Selective Deposition of Ruthenium Films by Using Ru(I) Precursors

Abstract

The disclosed and claimed invention relates to the use of Ru(I) precursors in ALD or ALD-like methods for the selective deposition of Ru films.

Description

[Technical field]

[0001] The disclosed and claimed invention relates to the use of Ru(I) precursors for use in atomic layer deposition (ALD) and ALD-like processes for selective Ru-containing film growth on at least one substrate. [Background technology]

[0002] Thin films, especially metal-containing thin films, have a variety of important applications in nanotechnology and in the fabrication of semiconductor devices. Examples of such applications include high refractive index optical coatings, corrosion protection coatings, photocatalytic self-cleaning glass coatings, biocompatible coatings, dielectric capacitor layers and gate dielectric insulating films in field effect transistors (FETs), capacitor electrodes, gate electrodes, adhesion diffusion barriers, and integrated circuits. Metallic and dielectric thin films are also used in microelectronic applications, such as high-κ dielectric oxides for dynamic random access memory (DRAM) applications, and ferroelectric perovskites used in infrared detectors and non-volatile ferroelectric random access memory (NV-FeRAM).

[0003] A variety of precursors can be used to form metal-containing thin films, and a variety of deposition techniques can be utilized, including reactive sputtering, ion-assisted deposition, sol-gel deposition, chemical vapor deposition (CVD) (also known as metalorganic CVD or MOCVD), atomic layer deposition (ALD) (also known as atomic layer epitaxy), and the like. CVD and ALD techniques are increasingly being used because they have the advantages of enhanced composition control, high film uniformity, and effective control of doping.

[0004] Conventional CVD is a chemical process in which precursors are used to form a thin film on a substrate surface. In a typical CVD process, precursors are flowed onto the surface of a substrate (e.g., a wafer) in a low-pressure or ambient pressure reaction chamber. The precursors react and / or decompose on the substrate surface to form a thin film of deposited material. Volatile by-products are removed by flowing gas through the reaction chamber. The deposited film thickness can be difficult to control because it depends on the coordination of many parameters, such as temperature, pressure, gas volumetric flow rate and uniformity, chemical depletion effects, and time.

[0005] ALD is also a method for the deposition of thin films. It is a self-limiting, continuous, and unique film growth technique based on surface reactions that can provide precise thickness control and can deposit conformal thin films of materials provided by precursors on surface substrates of various compositions. In ALD, the precursors are separated during the reaction. A first precursor is flowed onto the substrate surface, producing a monolayer on the substrate surface. Excess unreacted precursor is evacuated from the reaction chamber. A second precursor is then flowed onto the substrate surface and reacts with the first precursor to form a second monolayer of film on the first formed monolayer of film on the substrate surface. This cycle is repeated until a film of the desired thickness is formed.

[0006] In conventional chemical vapor deposition (CVD) methods, precursors and co-reactants are introduced into a deposition chamber via the gas phase to deposit a thin film on a substrate. On the other hand, in atomic layer deposition (ALD) or ALD-like methods, precursors and co-reactants are introduced into the deposition chamber sequentially, thus enabling surface-controlled layer-by-layer deposition and, importantly, self-limiting surface reactions to achieve atomic-level growth of thin films. The key to successful ALD deposition methods is the use of precursors that undergo a reaction scheme consisting of a sequence of separate self-limiting adsorption and reaction steps. One of the great advantages of ALD methods is that they offer much greater conformality than CVD for substrates with high aspect ratios, such as greater than 8.

[0007] However, the size of microelectronic components, such as semiconductor devices, is constantly shrinking, presenting several technical challenges and creating a demand for improved thin film technologies. In particular, microelectronic components may include features on or in a substrate that require filling, for example, to form conductive paths or to form interconnects. Filling such features, especially in smaller microelectronic components, can be difficult as these features can become increasingly thin or narrow. As a result, complete filling of the features, for example by ALD, would require infinitely long cycle times as the feature thickness approaches zero. Furthermore, when the feature thickness becomes thinner than the molecular size of the precursor, the feature cannot be completely filled. As a result, when ALD is performed, a hollow seam may remain in the center of the feature. The presence of such a hollow seam in the feature is undesirable as it may lead to device failure. Therefore, there is great interest in developing thin film deposition methods, particularly ALD methods, that can selectively grow films on more than one substrate and achieve improved filling of features on or in a substrate, such as depositing a metal-containing film such that the feature is substantially filled without voids.

[0008] As can be seen from the above, in conventional semiconductor device manufacturing, patterning is a "top-down" process based mainly on photolithography and etching, which is the main bottleneck for device size reduction. In contrast, area-selective deposition (e.g., CVD and ALD) is an alternative "bottom-up" patterning method for advanced semiconductor manufacturing, in which a metal layer (e.g., Ru) is grown on the bottom metal surface (e.g., Ru and TiN) adjacent to a passivated dielectric substrate, rather than on the dielectric (e.g., SiO2) sidewalls. See, e.g., FIG. 1. It is also desirable that these processes be oxygen-free and / or have relatively low resistance.

[0009] For future advanced node manufacturing, a process is needed to selectively grow Ru on the bottom metal surface of recessed features (i.e., the sidewalls of the recessed features are the dielectric layer surface such as SiO2 and Si3N4, and the bottom metal surface is Ru or TiN). Several methods are known with varying degrees of success, but they have drawbacks that make them unsuitable for advanced processes. Generally, oxygen-free processes to grow Ru films are limited to dodecacarbonyl ruthenium (DCR), which has several significant drawbacks (i.e., the stability of DCR decreases with increasing temperature; the Ru(0) center of DCR is only supported by CO, which leads to decomposition at relatively high temperatures; DCR requires CO as a carrier gas; and CVD Ru deposited by DCR leads to gap-fill problems in narrow vias and trenches).

