Methods for depositing blocking layers on conductive surfaces

Abstract

A method for selectively depositing a barrier layer on a conductive surface relative to a dielectric surface is described. In some embodiments, 4 to 8 substituted heterocyclic rings are exposed to a substrate to selectively form the barrier layer. In some embodiments, after the barrier layer is formed, the layer is selectively deposited on the dielectric surface. In some embodiments, the barrier layer is removed.

Description

Technical Field

[0001] The embodiments disclosed herein relate to a method for depositing a barrier layer on a metal surface. More specifically, the embodiments disclosed herein relate to a method for depositing a barrier layer on a metal surface to facilitate the deposition of material on a dielectric surface of a patterned substrate. Prior Technology

[0002] The semiconductor industry faces numerous challenges in its pursuit of rapidly scaling device miniaturization involving nanoscale features. These challenges include the introduction of complex manufacturing steps, such as multiple lithography steps, and the integration of high-performance materials. To maintain the pace of device miniaturization, selective deposition has shown promise due to its potential to eliminate costly lithography steps by simplifying the integration process.

[0003] Selective deposition of materials can be achieved in various ways. Chemical precursors can react selectively with one surface relative to another (metal or dielectric). Process parameters (such as pressure, substrate temperature, precursor partial pressure, and / or gas flow rate) can be adjusted to modulate the chemical kinetics of the reaction on a specific surface. Another possible approach involves surface pretreatment that can be used to activate and deactivate the surface of interest into the film deposition precursor.

[0004] A key challenge in achieving high-quality selective deposition is minimizing pinholes in the self-assembled monolayer (SAM) on the barrier surface. Pinholes are a major cause of selective failures. Higher-quality SAM layers minimize pinholes, thereby reducing defects. Another challenge is removing the SAM layer after subsequent deposition processes.

[0005] Therefore, there is a ongoing need in the art for processing methods to deactivate or block conductive surfaces. Additionally, there is a ongoing need in the art to provide high-quality, pinhole-free SAM precursors that are easily removed without damaging the substrate material. Summary of the Invention

[0006] One or more embodiments disclosed herein relate to a method for selectively depositing a barrier layer. The method includes exposing a substrate comprising a metallic material having a first surface and a dielectric material having a second surface to a barrier compound to selectively form a barrier layer on the first surface relative to the second surface. The barrier compound comprises a 4- to 8-membered heterocycle, the heterocycle comprising at least one heteroatom and at least one substituent selected from alkyl or aryl groups comprising 1 to 8 carbon atoms.

[0007] Additional embodiments disclosed herein relate to a method for selectively depositing a barrier layer. The method includes exposing a substrate comprising a metallic material having a first surface and a dielectric material having a second surface to a barrier compound to selectively form a barrier layer on the first surface relative to the second surface. The barrier compound has the general formula: , In each of the X series nitrogen, oxygen, sulfur or phosphorus, n is selected to maintain a neutral charge, R' is selected from hydrogen, alkyl or aryl containing 1 to 18 carbon atoms, and each R is independently selected from alkyl or aryl containing 1 to 8 carbon atoms.

[0008] Another embodiment disclosed herein relates to a method for selectively depositing a barrier layer. The method includes exposing a substrate comprising a metallic material having a first surface and a dielectric material having a second surface to a barrier compound to selectively form a barrier layer on the first surface relative to the second surface. The barrier compound comprises an amine containing at least one substituent comprising 1 to 18 carbon atoms. Simple Explanation of the Diagram

[0009] To gain a more detailed understanding of the features described above in this disclosure, a more specific description of the disclosure, which has been briefly summarized above, can be obtained with reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only typical embodiments of this disclosure and are not intended to limit its scope, as this disclosure allows for other equally effective embodiments.

[0010] Figure 1 illustrates a processing method according to one or more embodiments of this disclosure; and

[0011] Figure 2 shows a flowchart of a processing method according to one or more embodiments of this disclosure.

[0012] In the accompanying drawings, similar parts and / or features may have the same element symbols. Additionally, parts of the same type may be distinguished by a second mark following the element symbol with a dashed line to differentiate between similar parts. If only the first element symbol is used in this specification, this specification applies to any similar parts having the same first element symbol, regardless of the second element symbol. Implementation

[0013] The embodiments disclosed herein provide methods for selectively depositing barrier layers on conductive surfaces. The embodiments disclosed herein identify methods for depositing barrier layers that can be used individually or in combination.

