Patent ID: 9478434
Filing Date: 2016-10-25
CPC Classification: H01J,H01L

Claim Text:
1. A method of removing titanium nitride hardmasks, the method comprising: forming a carbon-containing layer over low-k dielectric walls over an underlying copper layer on a patterned substrate, wherein the low-k dielectric walls form a gap and the patterned substrate further comprises titanium nitride hardmasks above the low-k dielectric walls, wherein one of the titanium nitride hardmasks is wider than an underlying supporting low-k dielectric wall and the carbon-containing layer completely fills the gap; etching the carbon-containing layer to expose the titanium nitride hardmasks leaving behind a remainder of the carbon-containing layer; placing the patterned substrate in a substrate processing region of a substrate processing chamber; flowing a chlorine-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a remote plasma in the remote plasma region to produce plasma effluents; flowing the plasma effluents into the substrate processing region through through-holes in a showerhead disposed between the substrate processing region and the remote plasma region; forming a local plasma in the substrate processing region to further excite the plasma effluents; etching the titanium nitride hardmasks with the plasma effluents, wherein the plasma effluents do not react with the underlying copper layer as a result of a presence of the remainder of the carbon-containing layer; and removing the remainder of the carbon-containing layer.