[0010] For example, US10,014,213 describes the selective growth of Ru on bottom metal surfaces, which involves first treating a dielectric surface with a silane-type reactant to create a hydrophobic surface. Ru can then be grown on the bottom metal surface by vapor phase deposition. The silane-type reactant disclosed in the method includes (dimethylamino)trimethylsilane (DMATMS), and the Ru precursors used include DCR, Ru(DMPD)EtCp, Ru(DMPD)MeCp, and Ru(DMPD)2. However, DCR is an unstable Ru(O) precursor, which causes process problems by generating CO and / or CO2 by-products. In contrast, Ru(DMPD)EtCp, Ru(DMPD)MeCp, and Ru(DMPD)2 are inert Ru(II) complexes. Besides the lack of a practical way of enabling how to use these Ru(II) precursors, it is a well-established fact that the use of these precursors requires reaction with an oxygen source to produce the Ru film, which is highly undesirable in advanced processes due to the potential for oxidizing the underlayer.

[0011] US8,178,439 describes a method for selectively growing a Ru capping layer on the metal surface (Ru) of a planarized substrate, but not on a dielectric surface (SiO2) pretreated with DMATMS. The Ru precursor used in this patent is DCR (Ru(0)). However, unlike the process disclosed and claimed herein, the method described in US8,178,439 requires the growth of a Ru capping layer on a "planarized substrate" as opposed to a Ru layer on the bottom surface of a via or trench. US8,242,019 and US10,378,105 describe similarly flawed methods. As described below, DCR is an unstable Ru(0) precursor, which is unsuitable for selective deposition processes due to the formation of CO and CO2 by-products during use.

[0012] Considering the above, it is clear that there is a lack of suitable Ru precursors for atomic layer deposition (ALD) and ALD-like processes for selective Ru-containing film growth. DCR is a Ru(0) compound, whereas Ru(DMPD)EtCp, Ru(DMPD)MeCp and Ru(DMPD)2 are Ru(II) compounds. It is well known that DCR, being a Ru(O) compound with a relatively low oxidation state, leads to complex instability. The instability of DCR results in the formation of CO and CO2 by-products, which may damage the underlying substrate during processing. Furthermore, the instability of DCR means that it can only be used for CVD reactions, which may cause step coverage issues for advanced nodes. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] US10,014,213 [Patent Document 2] US8,178,439 [Patent Document 3] US8,242,019 [Patent Document 4] US10,378,105 [Non-patent literature]

[0014] [Non-Patent Document 1] George SM,et al.J.Phys.Chem.,1996,100,13121-13131 [Non-Patent Document 2] Chemical Vapour Deposition: Precursors,Processes,and Applications;Jones,AC;Hitchman,ML,Eds.,The Royal Society of Chemistry:Cambridge,2009;Chapter 1,pp.1-36 Summary of the Invention [Problem to be solved by the invention]

[0015] Given the above-mentioned shortcomings of Ru(0), it would be naturally preferable to select Ru compounds with higher oxidation states (i.e., I, II and III) to enhance the stability of selective deposition processes. However, it has not yet been reported that Ru(II) precursors (e.g., Ru(DMPD)EtCp, Ru(DMPD)MeCp and Ru(DMPD)2) can be used for atomic layer deposition (ALD) and ALD-like processes for selective Ru-containing film growth. In fact, no other Ru precursors with oxidation states I, II and III appear to be described in the known art for these types of selective deposition processes.

[0016] The disclosed and claimed invention provides the first example of a Ru(I) precursor successfully used for the selective ALD of Ru films. [Means for solving the problem]

[0017] In one aspect, the disclosed and claimed invention relates to atomic layer deposition (ALD) and ALD-like methods for selective Ru-containing film growth comprising, consisting essentially of, or consisting of: (i) pre-treating a surface of a dielectric substrate, such as a Si-containing substrate (e.g., SiO) with a surface conversion material (e.g., DMATMS or a similar material) to passivate the dielectric material by converting potentially reactive surface groups (e.g., -OH groups) to unreactive / less reactive groups (e.g., hydrophobic -CH groups), and thereafter (ii) selectively depositing a Ru-containing layer using a Ru(I) precursor in combination with a co-reactant (e.g., H) on a metal (e.g., Ru, TiN, W) substrate surface disposed in proximity to the passivated dielectric substrate, but not on the dielectric substrate surface.

[0018] In yet another aspect, the Ru(I) precursor used in the disclosed and claimed methods comprises a ruthenium pyrazolate precursor of formula 1:

[0019] [ka] During the ceremony, R 1 , R 2 , R 3 and R 4 are each independently H, substituted or unsubstituted C1-C 20 Linear, cyclic or branched alkyl, and substituted or unsubstituted C1-C 20 is selected from the group consisting of linear, branched or cyclic alkyl halides; R a and R b are each independently H, substituted or unsubstituted C1-C 20 Linear, cyclic or branched alkyl, and substituted or unsubstituted C1-C 20 is selected from the group consisting of linear, branched or cyclic alkyl halides; n is 2 or 3.

[0020] The Ru-Pz precursor is a member of the class of compounds included in Formula 1. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 are each independently one of -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH(CH3)2, and -C(CH3)3. In another aspect of this embodiment, R a and R b are each independently one of -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH(CH3)2, and -C(CH3)3. In another aspect of this embodiment, R a and R b are each independently H. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 are each independently one of -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH(CH3)2, and -C(CH3)3, and R a and R b is independently H. In another aspect of this embodiment, R 1 , R 2 , R 3 and R 4 In another aspect of this embodiment, one or more of R 1 , R 2 , R 3 and R 4 and one or more of R are each independently one of -CF3, -CF2CF3, -CF2CF2CF3, -CF(CF3)2, -C(CF3)3, and substituted or unsubstituted C1-C8 perfluoroalkyl. 1 and R 4 are the same group. In another aspect of this embodiment, R 2 and R 3are the same group. In another aspect of this embodiment, R 1 , R 2 , R 3 and R 4 are the same group. In one aspect of this embodiment, n is 2. In one aspect of this embodiment, n is 3. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 None of R is H. In one aspect of this embodiment, 1 , R 2 , R 3 and R 4 are H, respectively.

[0021] In yet another aspect, the Ru(I) precursors used in the disclosed and claimed methods include ruthenium pyrazolate precursors having the following structure:

[0022] [ka] (Here, “Ru-Pz1” and / or “RuP08”).

