Patent Publication Number: US-2022235458-A1

Title: Atomic layer deposition of protective coatings for semiconductor process chamber components

Description:
RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 15/495,624, filed Apr. 24, 2017, which claims priority to U.S. Provisional Patent Application No. 62/328,588, filed Apr. 27, 2016, both of which are herein incorporated by reference. This application is also related to U.S. patent application Ser. No. 15/847,251, filed Dec. 19, 2017, now U.S. Pat. No. 11,198,936 issued Dec. 14, 2021, and is also related to U.S. patent application Ser. No. 16/411,823, filed May 14, 2019, now U.S. Pat. No. 11,198,937 issued Dec. 14, 2021. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present disclosure relate to a method for preparing a protective coating for semiconductor process chamber components using atomic layer deposition (ALD), a multi-component protective coating, and a semiconductor process chamber component coated with a multi-component protective coating. 
     BACKGROUND 
     Various manufacturing processes expose semiconductor process chamber components to high temperatures, high energy plasma, a mixture of corrosive gases, high stress, and combinations thereof. These extreme conditions may erode the chamber components, corrode the chamber components, and increase the chamber components&#39; susceptibility to defects. It is desirable to reduce these defects and improve the components&#39; erosion and/or corrosion resistance in such extreme environments. Coating semiconductor process chamber components with protective coatings is an effective way to reduce defects and extend their durability. 
     Protective coating films are typically deposited on chamber components by a variety of methods, such as thermal spray, sputtering, or evaporation techniques. In these techniques, the surfaces of the chamber components that are not directly exposed to the vapor source (e.g., are not in a line of sight of a material source) are coated with either a significantly thinner film than surfaces that are directly exposed to the vapor source, poor quality film, a low-density film, or not coated at all. 
     SUMMARY 
     Some embodiments of the present invention cover a method for forming a multi-component coating composition on a semiconductor process chamber component. The method includes depositing a first film layer of a yttrium oxide or a yttrium fluoride onto a surface of a semiconductor process chamber component, wherein the first film layer is grown from at least two precursors using an atomic layer deposition process. The method further includes depositing a second film layer of an additional oxide or an additional fluoride onto the surface of the semiconductor process chamber component, wherein the second film layer is grown from at least two additional precursors using the atomic layer deposition process. The method further includes forming a multi-component composition comprising the first film layer and the second film layer. In some embodiments, the method may further include depositing at least one additional film layer, the at least one additional film layer comprising aluminum oxide or zirconium oxide, wherein the at least one additional film layer is grown from at least two additional precursor using the atomic layer deposition process. 
     In some embodiments, the present invention covers a coated semiconductor process chamber component. The coated semiconductor process chamber component may comprise a semiconductor process chamber component having a surface and a multi-component coating coated on the surface. In certain embodiments, the multi-component coating may comprise at least one first film layer of a yttrium oxide or a yttrium fluoride coated onto the surface using an atomic layer deposition process and at least one second film layer of an additional oxide or an additional fluoride coated onto the surface using an atomic layer deposition process. In some embodiments, the multi-component coating may further comprise at least one additional film layer comprising aluminum oxide or zirconium oxide coated onto the surface using an atomic layer deposition process. 
     In some embodiments, the present invention covers a multi-component coating composition for a surface of a semiconductor process chamber component. The multi-component coating composition may comprise at least one first film layer of a yttrium oxide or a yttrium fluoride coated onto the surface of the semiconductor process chamber component using an atomic layer deposition process and at least one second film layer of an additional oxide or an additional fluoride coated onto the surface of the semiconductor process chamber component using an atomic layer deposition process. The multi-component coating composition may be selected from the group consisting of YO x F y , YAl x O y , YZr x O y  and YZr x Al y O z . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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. 
         FIG. 1  depicts a sectional view of one embodiment of a processing chamber. 
         FIG. 2  depicts a deposition process in accordance with a variety of Atomic Layer Deposition techniques. 
         FIG. 3A  illustrates a method for forming a multi-component coating on a semiconductor process chamber component according to an embodiment. 
         FIG. 3B  illustrates a method for forming a multi-component coating on a semiconductor process chamber component according to an embodiment. 
         FIGS. 4A-4D  depict variations of a multi-component coating composition according to different embodiments. 
         FIG. 5A  depicts a coated chamber component (showerhead) according to an embodiment. 
         FIG. 5B  depicts a blown up view of a gas conduit having a large aspect ratio coated according to an embodiment. 
         FIG. 6  is a graph showing x-ray diffraction patterns of a stack of alternating layers of Al 2 O 3  and Y 2 O 3  as coated and after annealing. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Embodiments are described herein with reference to a multi-component coating that includes multiple layers that have been deposited using atomic layer deposition (also referred to as atomic monolayer deposition or ALD). Each component may be a constituent material that is included in one or more layer of the coating. One example of a multi-component coating is a coating that includes a first component of yttrium and a second component of oxygen, such as yttria (Y 2 O 3 ). In another example, a multi-component coating may include a first component of Y 2 O 3  and a second component of YF 3 . The first and second components may be arranged in different layers of the multi-component coating. In some embodiments, after processing such as annealing the multiple layers of the multi-component coating may interdiffuse to form a homogenous or approximately homogenous coating that includes the constituent materials of the different layers. For example, the multiple components from the different layers may form a solid state phase of a first film layer and a second film layer. In a further example, an alternating stack of Y 2 O 3  layers and YF 3  layers may interdiffuse to form a solid state phase of a yttrium oxy-fluoride. The multi-component coating may be a coating having multiple different oxides, multiple different fluorides, or a combination of one or more oxides and one or more fluorides that have or have not interdiffused. Alternatively, or additionally, the multi-component coating may be a coating having a mixture of a metal and oxygen, a metal and fluorine, a metal and oxygen and fluorine, or multiple metals with one or more of oxygen and fluorine. 
