Patent ID: 7785417

Claim:
A gas injector for supplying process gas to a plasma processing chamber wherein a semiconductor substrate is subjected to plasma processing, the as injector comprising: gas injector body of dielectric material and sized to extend in an axial direction through a chamber wall of the processing chamber such that a planar distal end surface of the gas injector body is exposed within the processing chamber, the gas injector body including a bore defined by a cylindrical side wall and an end fall and a plurality of gas passages in fluid communication with the bore, the gas passages adapted to supply process gas into the processing chamber, wherein the gas passages include gas inlets located in the end all and gas outlets located in the planar distal end surface of the gas injector body with the total area of the as outlets less than the cross-sectional area of the bore and the gas outlets are sized to inject the process gas at a subsonic, sonic or supersonic velocity; wherein all of the gas inlets are closer to a central axis of the bore than the gas outlets and all of the gas inlets are located equal distances from the central axis of the bore.