WO2023039425A1 - Methods of forming a plasma resistant coating of y-o-f and substrates having such coating - Google Patents

Abstract

A method of providing a Y-O-F coating to a surface of a substrate comprising: providing an ALD chamber containing a substrate; pulsing into the chamber an yttrium source material; pulsing into the chamber an oxygen source material, to develop an yttrium oxide layer; pulsing into the chamber an FCM, wherein the FCM is tris(hexafluoroacetylacetonate)yttrium (III); pulsing into the chamber an oxygen source material. The resulting coating formed is a Y- O-F coating. Also included are coatings or films prepared by the methods and substrates bearing such coatings or films.

Description

Methods of Forming A Plasma Resistant Coating of Y-O-F and Substrates Having Such Coating

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Serial No. 63/241,182, filed September 7, 2021, entitled " Methods of Forming A Plasma Resistant Coating of Y-O-F and Substrates Having Such Coating," the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] To prevent contamination of semiconductor wafers, semiconductor manufacturing equipment and flat panel display manufacturing equipment are made of high-purity materials that are resistant to erosion and particulate generation, during qualities are necessary because, during the manufacturing process, these materials are exposed to highly corrosive gases, particularly halogen-based corrosive gases such as fluorine and chorine-based gases. Thus, robust materials such as alumina and yttria have been applied, often as coatings or surface layers.

[0003] To apply or form such coatings, atomic layer deposition (“ALD”) methods are often used. ALD is a thin-film deposition technique based on the sequential use of a gas phase chemical process. ALD is considered a subclass of chemical vapor deposition. The majority of ALD reactions use two chemicals, typically called precursors. These precursors react with the surface of a material one at a time in a sequential, self-limiting, manner. Through the repeated exposure to separate precursors, a thin film is slowly deposited. Advantages of ALD include the ability to produce conformal, dense, and pinhole-free films or coatings that have the ability to coat complex 3D shapes and high-aspect ratio holes.

[0004] For semiconductor applications, ALD is commonly used to deposit films of oxides on substrates, such as, for example, an yttrium oxide film, or to deposit films of fluorides, such as, for example, a film of yttrium fluoride.

[0005] However, it has been noted that when ALD is used to deposit films of oxides, and the film is exposed to a fluorine plasma environment, the metal oxide may convert to a metal fluoride. Similarly, films of metal fluoride exposed to oxygen-containing plasmas undergo oxidation. In each instance, the “conversion” of the metal -ide leads to volume expansion of the film, and resulting compressive stresses, which in turn leads to cracking of the film and generates undesirable contaminating particulate matter in the reaction chamber.

[0006] The invention described herein overcomes this disadvantage by creating fluoride films that are also erosion resistant and therefore are useful in semiconductor manufacturing equipment and flat panel display manufacturing equipment, for example.

BRIEF DESCRIPTION OF THE INVENTION

[0007] Described herein is a method of providing a Y-O-F coating to a surface of a substrate comprising: providing an ALD chamber containing a substrate; pulsing into the chamber an yttrium source material; pulsing into the chamber an oxygen source material, to develop an yttrium oxide layer; pulsing into the chamber an FCM, wherein the FCM is tris(hexafluoroacetylacetonate)yttrium (III); pulsing into the chamber an oxygen source material. The resulting coating formed is a Y-O-F coating.

[0008] Also included are coatings or films prepared by the methods and substrates bearing such coatings or films.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0009] The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that different references to "an" or "one" embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.

[0010] In the drawings:

[0011] Fig. 1 is a schematic flow chart of the deposition method of the invention that results in a Y-O-F coating;

[0012] Fig. 2 shows the chemical structure of a fluorine-containing material (FCM) that may be used in the deposition methods of the invention;

[0013] Figure 3 is a graphical representation of the deposition process of the invention over time;

[0014] Figure 4 is a representation of the process of the invention at the atomic level;

[0015] Fig. 5 is a table listing exemplary precursors, one or more of which may be used in various combinations to deposit the films of the invention; [0016] Fig. 6 is a schematic of a coated part shown in cross-section bearing an exemplary coating of the invention and a “glue” layer of AIO3 on a substrate;

[0017] Fig. 7 is a table listing the deposition conditions for the deposition of YOF films of the invention on silicon wafers. The resultant films exhibited varying oxygen-to-fluorine ratios. [0018] Fig. 8 is a table listing the refractive indices (RI) of the films prepared by the parameters listed in the table of Fig. 7;

[0019] Fig. 9 is an EDS cross-sectional line scan of the film 6 prepared using one yttrium fluoride cycle to 11 yttrium oxide cycles (see table of Fig. 7);

[0020] Fig. 10 is an EDS cross-sectional line scan of the film 5 prepared using one yttrium fluoride cycle to 19 yttrium oxide cycles (see table of Fig. 7);

[0021] Fig. 11 is a TEM micrograph showing a cross-sectional view of film 6 (see table of Figure 7);

[0022] Fig. 12 is a TEM micrograph showing a cross-sectional view of film 5 (see table of Figure 7); and

[0023] Fig. 13 shows the XRD spectrums of four films prepared by the method of the invention (films

DETAILED DESCRIPTION OF THE INVENTION

[0024] The invention described herein includes methods of providing a coating to a surface of a substrate, substrates, and/or articles coated or provided with such films, including for example, semiconductor processing components and equipment.

