Etching Metal Oxides Using Fluorine and Metal Halides

Abstract

To provide a method for selective atomic layer etching of a metal oxide by removal with fluorination and a metal halide and provide a fluorine source to replace HF, which may be undesirable from a manufacturing standpoint.SOLUTION: A method includes a step 110, which is an etching process, performed by atomic layer etching (ALE) in a processing chamber containing nickel chamber material and exposing the surface of a substrate 600 having an oxide layer 610 thereon to a fluorinating agent to form a fluoride layer 620, and a step 120 of exposing the fluoride layer 620 to a halide etchant to remove the fluoride layer 620.SELECTED DRAWING: Figure 4A

Description

[Technical field]

[0001]

[0001] Embodiments of the present disclosure generally relate to methods for selective atomic layer etching of metal oxides using fluorine and metal halide sources. In particular, some embodiments of the present disclosure relate to methods for selective atomic layer etching of metal oxides by fluorination and removal with metal halides. Some embodiments of the present disclosure provide an alternative fluorine source to HF, which may be undesirable from a manufacturing standpoint. [Background technology]

[0002] As semiconductor device designs and material components increase in complexity, the selective removal of materials becomes important to the continued scaling and improvement of semiconductor devices.

[0003]

[0003] Selective atomic layer etching (ALE) has emerged as a precise etching method that exploits self-limiting surface reactions. Selective ALE of metal oxides (MOx) is particularly important for several semiconductor technologies, but can be difficult to achieve due to the inherent stability of these oxide materials. One such example is the selective removal of HfO2 during recess etching of high-k metal gate structures.

[0004]

[0004] Selective removal of metal oxides and nitrides is important for continued miniaturization and optimization in semiconductor manufacturing. Although several etching processes exist, they are either not selective or rely on HF as the fluorine source. HF is toxic and creates handling issues during manufacturing. An alternative fluorine source for metal oxide etching that avoids these concerns is desirable for widespread adoption of the etching process.

[0005] Therefore, there is a need for new sources of fluorine and metal halides for selectively removing metal oxides and metal nitrides. Summary of the Invention

[0006]

[0006] One or more embodiments of the present disclosure relate to an etching process that includes exposing a substrate surface having an oxide layer thereon to a fluorinating agent to convert a portion of the oxide layer to a fluoride layer, and exposing the fluoride layer to a halide etchant to remove the fluoride layer.

[0007]

[0007] An additional embodiment of the present disclosure relates to an etching process that includes exposing a substrate surface having an oxyhydride layer thereon to a fluorinating agent to form a fluoride layer, and exposing the fluoride layer to a halide etchant to remove the fluoride layer.

[0008]

[0008] A further embodiment of the present disclosure relates to an etching process that includes exposing a substrate surface having an oxide layer and a second material to a fluorinating agent in a process chamber that includes nickel chamber material to selectively convert a portion of the oxide layer to a fluoride layer. The second material includes one or more of TiN, SiN, TaN, SiO, AlO, LaO, carbon, silicon, or combinations thereof. The fluoride layer is exposed to a halide etchant to remove the fluoride layer.

[0009]

[0009] In order that the above-mentioned features of the present disclosure may be understood in detail, a more particular description of the present disclosure briefly summarized above will be made by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only typical embodiments of the present disclosure and therefore should not be considered as limiting its scope, and that the present disclosure may admit of other equally effective embodiments. [Brief description of the drawings]

[0010] [Figure 1] 1 is a flowchart of an example method according to one or more embodiments of the present disclosure. [Diagram 2] 1 is a flowchart of an example method according to one or more embodiments of the present disclosure. [Diagram 3]1 is a flowchart of an example method according to one or more embodiments of the present disclosure. [Figure 4A] 1 is a cross-sectional view of an exemplary substrate during processing in accordance with one or more embodiments of the present disclosure. [Figure 4B] 1 is a cross-sectional view of an exemplary substrate during processing in accordance with one or more embodiments of the present disclosure. [Figure 4C] 1 is a cross-sectional view of an exemplary substrate during processing in accordance with one or more embodiments of the present disclosure. [Figure 4D] 1 is a cross-sectional view of an exemplary substrate during processing in accordance with one or more embodiments of the present disclosure. [Figure 4E] 1 is a cross-sectional view of an exemplary substrate during processing in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011]

