Search

US-20260125822-A1 - DOPED SUBSTANTIALLY SINGLE-PHASE RARE EARTH OXIDE-ZIRCONIA MATERIALS AND METHODS OF MAKING THE SAME

US20260125822A1US 20260125822 A1US20260125822 A1US 20260125822A1US-20260125822-A1

Abstract

New substantially single-phase polycrystalline materials are disclosed. The new substantially single-phase polycrystalline materials generally include from 0.01-20 mol. % zirconia, at least 80 mol. % of one or more rare earth oxides (REO), and 40 to 7000 ppm aluminum by weight, wherein the substantially single-phase polycrystalline material comprises at least 95 wt. % of a solid-solution of REO-zirconia as measured by x-ray diffraction. The new substantially single-phase polycrystalline materials may realize a high density, such as a density of at least 95% of theoretical density, or higher. The new substantially single-phase polycrystalline materials may be in the form of a semiconductor component, including those suited for use in a plasma chamber environment.

Inventors

  • Steven Landin
  • David Henry Hook

Assignees

  • COORSTEK, INC.

Dates

Publication Date
20260507
Application Date
20251229

Claims (18)

  1. 1 . A substantially single-phase polycrystalline material comprising yttria (Y 2 O 3 ) and zirconia (ZrO 2 ), wherein the substantially single-phase polycrystalline material comprises from 0.01-20 mol. % zirconia and at least 80 mol. % yttria, and wherein the substantially single-phase polycrystalline material further comprises from 40 to 7000 ppm aluminum by weight, wherein the substantially single-phase polycrystalline material comprises at least 95 wt. % of a solid-solution of yttria-zirconia as measured by x-ray diffraction.
  2. 2 . The substantially single-phase polycrystalline material of claim 1 , comprising from 100 to 6000 ppm of the aluminum by weight.
  3. 3 . The substantially single-phase polycrystalline material of claim 1 , wherein the substantially single-phase polycrystalline material realizes a density of at least 95% of its theoretical density.
  4. 4 . The substantially single-phase polycrystalline material of claim 1 , comprising from 0.05 to 19.5 mol. % zirconia.
  5. 5 . The substantially single-phase polycrystalline material of claim 1 , comprising at least 95 mol. % yttria.
  6. 6 . The substantially single-phase polycrystalline material of claim 1 , wherein the substantially single-phase polycrystalline material comprises at least 96 wt. % of a solid-solution of yttria-zirconia.
  7. 7 . The substantially single-phase polycrystalline material of claim 1 , wherein the substantially single-phase polycrystalline material realizes an average grain size of not greater than 7 micrometers.
  8. 8 . The substantially single-phase polycrystalline material of claim 7 , wherein a standard deviation of the grain size is not greater than twice the average grain size.
  9. 9 . The substantially single-phase polycrystalline material of claim 7 , wherein the substantially single-phase polycrystalline material realizes a maximum grain size, and wherein the maximum grain size is not more than 20 times larger than the average grain size.
  10. 10 . The substantially single-phase polycrystalline material of claim 1 , wherein the substantially single-phase polycrystalline materials realizes at least equivalent plasma etch resistance as compared to a baseline material, wherein the baseline material is a single-phase polycrystalline material comprising 90 mol. % yttria and 10 mol. % zirconia and with less than 5 ppm of aluminum.
  11. 11 . A method comprising: (a) pressing a powder into a shaped component, wherein the powder comprises (i) 0.01-20 mol. % zirconia, (ii) at least 80 mol. % yttria, and (iii) from 40 to 7000 ppm of aluminum; (b) sintering the shaped component at a sintering temperature of from 1200-1800° C., thereby forming a sintered component, wherein the sintered component is polycrystalline, wherein the sintered component is substantially single-phase realizing at least 95 wt. % of a solid-solution of yttria-zirconia as measured by x-ray diffraction, and wherein the sintered component realizes a density of at least 95% of theoretical.
  12. 12 . The method of claim 11 , comprising, prior to the pressing step, formulating the powder and wherein the formulating step comprises blending a yttria powder and a zirconia powder, thereby producing a powder blend.
  13. 13 . The method of claim 12 , wherein the formulating step comprising contacting the powder blend with a liquid phase material comprising aluminum and wherein the liquid phase material is an aqueous aluminum-containing solution.
  14. 14 . The method of claim 12 , wherein the formulating comprises contacting the powder blend with a solid phase material comprising aluminum and wherein the solid phase material comprises aluminum-containing milling media, and wherein the formulating step comprises milling the powder blend with the aluminum-containing milling media, thereby effecting mass transfer of at least some aluminum to the powder blend.
  15. 15 . The method of claim 14 , wherein the aluminum-containing milling media comprises alpha alumina.
  16. 16 . The method of claim 11 , wherein the shaped component is monolithic.
  17. 17 . A substantially single-phase polycrystalline material comprising 0.1 to 20 mol. % zirconia (ZrO 2 ) and at least 80 wt. % of at least one rare earth oxide (REO), wherein the at least one rare earth oxide is selected from the group consisting of yttria, oxides of the Lanthanide series of elements, or combinations thereof, wherein the substantially single-phase polycrystalline material further comprises from 40 to 7000 ppm aluminum by weight, wherein the substantially single-phase polycrystalline material comprises at least 95 wt. % of a solid-solution of REO-zirconia as measured by x-ray diffraction.
  18. 18 . A method comprising: (a) pressing a powder into a shaped component, wherein the powder comprises (i) 0.01-20 mol. % zirconia, (ii) at least 80 wt. % of at least one rare earth oxide (REO), wherein the at least one rare earth oxide is selected from the group consisting of yttria, oxides of the Lanthanide series of elements, or combinations thereof, and (iii) from 40 to 7000 ppm of aluminum; (b) sintering the shaped component at a sintering temperature of from 1200-1800° C., thereby forming a sintered component, wherein the sintered component is polycrystalline, wherein the sintered component is substantially single-phase realizing at least 95 wt. % of a solid-solution of REO-zirconia as measured by x-ray diffraction, and wherein the sintered component realizes a density of at least 95% of theoretical, wherein the rare earth oxide comprises at least one of ytterbium oxide, erbium oxide, and ytterbium oxide.