[0025] As used herein, a coated substrate includes a substrate having at least the Y-O-F coating described herein, although the coating may include more than one coating or coating layer. The coating is deposited, most preferably, by an atomic layer deposition (ALD)-type process, on the substrate and extends axially from the substrate in the direction of coating growth.

[0026] ALD-type processes may include those can be carried out using commercially available ALD tools, process protocols, and chemical precursors (metal and non-metal), such as, for example, those available from Picosun (P-series and R-series ALD systems); Beneq Oy (TFS-series or P-series) Oxford Instruments (FlexAl and OpalAl ALD systems); and/or Veeco Instruments (Savannah, Fiji, and Phoenix ALD systems). [0027] A method of the invention includes providing a substrate. Substrates for use in the invention may be any material useful for the desired end applications. In some embodiments, one may prefer that the substrate is a non-ferrous metal, a non-ferrous metal alloy, a ferrous metal, or a ferrous metal alloy. Suitable materials may include substrates of titanium, aluminum, nickel, ceramics, aluminum alloys, steels, stainless steel, carbon steel, alloy steel, copper, copper alloys, lead, lead alloys, ceramics, quartz, a glass, a polymer, such as a high- performance polymer, and a fiberglass. The substrate may also combine materials, that is, a portion may be, for example, made of aluminum and an adjacent portion made of copper.

[0028] The substrate with the Y-O-F coating as described herein may make up or be part of a variety of components, such as, for example, components that are planar in nature or have a 3D geometry. For example, the component may be a chamber component, like a shower head, a chamber wall, a nozzle a plasma generation unit, a diffuser, a gas line interior, a chamber orifice, and the like.

[0029] The film of the invention may be deposited directly on a substrate (treated or untreated) and may be part of a multilayer film on one or more of several layers. In some embodiments, the substrate may be pre-coated with an “anchor” or “glue” layer, such as, for example, AIO3. An example of this embodiment is shown in Figure 6, where the glue layer is about 5 to about 50 nm in thickness, and the film prepared by the methods of the invention is about 10 to about 500 nm in thickness.

[0030] In its method aspect, the invention includes a method providing a Y-O-F coating to a surface of a substrate comprising: a) providing an ALD chamber; b) pulsing into the chamber an yttrium source material; c) pulsing into the chamber an oxygen source material, to develop an yttrium oxide layer; d) pulsing into the chamber a fluoride-containing material (FCM), and e) pulsing into the chamber an oxygen source material, preferably ozone, wherein the resulting coating formed is a Y-O-F coating.

[0031] Representations of the process are set forth in Figures. As an example, in an embodiment of the invention the method is carried out as follows:

[0032] A YOF film is deposited by alternately performing Y2O3 and YF3 ALD sub-cycles within a super-cycle. Y2O3 can be deposited from any number of yttrium precursors (yttrium source material) as described herein supra including cyclopentadiene-based (Cp) and aminobased, or heteroleptic precursor that includes Cp and amino groups plus an oxygen-containing source material such as water, ozone, oxygen. [0033] YF3 may be deposited using any FCM known or to be developed in the art, for example, using tri s(hexafluoroacetyl acetonate) yttrium (III) “YBeta-Prime”™ (available from Air Liquide Advanced Materials, Mount Bethel Pennsylvania) and ozone. As an example in this embodiment, sub-cycles can be from 1 each up to 32 each or various ratios between the two. One may act to limit the number of consecutive pulses for the first yttrium oxide subcycle and second yttrium fluoride sub-cycle or additional sub-cycles so that the yttrium oxide and yttrium fluoride mix rather than form distinct laminate layers.

[0034] In the practice of the method in an embodiment, the supercycle (which includes steps (b) to (e)) may be repeated for r times (or for r supercycles); steps (b) and (c) may be repeated m times (or form cycles) and the steps (d) and (e) may be repeated for n times (or n cycles), where r, m and n are each independently selected from any integer and/or the integers selected from, for example, about 1 to about 10,000, about 100 to about 5,000, and about 1,000 to about 2,000.