[0014] Before describing certain example embodiments of the present disclosure, it is to be understood that the present disclosure is not limited to the details of structure or process steps set forth in the following description as the present disclosure is capable of other embodiments and of being practiced or carried out in various ways.

[0012]

[0015] As used herein and in the appended claims, the term "substrate" refers to a surface or a portion of a surface on which a process acts. It will be understood by those skilled in the art that references to a substrate may refer to only a portion of the substrate, unless the context clearly indicates otherwise. Additionally, references to depositing on or etching from a substrate may refer to both a bare substrate and a substrate having one or more films or features deposited or formed thereon.

[0013]

[0016] As used herein, "substrate" refers to any substrate or material surface formed on a substrate on which a film treatment is performed during a manufacturing process. For example, substrate surfaces on which treatment may be performed include materials such as silicon, silicon oxide, strained silicon, silicon-on-insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, glass, sapphire, as well as other materials such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. Substrates include, but are not limited to, semiconductor wafers. Substrates may be exposed to pretreatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure, and / or bake the substrate surface. In addition to film treatment directly on the surface of the substrate itself, in this disclosure, any of the disclosed film treatment steps may also be performed on an underlayer formed on the substrate, as disclosed in more detail below, and the term "substrate surface" is intended to include the underlayer as the context indicates. Thus, for example, where a film / layer or partial film / layer has been removed from a substrate surface, the newly exposed surface of the film, layer, or substrate becomes the substrate surface.

[0014]

[0017] As used herein and in the appended claims, the terms "precursor," "reactant," "reactive gas," and the like are used interchangeably to refer to any gas species capable of reacting with the substrate surface.

[0015]

[0018] "Atomic layer etching" (ALE) or "cyclic etching" is a variation of atomic layer deposition in which a surface layer is removed from a substrate. As used herein, ALE refers to the sequential exposure of two or more reactive compounds to etch a layer of material on the substrate surface. The substrate, or a portion of the substrate, is exposed separately to two or more reactive compounds that are introduced into a reaction zone of a processing chamber.

[0016]

[0019] In a time-domain ALE process, exposure to each reactive compound is separated by a time delay to allow each compound to adhere to and / or react on the substrate surface and then be purged from the processing chamber. The reactive compounds are said to be exposed to the substrate sequentially.

[0017]

[0020] In one aspect of a time-domain ALE process, a first reactive gas (i.e., a first reactant or compound A) is pulsed into the reaction zone, followed by a first time delay. Then, a second reactant or compound B is pulsed into the reaction zone, followed by a second delay. During each time delay, a purge gas, such as argon, is introduced into the process chamber to purge the reaction zone or otherwise remove residual reactive compounds or reaction by-products from the reaction zone. Alternatively, the purge gas may flow continuously throughout the etching process, such that only the purge gas flows during the time delay between pulses of reactive compounds. The reactive compounds are alternately pulsed until the desired film or film thickness is removed from the substrate surface.

[0018]

[0021] The ALE process of pulsing compound A, purge gas, compound B, and purge gas is called a cycle. A cycle can start with either compound A or compound B, and each turn of the cycle can be continued until the desired thickness is removed.

[0019]

[0022] In a spatial ALE process, different portions of a substrate surface, or different portions of materials on a substrate surface, are exposed to two or more reactive compounds simultaneously such that any given point on the substrate is not substantially exposed to more than one reactive compound simultaneously. As used in this regard, the term "substantially" means that only a small portion of the substrate may be exposed to multiple reactive gases at the same time due to diffusion, as will be understood by those skilled in the art, and that simultaneous exposure is not intended.

