or prevent arcing between the annular electrode and the electrostatic chuck.

Embodiments of process kits for use in substrate processing chambers are provided herein. In some embodiments, a process kit for use in a substrate processing chamber includes an annular electrode configured to surround an electrostatic chuck, wherein the annular electrode includes an upper portion bonded to a lower portion and an annular channel disposed at an interface between the upper portion and the lower portion; wherein the annular electrode includes a first channel extending from a lower surface of the lower portion to the annular channel and a second channel extending from the lower surface of the lower portion to the annular channel; wherein the annular electrode is configured to flow a coolant from the first channel to the second channel via the annular channel to cool the annular electrode; and wherein the annular electrode includes at least one of a dielectric coating or a ceramic cap to reduce or prevent arcing between the annular electrode and the electrostatic chuck.

A microchannel plate is provided with a substrate including a front surface, a rear surface, and a side surface, a plurality of channels penetrating from the front surface to the rear surface of the substrate, a first film provided on at least an inner wall surface of the channel, a second film provided on the first film, and electrode layers provided on the front surface and the rear surface of the substrate. The first film is made of Al.sub.2O.sub.3. The second film is made of SiO.sub.2. The first film is thicker than the second film.

A microchannel plate is provided with a substrate including a front surface, a rear surface, and a side surface, a plurality of channels penetrating from the front surface to the rear surface of the substrate, a first film provided on at least an inner wall surface of the channel, a second film provided on the first film, and electrode layers provided on the front surface and the rear surface of the substrate. The first film is made of Al.sub.2O.sub.3. The second film is made of SiO.sub.2. The first film is thicker than the second film.