[0035] As seen above, the method includes a step of pulsing, into an ALD tool chamber, an yttrium source material. In some embodiments, any use of yttrium or yttrium source material may be substituted by zirconium and/or hafnium and zirconium source material and/or hafnium source material, thereby resulting in the formation of films of HfOF or ZrOF in addition to YOF, or combinations of these.

[0036] Such material may be, for example, cyclopentadienyl compound or a derivative of a cyclopentadienyl, e.g., those set forth in U.S. Patent No. 7,351,658, the contents of which are incorporated herein by reference, or for example, hexafluoro-acetylacetonate yttrium.

Preferably, the yttrium source material is yttrium (III) tris (methylcyclopentadienyl). Other yttrium precursors, known or to be developed can be used as desired, including, for example, those set forth in the co-pending application published as United States Patent Application Publication No. 2020/0131632 of Pavel et al., published April 30, 2020, the contents of which are incorporated herein by reference, especially Figure 6.

[0037] The method further includes steps of pulsing into the ALD tool chamber an oxygen source material. Preferably the material is ozone, O2, O2 plasmas (precursor H2O), H2O2, N2O, NO2, NO, and mixtures of the same. The source material may be the same or different for each step and or cycle. Other source material(s) known or to be developed can be used as desired, including, for example, those set forth in the co-pending application published as United States Patent Application Publication No. 2020/0131632 of Pavel et al., published April 30, 2020, the contents of which are incorporated herein by reference, especially Figure 6.

[0038] The FCM may be any reactive fluorinated yttrium source known or to be developed in the art, for example, tris(hexafluoroacetylacetonate)yttrium (III), i.e., a molecule having the structure shown in Figure 2. In some embodiments, the FCM may be a fluorinated anionic bidentate, in some instances preferably a P-diketonate such as hexafluoroacetylacetone (hfac). Other suitable FCMs are described in, for example, WO2021257641 Al, the contents of which are incorporated herein by reference.

[0039] In the practice of the invention, the source material(s) of any of the above may be the same or may be different for each step and/or each repetition of a cycle.

[0040] As desired, in between any of the steps, the chamber may be purged with, for example, nitrogen, argon, other inert gases, and mixtures of the same. It is noted that it is well within the skill set of a person of ordinary skill in the art to determine dose time and purges times for an ALD process. As is known in the art, ALD reactions are self-limiting. The ALD reaction must have optimized dosing concentrations and times plus optimized purge times for each of the source materials described above.

[0041] However, for exemplary purposes it is noted that in some embodiments of the invention it may be desirable to carry out the methods within the parameters listed below (each an independent parameter):

(i) a process temperature may be within the range of about 200 to about 350 or about 275 C to about 325 C;

(ii) a pulse time of yttrium precursors may be within the range of about 0.1 to about

20 seconds or about 0.5 to about 5 seconds;

(iii) a pulse time of FCM may be within the range of about 0.1 to about 20 seconds or about 0.5 to about 5 seconds;

(iv) an ozone may be used as the oxygen source material;

(v) a concentration of oxygen source material in the chamber may be about 5% to about 30% or about 15% to about 20%;

(vi) a pulse time of oxygen source material may be about 0.5 to about 20 seconds or about 2 to about 5 seconds;

(vii) purge times between an yttrium precursor and addition of oxygen source material may be about 1 to about 60 seconds or about 5 to about 20 seconds; (viii) a ratio of m.n cycles may be about 1 : 1 to about 40: 1 or about 9: 1 to about 20: 1; and

(ix) a thickness range for the deposited film may be about 10 nm to about 5000 nm or about 100 nm to about 1000 nm.

[0042] Also included within the scope of the invention are any coatings/films prepared by any of the methods described supra, substrates and/or components that bear multi-layer coatings prepared by any of the methods described supra or multi-layer coatings including films or coatings made by other methods as well as the method described herein, equipment or devices that contain any of such components and/or multi-layer coatings.

[0043] The coatings/films prepared by any of the methods described supra may be designed to have varying levels of content of materials - such relative levels will differ and can be tailored depending on the end use and/or end properties the fabricator wishes for the film or coating. However, as an example, in some embodiments, it may be desirable that the film has independently an oxygen content of about 10% to about 50% or about 20% to about 40% and a fluorine content of about 20% to about 70% or about 25% to about 40% (atomic percent AS measured by energy dispersive X-Ray spectroscopy and Rutherford b ackscattering).

[0044] EXAMPLE

[0045] A series of YOF films were deposited on silicon wafers in accordance with the method of the invention using an ATG Picosun P-300B reactor. Process parameters were varied to deposit films of various oxygen to fluorine ratios. Figure 7 contains a table that lists the deposition conditions for the films. The resultant films exhibited oxygen-to-fluorine ratios. The refractive indices (RI) of the films prepared by the parameters listed in the table of Fig. 7 are provided in the table of Figure 8.