[0020]

[0023] In one embodiment of a spatial ALE process, a first reactive gas and a second reactive gas are simultaneously supplied to a reaction zone but separated by an inert gas and / or vacuum curtain, and the substrate is moved relative to the gas supply such that any given point on the substrate is exposed to the first reactive gas and the second reactive gas.

[0021]

[0024] Some embodiments of the present disclosure relate to methods for etching or removing metal oxides from a substrate surface. Some methods of the present disclosure advantageously utilize fluorinating agents other than HF.

[0022]

[0025] Some methods of the present disclosure advantageously provide a method for selectively removing metal oxide materials over other substrate materials. As used in this context, terms such as "selectively removing one film over another" mean that a first amount is removed from a first surface or material while a second amount is removed from a second surface or material, the second amount being less than the first amount or no film being removed from the second surface. As used in this context, the term "over" does not mean that one surface is physically oriented over another surface, but rather refers to the relationship of thermodynamic or kinetic properties of a chemical reaction with one surface compared to the other surface.

[0023]

[0026] The selectivity of a process is commonly expressed as a multiple of the etch rate or ratio of etch rates between different surfaces. For example, if one surface etches 25 times faster than another surface, the process is described as having a selectivity of 25:1. In this regard, a higher ratio indicates a more selective process.

[0024]

[0027] One or more embodiments of the present disclosure relate to a method for removing metal oxides. In some embodiments, a substrate including an oxide surface can be treated with a fluorine source (also called a fluorinating agent), then purged, followed by treatment with a metal halide (also called a halide etchant), followed by purging. This cycle can be repeated to remove a predetermined thickness of metal oxide.

[0025]

[0028] 1 and 4A, method 100 begins at step 110, where a substrate 600 including an oxide layer 610 is exposed to a fluorinating agent to form a fluoride layer 620. Method 100 continues at step 120, where the fluoride layer 620 is exposed to a halide etchant to remove the fluoride layer 620. An exemplary reaction scheme of method 100 shown in FIGS. 1 and 4A is provided by Scheme 1.

[0026]

[0029] Scheme 1:

[0027]

[0030] Metal oxide + fluorine source → metal fluoride layer (1)

[0028]

[0031] Metal fluoride layer + metal halide → volatile products (2)

[0029]

[0032] In some embodiments, as shown in Scheme 1, oxide layer 610 comprises a metal oxide. In these embodiments, fluoride layer 620 may be referred to as a metal fluoride layer. In some embodiments, the metal oxide comprises one or more of hafnium oxide, tungsten oxide, molybdenum oxide, titanium oxide, or combinations thereof. In some embodiments, the metal oxide comprises or consists essentially of hafnium oxide.

[0030]

[0033] As used in this regard, a material consists essentially of a recited material if it is about 95%, 98%, 99%, or 99.5% or more of the recited material on an atomic basis.

[0031]

[0034] The fluorinating agent may include any suitable reactant for forming a fluoride termination on at least the surface of the oxide layer. In some embodiments, the fluorinating agent includes one or more of HF, NF3, a plasma thereof, or a combination thereof. In some embodiments, the fluorinating agent consists essentially of HF. In some embodiments, the fluorinating agent is substantially free of HF. In some embodiments, the fluorinating agent consists essentially of NF3.

[0032]

[0035] As used in this regard, a reactant consists essentially of a recited species if the reactant is about 95%, 98%, 99%, or 99.5% or more of the recited species on a molar basis, excluding diluents or other inert (non-reactive) species.

[0033]

[0036] As used in this regard, a reaction is substantially free of a recited species if no more than about 5%, 2%, 1%, or 0.5% of the reaction, excluding diluents or other inert (non-reactive) species, is made up of the recited species.