       FIG. 1  is a sectional view of a semiconductor processing chamber  100  having one or more chamber components that are coated with a multi-component coating in accordance with embodiments of the present invention. The processing chamber  100  may be used for processes in which a corrosive plasma environment having plasma processing conditions is provided. For example, the processing chamber  100  may be a chamber for a plasma etcher or plasma etch reactor, a plasma cleaner, and so forth. Examples of chamber components that may include a multi-component coating include chamber components with complex shapes and holes having large aspect ratios. Some example chamber components include a substrate support assembly  148 , an electrostatic chuck (ESC), a ring (e.g., a process kit ring or single ring), a chamber wall, a base, a gas distribution plate, a showerhead  130 , gas lines, a nozzle, a lid, a liner, a liner kit, a shield, a plasma screen, a flow equalizer, a cooling base, a chamber viewport, a chamber lid, and so on. The multi-component coating, which is described in greater detail below, is applied using an ALD process. ALD, which is described in greater detail with reference to  FIG. 2 , allows for the application of a conformal coating of relatively uniform thickness on all types of components including components with complex shapes and holes with large aspect ratios. 
     The multi-component coating may be grown or deposited using ALD with various ceramics including oxide based ceramics, nitride based ceramics and carbide based ceramics. Examples of oxide based ceramics include SiO 2  (quartz), Al 2 O 3 , Y 2 O 3 , Y 4 Al 2 O 9 , Y 2 O 3 —ZrO 2  and so on. Examples of carbide based ceramics include SiC, Si—SiC, and so on. Examples of nitride based ceramics include AlN, SiN, and so on. 
     In one embodiment, the processing chamber  100  includes a chamber body  102  and a showerhead  130  that enclose an interior volume  106 . The showerhead  130  may include a showerhead base and a showerhead gas distribution plate. Alternatively, the showerhead  130  may be replaced by a lid and a nozzle in some embodiments. The chamber body  102  may be fabricated from aluminum, stainless steel or other suitable material. The chamber body  102  generally includes sidewalls  108  and a bottom  110 . Any of the showerhead  130  (or lid and/or nozzle), sidewalls  108  and/or bottom  110  may include the multi-component coating. 
     An outer liner  116  may be disposed adjacent the sidewalls  108  to protect the chamber body  102 . The outer liner  116  may be fabricated and/or coated with a multi-component coating. In one embodiment, the outer liner  116  is fabricated from aluminum oxide. 
     An exhaust port  126  may be defined in the chamber body  102 , and may couple the interior volume  106  to a pump system  128 . The pump system  128  may include one or more pumps and throttle valves utilized to evacuate and regulate the pressure of the interior volume  106  of the processing chamber  100 . 
     The showerhead  130  may be supported on the sidewall  108  and/or top of the chamber body  102 . The showerhead  130  (or lid) may be opened to allow access to the interior volume  106  of the processing chamber  100  in some embodiments, and may provide a seal for the processing chamber  100  while closed. A gas panel  158  may be coupled to the processing chamber  100  to provide process and/or cleaning gases to the interior volume  106  through the showerhead  130  or lid and nozzle. Showerhead  130  is used for processing chambers used for dielectric etch (etching of dielectric materials). The showerhead  130  may include a gas distribution plate (GDP) having multiple gas delivery holes  132  throughout the GDP. The showerhead  130  may include the GDP bonded to an aluminum showerhead base or an anodized aluminum showerhead base. The GDP  133  may be made from Si or SiC, or may be a ceramic such as Y 2 O 3 , Al 2 O 3 , YAG, and so forth. Showerhead  130  and delivery holes  132  may be coated with a multi-component coating as described in more detail below with respect to  FIGS. 4A and 4B . As illustrated, the showerhead  130  has a multi-component coating  152  both on a surface of the showerhead  130  (e.g., e.g., on a surface of a showerhead base and/or a surface of a GDP) and on walls of gas conduits (also referred to as holes)  132  in the showerhead (e.g., in the showerhead base and/or GDP), in accordance with one embodiment. However, it should be understood that any of the other chamber components, such as gas lines, electrostatic chucks, nozzles and others, may also be coated with a multi-component coating. 
     For processing chambers used for conductor etch (etching of conductive materials), a lid may be used rather than a showerhead. The lid may include a center nozzle that fits into a center hole of the lid. The lid may be a ceramic such as Al 2 O 3 , Y 2 O 3 , YAG, or a ceramic compound comprising Y 4 Al 2 O 9  and a solid-solution of Y 2 O 3 —ZrO 2 . The nozzle may also be a ceramic, such as Y 2 O 3 , YAG, or the ceramic compound comprising Y 4 Al 2 O 9  and a solid-solution of Y 2 O 3 —ZrO 2 . The lid, showerhead  130  (e.g., including showerhead base, GDP and/or gas delivery conduits/holes) and/or nozzle may all be coated with a multi-component coating according to an embodiment. 
     Examples of processing gases that may be used to process substrates in the processing chamber  100  include halogen-containing gases, such as C 2 F 6 , SF 6 , SiCl 4 , HBr, NF 3 , CF 4 , CHF 3 , CH 2 F 3 , F, NF 3 , Cl 2 , CCl 4 , BCl 3  and SiF 4 , among others, and other gases such as O 2 , or N 2 O. Examples of carrier gases include N 2 , He, Ar, and other gases inert to process gases (e.g., non-reactive gases). The substrate support assembly  148  is disposed in the interior volume  106  of the processing chamber  100  below the showerhead  130  or lid. The substrate support assembly  148  holds the substrate  144  during processing and may include an electrostatic chuck bonded to a cooling plate. 
     An inner liner may be coated on the periphery of the substrate support assembly  148 . The inner liner may be a halogen-containing gas resist material such as those discussed with reference to the outer liner  116 . In one embodiment, the inner liner  118  may be fabricated from the same materials of the outer liner  116 . Additionally, the inner liner  118  may also be coated with a multi-component coating. 
       FIG. 2  depicts a deposition process in accordance with a variety of ALD techniques. Various types of ALD processes exist and the specific type may be selected based on several factors such as the surface to be coated, the coating material, chemical interaction between the surface and the coating material, etc. The general principle for the various ALD processes comprises growing a thin film layer by repeatedly exposing the surface to be coated to sequential alternating pulses of gaseous chemical precursors that chemically react with the surface one at a time in a self-limiting manner. 
       FIG. 2  illustrates an article  210  having a surface  205 . Article  210  may represent various semiconductor process chamber components including but not limited to substrate support assembly, an electrostatic chuck (ESC), a ring (e.g., a process kit ring or single ring), a chamber wall, a base, a gas distribution plate, gas lines, a showerhead, a nozzle, a lid, a liner, a liner kit, a shield, a plasma screen, a flow equalizer, a cooling base, a chamber viewport, a chamber lid, and so on. The article  210  and surface  205  may be made from a metal (such as aluminum, stainless steel), a ceramic, a metal-ceramic composite, a polymer, a polymer ceramic composite, or other suitable materials, and may further comprise materials such as AlN, Si, SiC, Al 2 O 3 , SiO 2 , and so on. 