[0014] As used herein, "substrate surface" refers to any portion of a substrate or a portion of the surface of a material formed on the substrate on which a film treatment is performed. For example, depending on the application, substrate surfaces on which treatments can be performed include materials such as silicon, silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials. Substrates include, but are not limited to, semiconductor wafers. Substrates may be exposed to pretreatment processes such as polishing, etching, reduction, oxidation, hydroxylation, annealing, UV curing, electron beam curing, and / or baking of the substrate surface. In addition to treatments performed directly on the surface of the substrate itself, any film treatment steps disclosed herein, as disclosed in more detail below, may also be performed on an underlying layer formed on the substrate, and the term "substrate surface" is intended to include such an underlying layer as indicated by the context. Thus, for example, where a film / layer or a portion of a film / layer has already been deposited on the substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface. The substrate can have various sizes, such as 200 mm or 300 mm diameter wafers, and rectangular or square panels. In some embodiments, the substrate comprises a rigid discrete material.

[0015] The embodiments disclosed herein advantageously provide a method for selectively forming a barrier layer on a conductive surface relative to a dielectric surface. Some embodiments advantageously provide additional methods for selectively depositing layers on a dielectric surface. Some embodiments advantageously provide additional methods for removing the barrier layer from the conductive surface.

[0016] As used in this specification and the accompanying claims, the phrases "metallic surface" or "dielectric surface" mean a surface with respect to a material having the aforementioned composition. Thus, a metallic surface is the surface of a metallic material. Similarly, a dielectric surface is the surface of a dielectric material.

[0017] As used in this specification and the accompanying claims, the terms "selective deposition of a film on one surface relative to another surface" and the like mean that a first amount of film is deposited on the first surface and a second amount of film is deposited on the second surface, wherein the second amount of film is less than the first amount of film, or no film is deposited on the second surface. The term "relative to" as used in this regard does not imply a physical orientation of one surface on top of another surface, but rather a relation to the thermodynamic or kinetic properties of the chemical reactions of the other surface with respect to the surface. For example, selectively depositing a cobalt film onto a copper surface relative to a dielectric surface means that a cobalt film is deposited on the copper surface and a small amount or no cobalt film is deposited on the dielectric surface; or that forming a cobalt film on the copper surface is thermodynamically or kinetically advantageous relative to forming a cobalt film on a dielectric surface. In some embodiments, "selective" means that the target material is formed on the selective surface at a rate greater than or equal to the formation rate on an unselected surface of about 10x, 15x, 20x, 25x, 30x, 35x, 40x, 45x, or 50x. In other words, the selectivity of the target material relative to the unselected surface is greater than or equal to about 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1 or 50:1.

[0018] Some embodiments disclosed herein integrate a barrier layer commonly referred to as a self-assembled monolayer (SAM). A self-assembled monolayer (SAM) consists of an ordered arrangement of spontaneously assembled organic molecules adsorbed on a surface. These molecules typically contain one or more portions (head groups) with affinity for the substrate and relatively long, inert, straight-chain hydrocarbon portions (tail groups).

[0019] In this case, SAM formation occurs via rapid adsorption (e.g., chemisorption, physisorption) of the molecular head groups at the surface and slow association of the molecular tail groups with each other via van der Waals interactions. The SAM precursor is selected such that the head groups selectively react with the substrate material that is blocked during deposition. Deposition is then performed, and the SAM can be removed via thermal decomposition (utilizing desorption of any byproducts), an integration-compatible ashing process, or a plasma-based removal process.

[0020] One or more embodiments disclosed herein relate to a method for selectively depositing a barrier layer on a first surface of a substrate relative to a second surface. The first surface is a surface of a metallic material. The second surface is a surface of a dielectric material.

[0021] The metallic material of the substrate can be any suitable conductive material. Suitable metallic materials include, but are not limited to, metals, metal nitrides, some metal oxides, metal alloys, combinations thereof, and other conductive materials. In some embodiments, the metallic material comprises one or more of copper, cobalt, tungsten, tantalum, titanium, ruthenium, iridium, their oxides, their nitrides, or combinations thereof. In some embodiments, the metallic material comprises one or more of chromium, manganese, iron, nickel, their oxides, their nitrides, or combinations thereof. In some embodiments, the metallic material is substantially composed of copper, cobalt, tungsten, tantalum, tantalum nitride, tantalum oxide, titanium, titanium oxide, titanium nitride, ruthenium, ruthenium oxide, or iridium. As used in this specification and the appended claims, the term "substantially composed of" means that the material is greater than or equal to about 95%, 98%, or 99% of the material on an atomic basis.

[0022] As used in this specification and the accompanying claims, the term "oxide" or similar means that the material contains a specified element. The term should not be construed as implying a specific ratio of elements. Thus, "oxide" or similar may encompass both stoichiometric ratios and non-stoichiometric ratios of elements.