Description

CROSS-REFERENCE TO RELATED APPLICATION This patent application is a continuation of International Patent Application No. PCT/US2024/035459, entitled “DOPED SUBSTANTIALLY SINGLE-PHASE RARE EARTH OXIDE-ZIRCONIA MATERIALS AND METHODS OF MAKING THE SAME,” filed Jun. 25, 2024, which claims priority to U.S. Provisional Patent Application No. 63/525,069, entitled, “DOPED SUBSTANTIALLY SINGLE-PHASE YTTRIA-ZIRCONIA MATERIALS AND METHODS OF MAKING THE SAME,” filed on Jul. 5, 2023. Each of the above-identified patent applications are hereby incorporated by reference in their entirety. BACKGROUND Corrosion and erosion resistance are critical properties for apparatus components and liners used in semiconductor processing chambers, where corrosive environments are present. Examples of corrosive plasma environments include plasmas used for cleaning of processing apparatus and plasmas used to etch semiconductor substrates. Yttrium oxide ceramics may realize plasma resistance properties, but yttrium oxide generally exhibits weak mechanical properties that limits its applications for general use in semiconductor processing components. SUMMARY OF THE DISCLOSURE Broadly, the present patent application relates to new substantially single-phase polycrystalline materials having improved properties. In one approach, the new substantially single-phase polycrystalline materials generally include: (A) one or more rare earth oxide (“REO”) materials and (B) zirconia (ZrO2). In one embodiment, the new materials may comprise a solid solution of REO-zirconia, wherein zirconium periodically substitutes for the REO material on the REO lattice. The new substantially single-phase polycrystalline materials generally include at least 80 mol. % of the one or more REO materials and from 0.01 to 20 mol. % zirconia. The new single-phase polycrystalline materials also generally include from 40 to 7000 ppm by weight of aluminum. In one embodiment, the one or more REO materials comprise one or more oxides of the Lanthanide series of elements. In one embodiment, the one or more REO materials at least include yttrium oxide (yttria). In another embodiment, the one or more REO materials at least include ytterbium oxide (ytterbia). In another embodiment, the one or more REO materials at least include both yttrium oxide and ytterbium oxide. Other combinations of REO materials may be used. In one embodiment, at least one rare earth sesquioxide having the formula RE2O3 (e.g., Y2O3, Yb2O3, Gd2O3, Er2O3, and Dy2O3, among others) is used as a REO material. For purposes of illustration, reference is now made to yttria-zirconia materials. It is to be appreciated that the yttria-zirconia disclosures herein generally apply to other REO-zirconia materials. As noted above, the new substantially single-phase polycrystalline materials may comprise (or consist of, or consist essentially of) a solid solution of yttria-zirconia, wherein zirconium periodically substitutes for yttrium on the yttria cubic lattice. To facilitate the substantially single-phase solid solution, the new single-phase polycrystalline materials generally include from 0.01 to 20 mol. % zirconia and at least 80 mol. % yttria. The new single-phase polycrystalline materials also generally include from 40 to 7000 ppm by weight of aluminum. The new substantially single-phase polycrystalline materials may realize a high density, such as a density of at least 95% of theoretical density. The new substantially single-phase polycrystalline materials may realize a fine grain structure (e.g., an average grain size of not greater than 7 micrometers). The new substantially single-phase polycrystalline materials may realize a uniform grain structure (e.g., less than 10% of the grains are more than twice the average grain size). The new substantially single-phase polycrystalline materials may be resistant to erosion by halogen plasmas. The new substantially single-phase polycrystalline materials may be in the form of a monolithic (bulk) material, such as in the form of a shaped component. The shaped component may be suited for use, for instance, as a semiconductor component, including semiconductor components suited for use in a plasma processing chamber. Additional details are provided below. i. Substantially Single-Phase Material Compositions and Microstructures As noted above, the new substantially single-phase polycrystalline materials may comprise (and may consist of, or consist essentially of) (i) a yttria-zirconia solid solution phase and (ii) from 40 to 7000 ppm of aluminum, which aluminum may also be present within the solid solution phase and/or may be present in another phase (e.g., the YAM phase (Y4Al2O9)). As used herein, “substantially single-phase polycrystalline materials” means polycrystalline materials having at least 95 wt. % of a solid solution of yttria-zirconia (or REO-zirconia, if other REOs are used) as determined using x-ray diffraction (XRD). In other words, up to 5 wt. % of phases other tha