Lithium metal surface modification using carbonate passivation

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.