[0023] In yet another aspect, the Ru(I) precursors used in the disclosed and claimed methods include ruthenium pyrazolate precursors having the following structure:

[0024] [ka] (Here, “Ru-Pz2”).

[0025] In yet another aspect, the Ru(I) precursors used in the disclosed and claimed methods include ruthenium pyrazolate precursors having the following structure:

[0026] [ka] (Here, “Ru-Pz3”).

[0027] In yet another aspect, the Ru(I) precursors used in the disclosed and claimed methods include ruthenium pyrazolate precursors having the following structure:

[0028] [ka] (Here, “Ru-Pz4”).

[0029] In yet another aspect, the Ru(I) precursors used in the disclosed and claimed methods include ruthenium pyrazolate precursors having the following structure:

[0030] [ka] (Here, “Ru-Pz5”).

[0031] In yet another aspect, the Ru(I) precursors used in the disclosed and claimed methods include ruthenium pyrazolate precursors having the following structure:

[0032] [ka] (Here, “Ru-Pz6” and / or “RuP10”).

[0033] Without being bound by theory, it is believed that the positive charge of the Ru(I) core reduces the lability of the coordinated CO groups and ligands, enhancing the stability of the deposition process. Compared to Ru(0) precursors (e.g., DCR), the inert nature of Ru(I) precursors indicates the ability to grow Ru films in the ALD mode for future nodes.

[0034] In another aspect, the disclosed and claimed invention relates to films grown from the disclosed and claimed methods. In another aspect, the disclosed and claimed invention relates to the use of Ru(I) precursors in ALD or ALD-like processes to selectively deposit Ru-containing films on metal substrates located in proximity to passivated dielectric materials. In one embodiment of this aspect, the Ru(I) precursor comprises a ruthenium pyrazolate precursor as described above.

[0035] This summary section is not intended to identify every aspect and / or progressively novel aspect of the disclosed and claimed invention. Instead, this summary provides only a preliminary description of various aspects and corresponding points of novelty over conventional and known techniques. For additional details and / or possible perspectives of the disclosed and claimed invention and aspects, reference is made to the detailed description of the invention and corresponding drawings, which are further described below.

[0036] The order in which the different steps described herein are presented is provided for purposes of clarity. In general, the steps disclosed herein may be performed in any suitable order. Additionally, although different features, techniques, configurations, etc. described herein may each be described in different parts of this specification, it is intended that each of these concepts can be implemented independently of one another or in combination with one another, where appropriate. Thus, the invention as disclosed and claimed can be embodied and viewed in many different ways.

[0037] The accompanying drawings provide a further understanding of the disclosed invention, and are incorporated in and constitute a part of this specification, illustrating embodiments of the disclosed invention and, together with the detailed description of the invention, serve to explain the principles of the disclosed invention. [Brief description of the drawings]

[0038] [Figure 1] FIG. 1 shows a target for a selective deposition process. [Diagram 2]FIG. 2 shows the effect of passivation on Ru film thickness grown from Ru(I) precursors on various substrates. [Diagram 3] FIG. 3 shows the effect of passivation on Ru film growth (cycling) grown from a Ru(I) precursor. [Figure 4] FIG. 4 shows the effect of passivation on Ru film thickness grown from Ru(II) precursors on various substrates. [Diagram 5] Figure 1 shows the effect of passivation on Ru film thickness grown from a Ru(I) precursor on Si3N4.

[0039] definition Unless otherwise stated, the following terms used in the specification and claims have the following meanings in this application.

[0040] For purposes of the disclosed and claimed invention, the numbering scheme for the Periodic Groups follows the IUPAC Periodic Table of the Elements.

[0041] The term "and / or" as used herein in phrases such as "A and / or B" is intended to encompass "A and B," "A or B," or "A" and "B."

[0042] The terms "substituent," "residue," "group," and "moiety" may be used interchangeably.

[0043] As used herein, the terms "metal-containing complex" (or more simply, "complex") and "precursor" are used interchangeably and refer to a metal-containing molecule or compound that can be used to produce a metal-containing film by a deposition method such as, for example, ALD or CVD. The metal-containing complex can be deposited, adsorbed, decomposed, delivered and / or distributed onto a substrate or a surface thereof such that a metal-containing film is formed.

[0044] As used herein, the term "metal-containing film" includes elemental metal films, as defined in more detail below, as well as films that contain one or more elements in addition to the metal, such as metal oxide films, metal nitride films, metal silicide films, metal carbide films, and similar films. As used herein, the terms "elemental metal film" and "pure metal film" are used interchangeably and refer to films that consist of or consist essentially of pure metal. For example, an elemental metal film may contain 100% pure metal, or an elemental metal film may contain at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, at least about 99.9%, or at least about 99.99% pure metal, along with one or more impurities. Unless otherwise indicated by context, the term "metal film" is to be construed to mean an elemental metal film.

[0045] As used herein, the term "vapor deposition method" is used to refer to any type of vapor deposition technique, including but not limited to CVD and ALD. In various embodiments, CVD can take the form of conventional (i.e., continuous flow) CVD, liquid injection CVD, or photoassisted CVD. CVD can also take the form of a pulsed technique, i.e., pulsed CVD. ALD is used to form metal-containing films by evaporating and / or flowing at least one metal complex disclosed herein onto a substrate surface. For conventional ALD processes, see, for example, George SM, et al. J. Phys. Chem., 1996, 100, 13121-13131. In other embodiments, ALD can take the form of conventional (i.e., pulsed injection) ALD, liquid injection ALD, photoassisted ALD, plasma-assisted ALD, or plasma-enhanced ALD. The term "vapor deposition process" also encompasses various vapor deposition techniques described in Chemical Vapour Deposition: Precursors, Processes, and Applications; Jones, AC; Hitchman, ML, Eds., The Royal Society of Chemistry: Cambridge, 2009; Chapter 1, pp. 1-36 (Non-Patent Document 2).