[0046] The films prepared were analyzed by energy dispersive spectroscopy (EDS). Fig. 9 is an EDS cross-sectional line scan of the film 6 prepared using one yttrium fluoride cycle to 11 yttrium oxide cycles (see table of Fig. 7). The EDS lines scan shows the film to be homogenous.

[0047] Figure 10 is an EDS cross-sectional line scan of the film 5 prepared using one yttrium fluoride cycle to 19 yttrium oxide cycles (see table of Fig. 7). The EDS lines scan shows the film to be homogenous, like that above. [0048] The films prepared were analyzed by transmission electron microscopy (TEM).

Figure 11 is a TEM micrograph showing a cross-sectional view of film 6 (see table of Figure 7). It demonstrates the homogenous YOF composition of a mixed film as prepared by the inventive method. [0049] Figure 12 is a TEM micrograph showing a cross-sectional view of film 5 (see table of Figure 7). It demonstrates the homogenous YOF composition of a mixed film as prepared by the inventive method.

[0050] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

9 CLAIMS What is claimed is:

1. A method of providing a Y-O-F coating to a surface of a substrate comprising: a) providing an ALD chamber containing a substrate; b) pulsing into the chamber an yttrium source material; c) pulsing into the chamber an oxygen source material, to develop an yttrium oxide layer; d) pulsing into the chamber an FCM, wherein the FCM is tris(hexafluoroacetylacetonate)yttrium (III); e) pulsing into the chamber an oxygen source material, wherein the resulting coating formed is a Y-O-F coating.

2. The method of claim 1 wherein the oxygen source material of step c and step e are different.

3. The method of claim 1 wherein the oxygen source material of step c and step e are the same.

4. The method of claim 1 wherein the substrate is selected from a non-ferrous metal, a non-ferrous metal alloy, a ferrous metal, and a ferrous metal alloy.

5. The method of claim 1 wherein the substrate is selected from titanium, aluminum, nickel, zinc, aluminum alloys, steels, stainless steel, carbon steel, alloy steel, copper, copper alloys, nickel alloys, ceramic, silicon, lead, and lead alloys.

6. The method of claim 1 wherein the substrate is a chamber component.

7. The method of claim 1 wherein the substrate is selected from a shower head, a chamber wall, a nozzle a plasma generation unit, a diffuser, a gas line interior, and a chamber orifice.

8. The method of claim 1 wherein the substrate is selected from a planar member and a 3D shape, a 3D shape with high aspect ratio features and a 3D shape with medium and low aspect ratio features.

9. The method of claim 1 wherein the yttrium source material is selected from cyclopentadiene-based (Cp) materials, amino-based material, a heteroleptic precursor that includes Cp and amino.

10. The method of claim 1 wherein the yttrium source material is yttrium (III) tris (methylcyclopentadienyl).

11. The method of claim 1 wherein the oxygen source material is selected from ozone, O2, O2 plasmas (precursor H2O), H2O2, N2O, NO2, NO, and mixtures of the same.

12. The method of claim 1 wherein the FCM is selected from a fluorinated anionic bidentate, a fluorinated anionic bidentate that is a P-diketonate , and hexafluoroacetyl acetone.

13. The method of claim 1 wherein the FCM is tris(hexafluoroacetylacetonate)yttrium (III)

14. The method of claim 1 wherein the method further includes one or more purge steps after at least one of steps b, c, d, or e.

15. A coating or film prepared by the method of claim 1.

16. The coating or film of claim 15 having an oxygen content of about 10% to about 50% (atomic percent)

17. The coating or film of claim 15 having an oxygen content of about 20% to about 40% (atomic percent)

18. The coating or film of claim 15 having a fluorine content of about 20% to about 70% (atomic percent).

19. The coating or film of claim 15 having a fluorine content of about 25% to about 40% (atomic percent).

20. The coating or film of claim 15 having a thickness of about 10 nm to about 5000 nm.

21. The coating or film of claim 15 wherein the coating or film is substantially homogenous throughout.

22. The coating or film of claim 15 exhibiting reduced particulate generation when exposed to an oxygen plasma as compared to a film made wholly of yttrium oxide.

23. The coating or film of claim 15 exhibiting reduced particulate generation when exposed to a fluorine plasma.

24. A component comprising the coating of claim 15.

25. The component of claim 22 selected from the group consisting of semiconductor manufacturing equipment, flat panel display manufacturing equipment, a shower head, a chamber wall, a nozzle a plasma generation unit, a diffuser, a gas line interior, and a chamber orifice, chamber liner, chamber lid.