[0034]

[0037] In some embodiments, the fluorinating agent comprises one or more of an organic fluoride, an organic acid fluoride, a metal fluoride, or a combination thereof. In some embodiments, the organic fluoride has a general formula of CxHyFz, where x is 1-16, y is 0-33, and z is 1-34. In some embodiments, the organic acid fluoride has a general formula of CxHyOwFz, where x is 1-16, y is 0-33, w is 1-8, and z is 1-34.

[0035]

[0038] In some embodiments, the metal fluoride has a general formula of MFz, where M is selected from one or more of molybdenum, tungsten, vanadium, niobium, titanium, or tantalum, and z is 1 to 6. In some embodiments, the metal fluoride comprises or consists essentially of MoF6, WF6, VF3, VF4, VF5, NbF5, TiF4, or TaF5.

[0036]

[0039] In some embodiments, the fluorinating agent is flowed with an additional gas, hi some embodiments, the additional gas is selected from one or more of O2, N2O, NH3, or H2.

[0037]

[0040] After the fluoride layer is formed, the fluoride layer 620 is exposed to a halide etchant to remove the fluoride layer 620. In some embodiments, the halide etchant is referred to as a metal halide. In some embodiments, the halide etchant includes one or more species having a general formula of EX3, where E includes one or more of aluminum (Al) or boron (B) and X includes one or more of Cl, Br, or I. In some embodiments, the halide etchant includes or consists essentially of BCl3.

[0038]

[0041] In some embodiments, the halide etchant comprises or consists essentially of one or more species having the general formula of MXy, where M comprises one or more of Ti, Sn, Mo, W, or Nb, X comprises one or more of Cl, Br, or I, and y is 1-6. In some embodiments, the halide etchant comprises or consists essentially of one species having the general formula of MXy, where M comprises one or more of Ti, Sn, Mo, W, or Nb, X comprises one or more of Cl or Br, and y is 1-6.

[0039]

[0042] In some embodiments, exposing the oxide layer to a fluorinating agent produces a fluoride layer that is on average at most one monolayer thick. Without being bound by theory, it is believed that the surface terminations of the oxide layer react with the fluorinating agent to produce fluoride terminations on the surface of the oxide layer. This surface reaction is limited to the exposed surface of the oxide layer and affects only the top layer of atoms of the oxide layer. Thus, in some embodiments, the method 100 removes an oxide layer that is one monolayer thick or less.

[0040]

[0043] In some embodiments, the method 100 is repeated. After removing the bulk fluoride layer, a new layer of oxide layer is exposed. The method 100 can be repeated to remove a predetermined amount or thickness of the oxide layer.

[0041]

[0044] Additional embodiments relate to methods of removing etch residues or other contaminants from a metal oxide surface prior to performing the above-described method 100 to etch the oxide layer. Referring to Figures 1 and 4B, in these embodiments, the method 100 begins at step 105 where contaminants 630 are cleaned from an oxide layer 610 on a substrate 600. Once the contaminants 630 have been removed from the surface of the oxide layer 610, the method 100 continues as described above by exposing the oxide layer 610 to a fluorinating agent to form a fluoride layer 620 and exposing the fluoride layer 620 to a halide etchant to remove the fluoride layer 620.

[0042]

[0045] In some embodiments, the contaminants include carbon film or moisture on the surface of the oxide layer 610. Without being bound by theory, it is believed that these residues may interfere with the fluorination and removal of the oxide layer 610. In some embodiments, prior to the disclosed method 100, an etching process is performed, resulting in etching residues or contaminants including moisture and / or carbon film.

[0043]

[0046] In step 105, the etch residues or contaminants 630 can be removed by exposing the substrate to a radical cleaning process. In some embodiments, the radicals in the cleaning process are H * , O.H. * , O * or H2O * In some embodiments, the radicals are generated by passing a radical gas over a hot wire. In some embodiments, the radicals are generated by forming a plasma from the radical gas. In some embodiments, the plasma is generated by a remote plasma source.

