GAS DISTRIBUTION SHOWERHEAD FOR INDUCTIVELY COUPLED PLASMA ETCH REACTOR

摘要

A two piece ceramic showerhead includes upper and lower plates which deliver process gas to an inductively coupled plasma processing chamber. The upper plate overlies the lower plate and includes radially extending gas passages which extend inwardly from an outer periphery of the upper plate, axially extending gas passages in fluid communication with the radially extending gas passages and an annular recess forming a plenum between the upper and lower plates. The lower plate includes axially extending gas holes in fluid communication with the plenum. The upper plate can include eight radially extending gas passages evenly spaced around the periphery of the upper plate and the lower plate can include inner and outer rows of gas holes. The two piece ceramic showerhead forms a dielectric window of the chamber through which radiofrequency energy generated by an antenna is coupled into the chamber. A gas delivery system delivers process gas to a plenum between the upper and lower plates having a gas volume of no greater than 500 cm3. The gas holes in the lower plate extend between the plenum and a plasma exposed yttria coated surface of the lower plate. The gas delivery system is operable to supply an etching gas and a deposition gas into the processing chamber such that the etching gas in the plenum can be replaced with the deposition gas within about 200 milliseconds and vice versa.

主权项

1. A lower plate of a ceramic showerhead assembly useful in an inductively coupled plasma processing apparatus wherein semiconductor substrates supported on a substrate support are subjected to plasma etching, the lower plate comprising:
a lower surface having a lower central portion and a lower outer portion; a stepped upper surface having an upper central portion and an upper outer portion, wherein the upper central portion is thicker than the upper outer portion, wherein the upper outer portion includes an annular zone; and a plurality of gas holes located in the annular zone and axially extending between the stepped upper surface and the lower surface; wherein the lower surface includes a lower vacuum sealing surface located on the lower outer portion; and wherein the upper outer portion includes inner and outer upper vacuum sealing surfaces defining the annular zone.