[0046] Throughout this specification, the terms "ALD or ALD-like" or "ALD and ALD-like" refer to a process that includes, but is not limited to, the following process steps: (i) sequentially introducing reactants, including Ru-Pz precursor (ia) and co-reactant (ib), into a reactor, such as a single-wafer ALD reactor, a semi-batch ALD reactor, or a batch furnace ALD reactor; (ii) exposing the substrate to reactants, including Ru-Pz precursor (iia) and co-reactant (iib), by moving or rotating the substrate to different sections of the reactor, where each section is separated by an inert gas curtain, i.e., a spatial ALD reactor or a roll-to-roll ALD reactor. A typical cycle of an ALD or ALD-like process includes at least steps (i) and (ii) above.

[0047] As used herein, the term "feature" refers to an opening in a substrate that may be defined by one or more sidewalls, a bottom surface, and a top corner. In various aspects, a feature can be a via, a trench, a contact, a dual damascene, etc.

[0048] The terms "about" or "approximately" when used in connection with a measurable, numerical variable refer to the indicated value of the variable and all values ​​of the variable that are within experimental error of the indicated value (e.g., within a 95% confidence limit of the mean) or within a percentage of the indicated value (e.g., ±10%, ±5%), whichever is greater.

[0049] The disclosed and claimed precursors are preferably substantially free of water. As used herein, "substantially free" when referring to water means less than 5000 ppm (by weight) as measured by proton NMR or Karl Fischer titration, preferably less than 3000 ppm as measured by proton NMR or Karl Fischer titration, more preferably less than 1000 ppm as measured by proton NMR or Karl Fischer titration, and most preferably less than 100 ppm as measured by proton NMR or Karl Fischer titration.

[0050] The disclosed and claimed precursors preferably contain metal ions or metals, such as Li + (Li), Na + (Na), K + (K), Mg 2+ (Mg), Ca 2+ (Ca), Al 3+ (Al), Fe 2+ (Fe), Fe 3+ (Fe), Ni 2+ (Fe), Cr 3+ The precursor is also substantially free of Cr, Ti, V, Mg, Mn, Co, Ni, Cu, or Zn. These metal ions or metals are potentially present from the feedstock / reactor used to synthesize the precursor. As used herein, "substantially free" means less than 5 ppm (by weight) as measured by ICP-MS, preferably less than 3 ppm, more preferably less than 1 ppm, and most preferably less than 0.1 ppm when referring to Li, Na, K, Mg, Ca, Al, Fe, Ni, Cr, Ti, V, Mn, Co, Ni, Cu, or Zn.

[0051] Unless otherwise specified, "alkyl" means C1 to C 20 "Alkyl" refers to a hydrocarbon group, which can be linear, branched (e.g., methyl, ethyl, propyl, isopropyl, tert-butyl, and the like) or cyclic (e.g., cyclohexyl, cyclopropyl, cyclopentyl, and the like). These alkyl portions may be substituted or unsubstituted as described below. The term "alkyl" refers to any of C1 to C6 20It refers to such moieties having carbon. For structural reasons, linear alkyl is understood to start from C1, while branched alkyl and cyclic alkyl are understood to start from C3. Furthermore, moieties derived from alkyl as described below, such as alkyloxy and perfluoroalkyl, are understood to have the same carbon number range unless otherwise stated. If a different alkyl group length is specified above, the above definition of alkyl is still valid in that it includes all types of alkyl moieties above, and the above structural considerations regarding the minimum carbon number of a given type of alkyl group still apply.

[0052] Halo or halide refers to a halogen, F, Cl, Br, or I, attached to an organic moiety by one bond. In some embodiments, the halogen is F. In other embodiments, the halogen is Cl.

[0053] Alkyl halides are fully or partially halogenated C1-C 20 Refers to alkyl.

[0054] Perfluoroalkyl refers to a linear, cyclic or branched saturated alkyl group as defined above in which all of the hydrogens have been replaced with fluorine (eg, trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluorobutyl, perfluoroisopropyl, perfluorocyclohexyl, and the like).

[0055] The disclosed and claimed precursors are preferably substantially free of organic impurities originating from raw materials used during synthesis or by-products generated during synthesis. Examples include, but are not limited to, alkanes, alkenes, alkynes, dienes, ethers, esters, acetates, amines, ketones, amides, aromatics, etc. As used herein, the term "free" of organic impurities means less than 1000 ppm as measured by GC, preferably less than 500 ppm (by weight) as measured by GC, and most preferably less than 100 ppm (by weight) as measured by GC or other analytical characterization. Importantly, the precursors preferably have a purity of 98% by weight or more, more preferably 99% by weight or more, as measured by GC, when used as precursors for depositing ruthenium-containing films.

[0056] The section headings used herein are for organizational purposes only and should not be construed as limiting the subject matter described. All references or portions of references cited herein, including but not limited to patents, patent applications, papers, books, and treatises, are incorporated herein in their entirety for all purposes. In the event that the definitions of terms in any of the references and similar materials incorporated herein conflict with those herein, the definitions herein shall control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to be limiting with respect to the invention as set forth in the claims. The objectives, features, advantages and concepts of the disclosed invention will be apparent to those skilled in the art from the description set forth herein, and further, the disclosed invention can be easily implemented by those skilled in the art based on the description set forth herein. Any description of a "preferred embodiment" and / or examples showing a preferred mode for carrying out the disclosed invention is included for illustrative purposes and is not intended to limit the scope of the claims.

[0058] It will also be apparent to those skilled in the art that various modifications may be made in the practice of the disclosed invention based on the aspects described herein without departing from the spirit and scope of the invention disclosed herein.

[0059] As noted above, the disclosed and claimed invention relates to atomic layer deposition (ALD) and ALD-like methods for selective Ru-containing film growth comprising, or consisting essentially of, (i) passivating a dielectric material by pre-treating the surface of the dielectric material with a surface conversion material, and thereafter (ii) selectively depositing a Ru-containing film using a Ru(I) precursor in combination with a co-reactant.

[0060] In one embodiment, the ALD or ALD-like method for selectively depositing a Ru-containing layer or film on a metal substrate disposed in proximity to a dielectric material comprises the steps of: (i) passivating a dielectric material by exposing a surface of the dielectric material to a surface conversion material; and (ii) selectively depositing a Ru-containing layer on a surface of a metal substrate using a Ru(I) precursor in combination with a co-reactant; Includes.