[0044]

[0047] An exemplary reaction scheme of method 100 including step 105 is provided by Scheme 2.

[0045]

[0048] Scheme 2:

[0046]

[0049] Moisture / carbon bearing surface + plasma → metal oxide (1)

[0047]

[0050] Metal oxide + fluorine source → metal fluoride layer (2)

[0048]

[0051] Metal fluoride layer + metal halide → volatile products (3)

[0049]

[0052] 4C, in some embodiments, the method 100 selectively removes the oxide layer 610 as compared to other materials 640 on the exposed surface of the substrate 600. In some embodiments, the other materials may include or consist essentially of TiN, TaN, SiN, SiO2, Al2O3, carbon-based materials, or combinations thereof.

[0050]

[0053] In some embodiments, the selectivity for removal of oxide layer 610 compared to other materials 640 is about 5:1 or greater, about 10:1 or greater, about 15:1 or greater, about 20:1 or greater, or about 25:1 or greater.

[0051]

[0054] In a particular embodiment, the hafnium oxide layer is etched by exposure to NF3 / H2 and BCl3. The process is selective to TiN, SiN, SiO2, Al2O3, and carbon with a selectivity of about 20:1 or greater.

[0052]

[0055] Additional embodiments of the present disclosure relate to methods of increasing the selectivity of the above method 100 by performing the method in a process chamber that includes nickel chamber material, hi some embodiments, the nickel chamber material is found as part of one or more of the process kit, showerhead, pedestal, or confinement rings.

[0053]

[0056] As described above, the substrate 600 including the oxide layer 610 is exposed to a fluorinating agent to form a fluoride layer 620. The chamber is then purged. The fluoride layer is exposed to a halide etchant and the chamber is purged again. This cycle can be repeated to remove a predetermined thickness of the oxide layer 610. The fluorinating agent and halide etchant used can be any of the fluorinating agents and / or halide etchants described above.

[0054]

[0057] The inventors have surprisingly discovered that when performed in a process chamber comprising nickel chamber material, the oxide layer is selectively removed over TiN, SiN, TaN, SiO, AlO, LaO, carbon and silicon, in some embodiments, the selectivity of the oxide layer compared to silicon is about 5:1 or greater, about 10:1 or greater, about 15:1 or greater, about 20:1 or greater, about 25:1 or greater, about 30:1 or greater, about 35:1 or greater, about 40:1 or greater, about 45:1 or greater, or about 50:1 or greater.

[0055]

[0058] Some embodiments of the present disclosure relate to a method for removing metal oxides of thickness greater than an atomic layer in a single process cycle. Referring to Figures 2 and 4D, the method 200 begins at step 210, where a substrate 600 including an oxide layer 610 is exposed to a fluorinating agent to form a bulk fluoride layer 650 of thickness T.

[0056]

[0059] The fluorinating agent used in method 200 can be any of the fluorinating agents described above with respect to method 100. To achieve a depth of fluorination, in some embodiments, the fluorinating agent can further include H2.

[0057]

[0060] In some embodiments, the thickness of the bulk fluoride layer is about 5 Å or more, about 10 Å or more, about 15 Å or more, or about 20 Å or more. In some embodiments, the thickness of the bulk fluoride layer is in the range of about 5 Å to about 30 Å, or in the range of about 7 Å to about 20 Å, or in the range of about 10 Å to about 15 Å.

[0058]

[0061] Method 200 continues at step 220 by exposing bulk fluoride layer 650 to a halide etchant to remove bulk fluoride layer 650. The halide etchant used in method 200 can be any of the halide etchants described above with respect to method 100. An exemplary reaction scheme of method 200 shown in FIG. 2 is provided by Scheme 3.

