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 system for plasma-assisted etching of a metal oxide, comprising:
a wafer holder in a chamber configured to hold a wafer with the metal oxide;
a first gas line connected to the chamber and configured to deliver a gas to the chamber;
a plasma generator in the chamber and configured to generate a plasma of the gas;
a plate in the chamber and configured to filter radicals from the plasma of the gas; and
a second gas line connected to the chamber and configured to deliver a precursor across the wafer for a ligand exchange reaction on the metal oxide, wherein the radicals accelerate the ligand exchange reaction.
2 . The system of claim 1 , further comprising an additional plate between the plasma generator and the plate to distribute a plasma of the gas across the chamber.
3 . The system of claim 1 , further comprising an additional plate between the plate and the wafer to distribute the precursor across the wafer.
4 . The system of claim 1 , further comprising a heating system connected to the wafer holder and configured to heat the wafer.
5 . The system of claim 1 , further comprising a vaporizer connected to the second gas line and configured to vaporize the precursor.
6 . The system of claim 1 , wherein the gas comprises fluorine and the plasma of the gas fluorinates a surface of the metal oxide before the ligand exchange reaction.
7 . The system of claim 1 , wherein the gas comprises argon and the radicals of the gas accelerate the ligand exchange reaction.
8 . The system of claim 1 , wherein the gas comprises hydrogen and the plasma of the gas cleans a surface of the metal oxide after the ligand exchange reaction.
9 . A system for plasma-assisted etching of a metal oxide; comprising:
a chamber comprising:
a wafer holder configured to hold a wafer having the metal oxide; and
a plasma generator configured to generate a first plasma from a first gas and a second plasma from a second gas;
a first gas line connected to a top surface of the chamber and configured to deliver the first gas above the wafer; and
a second gas line connected to a sidewall of the chamber and configured to deliver the second gas across the wafer.
10 . The system of claim 9 , further comprising a third gas line connected to the top surface of the chamber and configured to deliver a precursor above the wafer for a ligand exchange reaction on the metal oxide.
11 . The system of claim 9 , wherein the first gas comprises fluorine and the first plasma of the first gas modifies a surface of the metal oxide.
12 . The system of claim 9 , wherein the second gas comprises hydrogen and the second plasma of the second gas cleans a surface of the metal oxide.
13 . The system of claim 9 , further comprises an additional chamber connected to the chamber, wherein the additional chamber comprises:
an additional wafer holder configured to hold the wafer with the metal oxide;
a fourth gas line connected to the additional chamber and configured to deliver a precursor above the wafer for a ligand exchange reaction on the metal oxide; and
a connector configured to connect the chamber to the additional chamber and transfer the wafer between the chamber and the additional chamber.
14 . The system of claim 13 , wherein the additional chamber further comprises a plate configured to distribute the precursor across the wafer.
15 . The system of claim 13 , wherein the additional chamber further comprises a heating system connected to the additional wafer holder and configured to heat the wafer.
16 . A method for plasma-assisted etching of a metal oxide, comprising:
providing a wafer having the metal oxide in a chamber, wherein the wafer is held by a wafer holder in the 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;
filtering 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.
17 . The method of claim 16 , further comprising distributing the plasma of the gas across the chamber with an additional plate between the plasma generator and the plate.
18 . The method of claim 16 , further comprising distributing the precursor across the wafer with an additional plate between the plate and the wafer.
19 . The method of claim 16 , further comprising heating the wafer with a heating system connected to the wafer holder.
20 . The method of claim 16 , further comprising vaporizing the precursor with a vaporizer connected to the second gas line.