[0061] In another embodiment, the ALD or ALD-like method for selectively depositing a Ru-containing layer or film on a metal substrate disposed proximate a dielectric material comprises the steps of: (i) passivating a dielectric material by exposing a surface of the dielectric material to a surface conversion material; and (ii) selectively depositing a Ru-containing layer on a surface of a metal substrate using a Ru(I) precursor in combination with a co-reactant; It essentially consists of:

[0062] In another embodiment, the ALD or ALD-like method for selectively depositing a Ru-containing layer or film on a metal substrate disposed proximate a dielectric material comprises the steps of: (i) passivating a dielectric material by exposing a surface of the dielectric material to a surface conversion material; and (ii) selectively depositing a Ru-containing layer on a surface of a metal substrate using a Ru(I) precursor in combination with a co-reactant; It consists of:

[0063] Further aspects of the above method and aspects of the above steps are described below.

[0064] Step (i): Passivation of the dielectric material As noted above, the first step of the disclosed and claimed method involves passivating a dielectric material by pre-treating a surface of the dielectric material disposed adjacent a metal substrate by exposing the surface to a surface conversion material to render the dielectric completely or substantially inert to Ru deposition.

[0065] A. Dielectric materials In one embodiment, the surface of the dielectric substrate and / or dielectric material comprises Si. In one aspect of this embodiment, the surface of the dielectric substrate and / or dielectric material comprises one or more of SiO2 and Si3N4. In one embodiment, the surface of the dielectric substrate and / or dielectric material comprises SiO2. In one embodiment, the surface of the dielectric substrate and / or dielectric material comprises Si3N4.

[0066] B. Surface conversion materials In one embodiment, the surface conversion material is any suitable material capable of converting potentially reactive surface groups to unreactive / less reactive groups. In one embodiment, the surface conversion material is capable of converting reactive -OH groups to unreactive / less reactive groups. In one embodiment, the surface conversion material is capable of converting reactive -OH groups to non-reactive / less reactive hydrophobic -CH3 groups. In one embodiment, the surface conversion material comprises one or more of DMATMS ((dimethylamino)trimethylsilane) and OTS (octadecyltrichlorosilane). In one embodiment, the surface conversion material comprises DMATMS. In one embodiment, the surface conversion material comprises OTS (octadecyltrichlorosilane).

[0067] C. Condition The pretreatment step can be carried out at any suitable temperature. However, lower temperatures are generally preferred. In one embodiment, the pretreatment step is carried out at a temperature ranging from about 150° C. to about 350° C. In one embodiment, the pretreatment step is carried out at a temperature ranging from about 225° C. to about 325° C. In one embodiment, the pretreatment step is carried out at a temperature ranging from about 200° C. to about 350° C. In one embodiment, the pretreatment step is carried out at a temperature ranging from about 250° C. to about 300° C. In one embodiment, the pretreatment step is carried out at a temperature ranging from about 225° C. to about 275° C. In one embodiment, the pretreatment step is carried out at a temperature ranging from about 200° C. In one embodiment, the pretreatment step is carried out at a temperature of about 225° C. In one embodiment, the pretreatment step is carried out at a temperature of about 250° C. In one embodiment, the pretreatment step is carried out at a temperature of about 275° C. In one embodiment, the pretreatment step is carried out at a temperature of about 300° C. In one embodiment, the pretreatment step is carried out at a temperature of about 325° C. In one embodiment, the pretreatment step is carried out at a temperature of about 350° C.

[0068] When performing the pretreatment step, the pulse / purge cycle for the surface conversion material can be adjusted accordingly. In one embodiment, the pulse time is from about 0.1 to about 10 seconds. In one embodiment, the pulse time is from about 0.1 to about 5 seconds. In one embodiment, the pulse time is from about 0.1 to about 2 seconds. In one embodiment, the pulse time is from about 0.1 to about 1 second. In one embodiment, the pulse time is from about 0.5 to about 2 seconds. In one embodiment, the pulse time is from about 0.5 to about 1 second. In one embodiment, the pulse time is from about 0.1 to about 10 seconds. In one embodiment, the pulse time is about 0.1 seconds. In one embodiment, the pulse time is about 0.5 seconds. In one embodiment, the pulse time is about 1 second. In one embodiment, the pulse time is about 2 seconds. In any of the above embodiments, the purge time is from about 0.1 to about 10 seconds.

[0069] The pulse / purge cycles can be repeated in any number of permutations. In one embodiment, for example, the cycles can be repeated as many times as desired (e.g., 50, 75, 100, 110, 120, 130, 140, 150, etc. cycles). In one embodiment, the number of cycles is between 5 and 300. In one embodiment, the number of cycles is between 10 and 250. In one embodiment, the number of cycles is between 20 and 200. In one embodiment, the number of cycles is between 30 and 150. In one embodiment, the number of cycles is about 30. In one embodiment, the number of cycles is about 40. In one embodiment, the number of cycles is about 50. In one embodiment, the number of cycles is about 75. In one embodiment, the number of cycles is about 100. In one embodiment, the number of cycles is about 150. In one embodiment, the number of cycles is about 200. In one embodiment, the number of cycles is about 250. In one embodiment, the number of cycles is about 300.

[0070] The method for pretreatment exposure can also be varied. In one embodiment, the substrate can be exposed to the surface conversion material in a continuous flow mode. In another embodiment, the substrate can be exposed to the surface conversion material in a trapping mode.

[0071] Any suitable inert carrier gas may be used in carrying out the cycle. In one embodiment, the carrier gas comprises argon. In one embodiment, the carrier gas comprises nitrogen. In one embodiment, the carrier gas comprises helium. In one embodiment, the surface conversion material and the carrier gas are flowed together at between about 5 sccm and about 20 sccm. In one embodiment, the surface conversion material and the carrier gas are flowed together at between about 10 sccm and about 15 sccm. In one embodiment, the surface conversion material and the carrier gas are flowed together at about 10 sccm. In one embodiment, the surface conversion material and the carrier gas are flowed together at about 15 sccm. In one embodiment, the surface conversion material and the carrier gas are flowed together at about 20 sccm.