     Each individual chemical reaction between a precursor and the surface is known as a “half-reaction.” During each half reaction, a precursor is pulsed onto the surface for a period of time sufficient to allow the precursor to fully react with the surface. The reaction is self-limiting as the precursor will only react with a finite number of available reactive sites on the surface, forming a uniform continuous adsorption layer on the surface. Any sites that have already reacted with a precursor will become unavailable for further reaction with the same precursor unless and/or until the reacted sites are subjected to a treatment that will form new reactive sites on the uniform continuous coating. Exemplary treatments may be plasma treatment, treatment by exposing the uniform continuous adsorption layer to radicals, or introduction of a different precursor able to react with the most recent uniform continuous film layer adsorbed to the surface. 
     In  FIG. 2 , article  210  having surface  205  may be introduced to a first precursor  260  for a first duration until a first half reaction of the first precursor  260  with surface  205  partially forms layer  215  by forming an adsorption layer  214 . Subsequently, article  210  may be introduced to a second precursor  265  (also referred to as a reactant) to cause a second half reaction to react with the adsorption layer  214  and fully form the layer  215 . The first precursor  260  may be a precursor for aluminum or another metal, for example. The second precursor  265  may be an oxygen precursor if the layer  215  is an oxide or a fluorine precursor if the layer  215  is a fluoride. Layer  215  may be uniform, continuous and conformal. The article  210  may alternately be exposed to the first precursor  260  and second precursor  265  up to x number of times to achieve a target thickness for the layer  215 . X may be an integer from 1 to 100, for example. 
     Subsequently, article  210  having surface  205  and layer  215  may be introduced to a third precursor  270  that reacts with layer  215  to partially form a second layer  220  by forming a second adsorption layer  218 . Subsequently, article  210  may be introduced to another precursor  275  (also referred to as a reactant) to cause a second half reaction to fully form the layer  220 . The second film layer  220  may be uniform, continuous and conformal. The article  210  may alternately be exposed to the third precursor  270  and fourth precursor  275  up to y number of times to achieve a target thickness for the layer  220 . Y may be an integer from 1 to 100, for example. 
     Thereafter, the sequence of introducing the article  210  to precursors  260  and  265  x number of times and then to precursors  270  and  275  y number of times may be repeated and performed n number of times. N may be an integer from 1 to 100, for example. A result of the sequence may be to grow additional alternating layers  225 ,  230 ,  235 ,  240 ,  245 , and  250 . The number and thickness of the layers may be selected based on the targeted coating thickness and properties. The various layers may remain intact or in some embodiments may be interdiffused. 
     The surface reactions (e.g., half-reactions) are done sequentially. Prior to introduction of a new precursor, the chamber in which the ALD process takes place may be purged with an inert carrier gas (such as nitrogen or air) to remove any unreacted precursor and/or surface-precursor reaction byproducts. At least two precursors are used. In some embodiments, more than two precursors may be used to grow film layers having the same composition (e.g., to grow multiple layers of Y 2 O 3  on top of each other). In other embodiments, different precursors may be used to grow different film layers having different compositions. 
     ALD processes may be conducted at various temperatures depending on the type of ALD process. The optimal temperature range for a particular ALD process is referred to as the “ALD temperature window.” Temperatures below the ALD temperature window may result in poor growth rates and non-ALD type deposition. Temperatures above the ALD temperature window may result in thermal decomposition of the article or rapid desorption of the precursor. The ALD temperature window may range from about 20° C. to about 400° C. In some embodiments, the ALD temperature window is between about 150-350° C. 
     The ALD process allows for conformal film layers having uniform film thickness on articles and surfaces having complex geometric shapes, holes with large aspect ratios, and three-dimensional structures. Sufficient exposure time of the precursor to the surface enables the precursor to disperse and fully react with the surface in its entirety, including all of its three-dimensional complex features. The exposure time utilized to obtain conformal ALD in high aspect ratio structures is proportionate to the square of the aspect ratio and can be predicted using modeling techniques. Additionally, the ALD technique is advantageous over other commonly used coating techniques because it allows in-situ on demand material synthesis of a particular composition or formulation without the need for a lengthy and difficult fabrication of source materials (such as powder feedstock and sintered targets). 
     With the ALD technique, multi-component films such as YO x F y , YAl x O y , YZr x O y , and YZr x Al y O z  can be grown, for example, by proper sequencing of the precursors used to grow Y 2 O 3 , Al 2 O 3 , YF 3 , and ZrO 2 , as illustrated in more detail in the examples below. 
       FIG. 3A  illustrates a method  300  for forming a multi-component coating on a semiconductor process chamber component according to an embodiment. The method may optionally begin by selecting a composition for the multi-component coating. The composition selection and method of forming may be performed by the same entity or by multiple entities. Pursuant to block  305 , the method comprises depositing a first film layer of a yttrium oxide or a yttrium fluoride onto a surface of a semiconductor process chamber component, wherein the first film layer is grown from at least two precursors using an ALD process. Pursuant to block  310 , the method further comprises depositing a second film layer of an additional oxide or an additional fluoride onto the surface of the semiconductor process chamber component, wherein the second film layer is grown from at least two additional precursors using the ALD process. Note that the first film may be deposited before or after the second film is deposited. Accordingly, the first film may be deposited over the second film or the second film may be deposited over the first film. In some embodiments, pursuant to block  315 , the method may optionally further comprise depositing at least one additional film layer, the at least one additional film layer comprising aluminum oxide or zirconium oxide, wherein the at least one additional film layer is grown from additional precursors using the ALD process. 
     In some embodiments, when the first film layer comprises yttrium oxide, the layer may be formed by the following process sequence: 
     1) Reaction of a precursor with the substrate surface. The precursor may include tris(N,N-bis(trimethylsilyl)amide)yttrium(III), tris(cyclopentadienyl)yttrium(III), tris(butylcyclopentadienyl)yttrium(III), or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III).
 
