SHOWERHEAD WITH REDUCED BACKSIDE PLASMA IGNITION

摘要

Embodiments of the present disclosure relate to a showerhead assembly for use in a processing chamber. The showerhead assembly includes a porous insert disposed in a space defined between a gas distribution plate and a base plate to moderate the corrosive radicals resulting from plasma ignition to reduce particle issues and metal contamination in the chamber. The porous insert is a conductive material, such as metal, used to reduce the gap electrical field strength, or may be a dielectric material such as ceramic, polytetrafluoroethylene, polyamide-imide, or other materials with a low dielectric loss and high electrical field strength under conditions of high frequency and strong electric fields. As such, the electrical breakdown threshold is enhanced. The porous insert may reduce and/or eliminate showerhead backside plasma ignition and may include multiple concentric narrow rings that cover gas holes of the gas distribution plate.

主权项

1. A showerhead assembly for use in a processing chamber, comprising:
a gas distribution plate having a plurality of gas holes extending through a first surface of the gas distribution plate; a base plate having at least one or more gas delivery holes extending through a first surface of the base plate, the first surface of the base plate and the first surface of the gas distribution plate defining a space therebetween; and a porous insert located in the space, wherein a gas flow path though the showerhead assembly is defined through the one or more gas delivery holes extending through the base plate, the porous insert, and the gas holes of the gas distribution plate.