[0072] Any suitable inert purge gas may be used in carrying out the cycle. In one embodiment, the purge gas comprises argon. In one embodiment, the purge gas comprises nitrogen. In one embodiment, the purge gas comprises helium. In one embodiment, the purge gas comprises one or more of argon, nitrogen, and helium.

[0073] In one embodiment, the purge gas is flowed at between about 30 sccm and about 60 sccm. In one embodiment, the purge gas is flowed at between about 40 sccm and about 50 sccm. In one embodiment, the purge gas is flowed at about 30 sccm. In one embodiment, the purge gas is flowed at about 40 sccm. In one embodiment, the purge gas is flowed at about 50 sccm. In one embodiment, the purge gas is flowed at about 60 sccm.

[0074] The pretreatment step can be performed at any suitable chamber pressure. In one embodiment, the pressure is between about 5 torr and 15 torr. In one embodiment, the pressure is between about 8 torr and about 12 torr. In one embodiment, the pressure is about 7 torr. In one embodiment, the pressure is about 8 torr. In one embodiment, the pressure is about 9 torr. In one embodiment, the pressure is about 10 torr. In one embodiment, the pressure is about 11 torr. In one embodiment, the pressure is about 12 torr. In one embodiment, the pressure is about 13 torr. In one embodiment, the pressure is about 14 torr. In one embodiment, the pressure is about 15 torr.

[0075] Step 2(ii): Ru film growth As noted above, the second step of the disclosed and claimed method involves selectively growing a Ru-containing film on a surface of a metal substrate disposed in proximity to a passivated dielectric substrate using a Ru(I) precursor in combination with a co-reactant.

[0076] A. Ru(I) Precursors As noted above, the disclosed and claimed methods utilize Ru(I) precursors. Without being bound by theory, it is believed that the positive charge of the Ru(I) core reduces the lability of the coordinated CO groups and ligands, thus enhancing the stability of the selective deposition process.

[0077] In one embodiment, the Ru(I) precursor used in the disclosed and claimed methods comprises a ruthenium pyrazolate precursor of formula I:

[0078] [ka] During the ceremony, R 1 , R 2 , R 3 and R 4 are each independently H, substituted or unsubstituted C1-C 20 Linear or branched alkyl, and substituted or unsubstituted C1-C20 is selected from the group consisting of linear, branched or cyclic alkyl halides; R a and R b are each independently H, substituted or unsubstituted C1-C 20 Linear or branched alkyl, and substituted or unsubstituted C1-C 20 is selected from the group of linear, branched or cyclic alkyl halides, and n is 2 or 3.

[0079] The Ru-Pz precursor is a member of the class of compounds included in Formula 1. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 are each independently one of -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH(CH3)2, and -C(CH3)3. In another aspect of this embodiment, R a and R b are each independently one of -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH(CH3)2, and -C(CH3)3. In another aspect of this embodiment, R a and R b are each independently H. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 are each independently one of -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH(CH3)2, and -C(CH3)3, and R a and R b is independently H. In another aspect of this embodiment, R 1 , R 2 , R 3 and R 4 In another aspect of this embodiment, one or more of R 1 , R 2 , R3 and R 4 and one or more of R are each independently one of -CF3, -CF2CF3, -CF2CF2CF3, -CF(CF3)2, -C(CF3)3, and substituted or unsubstituted C1-C8 perfluoroalkyl. 1 and R 4 are the same group. In another aspect of this embodiment, R 2 and R 3 are the same group. In another aspect of this embodiment, R 1 , R 2 , R 3 and R 4 are the same group. In one aspect of this embodiment, n is 2. In one aspect of this embodiment, n is 3. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 are each independently one of -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH(CH3)2, and -C(CH3)3; R a and R b are each independently H and n is 2. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 are each independently one of -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH(CH3)2, and -C(CH3)3; R a and R b are each independently H and n is 3. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 is not H. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 is not H. In one aspect of this embodiment, R 1 , R 2 , R3 , R 4 R 1 , R a and R b Each is H. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 are each independently one of H, -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH2CH(CH3)2, and -C(CH3)3; R a and R b are each independently H and n is 3. In one aspect of this embodiment, R 1 , R 2 , R 3 and R 4 are each independently H, and R a and R b are each independently H, and n is 3.

[0080] In one embodiment, the Ru(I) precursor used in the disclosed and claimed methods comprises a ruthenium pyrazolate precursor having the following structure:

[0081] [ka] (Here, “Ru-Pz1” and / or “RuP08”).

[0082] In one embodiment, the Ru(I) precursor used in the disclosed and claimed methods comprises a ruthenium pyrazolate precursor having the following structure:

[0083] [ka] (Here, “Ru-Pz2”).

[0084] In one embodiment, the Ru(I) precursor used in the disclosed and claimed methods comprises a ruthenium pyrazolate precursor having the following structure:

[0085] [ka] (Here, “Ru-Pz3”).

[0086] In one embodiment, the Ru(I) precursor used in the disclosed and claimed methods comprises a ruthenium pyrazolate precursor having the following structure:

[0087] [ka] (Here, “Ru-Pz4”).

[0088] In one embodiment, the Ru(I) precursor used in the disclosed and claimed methods comprises a ruthenium pyrazolate precursor having the following structure:

[0089] [ka] (Here, “Ru-Pz5”).

[0090] In yet another aspect, the Ru(I) precursor used in the disclosed and claimed methods comprises a ruthenium pyrazolate precursor having the following structure:

[0091] [ka] (Here, “Ru-Pz6” and / or “RuP10”).

[0092] In one embodiment, the Ru(I) precursors used in the disclosed and claimed methods can include mixtures or combinations of more than one of the Ru(I) precursors listed above.

[0093] B. Coreactants In one embodiment, the co-reactant is oxygen-free and includes one or more of a halogen co-reactant and a nitrogen-containing co-reactant. In one embodiment, the oxygen-free co-reactant includes one or more of ammonia, hydrazine, alkylhydrazine, and alkylamine. In one embodiment, the co-reactant includes one or more of H2 and NH3. In one embodiment, the co-reactant includes H2. The inventors note that the disclosed and claimed methods can alternatively be practiced using oxygen co-reactants (e.g., ozone, elemental and molecular oxygen / O2, hydrogen peroxide, and nitrous oxide), either alone or in combination with oxygen-free co-reactants.