[0059]

[0062] Scheme 3:

[0060]

[0063] Metal oxide + fluorine source → bulk fluoride layer (1)

[0061]

[0064] Bulk fluoride layer + metal halide → volatile products (2)

[0062]

[0065] Some embodiments of the present disclosure relate to methods of etching metal oxyhydride materials rather than the oxide layers described above. Referring to Figures 3 and 4E, the method 300 begins at step 310 by exposing an oxide layer 610 to an oxidizing plasma to form an oxyhydride layer 660.

[0063]

[0066] The oxyhydride layer 660 can be formed by exposing the oxide layer to an oxidizing plasma. In some embodiments, the oxidizing plasma is a remote plasma. In some embodiments, the oxidizing plasma includes one or more radicals of water, peroxide, alcohol, or combinations thereof. In some embodiments, the oxidizing plasma includes one or more radicals of OH * Contains radicals.

[0064]

[0067] Method 300 continues at step 320 by exposing oxyhydride layer 660 to a fluorinating agent to form fluoride layer 670. The fluorinating agent used in method 300 can be any of the fluorinating agents described above with respect to method 100.

[0065]

[0068] The method 300 continues at step 330 by exposing the fluoride layer to a halide etchant to remove the fluoride layer 670. 3 The halide etchant used in method 00 can be any of the halide etchants described above with respect to method 100.

[0066]

[0069] An exemplary reaction scheme for method 300 shown in FIG.

[0067]

[0070] In some embodiments, the method 300 is repeated to remove a predetermined thickness of the oxide layer 610 and / or the oxyhydride layer 660.

[0068]

[0071] Scheme 4:

[0069]

[0072] Oxide layer +OH * Radical → Acid Hydride Layer (A)

[0070]

[0073] Acid hydride layer + fluoride source → fluoride layer (1)

[0071]

[0074] Fluoride layer + metal halide → volatile products (2)

[0072]

[0075] References throughout this specification to "one embodiment," "a particular embodiment," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of phrases such as "in one or more embodiments," "in a particular embodiment," "in one embodiment," or "in an embodiment" in various places throughout this specification do not necessarily refer to the same embodiment of the present disclosure. Furthermore, particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0073]

[0076] Although the disclosure herein has been described with reference to specific embodiments, those skilled in the art will recognize that the described embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed method and apparatus without departing from the spirit and scope of the disclosure. Thus, the disclosure may include modifications and variations that come within the scope of the appended claims and their equivalents.

Claims

1. A method for producing a fluoride layer comprising: exposing a substrate surface having an oxide layer thereon, the oxide layer comprising one or more of hafnium, tungsten, molybdenum, and titanium, to a fluorinating agent to form a fluoride layer; The fluoride layer is formed of a compound having the general formula EX ３ removing the fluoride layer by exposing the fluoride layer to a halide etchant comprising a compound having the formula: Including, The etching process, wherein the fluorinating agent comprises one or more of an organic fluoride, an organic acid fluoride, a metal fluoride, combinations thereof, and plasmas thereof.

2. 2. The etching process of claim 1, wherein the oxide layer consists essentially of hafnium oxide.

3. The etching process of claim 1, wherein the organic fluoride has the general formula CxHyFz (x is 1 to 16, y is 0 to 33, z is 1 to 34), and the organic acid fluoride has the general formula CxHyOwFz (x is 1 to 16, y is 0 to 33, w is 1 to 8, z is 1 to 34).

4. 2. The etching process of claim 1, wherein E comprises boron (B).

5. A method for producing a fluoride layer comprising: exposing a substrate surface having an oxide layer thereon, the oxide layer comprising one or more of hafnium, tungsten, molybdenum, and titanium, to a fluorinating agent to form a fluoride layer; exposing the fluoride layer to a halide etchant comprising a compound having a general formula EX3, where E comprises one or more of aluminum (Al) and boron (B), and X comprises one or more of Cl, Br, and I, to remove the fluoride layer; Including, 1. An etching process wherein the halide etchant comprises a compound having a general formula MXy, where M comprises one or more of titanium (Ti), tin (Sn), molybdenum (Mo), tungsten (W), and niobium (Nb), and X comprises one or more of Cl, Br, and I, and y is 1-6.