[0023] The dielectric material of the substrate can be any suitable material. Suitable dielectric materials include, but are not limited to, silicon oxide (e.g., SiO₂), silicon nitride, silicon carbide, and combinations thereof (e.g., SiCON). In some embodiments, the dielectric material is substantially composed of silicon dioxide (SiO₂). In some embodiments, the dielectric material comprises silicon nitride. In some embodiments, the dielectric material is substantially composed of silicon nitride.

[0024] Referring to Figures 1 and 2, method 200 begins with a substrate 105, which includes a metallic material 110 having a first surface 112 and a dielectric material 120 having a second surface 122. In step 210, the substrate 105 is exposed to a barrier compound (not shown) to selectively form a barrier layer 130 on the first surface 112 relative to the second surface 122. The barrier layer 130 forms the barrier first surface 132.

[0025] In some embodiments, method 200 continues at step 220 by selectively depositing material 125 on a second surface 122 relative to a first surface 132 of a barrier. In some embodiments, material 125 is a dielectric material. In some embodiments, the composition of material 125 may be selected from the same dielectric material as dielectric material 120. In some embodiments, the material comprises silicon nitride. In some embodiments, the material comprises a metal, a metal oxide, a metal nitride, or a dielectric material.

[0026] The deposition of material 125 can be performed via any suitable process. In some embodiments, material 125 is deposited by atomic layer deposition. Another suitable process may include exposing the substrate to a silicon halide and hydrogen, an oxidant (e.g., water), or ammonia. Suitable silicon halides include, but are not limited to, dichlorosilane (DCS), trichlorosilane (TCS), tetrachlorosilane (SiCl4), tetrabromosilane (SiBr4), tetraiodosilane (SiI4), and hexachlorodisilane (HCDS).

[0027] In some embodiments, material 125 is deposited with a thickness ranging from about 10 Å to about 50 Å, or from about 12 Å to about 35 Å, or from about 15 Å to about 20 Å. In some embodiments, the barrier layer and deposited material are repeatedly formed until the layer has a thickness greater than or equal to about 50 Å, greater than or equal to about 75 Å, greater than or equal to about 100 Å, or greater than or equal to about 150 Å.

[0028] In some embodiments, method 200 continues at step 230 by removing barrier layer 130 to expose first surface 112. In some embodiments, barrier layer 130 is removed using a selective etching process. Similar to barrier layer 130 disclosed herein, oxygen-based and fluorine-based etching are known for etching carbon-based films.

[0029] One non-limiting example of removing the barrier layer is via oxygen-based distal plasma. In this example, oxygen-based distal plasma etching removes the barrier layer but also oxidizes the first surface. To restore the original surface composition, the surface can be reduced. Suitable reduction processes include, but are not limited to, using plasmas containing hydrogen or ammonia and thermal annealing containing hydrogen or ammonia. In some embodiments, oxygen plasma, fluorine plasma, hydrogen plasma, and ammonia plasma can be generated independently distally or internally, and are electrically or inductively coupled.

[0030] Another non-limiting example of removing a barrier layer is by using a removal plasma, including hydrogen plasma (i.e., plasma generated by hydrogen), ammonia plasma, or a combination thereof. Without being bound by theory, the inventors have found that removing a barrier layer attached to a metallic material via a metal-nitrogen bond is readily achieved by protonating nitrogen atoms, thereby allowing the barrier compound to leave the surface.

[0031] In some embodiments, as shown at step 205, method 200 may further include cleaning a first surface before exposing the substrate to the barrier compound. In some embodiments, cleaning the first surface includes exposing the first surface to a solution containing acetic acid and ethanol. In some embodiments, the solution is an ethanol solution of 10% acetic acid (i.e., 10% v / v acetic acid in ethanol or 10% w / w acetic acid in ethanol).

[0032] In some embodiments, cleaning the first surface includes exposing the first surface to hydrogen or ammonia. In some embodiments, hydrogen or ammonia is ignited to form a plasma (e.g., hydrogen plasma). In some embodiments, the plasma is conductively coupled plasma (CCP). In some embodiments, the plasma is inductively coupled plasma (ICP).

[0033] Unbound by theory, it is believed that cleaning the first surface leads to a higher prevalence of H-termini or N-termini on the first surface. It is believed that these termini are reaction sites that block compounds.

[0034] In some embodiments, the blocking compound comprises a 4- to 8-membered heterocycle, the heterocycle comprising a heteroatom and at least one substituent selected from hydrogen, alkyl, or aryl groups comprising 1 to 8 carbon atoms. In some embodiments, the substituent is not hydrogen. In some embodiments, the heteroatom is selected from nitrogen, oxygen, sulfur, or phosphorus. In some embodiments, the heterocycle is aromatic.