[0094] C. Metal base material In one embodiment, the metal substrate comprises one or more of Ru, TiN, W, Cu, and Co.

[0095] In one embodiment, the metal substrate comprises Ru.

[0096] In one embodiment, the metal substrate comprises one or more of TiN.

[0097] In one embodiment, the metal substrate comprises one or more of W.

[0098] In one embodiment, the metal substrate comprises one or more of Cu.

[0099] In one embodiment, the metal substrate comprises one or more of Co.

[0100] D. Conditions The Ru film growth step can be performed at any suitable temperature. However, lower temperatures are generally preferred. In one embodiment, the Ru film growth step is performed at a temperature ranging from about 150° C. to about 350° C. In one embodiment, the Ru film growth step is performed at a temperature ranging from about 225° C. to about 325° C. In one embodiment, the Ru film growth step is performed at a temperature ranging from about 200° C. to about 300° C. In one embodiment, the Ru film growth step is performed at a temperature ranging from about 250° C. to about 300° C. In one embodiment, the Ru film growth step is performed at a temperature ranging from about 225° C. to about 275° C. In one embodiment, the Ru film growth step is performed at a temperature of about 200° C. In one embodiment, the Ru film growth step is performed at a temperature of about 225° C. In one embodiment, the Ru film growth step is performed at a temperature of about 250° C. In one embodiment, the Ru film growth step is performed at a temperature of about 275° C. In one embodiment, the Ru film growth step is performed at a temperature of about 300° C. In one embodiment, the Ru film growth step is performed at a temperature of about 325° C. In one embodiment, the Ru film growth step is performed at a temperature of about 350° C.

[0101] When performing the Ru film growth step, the Ru(I) precursor pulse time can be adjusted accordingly. In one embodiment, the Ru(I) precursor pulse time is between about 1 second and about 20 seconds. In one embodiment, the Ru(I) precursor pulse time is between about 3 seconds and about 17 seconds. In one embodiment, the Ru(I) precursor pulse time is between about 5 seconds and about 15 seconds. In one embodiment, the Ru(I) precursor pulse time is between about 7 seconds and about 12 seconds. In one embodiment, the Ru(I) precursor pulse time is about 5 seconds. In one embodiment, the Ru(I) precursor pulse time is about 6 seconds. In one embodiment, the Ru(I) precursor pulse time is about 7 seconds. In one embodiment, the Ru(I) precursor pulse time is about 8 seconds. In one embodiment, the Ru(I) precursor pulse time is about 9 seconds. In one embodiment, the Ru(I) precursor pulse time is about 10 seconds. In one embodiment, the Ru(I) precursor pulse time is about 11 seconds. In one embodiment, the Ru(I) precursor pulse time is about 12 seconds. In one embodiment, the Ru(I) precursor pulse time is about 13 seconds. In one embodiment, the Ru(I) precursor pulse time is about 14 seconds. In one embodiment, the Ru(I) precursor pulse time is about 15 seconds.

[0102] When performing the Ru film growth step, the coreactant pulse time can be adjusted accordingly. In one embodiment, the coreactant pulse time is between about 20 seconds and about 60 seconds. In one embodiment, the coreactant pulse time is between about 30 seconds and about 50 seconds. In one embodiment, the coreactant pulse time is between about 35 seconds and about 45 seconds. In one embodiment, the coreactant pulse time is about 20 seconds. In one embodiment, the coreactant pulse time is about 30 seconds. In one embodiment, the coreactant pulse time is about 7 seconds. In one embodiment, the coreactant pulse time is about 40 seconds. In one embodiment, the coreactant pulse time is about 50 seconds. In one embodiment, the coreactant pulse time is about 60 seconds.

[0103] During the Ru film growth step, the co-reactant is flowed at between about 150 sccm and about 450 sccm. In one embodiment, the co-reactant is flowed at between about 200 sccm and about 400 sccm. In one embodiment, the co-reactant is flowed at between about 250 sccm and about 350 sccm. In one embodiment, the co-reactant is flowed at between about 275 sccm and about 325 sccm. In one embodiment, the co-reactant is flowed at about 150 sccm. In one embodiment, the co-reactant is flowed at about 200 sccm. In one embodiment, the co-reactant is flowed at about 250 sccm. In one embodiment, the co-reactant is flowed at about 300 sccm. In one embodiment, the co-reactant is flowed at about 350 sccm. In one embodiment, the co-reactant is flowed at about 400 sccm. In one embodiment, the co-reactant is flowed at about 450 sccm.

[0104] The Ru film growth step can be performed at any suitable chamber pressure. In one embodiment, the pressure is between about 5 torr and 15 torr. In one embodiment, the pressure is between about 8 torr and about 12 torr. In one embodiment, the pressure is about 7 torr. In one embodiment, the pressure is about 8 torr. In one embodiment, the pressure is about 9 torr. In one embodiment, the pressure is about 10 torr. In one embodiment, the pressure is about 11 torr. In one embodiment, the pressure is about 12 torr. In one embodiment, the pressure is about 13 torr. In one embodiment, the pressure is about 14 torr. In one embodiment, the pressure is about 15 torr.

[0105] Any of the above step 1 conditions can be combined with any of the above step 2 conditions. In one embodiment, steps (i) and (ii) are both performed at about the same temperature. In one embodiment, steps (i) and (ii) are both performed at a temperature from about 150° C. to about 350° C. In one embodiment, steps (i) and (ii) are both performed at a temperature of about 250° C. EXAMPLES

[0106] More specific aspects of the present disclosure, and experimental results in support of such aspects, are described below. These examples are provided below to more fully explain the disclosed invention, and should not be construed as limiting the disclosed invention in any manner.

[0107] It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed invention and the specific examples provided herein without departing from the spirit or scope of the disclosed invention. Thus, the disclosed invention, including the description provided by way of the following examples, is intended to cover modifications and variations of the disclosed invention that come within the scope of any claims and their equivalents.

