Methods and apparatus for etching semiconductor wafers
AssigneeLam Research Corporation
InventorSusan C. Abraham
Life of this patent
Estimating the term…
Abstract
A method for etching a TiN layer of a wafer stack in a plasma processing chamber. The method includes the step of etching at least partially through the TiN layer using a first chemistry, which preferably includes a TiN etchant, a noble gas, and a polymer-forming chemical. In one embodiment, the TiN etchant is Cl.sub.2, the noble gas is argon, and the polymer-forming chemical is CHF.sub.3.
Claims21
In a plasma processing chamber, a method for etching a wafer stack, said wafer stack comprising a given layer, an aluminum-containing layer and a TiN barrier layer, said given layer representing one of a first layer that consists essentially of TiN and a second layer that consists essentially of Ti, said given layer being disposed above said aluminum-containing layer, said aluminum-containing layer being disposed above said TiN barrier layer, said method comprising:
- etching at least partially through said given layer using a first chemistry, said first chemistry comprising an etchant configured for etching said given layer, a noble gas, and a polymer-forming chemical, said polymer-forming chemical being one of N.sub.2 and CHF.sub.3 ;
- etching at least partially through said aluminum-containing layer using a second chemistry different from said first chemistry;
- and
- etching at least partially through said TiN barrier layer using said first chemistry.
In a plasma processing chamber, a method for etching through a selected portion of layers of a wafer stack, said wafer stack comprising a TiN anti-reflective coating (ARC) layer, a metallization layer and a TiN barrier layer, said TiN ARC layer being disposed above said metallization layer, said metallization layer being disposed above said TiN barrier layer said method comprising:
- etching at least partially through said TiN ARC layer of said wafer stack with a first chemistry, said first chemistry comprising a TiN etchant, a noble gas, and a polymer-forming chemical, said polymer-forming chemical being one of N.sub.2 and CHF.sub.3 ;
- etching at least partially through said metallization layer using a second chemistry different from said first chemistry and
- etching at least partially through said TiN barrier layer using said first chemistry.
A method for forming an integrated circuit, said method including:
- providing a substrate having thereon a given layer, a metallization layer and a TiN barrier layer, said metallization layer being disposed below said given layer, said TiN barrier layer being disposed below said metallization layer, said given layer representing one of a first layer that consists essentially of TiN and a second layer that consists essentially of TI
- etching at least partially through said given layer using a first chemistry, said first chemistry comprising Cl.sub.2, a noble gas, and CHF.sub.3 ;
- subsequently etching at least partially through said metallization layer with a second chemistry different from said first chemistry;
- and
- etching at least partially through said TiN barrier layer with said first chemistry.
Dependencies are inferred from the claim text.