Plasma-assisted etching of metal oxides
The present disclosure describes methods and systems for plasma-assisted etching of a metal oxide. The method includes modifying a surface of the metal oxide with a first gas, removing a top portion of the metal oxide by a ligand exchange reaction, and cleaning the surface of the metal oxide with a second gas.
1 . A method, comprising:
providing a wafer having a metal oxide, wherein the wafer is held by a wafer holder in a chamber;
delivering a gas to the chamber via a first gas line connected to the chamber;
generating a plasma of the gas with a plasma generator in the chamber;
generating radicals from the plasma of the gas with a plate in the chamber; and
delivering, via a second gas line connected to the chamber, a precursor to the wafer for a ligand exchange reaction on the metal oxide, wherein the radicals accelerate the ligand exchange reaction.
2 . The method of claim 1 , further comprising distributing the plasma of the gas across the chamber with an additional plate between the wafer and the plate.
3 . The method of claim 1 , further comprising distributing the precursor across the wafer with an additional plate between the plate and the wafer.
4 . The method of claim 1 , further comprising heating the wafer with a heating system connected to the wafer holder for the ligand exchange reaction.
5 . The method of claim 1 , further comprising vaporizing the precursor with a vaporizer connected to the second gas line.
6 . The method of claim 1 , further comprising activating the ligand exchange reaction on the metal oxide with the precursor under a thermal condition.
7 . The method of claim 1 , further comprising:
delivering an additional gas to the chamber via the first gas line;
generating an additional plasma of the additional gas with the plasma generator; and
cleaning a surface of the metal oxide with the additional plasma after the ligand exchange reaction.
8 . The method of claim 7 , wherein the cleaning of the surface of the metal oxide comprises:
generating additional radicals from the additional plasma of the additional gas with the plate; and
cleaning the surface of the metal oxide with the additional radicals.
9 . The method of claim 1 , wherein the metal oxide comprises hafnium oxide, aluminum oxide, or zirconium oxide.
10 . A method, comprising:
distributing, with a first plate, a first gas across a surface of a metal oxide on a wafer in a chamber;
generating, with a second plate, first radicals from a plasma of the first gas;
modifying the surface of the metal oxide with the first radicals;
distributing, with the first plate, a second gas across the surface of the metal oxide;
generating, with the second plate, second radicals from the second gas; and
accelerating a ligand exchange reaction on the surface of the metal oxide with the second radicals.
11 . The method of claim 10 , further comprising:
vaporizing a precursor with a vaporizer connected to the chamber;
distributing, with a third plate, the vaporized precursor across the surface of the metal oxide; and
activating the ligand exchange reaction with the precursor.
12 . The method of claim 10 , further comprising heating the wafer with a heating system for the ligand exchange reaction.
13 . The method of claim 10 , further comprising:
delivering a third gas to the chamber;
generating third radicals from a plasma of the third gas with the second plate; and
cleaning the surface of the metal oxide with the third radicals after the ligand exchange reaction.
14 . The method of claim 10 , further comprising activating the ligand exchange reaction on the metal oxide with a precursor under a thermal condition.
15 . The method of claim 10 , further comprising removing a top portion of the metal oxide with the ligand exchange reaction.
16 . A method, comprising:
distributing, with a first plate, a gas across a surface of a metal oxide on a wafer in a chamber;
generating, with a second plate, radicals from a plasma of the gas;
modifying the surface of the metal oxide with the radicals;
distributing, with a third plate, a precursor across the surface of the metal oxide; and
removing a top portion of the metal oxide by the precursor with a ligand exchange reaction.
17 . The method of claim 16 , further comprising:
vaporizing the precursor with a vaporizer connected to the chamber; and
activating the ligand exchange reaction with the vaporized precursor under a thermal condition.
18 . The method of claim 16 , further comprising heating the wafer with a heating system for the ligand exchange reaction.
19 . The method of claim 16 , further comprising:
delivering an additional gas to the chamber;
generating additional radicals from a plasma of the additional gas with the second plate; and
cleaning the surface of the metal oxide with the additional radicals after the ligand exchange reaction.
20 . The method of claim 16 , further comprising:
delivering an additional gas to the chamber;
generating additional radicals from a plasma of the additional gas with the second plate; and
accelerating the ligand exchange reaction with the additional radicals.