[0108] Materials and Methods: RuPz1 (EMD Performance Materials) was used as received without further purification. ALD experiments were carried out using a CN1 ATOMIC-PREMIUM reactor. An Epsilon 3XLE spectrometer was used to analyze the thickness of the Ru films grown on the substrates.

[0109] Example 1 In this example, Ru-Pz1 (also known as PuP08) was used as a Ru(I) precursor with H2 gas as a co-reactant to selectively deposit Ru films on three different substrates, namely Ru, TiN, and SiO2.

[0110] Step 1: Passivation The first step was performed using DMATMS as the surface conversion material and Ar as the carrier and purge gas. The following process conditions were used:

[0111] [Table 1]

[0112] Step 2: Ru deposition The second step was carried out using Ru-Pz1 (also known as RuP08) as the Ru(I) precursor and H2 as the co-reactant. The following process conditions were used:

[0113] [Table 2]

[0114] Figures 2 and 5 show the effect of passivation on Ru film growth from Ru(I) precursors on various substrates, respectively. Figure 3 shows that the process used in this example can suppress Ru growth on SiO2 within 30 cycles. Collectively, the data in Figures 2, 3, and 5 show that DMATMS passivates SiO2 and Si3N4 surfaces (reducing Ru film growth), and that the DMATMS / Ru-Pz1 / H2 used in this example selectively (and rapidly) grows Ru films on the target Ru and TiN, but not on the passivated SiO2 and Si3N4.

[0115] Comparative Example In this comparative example, Ru(II) precursor (i.e., RuDMBD) was used to grow Ru films on three different substrates, i.e., Ru, ALD TiN, and SiO2.

[0116] Step 1: Passivation The first step was carried out using DMATMS as the surface conversion material and argon as the carrier and purge gas. The following process conditions were used:

[0117] [Table 3]

[0118] Step 2: Ru deposition The second step was carried out using RuDMBD as the Ru(II) precursor and argon as the purge gas. The following process conditions were used:

[0119] [Table 4]

[0120] Figure 4 shows the effect of passivation on Ru film thickness grown from Ru(II) precursors on various substrates. As shown in Figure 4, the use of DMATMS to passivate SiO2 does not reduce the growth of Ru films grown from RuDMBD. Therefore, the passivation step does not result in selective deposition of Ru.

[0121] Summary It has been demonstrated that passivation (e.g., with DMATMS) is not universally applicable for all Ru precursors (e.g., Ru(II) precursors such as RuDMBD) and therefore does not predictably promote selective Ru deposition. In addition, it has been shown for the first time that Ru(I) precursors can be used for selective deposition (e.g., Ru-Pz1 / Ru-P08).

[0122] While the disclosed and claimed invention has been described and illustrated with a certain degree of detail, it will be apparent that this disclosure is made by way of example only, and that those skilled in the art may resort to numerous variations in the conditions and sequence of steps without departing from the spirit and scope of the disclosed and claimed invention.

Claims

1. 1. An ALD or ALD-like method for selectively depositing a Ru-containing layer or film on a metal substrate disposed in proximity to a dielectric material, comprising: (i) passivating a surface of the dielectric material by exposing the surface of the dielectric material to a surface conversion material; and (ii) selectively depositing a Ru-containing layer on the surface of a metal substrate using a Ru(I) precursor in combination with a co-reactant; The method comprising:

2. The method of claim 1 , wherein the dielectric material comprises Si.

3. The method of claim 1 or 2, wherein the surface conversion material converts --OH groups to less reactive or non-reactive groups.

4. 3. The method of claim 1 or 2, wherein the surface conversion material comprises one or more of DMATMS and OTS.

5. 3. The method of claim 1 or 2, wherein step (i) is carried out at a temperature in the range of from approximately 150° C. to approximately 350° C.

6. 3. The method of claim 1 or 2, wherein step (i) comprises delivering the surface conversion material as a pulse for about 0.1 seconds to about 10 seconds.

7. 3. The method of claim 1 or 2, wherein the Ru(I) precursor comprises a ruthenium pyrazolate precursor of formula 1. 【Chemistry 1】 However, in the formula, R １ , R ２ , R ３ and R ４ are each independently H, substituted or unsubstituted C １ ~C ２０ Linear, cyclic or branched alkyl, and substituted or unsubstituted C １ ~C ２０ is selected from the group consisting of linear, branched or cyclic alkyl halides; R ａ and R ｂ are each independently H, substituted or unsubstituted C １ ~C ２０ Linear, cyclic or branched alkyl, and substituted or unsubstituted C １ ~C ２０ is selected from the group consisting of linear, branched or cyclic alkyl halides; n is 2 or 3.

8. 3. The method of claim 1 or 2, wherein the Ru(I) precursor comprises a ruthenium pyrazolate precursor of formula 1. 【Chemistry 4】 However, in the formula, R １ , R ２ , R ３ and R ４ are each independently -CH ３ , -CF3, -CH ２ CH ３ , C.H. ２ CH ２ CH ３ , -CH(CH ３ ) ２ , -CH ２ CH (CH ３ ) ２ and -C(CH ３ ) ３ It is one of; R ａ and R ｂ are H, and n is 3.

9. 3. The method of claim 1 or 2, wherein the Ru(I) precursor comprises one or more ruthenium pyrazolate precursors selected from the group consisting of: 【Chemistry 5】

10. The co-reactant is H ２ and N.H. ３ The method of claim 1 or 2, comprising one or more of the following:

11. The method of claim 1 or 2, wherein the metal substrate comprises one or more of Ru, TiN, W, Cu and Co.

12. 3. The method of claim 1 or 2, wherein step (ii) is carried out at a temperature in the range of from approximately 150° C. to approximately 350° C.

13. 3. The method of claim 1 or 2, wherein step (ii) is carried out at a pressure between about 5 torr and about 15 torr.

14. 3. The method of claim 1 or 2, wherein the Ru(I) precursor pulse time is between about 1 second and about 20 seconds.

15. 3. The method of claim 1 or 2, wherein the co-reactant pulse time is between about 20 seconds and about 60 seconds.

16. 3. The method of claim 1 or 2, wherein step (i) and step (ii) are both carried out at about the same temperature.

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