Systems and methods for material breakthrough

Abstract

Methods may be performed to limit footing, pitch walking, and other alignment issues. The methods may include forming a treatment gas plasma within a processing region of a semiconductor processing chamber. The methods may further include directing effluents of the treatment gas plasma towards a semiconductor substrate within the processing region of the semiconductor processing chamber, and anisotropically modifying a surface of a first material on the semiconductor substrate with the effluents of the treatment gas plasma. The methods may also include passivating a surface of a second material on the semiconductor substrate with the effluents of the treatment gas plasma. The methods may further include forming a remote fluorine-containing plasma to produce fluorine-containing plasma effluents, and flowing the fluorine-containing plasma effluents to the processing region of the semiconductor processing chamber. The methods may also include selectively removing the modified surface of the first material from the semiconductor substrate.

1 . An etching method comprising:
 forming a treatment gas plasma from a treatment gas precursor within a processing region of a semiconductor processing chamber;   directing effluents of the treatment gas plasma towards a semiconductor substrate within the processing region of the semiconductor processing chamber;   anisotropically modifying a surface of a first material on the semiconductor substrate with the effluents of the treatment gas plasma;   passivating a surface of a second material on the semiconductor substrate with the effluents of the treatment gas plasma, wherein passivating the surface of the second material comprises increasing a density of a surface layer of the second material;   forming a remote plasma from a fluorine-containing precursor to produce fluorine-containing plasma effluents;   flowing the fluorine-containing plasma effluents to the processing region of the semiconductor processing chamber; and   selectively removing the modified surface of the first material from the semiconductor substrate.   
     
     
         2 . The etching method of  claim 1 , at least some of the effluents of the treatment gas plasma penetrates into the second material to increase the density of the surface layer of the second material. 
     
     
         3 . The etching method of  claim 1 , wherein the treatment gas precursor comprises a mixture of a first precursor and a second precursor, and wherein anisotropically modifying the surface of the first material comprises anisotropically modifying the surface of the first material with plasma effluents of the first precursor. 
     
     
         4 . The etching method of  claim 3 , wherein the first precursor comprises at least one of a nitrogen-containing precursor or a hydrogen-containing precursor. 
     
     
         5 . The etching method of  claim 3 , wherein passivating the surface of the second material comprises passivating the surface of the second material with plasma effluents of the second precursor. 
     
     
         6 . The etching method of  claim 3 , wherein the second precursor comprises at least one of an oxygen-containing precursor or a nitrogen-containing precursor. 
     
     
         7 . The etching method of  claim 3 , wherein the mixture comprises less than or about 20% of the second precursor. 
     
     
         8 . The etching method of  claim 1 , wherein the first material comprises a spacer material including an oxide material. 
     
     
         9 . The etching method of  claim 1 , wherein the second material comprises a hardmask material including a nitride material. 
     
     
         10 . The etching method of  claim 1 , wherein selectively removing the modified surface of the first material removes substantially none of the modified surface of the second material from the semiconductor substrate. 
     
     
         11 . An etching method comprising:
 forming a bias plasma from a carbon-containing precursor within a processing region of a semiconductor processing chamber to produce carbon-containing plasma effluents;   selectively depositing a carbon-containing protective layer at a surface of a first material on a semiconductor substrate within the processing region of the semiconductor processing chamber with the carbon-containing plasma effluents; and   selectively removing a surface of a second material on the semiconductor substrate.   
     
     
         12 . The etching method of  claim 11 , wherein the carbon-containing precursor comprises methane. 
     
     
         13 . The etching method of  claim 12 , wherein the carbon-containing precursor further comprises a dilution gas, and wherein a ratio of a flow rate of the dilution gas to a flow rate of methane is about 2:1. 
     
     
         14 . The etching method of  claim 11 , further comprising depositing a carbon-containing protective layer at a surface of the second material. 
     
     
         15 . The etching method of  claim 14 , wherein a ratio of a thickness of the carbon-containing protective layer deposited at the surface of the first material to a thickness of the carbon-containing protective layer deposited at the surface of the second material is at least about 3:1. 
     
     
         16 . The etching method of  claim 14 , further comprising:
 forming a treatment gas plasma from a treatment gas precursor within the processing region of the semiconductor processing chamber;   anisotropically modifying the surface of the second material with effluents of the treatment gas plasma;   forming a remote plasma from a fluorine-containing precursor to produce fluorine-containing plasma effluents;   flowing the fluorine-containing plasma effluents to the processing region of the semiconductor processing chamber; and   selectively removing the modified surface of the first material from the semiconductor substrate with the fluorine-containing plasma effluents.   
     
     
         17 . The etching method of  claim 11 , wherein the carbon-containing precursor comprises a fluorine and carbon-containing precursor. 
     
     
         18 . The etching method of  claim 17 , wherein the carbon-containing precursor further comprises a dilution gas, and wherein a ratio of a flow rate of the dilution gas to a flow rate of the fluorine and carbon-containing precursor is between about 20:1 and about 200:1. 
     
     
         19 . The etching method of  claim 11 , wherein the carbon-containing protective layer comprises a layer of carbon. 
     
     
         20 . The etching method of  claim 11 , wherein the first material comprises a spacer material including an oxide material, and wherein the second material comprises a hardmask material including a nitride material.