6. 2. The etching process of claim 1, further comprising repeating exposure to said fluorinating agent and said halide etchant to remove a predetermined thickness of said oxide layer.

7. A method for producing a fluoride layer comprising: exposing a substrate surface having an oxide layer thereon comprising one or more of hafnium, tungsten, molybdenum, and titanium to a fluorinating agent to form a fluoride layer; exposing the fluoride layer to a halide etchant comprising a compound having a general formula EX3, where E comprises one or more of aluminum (Al) and boron (B), and X comprises one or more of Cl, Br, and I, to remove the fluoride layer; Including, The fluorinating agent is hydrogen (H ２ ) and the fluoride layer has a thickness in the range of about 10 Å to about 15 Å.

8. 8. The etching process of claim 7, wherein the fluoride layer is formed in a process chamber comprising a nickel chamber material.

9. A method for cleaning a substrate comprising: exposing a substrate surface to a cleaning plasma comprising one or more of H*, OH*, O*, and H2O*; exposing the substrate surface having an oxide layer thereon comprising one or more of hafnium, tungsten, molybdenum, and titanium to a fluorinating agent after exposing the substrate surface to the cleaning plasma to form a fluoride layer; exposing the fluoride layer to a halide etchant comprising a compound having a general formula EX3, where E comprises one or more of aluminum (Al) and boron (B), and X comprises one or more of Cl, Br, and I, to remove the fluoride layer; An etching process comprising:

10. The etching process of claim 9 , wherein the cleaning plasma removes carbon films and / or moisture from the substrate surface.

11. The etching process of claim 10 , wherein the carbon film and / or moisture is a result of an etching process.

12. A method for producing a fluoride layer comprising: exposing a substrate surface having an oxide layer thereon comprising one or more of hafnium, tungsten, molybdenum, and titanium to a fluorinating agent to form a fluoride layer; exposing the fluoride layer to a halide etchant comprising a compound having a general formula EX3, where E comprises one or more of aluminum (Al) and boron (B), and X comprises one or more of Cl, Br, and I, to remove the fluoride layer; Including, An etching process wherein the substrate surface has at least one other material thereon, and the oxide layer is selectively etched relative to the at least one other material.

13. The at least one other material is TiN, TaN, SiN, SiO ２ , Al ２ O ３ 13. The etching process of claim 12, further comprising one or more of:

14. 13. The etching process of claim 12, wherein the selectivity of the etching process is about 10:1 or greater.

15. A method for producing a fluoride layer comprising: exposing a substrate surface having an oxyhydride layer thereon formed by exposing an oxide layer comprising one or more of hafnium, tungsten, molybdenum, and titanium to a plasma formed from one or more of H2O, H2O2, and an alcohol, to a fluorinating agent to form a fluoride layer; The fluoride layer is formed of a compound having the general formula EX ３ removing the fluoride layer by exposing the fluoride layer to a halide etchant comprising a compound having the formula: The etching process includes

16. 16. The etching process of claim 15, wherein the oxide layer consists essentially of hafnium oxide.

17. A method of selectively converting a portion of the oxide layer to a fluoride layer, comprising exposing a substrate surface having an oxide layer comprising one or more of hafnium, tungsten, molybdenum, and titanium, and a second material comprising one or more of TiN, SiN, TaN, SiO, AlO, LaO, carbon, silicon, and combinations thereof, to a fluorinating agent in a process chamber comprising a nickel chamber material; The fluoride layer is formed of a compound having the general formula EX ３ removing the fluoride layer by exposing the fluoride layer to a halide etchant comprising a compound having the formula: The etching process includes

18. 20. The etch process of claim 17, wherein the second material consists essentially of silicon and the etch process has a selectivity of about 20:1 or greater.

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