2) Purging of non-reacted precursor from the ALD process chamber.
 
3) Reaction of a second precursor with the surface. The second precursor may include H 2 O, O 2 , or O 3 .
 
4) Purging of the second non-reacted precursor from the ALD process chamber.
 
In some embodiments, when the first film layer comprises yttrium fluoride, the two precursors used may be tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III) and TiF 4 .
 
     In some embodiments, when the second film layer comprises aluminum oxide, one precursor may include diethylaluminumethoxide, tris(ethylmethylamido)aluminum, aluminum sec-butoxide, aluminum tribromide, aluminum trichloride, triethylaluminum, triisobutylaluminum, trimethylaluminum, or tris(diethylamido)aluminum. The second precursor may include H 2 O, O 2 , or O 3 . In some embodiments, when the second film layer comprises zirconium oxide, one precursor may include zirconium (IV) bromide, zirconium (IV) chloride, zirconium (IV) tert-butoxide, tetrakis(diethylamido)zirconium (IV), tetrakis(dimethylamido)zirconium (IV), or tetrakis(ethylmethylamido)zirconium (IV). The second precursor may include H 2 O, O 2 , or O 3 . 
     The precursors listed above or any other suitable precursors may be used each time a yttrium oxide layer, a yttrium fluoride layer, an aluminum oxide layer, or a zirconium oxide layer is grown using ALD, regardless of whether it is the first, second, or Nth layer, where the Nth layer would represent the finite number of layers grown on the surface of the semiconductor process chamber component and selected based on targeted protective coating thickness and properties. 
     Pursuant to block  325 , the method ultimately comprises forming a multi-component composition of the first film layer, the second film layer, and any additional film layers. In some embodiments, pursuant to block  320 , forming the multi-component composition comprises annealing the semiconductor process chamber component comprising the first film layer, the second film layer, and any additional film layers deposited onto the semiconductor process chamber component. In some embodiments, the annealing may result in a multi-component composition comprising an interdiffused solid state phase of the at least one first film layer and the at least one second film layer and any of at least one additional film layers (if present). Annealing may be performed at a temperature ranging from about 800° C. to about 1800° C., from about 800° C. to about 1500° C., or from about 800° C. to about 1000° C. The annealing temperature may be selected based on the material of construction of the article, surface, and film layers so as to maintain their integrity and refrain from deforming, decomposing, or melting any or all of these components. 
       FIG. 3B  illustrates a method  350  for forming a multi-component coating on a semiconductor process chamber component according to an embodiment. The method may optionally begin by selecting a composition for the multi-component coating. The composition selection and method of forming may be performed by the same entity or by multiple entities. 
     Pursuant to block  355 , the method comprises depositing a film layer of a first oxide or a first fluoride onto a surface of an article via ALD. Pursuant to block  360 , the method further comprises depositing a film layer of a second oxide or a second fluoride onto the surface of the article via ALD. Note that the film layer of the first oxide or first fluoride may be deposited before or after the film layer of the second oxide or the second fluoride is deposited. Accordingly, the film layer of the first oxide or first fluoride may be deposited over the film layer of the second oxide or the second fluoride in some embodiments. In other embodiments, the film layer of the second oxide or second fluoride may be deposited over the film layer of the first oxide or the first fluoride. In some embodiments, pursuant to block  365 , the method may optionally further comprise depositing an additional film layer of a third oxide or a third fluoride onto the surface of the article via ALD. 
     In some embodiments, pursuant to block  370 , the method may further comprise determining whether additional layers are to be added. Determining whether additional layers and/or how many layers are to be added can be either done in-situ, or prior to initiating the depositions (e.g., in the optional multi-component composition selection process). If additional layers are to be added, blocks  355 ,  360 , and optionally  365  may be repeated. If no additional layers are to be added, the method proceeds to form a multi-component composition comprising all film layers deposited onto the surface of the article. 
     In some embodiments, when the first oxide, second oxide, or third oxide of any of the film layers comprises yttrium oxide, one precursor used to form yttrium oxide by ALD may be selected from tris(N,N-bis(trimethylsilyl)amide)yttrium(III), tris(cyclopentadienyl)yttrium(III), tris(butylcyclopentadienyl)yttrium(III), or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III), and the second precursor may be selected from H 2 O, O 2 , or O 3 . In some embodiments, when the first fluoride, second fluoride, or third fluoride of any of the film layers comprises yttrium fluoride, the two precursors used to form this film may be tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III) and TiF 4 . 
     In some embodiments, when the first oxide, second oxide, or third oxide of any of the film layers comprises aluminum oxide, one precursor used to form aluminum oxide by ALD may be selected from diethylaluminumethoxide, tris(ethylmethylamido)aluminum, aluminum sec-butoxide, aluminum tribromide, aluminum trichloride, triethylaluminum, triisobutylaluminum, trimethylaluminum, or tris(diethylamido)aluminum, and the second precursor may be selected from H 2 O, O 2 , or O 3 . In some embodiments, when the first oxide, second oxide, or third oxide of any of the film layers comprises zirconium oxide, one zirconium oxide precursor may be selected from zirconium (IV) bromide, zirconium (IV) chloride, zirconium (IV) tert-butoxide, tetrakis(diethylamido)zirconium (IV), tetrakis(dimethylamido)zirconium (IV), or tetrakis(ethylmethylamido)zirconium (IV), and the second precursor may be selected from H 2 O, O 2 , or O 3 . 
     The listed precursors or any other suitable precursors may be used each time a yttrium oxide layer, a yttrium fluoride layer, an aluminum oxide layer, or a zirconium oxide layer is grown using ALD, regardless of whether it is the first, second, or Nth film layer, where the Nth film layer would represent a finite number of film layers grown on the surface of the article and selected based on targeted protective coating thickness and properties. 
     In some embodiments, the method may proceed to optional block  375  where the multi-component composition of all film layers deposited onto the surface of the article may be annealed. In some embodiments, the annealing may result in a multi-component composition comprising an interdiffused solid state phase of all film layers deposited onto the surface of the article. Annealing may be performed at a temperature ranging from about 800° C. to about 1800° C., from about 800° C. to about 1500° C., or from about 800° C. to about 1000° C. The annealing temperature may be selected based on the material of construction of the article, surface, and film layers so as to maintain their integrity and refrain from deforming, decomposing, or melting any or all of these components. 
