Systems and methods for tungsten-containing film removal
Exemplary etching methods may include flowing a halogen-containing precursor into a remote plasma region of a semiconductor processing chamber while striking a plasma to produce plasma effluents. The methods may include contacting a substrate housed in a processing region with the plasma effluents. The substrate may define an exposed region of tungsten oxide. The contacting may produce a tungsten oxy-fluoride material. The methods may include flowing an etchant precursor into the processing region. The methods may include contacting the tungsten oxy-fluoride material with the etchant precursor. The methods may include removing the tungsten oxy-fluoride material.
1. An etching method comprising:
flowing a halogen-containing precursor into a remote plasma region of a semiconductor processing chamber while striking a plasma to produce plasma effluents;
contacting a substrate housed in a processing region with the plasma effluents, wherein the substrate defines an exposed region of tungsten oxide, and wherein the contacting produces a tungsten oxy-fluoride material;
increasing a pressure in the semiconductor processing chamber;
flowing an etchant precursor into the processing region;
contacting the tungsten oxy-fluoride material with the etchant precursor; and
removing the tungsten oxy-fluoride material.
2. The etching method of claim 1 , wherein the halogen-containing precursor comprises fluorine, and wherein the etchant precursor comprises a chlorine-containing precursor.
3. The etching method of claim 2 , wherein the halogen-containing precursor comprises nitrogen trifluoride, the method further comprising:
flowing hydrogen with the halogen-containing precursor.
4. The etching method of claim 3 , wherein a flow rate of the hydrogen is at least twice a flow rate of the halogen-containing precursor.
5. The etching method of claim 1 , wherein the semiconductor processing chamber is maintained plasma-free during the flowing of the etchant precursor.
6. The etching method of claim 1 , wherein the etching method is performed at a temperature greater than or about 150 ° C.
7. The etching method of claim 1 , wherein a pressure in the semiconductor processing chamber is maintained below 15 Torr while flowing the halogen-containing precursor.
8. The etching method of claim 7 , wherein a pressure in the semiconductor processing chamber is maintained above 15 Torr while flowing the etchant precursor.
9. The etching method claim 1 , wherein the substrate may further comprise an exposed region of silicon oxide.
10. The etching method claim 9 , wherein a trench is formed through the silicon oxide to define the exposed region of tungsten oxide.
11. An etching method comprising:
forming a plasma of a first halogen-containing precursor to produce plasma effluents in a remote plasma region of a semiconductor processing chamber;
flowing the plasma effluents into a processing region of the semiconductor processing chamber at a first pressure;
contacting a substrate housed in the processing region with the plasma effluents, wherein the substrate comprises an exposed region of tungsten oxide overlying a region of tungsten at a base of a trench defined in the substrate, and wherein the plasma effluents halogenate the tungsten oxide;
flowing a second halogen-containing precursor into the processing region of the semiconductor processing chamber at a second pressure, wherein the second pressure is greater than the first pressure; and
removing the halogenated tungsten oxide.
12. The etching method of claim 11 , wherein the first halogen- containing precursor comprises fluorine, and wherein the second halogen-containing precursor comprises boron trichloride.
13. The etching method of claim 11 , further comprising halting plasma formation prior to flowing the second halogen-containing precursor.
14. The etching method of claim 11 , wherein the first halogen- containing precursor comprises nitrogen trifluoride, the method further comprising:
flowing hydrogen with the first halogen-containing precursor.
15. The etching method of claim 14 , wherein a flow rate of the hydrogen is at least twice a flow rate of the first halogen-containing precursor.
16. The etching method of claim 11 , wherein a pressure in the semiconductor processing chamber is maintained below 15 Torr while flowing the first halogen-containing precursor.
17. The etching method of claim 16 , wherein a pressure in the semiconductor processing chamber is maintained above 15 Torr while flowing the second halogen-containing precursor.
18. An etching method comprising:
forming a plasma of a fluorine-containing precursor to produce plasma effluents in a remote plasma region of a semiconductor processing chamber;
flowing the plasma effluents into a processing region of the semiconductor processing chamber;
contacting a substrate housed in the processing region with the plasma effluents, wherein the substrate comprises an exposed region of tungsten oxide overlying a region of tungsten, and wherein the plasma effluents fluorinate the tungsten oxide;
increasing a pressure within the semiconductor processing chamber subsequent to contacting the substrate with the plasma effluents;
flowing a chlorine-containing precursor into the processing region of the semiconductor processing chamber;
contacting the substrate with the chlorine-containing precursor; and
removing the tungsten oxide.
19. The etching method of claim 18 , further comprising:
flowing hydrogen with the fluorine-containing precursor, wherein a flow rate of the hydrogen is at least twice a flow rate of the fluorine-containing precursor.
20. The etching method of claim 18 , wherein a pressure in the semiconductor processing chamber is maintained below or about 10 Torr while flowing the fluorine-containing precursor, and wherein a pressure in the semiconductor processing chamber is maintained above or about 20 Torr while flowing the chlorine-containing precursor.