Embodiments described herein relate to apparatus and coating methods to reduce chamber arcing, for example, in HDP-CVD, PECVD, PE-ALD and Etch chambers. The apparatus include a ring shaped gas distributor used for in-situ deposition of coating materials, and a process chamber including the same. The ring shaped gas distributor includes a ring shaped body having at least one gas entrance port disposed on a first side thereof and a plurality of gas distribution ports disposed on a first surface of the ring shaped body. The plurality of gas distribution ports are arranged in a plurality of evenly distributed rows. The plurality of gas distribution ports in a first row of the plurality of evenly distributed rows is adapted to direct gas at an exit angle different from an exit angle of the plurality of gas distribution ports in a second row of the plurality of evenly distributed rows.