       FIGS. 4A-4D  depict variations of a multi-component coating composition according to different embodiments.  FIG. 4A  illustrates a multi-component coating composition for a surface  405  of an article  410  according to an embodiment. Surface  405  may be the surface of various articles  410 . For example, articles  410  may include carious semiconductor process chamber components including but not limited to substrate support assembly, an electrostatic chuck (ESC), a ring (e.g., a process kit ring or single ring), a chamber wall, a base, a gas distribution plate, gas lines, a showerhead, a nozzle, a lid, a liner, a liner kit, a shield, a plasma screen, a flow equalizer, a cooling base, a chamber viewport, a chamber lid, and so on. The semiconductor process chamber component may be made from a metal (such as aluminum, stainless steel), a ceramic, a metal-ceramic composite, a polymer, a polymer ceramic composite, or other suitable materials, and may further comprise materials such as AlN, Si, SiC, Al 2 O 3 , SiO 2 , and so on. 
     In  FIG. 4A , the multi component coating composition comprises: at least one first film layer  415  of a yttrium oxide or a yttrium fluoride coated onto surface  405  of article  410  using an ALD process and at least one second film layer  425  of an additional oxide or an additional fluoride coated onto surface  405  of article  410  using an ALD process. 
       FIG. 4A  illustrates an embodiment where the multi-component coating composition comprises a stack of alternating layers of the first layer  415  and the second layer  425 , where the layers are intact and not interdiffused, where there is an equal number of each of the layers (four  415  layers and four  425  layers), and where all layers are of equal uniform thickness. In some embodiments, the first film layer is deposited prior to the deposition of the second film layer, and the second film layer is deposited over the first film layer. In some embodiments, the order may be reversed. 
       FIG. 4B  illustrates an embodiment where the multi-component coating composition, deposited on surface  405  of article  410  (e.g., a semiconductor process chamber component as described above), comprises a stack of alternating layers of the first layer  415 , second layer  425 , and at least one additional layer  435 , where the layers are intact and deposited and/or grown at a predetermined order and with a uniform equal thickness. However, the number of layers may not be equal and certain layers may be more prevalent than others (e.g., three  415  layers, three  425  layers, two  435  layers). 
     In some embodiments, the at least one first film layer comprises a first continuous monolayer, and the at least one second film layer comprises a second continuous monolayer. In some embodiments, at least one additional layer may comprise at least one additional monolayer. 
     In other embodiments, the at least one first film layer comprises a first thick layer having a uniform thickness, the uniform thickness ranging from that of two monolayers to about 1 micrometer, and wherein the at least one second film layer comprises a second thick layer having the uniform thickness of the first film layer. In yet other embodiments, at least one additional film layer may comprise at least one additional thick layer having the uniform thickness of the other two thick layers. 
     In some embodiments, the multi-component coating composition may comprise at least one first film layer, at least one second film layer, and optionally one or more additional film layers, wherein the layers may vary in thickness. For example, some layers may be monolayers and some layers may be thick layers. 
       FIG. 4C  illustrates an embodiment where the multi-component coating, deposited on surface  405  of article  410 , comprises a stack of intact uniform film layers without a fixed order or fixed thickness. The multi-component coating comprises a first thick layer  420  having a first thickness, a second thick layer  430  having a second thickness different from the first thickness, and at least one additional thick layer  440  having a third thickness different from the first and the second thickness. Certain layers may be more prevalent than others so as to achieve certain properties (such as erosion/corrosion resistance) for the multi-component coating (e.g., two of the first thick layers  420 , one second thick layer  430 , one and one additional thick layer  440  layer). 
     In some embodiments, the various film layers illustrated in  FIGS. 4A through 4C  may have the same composition. In other embodiments, the compositions of the layers may be different. In some embodiments, the various film layers may have similar properties such as thickness, porosity, plasma resistance, CTE. In other embodiments, each film layer may have different properties. It is to be understood that although  FIGS. 4A-4C  depict a certain number of film layers, the Figures are not intended to be limiting, and more or less film layers may be deposited onto the surface in certain embodiments. In some embodiments, the entire surface of semiconductor process chamber component may be coated. In other embodiments, at least a portion of the semiconductor process chamber components&#39; surface may be coated. 
       FIG. 4D  illustrates an embodiment where the multi-component coating composition  450 , deposited on surface  405  of article  410 , comprises an interdiffused solid state phase of the at least one first film layer, the at least one second film layer, and optionally the at least one additional film layer. 
     In some embodiments, the multi-component coating composition, whether comprising intact layers or an interdiffused solid state phase, is selected from the group consisting of YO x F y , YAl x O y , YZr x O y  and YZr x Al y O z . The processes for creating these various multi-component coating compositions are illustrated in the examples below. 
       FIG. 5A  illustrates a bottom view of a showerhead  500 . The showerhead example provided below is just an exemplary chamber component whose performance may be improved by the use of the multi-component coating as set forth in embodiments herein. It is to be understood that the performance of other chamber components may also be improved when coated with the multi-component coating disclosed herein. The showerhead  500 , as depicted here, was chosen as an illustration of a semiconductor process chamber component having a surface with complex geometry and holes with large aspect ratios. 
     The complex geometry of lower surface  505  is configured to receive a multi-component coating. Lower surface  505  of showerhead  500  defines gas conduits  510  arranged in evenly distributed concentric rings. In other embodiments, gas conduits  510  may be configured in alternative geometric configurations and may have as many or as few gas conduits as needed depending on the type of reactor and/or process utilized. The multi-component coating is grown on surface  505  and in gas conduit holes  510  using the ALD technique which enables a conformal coating of relatively uniform thickness on the surface as well as in the gas conduit holes despite the complex geometry and the large aspect ratios of the holes. 
     Showerhead  500  may be exposed to corrosive chemistries such fluorine and may erode due to plasma interaction with the showerhead. The multi-component coating layer may reduce such plasma interactions and improve the showerhead&#39;s durability. The multi-component coating layer deposited with ALD maintains the relative shape and geometric configuration of the lower surface  505  and of the gas conduits  510  so as to not disturb the functionality of the showerhead. Similarly, when applied to other chamber components, the multi-component coating may maintain the shape and geometric configuration of the surface it is intended to coat so as to not disturb the component&#39;s functionality, provide plasma resistance, and improves erosion and/or corrosion resistance throughout the entire surface. 
