Patent ID: 7984891

Claim:
A method of fabricating a gas distribution assembly for use in semiconductor processing equipment, wherein said method comprises: a) providing a plurality of metal layers, wherein at least one of said metal layers has been patterned to have a feature which passes entirely through said metal layer, and where an average roughness of a bonding surface of said plurality of metal layers ranges from about 0.1 microinches Ra to about 30 microinches Ra, and where the thickness of at least one of said plurality of metal layers ranges from about 0.0005 inch to about 0.06 inch; b) aligning said plurality of metal layers so that each bonding surface of a metal layer is in contact with a bonding surface of another metal layer and so that at least a portion of patterned metal layers are aligned in a manner to provide a fluid flow path; and c) diffusion bonding said aligned plurality of metal layers while applying a temperature ranging from about 1000° C. to about 1300° C. for a time period ranging from about 3 hours to about 6 hours, and sufficient pressure to provide bonding of said metal layers such that bonded surfaces do not absorb or release process fluids, do not contribute to impurities in process fluids passing through said gas distribution assembly , and meet a SEMI F1 standard for leak rate to an exterior environment from said gas distribution assembly, where a leak rate must be 1×10 −9 cc/sec or less for at least 15 seconds, at a pressure difference of 1 atm He.