Yttrium fluoride films and methods of preparing and using yttrium fluoride films
Described are yttrium fluoride compositions, including deposited films, e.g., coatings, that contain yttrium fluoride; methods of preparing yttrium fluoride compositions and deposited film coatings that contain yttrium fluoride; as well as substrates that have a deposited film coating that contains yttrium fluoride at a surface and methods and equipment that include the substrates.
1. A method of preparing yttrium fluoride, the method comprising:
depositing an alumina layer onto a substrate to form a surface,
depositing an yttrium oxide film onto the surface by atomic layer deposition, and
exposing the yttrium oxide film to molecular fluorine source vapor and an elevated temperature to convert yttrium oxide of the yttrium oxide film to yttrium fluoride, wherein the molecular fluorine source vapor is derived by heating fluorinated polymer, wherein an outer surface of the yttrium oxide film is converted into YF 3 , wherein the elevated temperature is above 300 degrees Celsius, and wherein the method does not include plasma.
2. The method of claim 1 , wherein exposing the yttrium oxide film to fluorine and an elevated temperature forms an yttrium fluoride portion of the yttrium oxide film, the yttrium fluoride portion having a thickness between a surface of the yttrium oxide and a location below the surface of the yttrium oxide at which the film contains 20 atomic percent oxygen.
3. The method of claim 2 , wherein the yttrium fluoride portion has a thickness in a range from 10 to 200 nanometers.
4. The method of claim 1 , wherein the fluorinated polymer is a homopolymer or copolymer comprising polymerized fluoroolefin monomers.
5. The method of claim 4 , wherein the fluorinated polymer comprises: polymerized perfluoroalkylethylene having a C 1 -C 10 perfluoroalkyl group; polytetrafluoroethylene (PTFE); a tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer (PFA); a tetrafluoroethylene/hexafluoropropylene copolymer (FEP); a tetrafluoroethylene/perfluoro(alkyl vinyl ether)/hexafluoropropylene copolymer (EPA); polyhexafluoropropylene; an ethylene/tetrafluoroethylene copolymer (ETFE); poly trifluoroethylene; polyvinylidene fluoride (PVDF); polyvinyl fluoride (PVF); polychlorotrifluoroethylene (PCTFE); an ethylene/chlorotrifluoroethylene copolymer (ECTFE); or a combination thereof.
6. The method of claim 4 , wherein the molecular fluorine source vapor comprises CF 4 , C 2 F 4 , C 3 F 6 , C 4 F 8 , CHF 3 , C 2 H 2 F 2 , C 2 F 6 , HF, CH 3 F, or a combination thereof.