Lithium metal surface modification using carbonate passivation
Exemplary processing methods may include translating a lithium film beneath a first showerhead. The methods may include introducing an oxidizer gas through the first showerhead onto the lithium film. The methods may include forming an oxide monolayer on the lithium film. The oxide monolayer may be or include the oxidizer gas adsorbed on the lithium film. The methods may include translating the lithium film beneath a second showerhead after forming the oxide monolayer. The methods may include introducing a carbon source gas through the first showerhead onto the lithium film. The methods may also include converting the oxide monolayer into a carbonate passivation layer through reaction of the oxide monolayer with the carbon source gas.
1. A method of processing a lithium film, the method comprising:
depositing a lithium film on a substrate, wherein the substrate is a Group IV suboxide;
planarizing the lithium film, wherein planarizing the lithium film comprises laser planarization;
translating the lithium film beneath a first showerhead;
introducing an oxidizer gas and an inert carrier gas through the first showerhead onto the lithium film, wherein the oxidizer is provided at a flow rate below 0.1 sccm;
forming an oxide monolayer on the lithium film, the oxide monolayer comprising the oxidizer gas adsorbed on the lithium film;
translating the lithium film beneath a second showerhead after forming the oxide monolayer;
introducing a second gas comprising a carbon source gas through the second showerhead onto the lithium film; and
converting the oxide monolayer into a carbonate passivation layer through reaction of the oxide monolayer with the carbon source gas.
2. The method of claim 1 , wherein the substrate is held under tension between two tensioning elements of a film deposition system.
3. The method of claim 1 , wherein:
the first showerhead comprises a first plurality of showerhead units oriented along a first axis;
the second showerhead comprises a second plurality of showerhead units oriented parallel to the first axis and offset from the first showerhead by a first distance; and the method further comprising:
translating the lithium film beneath the first showerhead comprises motion perpendicular to the first axis.
4. The method of claim 1 , wherein the first showerhead and the second showerhead each comprise a plurality of inlets and a plurality of outlets in an arrangement, wherein the plurality of outlets are positioned to remove excess gas from a region between the plurality of outlets and the lithium film, and wherein an orientation of the plurality of outlets define a flow pattern limiting excess gas flow parallel to the lithium film external to the region.
5. The method of claim 1 , further comprising:
forming a pattern in a surface of the lithium film, the pattern defining a plurality of recesses in the surface of the lithium film.
6. The method of claim 1 , further comprising:
forming a pattern in the carbonate passivation layer, the pattern defining a plurality of recesses in the carbonate passivation layer, wherein the plurality of recesses reveal a surface of the lithium film.
7. The method of claim 1 , wherein the oxidizer gas is present in an inert carrier gas at a concentration of greater than or about 1.0 ppm.
8. The method of claim 1 , wherein the second gas further comprises an inert gas, and wherein the second gas includes carbon dioxide (CO 2 ) at greater than 40 vol. %.
9. The method of claim 1 , wherein the oxidizer comprises water vapor (H 2 O).
10. A method of processing a metal film comprising:
forming an oxide monolayer on a metal film, the oxide monolayer comprising an oxidizer gas adsorbed on the metal film, wherein the oxide monolayer is formed from an oxidizer gas present in an inert carrier gas at a concentration of greater than or about 1.0 ppm, and wherein the oxidizer is provided at a flow rate below 0.1 sccm;
converting the oxide monolayer into a carbonate passivation layer through reaction of the oxide monolayer with a carbon source gas; and
patterning the metal film with a pattern defining a plurality of recesses, wherein the pattern defines the plurality of recesses in the carbonate passivation layer, and wherein the plurality of recesses reveal a surface of the metal film.
11. The method of claim 10 , wherein patterning the metal film comprises:
depositing a substrate layer onto a current collector;
forming the pattern in the substrate layer; and
depositing the metal film on the substrate layer.
12. The method of claim 11 , wherein forming the pattern in the substrate layer comprises ablating the substrate layer with a laser.
13. The method of claim 10 , wherein the pattern is formed on the metal film after converting the oxide monolayer into the carbonate passivation layer, and wherein the plurality of recesses are defined in the carbonate passivation layer.
14. The method of claim 13 , wherein patterning the metal film comprises:
emitting a light beam from a coherent light source;
receiving the light beam by a diffractive optical element, configured to shape and redirect the light beam toward the metal film; and
irradiating the metal film at a plurality of positions corresponding to the pattern.
15. The method of claim 10 , wherein patterning the metal film comprises:
advancing the metal film between two or more rollers, wherein:
a first roller of the two of more rollers comprises a micro-needle array, the micro-needle array configured to transfer the pattern into the metal film; and
a second roller of the two or more rollers supports the metal film against the first roller.
16. The method of claim 10 , wherein the metal film is formed on a substrate, and wherein the substrate is a Group IV suboxide.