Patent ID: 7211518

Claim:
A method for forming features in dielectric layers and opening barrier layers for a plurality of wafers and cleaning an etch chamber after processing and removing each wafer of the plurality of wafers, comprising: placing a wafer of the plurality of wafers into the etch chamber wherein the wafer has a barrier layer over the wafer and a dielectric layer over the barrier layer; etching the dielectric layer; opening the barrier layer; removing the wafer from the etch chamber; and providing a waferless automatic cleaning of the etch chamber without the wafer, comprising: providing a waferless automatic cleaning gas consisting essentially of oxygen and nitrogen to the etch chamber, wherein a flow ratio of oxygen to nitrogen of the waferless automatic cleaning gas is between 1:99 to 298; and forming a waferless automatic cleaning plasma from the waferless automatic cleaning gas to clean the etch chamber.