[0035] The list of exemplary blocking compounds includes: and . For each of the above compounds, the R group represents an alkyl or aryl group containing 1 to 8 carbon atoms and may be suspended on the ring at any suitable position.

[0036] In some embodiments, the heterocycle comprises more than one heteroatom. In some embodiments, the heterocycle comprises two heteroatoms. In some embodiments, all heteroatoms of the heterocycle are identical. In some embodiments, the heteroatoms are positioned adjacent to each other (e.g., substituted pyrazolidine). In some embodiments, the heteroatom is positioned to have at least one inserted carbon atom (e.g., substituted imidazoidine).

[0037] Another non-limiting list of blocking compounds includes: and .

[0038] In some embodiments, the heterocycle is substituted with an aminomethyl group at the 2-carbon position. In other words, in some embodiments, the heterocycle is a 2-aminomethyl heterocycle. Exemplary blocking compounds with an aminomethyl group substituted at the 2-carbon position are...

[0039] In some embodiments, each R" is selected from hydrogen or an alkyl group containing 1 to 4 carbon atoms.

[0040] In some embodiments, the blocking compound has the general formula: ,

[0041] In each of the X series, nitrogen, oxygen, sulfur, or phosphorus, n is selected to maintain a neutral charge, R' is selected from hydrogen, alkyl or aryl groups containing 1 to 18 carbon atoms, and each R is independently selected from alkyl or aryl groups containing 1 to 8 carbon atoms. In some embodiments, each X series is identical.

[0042] In some embodiments, the blocking compound comprises an amine containing at least one substituent having 1 to 18 carbon atoms. In some embodiments, the amine is a primary amine (R'NH₂). In some embodiments, the amine is a secondary amine (R'₂NH). In some embodiments, the amine is a tertiary amine (R'₃N). In the case of secondary or tertiary amines, the substituent R' may be the same or different. In some embodiments, at least one R' group contains 4 to 18 carbon atoms, 6 to 18 carbon atoms, 8 to 18 carbon atoms, or 12 to 18 carbon atoms. In some embodiments, the substituent does not contain silicon.

[0043] Although the disclosure herein has been described with reference to specific embodiments, it will be understood that these embodiments are merely illustrative of the principles and applications of this disclosure. Those skilled in the art will readily recognize that various modifications and variations can be made to the methods and apparatus disclosed herein without departing from the spirit and scope of this disclosure. Therefore, this disclosure is intended to include modifications and variations within the scope of the appended claims and their equivalents.

[0044] 105:Substrate 110: Metallic materials 112: First Surface 120: Dielectric material 122: Second Surface 125: Materials 130: Barrier Layer 132: The first surface of the barrier 200: Method 205: Steps 210: Steps 220: Steps 230: Steps

[0045] Domestic storage information (please note in order of storage institution, date, and number) none Overseas storage information (please note in the order of storage country, institution, date, and number) none

Claims

1. A method for selectively depositing a barrier layer, the method comprising the steps of: exposing a substrate comprising a metallic material having a first surface and a dielectric material having a second surface to a barrier compound to selectively form a barrier layer on the first surface relative to the second surface, the barrier compound comprising a 4- to 8-membered heterocycle, the heterocycle comprising at least one heteroatom and at least one substituent selected from alkyl or aryl groups comprising 1 to 8 carbon atoms, wherein the heterocycle is a 2-aminomethyl heterocycle.

2. The method as described in claim 1, wherein the heteroatom is selected from nitrogen, oxygen, sulfur, or phosphorus.

3. The method as described in claim 2, wherein the heteroatom nitrogen system is described.

4. The method as described in claim 1, wherein the heterocyclic compound is aromatic.

5. The method of claim 1, wherein the heterocycle comprises more than one heteroatom.

6. The method as described in claim 5, wherein the heteroatoms are adjacent.

7. The method of claim 1, wherein the metallic material comprises a metal, a metal alloy, a metal oxide, a metal nitride, or a combination thereof.

8. The method of claim 6, wherein the metallic material comprises one or more of copper, cobalt, tungsten, tantalum, titanium, ruthenium, iridium, their oxides, their nitrides, or combinations thereof.

9. The method of claim 1, further comprising the step of selectively depositing a material on the second surface after selectively forming the barrier layer.

10. The method of claim 8, wherein the metallic material comprises a metal, a metal oxide, or a metal nitride.

11. The method of claim 1, further comprising the step of: exposing the substrate to a removal plasma to remove the barrier layer from the first surface.

12. The method of claim 11, wherein the removal plasma comprises hydrogen plasma, ammonia plasma, or a combination thereof.

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