     The resistance of the coating material to plasma is measured through “etch rate” (ER), which may have units of Angstrom/min (A/min), throughout the duration of the coated components&#39; operation and exposure to plasma. Plasma resistance may also be measured through an erosion rate having the units of nanometer/radio frequency hour (nm/RFHr), where one RFHr represents one hour of processing in plasma processing conditions. Measurements may be taken after different processing times. For example, measurements may be taken before processing, after 50 processing hours, after 150 processing hours, after 200 processing hours, and so on. An erosion rate lower than about 100 nm/RFHr is typical for a multi-component plasma resistant coating material. Variations in the composition of the multi-component coating grown on the showerhead or on any other semiconductor process chamber component may result in multiple different plasma resistances or erosion rate values. Additionally, a multi-component coating with a single composition exposed to various plasmas could have multiple different plasma resistances or erosion rate values. For example, a plasma resistant material may have a first plasma resistance or erosion rate associated with a first type of plasma and a second plasma resistance or erosion rate associated with a second type of plasma. 
       FIG. 5B  depicts a blown up view of a gas conduit  510  having a large aspect ratio coated according to an embodiment. Gas conduit  510  may have a length L and a diameter D. Gas conduit  510  may have a large aspect ratio defined as L:D, wherein the aspect ratio may range from about 50:1 to about 100:1. In some embodiments, the aspect ratio may be lower than 50:1 or greater than 100:1. 
     Gas conduit  510  may have an interior surface  555  which may be coated with a multi-component coating. The multi-component coating may comprise at least one first layer  560  and at least one second layer  565  and optionally at least one additional layer (not shown). The first film layer may comprise yttrium oxide or yttrium fluoride. The second film layer may comprise an additional oxide or an additional fluoride. The optional at least one additional layer may comprise aluminum oxide or zirconium oxide. All layers may be coated using an ALD process. The ALD process may grow conformal coating layers of uniform thickness throughout the interior surface of gas conduit  510  despite its large aspect ratio while ensuring that the final multi-component coating may also be thin enough so as to not plug the gas conduits in the showerhead. 
     In some embodiments, the multi-component coating may comprise intact layers of at least one first layer, at least one second layer, and optionally at least one additional layer. In an embodiment, the first, second, and any optional additional layers may alternate at a predetermined order. In another embodiment, the first, second, and any optional additional layers may be present in any order. In some embodiments, there may be an equal number of each one of the first, of the second, and of any optional additional layer. In other embodiments, some of the layers may be more prevalent than other layers so as to achieve certain properties for the multi-component coating. Certain properties may be plasma resistance and erosion/corrosion resistance that would improve the durability of the coated semiconductor process chamber component. 
     In some embodiments, the intact layers may comprise monolayers of uniform thickness. In other embodiments, the intact layers may comprise thicker layers of uniform thickness. Each thicker layer may have a thickness ranging from that of two monolayers to about 1 micrometer. In yet other embodiments, the intact layers may comprise a combination of monolayers and thick layers. 
     In other embodiments, the multi-component coating may comprise interdiffused solid state phase of at least one first layer, at least one second layer, and optionally at least one additional layer. In an embodiment, an interdiffused solid state phase of the various layers may be obtained through annealing. The composition of the layers, number of layers, frequency of each layer, and thickness of the layers will all contribute to the final properties of the multi-component coating layer. 
     The following examples are set forth to assist in understanding the embodiments described herein and should not be construed as specifically limiting the embodiments described and claimed herein. Such variations, including the substitution of all equivalents now known or later developed, which would be within the purview of those skilled in the art, and changes in formulation or minor changes in experimental design, are to be considered to fall within the scope of the embodiments incorporated herein. These examples may be achieved by performing method  300  or method  350  described above. 
     Example 1—Forming a YO x F y  Coating from Yttrium Oxide and Yttrium Fluoride Monolayers 
     The first layer may be a yttrium oxide monolayer grown using ALD from a precursor selected from tris(N,N-bis(trimethylsilyl)amide)yttrium (III) tris(cyclopentadienyl)yttrium(III), tris(butylcyclopentadienyl)yttrium(III), or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III), and a second precursor selected from H 2 O, O 2  or O 3 . The second layer may be yttrium fluoride monolayer grown using ALD from a single combination of the precursors tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III) and TiF 4 . The resulting multi-component coating may comprise YO x F y  where X and Y depend on the number of repetitions of the first and the second layer. 
     Example 2—Forming a YAl x O y  Coating from Yttrium Oxide and Aluminum Oxide Monolayers 
     The first layer may be a yttrium oxide monolayer grown using ALD from a precursor selected from tris(N,N-bis(trimethylsilyl)amide)yttrium (III), tris(cyclopentadienyl)yttrium(III), tris(butylcyclopentadienyl)yttrium(III), or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III), and a second precursor selected from H 2 O, O 2 , or O 3 . The second layer may be aluminum oxide monolayer grown using ALD from a precursor selected from diethylaluminumethoxide, tris(ethylmethylamido)aluminum, aluminum sec-butoxide, aluminum tribromide, aluminum trichloride, triethylaluminum, triisobutylaluminum, trimethylaluminum, or tris(diethylamido)aluminum, and a second precursor selected from H 2 O, O 2 , or O 3 . The resulting multi component coating may comprise YAl x O y  where X and Y depend on the number of repetitions of the first and the second layer. 
     In some experiments stacks of alternating layers of Y 2 O 3  and Al 2 O 3  were deposited via ALD, where each may layer had a thickness of 5 nm. Other thicknesses may also be used for the individual layers, such as anywhere from a few Angstroms to about 10 nm or thicker. A total coating thickness in the experiments was about 200 nm. Samples were annealed at temperatures of 500° C., 750° C., 800° C., 900° C. and or 1000° C. for 12 hrs. The annealed and as-coated samples were analyzed by grazing incidence x-ray diffraction to determine a microstructure of the coating for each of the samples. Testing showed that the coating transformed from an amorphous structure to a mostly crystalline structure consisting primarily of the cubic Y 3 Al 5 O 12  or Y 3 Al 5 O 13  (i.e., yttrium aluminum garnet) phase as a result of annealing at temperatures of 800° C. and above. At temperatures of 500° C. and °750 C, crystallization of Y 2 O 3  occurred but the yttrium aluminum garnet phase did not form. For example, after annealing at 500° C. an amorphous phase and a crystalline Y 2 O 3  phase were formed. The amorphous phase may contain some Y 2 O 3  that has not crystalized. Table 1 below shows the phase identification of a stack of alternating layer films of Al 2 O 3 /Y 2 O 3 , as-deposited and annelated at various temperatures. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Phase Identification of Al 2 O 3 /Y 2 O 3  Alternating Layer Films, 
               
