Method and apparatus for providing radical species to a processing volume of a processing chamber

A processing system, comprising:

• a processing chamber, having a chamber body which defines a processing volume;
• a remote plasma source;
• and
• a gas injection assembly fluidly coupling the remote plasma source to the processing chamber, wherein the gas injection assembly comprises:
• a metal body;
• a rigid dielectric liner disposed in the metal body, wherein the rigid dielectric liner defines a mixing volume;
• a first flange comprising a first mounting surface;
• a second flange comprising a second mounting surface;
• and
• one or more gas injection ports formed through the metal body and the rigid dielectric liner, wherein
• a length of the gas injection assembly, measured along a longitudinal axis thereof between a plane of the first mounting surface and a plane of the second mounting surface, is between about 25 mm and about 150 mm, and
• the longitudinal axis of the gas injection assembly forms an angle with a longitudinal axis of a gas inlet port formed in a sidewall of a to be coupled processing chamber, and wherein the angle is between about 10° and about 70°.

A method of processing a substrate, comprising:

• positioning a substrate in a processing volume of a processing chamber, wherein the processing volume is in fluid communication with a remote plasma source via a gas injection assembly disposed therebetween;
• forming a plasma of a first gas in the remote plasma source;
• flowing the plasma into a mixing volume of the gas injection assembly;
• flowing a second gas to the mixing volume through one or more gas injection ports in fluid communication therewith;
• dissociating molecules of the second gas into radical species thereof;
• flowing the radical species into the processing volume of the processing chamber;
• and
• exposing the substrate to the radical species.