Apparatus for gas injection in a physical vapor deposition chamber

An apparatus for gas injection comprising:

• a gas source;
• a gas injection line coupled to the gas source;
• shield having an annular one-piece body that substantially encompasses an entire inner processing volume, a top opening disposed at a top portion of the shield, an upper support lip that extends radially outward from the top opening, and a bottom opening disposed at a bottom portion of the shield, wherein the shield includes a plurality of gas distribution vents disposed through the body;
• and
• a target and a substrate in the inner processing volume of the shield, wherein the top portion of the shield is disposed about a peripheral edge of a target, and wherein the bottom portion of the shield extends below a top surface of a substrate support;
• and
• a gas injection adapter externally surrounding the shield, the gas injection adapter further comprising:
• a gas inlet line coupled to the gas injection line;
• and
• a plurality of interconnected gas channels with a first end coupled to the gas inlet line, and a second end comprising multiple ports coupled to a sealed gas pocket formed between the gas injection adapter and the shield, wherein the gas injection adapter supports the shield via the upper support lip, wherein the sealed gas pocket extends from the upper support lip of the shield to the bottom portion of the shield, wherein the sealed gas pocket is sealed at a top portion of the shield and at a bottom portion of the shield by at least one flexible member disposed between the shield and gas injection adapter, and wherein the sealed gas pocket is coupled to the vents formed in the shield such that gas in the sealed gas pocket is uniformly distributed into the inner volume.