               
                 As-Deposited and Annealed at Various Temperatures 
               
            
           
           
               
               
            
               
                 Annealing Temperature 
                 Phase Identified 
               
               
                   
               
               
                 No annealing 
                 Amorphous 
               
               
                 500° C. 
                 Amorphous 
               
               
                   
                 Y 2 O 3  - Cubic, SG: Fm-3m (225) 
               
               
                 750° C. 
                 Amorphous 
               
               
                   
                 Y 2 O 3  - Cubic, SG: Fm-3m (225) 
               
               
                 800° C. 
                 Y 3 Al 5 O 13  - Cubic, SG: Ia-3d (230) 
               
               
                   
                 Minor/trace phase: 
               
               
                   
                 YAlO 3  - Hexagonal, SG: P63/mmc (194) 
               
               
                 900° C. 
                 Y 3 Al 5 O 13  - Cubic, SG: Ia-3d (230) 
               
               
                   
                 Minor/Trace Phases: 
               
               
                   
                 Y 2 O 3  - Cubic, SG: ia-3 (206) 
               
               
                   
                 Al 2.66 O 4  (Aluminum Oxide (gamma)) - Cubic, 
               
               
                   
                 SG: Fd-3m (227) 
               
               
                 1000° C.  
                 Y 3 Al 5 O 12  - Cubic, SG: Ia-3d (230) 
               
               
                   
                 Minor/Trace Phases: 
               
               
                   
                 Y 4 Si 4 O 14  - Triclinic, SG: P-1 (2) 
               
               
                   
                 Amorphous 
               
               
                   
               
            
           
         
       
     
       FIG. 6  is a graph showing x-ray diffraction patterns of a stack of alternating layers of Al 2 O 3  and Y 2 O 3  as coated  605  and after annealing  610  at a temperature of 1000° C. for 12 hours. As shown, the stack of alternating layers diffused into each other and formed a Y 3 Al 5 O 12  after annealing. 
     Example 3—Forming a YZr x O y  Coating from Yttrium Oxide and Zirconium Oxide Monolayers 
     The first layer may be a yttrium oxide monolayer grown using ALD from a precursor selected from tris(N,N-bis(trimethylsilyl)amide)yttrium (III), tris(cyclopentadienyl)yttrium(III), tris(butylcyclopentadienyl)yttrium(III), or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III), and a second precursor selected from H 2 O, O 2 , or O 3 . The second layer may be zirconium oxide monolayer grown using ALD from a precursor selected from zirconium (IV) bromide, zirconium (IV) chloride, zirconium (IV) tert-butoxide, tetrakis(diethylamido)zirconium (IV), tetrakis(dimethylamido)zirconium (IV), or tetrakis(ethylmethylamido)zirconium (IV), and a second precursor selected from H 2 O, O 2 , or O 3 . The resulting multi component coating may comprise YZr x O y  where X and Y depend on the number of repetitions of the first and the second layer. 
     Example 4—Forming a YZr x Al y O z  Coating from Yttrium Oxide, Zirconium Oxide, and Aluminum Oxide Monolayers 
     The first layer may be a yttrium oxide monolayer grown using ALD from a precursor selected from tris(N,N-bis(trimethylsilyl)amide)yttrium (III), tris(cyclopentadienyl)yttrium(III), tris(butylcyclopentadienyl)yttrium(III), or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III), and a second precursor selected from H 2 O, O 2 , or O 3 . The second layer may be zirconium oxide monolayer grown using ALD from a precursor selected from zirconium (IV) bromide, zirconium (IV) chloride, zirconium (IV) tert-butoxide, tetrakis(diethylamido)zirconium (IV), tetrakis(dimethylamido)zirconium (IV), or tetrakis(ethylmethylamido)zirconium (IV), and a second precursor selected from H 2 O, O 2 , or O 3 . The at least one additional layer may be aluminum oxide monolayer grown using ALD from a precursor selected from diethylaluminum ethoxide, tris(ethylmethylamido)aluminum, aluminum sec-butoxide, aluminum tribromide, aluminum trichloride, triethylaluminum, triisobutylaluminum, trimethylaluminum, or tris(diethylamido)aluminum, and a second precursor selected from H 2 O, O 2 , or O 3 . The resulting multi component coating may comprise YZr x Al y O z  where X, Y, and Z depend on the number of repetitions of the first, second, and at least one additional layer. 
     Example 5—Forming a YO x F y  Coating from Yttrium Oxide and Yttrium Fluoride Thick Layers 
     The first layer may be a yttrium oxide thick layer grown using ALD from at least one precursor selected from tris(N,N-bis(trimethylsilyl)amide)yttrium (III), tris(cyclopentadienyl)yttrium(III), tris(butylcyclopentadienyl)yttrium(III), or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III), and at least one precursor selected from H 2 O, O 2 , or O 3 . The second layer may be yttrium fluoride thick layer grown using ALD from the precursors tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III) and TiF 4 . The resulting multi component coating may comprise YO x F y  where X and Y depend on the number of repetitions of the first and the second layer. 
     Example 6—Forming a YAl x O y  Coating from Yttrium Oxide and Aluminum Oxide Thick Layers 
     The first layer may be a yttrium oxide thick layer grown using ALD from at least one precursor selected from tris(N,N-bis(trimethylsilyl)amide)yttrium (III), tris(cyclopentadienyl)yttrium(III), tris(butylcyclopentadienyl)yttrium(III), or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III), and at least one precursor selected from H 2 O, O 2 , or O 3 . The second layer may be aluminum oxide thick layer grown using ALD from at least one precursor selected from diethylaluminum ethoxide, tris(ethylmethylamido)aluminum, aluminum sec-butoxide, aluminum tribromide, aluminum trichloride, triethylaluminum, triisobutylaluminum, trimethylaluminum, or tris(diethylamido)aluminum, and at least one precursor selected from H 2 O, O 2 , or O 3 . The resulting multi component coating may comprise YAl x O y  where X and Y depend on the number of repetitions of the first and the second layer. 
     Example 7—Forming a YZr x O y  Coating from Yttrium Oxide and Zirconium Oxide Thick Layers 
     The first layer may be a yttrium oxide thick layer grown using ALD from at least one precursor selected from tris(N,N-bis(trimethylsilyl)amide)yttrium (III), tris(cyclopentadienyl)yttrium(III), tris(butylcyclopentadienyl)yttrium(III), or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III), and at least one precursor selected from H 2 O, O 2 , or O 3 . The second layer may be zirconium oxide thick layer grown using ALD from at least one precursor selected from zirconium (IV) bromide, zirconium (IV) chloride, zirconium (IV) tert-butoxide, tetrakis(diethylamido)zirconium (IV), tetrakis(dimethylamido)zirconium (IV), or tetrakis(ethylmethylamido)zirconium (IV), and at least one precursor selected from H 2 O, O 2 , or O 3 . The resulting multi component coating may comprise YZr x O y  where X and Y depend on the number of repetitions of the first and the second layer. 
     Example 8—Forming a YZr x Al y O z  Coating from Yttrium Oxide, Zirconium Oxide, and Aluminum Oxide Thick Layers 
     The first layer may be a yttrium oxide thick layer grown using ALD from at least one precursor selected from tris(N,N-bis(trimethylsilyl)amide)yttrium (III), tris(cyclopentadienyl)yttrium(III), tris(butylcyclopentadienyl)yttrium(III), or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III), and at least one precursor selected from H 2 O, O 2 , or O 3 . The second layer may be zirconium oxide thick layer grown using ALD from at least one precursor selected from zirconium (IV) bromide, zirconium (IV) chloride, zirconium (IV) tert-butoxide, tetrakis(diethylamido)zirconium (IV), tetrakis(dimethylamido)zirconium (IV), or tetrakis(ethylmethylamido)zirconium (IV), and at least one precursor selected from H 2 O, O 2 , or O 3 . The at least one additional layer may be aluminum oxide thick layer grown using ALD from at least one precursor selected from diethylaluminum ethoxide, tris(ethylmethylamido)aluminum, aluminum sec-butoxide, aluminum tribromide, aluminum trichloride, triethylaluminum, triisobutylaluminum, trimethylaluminum, or tris(diethylamido)aluminum, and at least one precursor selected from H 2 O, O 2 , or O 3 . The resulting multi component coating may comprise YZr x Al y O z  where X, Y, and Z depend on the number of repetitions of the first, second, and at least one additional layer. 
     The preceding description sets forth numerous specific details such as examples of specific systems, components, methods, and so forth, in order to provide a good understanding of several embodiments of the present invention. It will be apparent to one skilled in the art, however, that at least some embodiments of the present invention may be practiced without these specific details. In other instances, well-known components or methods are not described in detail or are presented in simple block diagram format in order to avoid unnecessarily obscuring the present invention. Thus, the specific details set forth are merely exemplary. Particular implementations may vary from these exemplary details and still be contemplated to be within the scope of the present invention. 
     Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. In addition, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” When the term “about” or “approximately” is used herein, this is intended to mean that the nominal value presented is precise within ±10%. 
     Although the operations of the methods herein are shown and described in a particular order, the order of the operations of each method may be altered so that certain operations may be performed in an inverse order or so that certain operation may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or sub-operations of distinct operations may be in an intermittent and/or alternating manner. 
     It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.