Deposition of Semiconductor Integrated Film

Abstract

To provide methods for enhancing the efficiency in a lithographic process for depositing a photoresist layer on a substrate using vapor phase processes.SOLUTION: A method of depositing a metal oxo photoresist using dry deposition processes comprises forming a first metal oxo film on a substrate with a first vapor phase process including a first metal precursor vapor and a first oxidant vapor, and forming a second metal oxo film over the first metal oxo film with a second vapor phase process including a second metal precursor vapor and a second oxidant vapor.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] Background 1) Field

[0001] Embodiments of the present disclosure relate to the field of semiconductor processing, and more particularly, to a method of depositing a photoresist layer on a substrate using a vapor phase process.

Background Art

[0002] 2) Description of Related Art

[0002] Lithography has been used in the semiconductor industry for decades to create 2D and 3D patterns in microelectronic devices. The lithography process includes spin-on deposition of a film (photoresist), irradiation of the film with a selected pattern by an energy source (exposure), and removal (etching) of the exposed (positive tone) or unexposed (negative tone) regions of the film by dissolving in a solvent. A bake is performed to drive out the remaining solvent.

[0003]

[0003] The photoresist must be a material sensitive to radiation, and when irradiated, a chemical conversion occurs in the exposed portion of the film, enabling a change in solubility between the exposed and unexposed regions. This change in solubility is used to remove either the exposed or unexposed regions of the photoresist (etching). Thus, the photoresist is developed and the pattern can be transferred by etching to the underlying thin film or substrate. After the pattern is transferred, the residual photoresist is removed, and by repeating this process multiple times, 2D and 3D structures used in microelectronic devices can be obtained.

[0004]

[0004] In a lithography process, several characteristics are important. Such important characteristics include sensitivity, resolution, low line edge roughness (LER), etch resistance, and the ability to form thinner layers. High sensitivity means that the energy required to change the solubility of the deposited film is low. This improves the efficiency of the lithography process. Resolution and LER determine how narrow features can be achieved by the lithography process. For pattern transfer to form deep structures, higher etch-resistant materials are required. Higher etch-resistant materials also enable thinner films. Thinner films enhance the efficiency of the lithography process.

Summary of the Invention

[0005]

[0005] Embodiments disclosed herein include a method of forming a metal oxo photoresist in a vapor phase process. In one embodiment, a method of forming a photoresist layer on a substrate includes forming a first metal oxo film on the substrate in a first vapor phase process including a first metal precursor vapor and a first oxidant vapor, and forming a second metal oxo film on the first metal oxo film using a second vapor phase process including a second metal precursor vapor and a second oxidant vapor.

[0006]

[0006] In a further embodiment, a method of forming a photoresist layer on a substrate in a vacuum chamber includes providing a metal precursor vapor of the general formula MR x L y (where M is a metal, R is a leaving group, L is a ligand, x is between 0 and 6, and y is between 0 and 6) into the vacuum chamber. The method may further include providing an oxidant vapor to the vacuum chamber, and the reaction between the metal precursor vapor and the oxidant vapor results in the formation of a photoresist layer on the surface of the substrate, and the photoresist layer is a metal oxo-containing material.

[0007]

[0007] In a further embodiment, a method of forming a photoresist layer on a substrate in a vacuum chamber includes initiating a deposition cycle. In one embodiment, the deposition cycle includes a metal precursor vapor of the general formula MR x Ly (In the formula, M is a metal, R is a leaving group, L is a ligand, x is between 0 and 6, and y is between 0 and 6.) Providing a metal precursor vapor to a vacuum chamber. In one embodiment, the metal precursor vapor is absorbed onto a surface on a substrate. The deposition cycle can further include purging the vacuum chamber and providing an oxidant vapor to the vacuum chamber, and a photoresist layer is formed on the surface of the substrate by a reaction between the metal precursor absorbed on the surface on the substrate and the oxidant vapor. In one embodiment, the photoresist layer is a metal oxo-containing material. In one embodiment, the deposition cycle can further include purging the vacuum chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0008]

Figure 1

[0008] Chemical formula of the synthesis of a metal precursor used in a vapor deposition process to form a metal oxo film according to an embodiment of the present disclosure.

Figure 2

[0009] A flowchart showing a process of forming a photoresist on a substrate using a chemical vapor deposition (CVD) process according to an embodiment of the present disclosure.

Figure 3

[0010] A flowchart showing a process of forming a photoresist on a substrate using an atomic layer deposition (ALD) process according to an additional embodiment of the present disclosure.

Figure 4

[0011] A cross-sectional view of a metal oxo photoresist on a substrate according to an embodiment of the present disclosure.

Figure 5

[0012] A flowchart showing a process of forming a photoresist having a non-uniform composition through the thickness of the photoresist according to an embodiment of the present disclosure.

Figure 6A

[0013] A cross-sectional view of a metal oxo photoresist on a substrate according to an embodiment of the present disclosure, wherein the metal oxo photoresist includes a first layer and a second layer having different material compositions.

Figure 6B

[0014] A cross-sectional view of a metal-oxo photoresist on a substrate according to an embodiment of the present disclosure, the metal-oxo photoresist including a plurality of layers that provide a composition gradient across the thickness of the metal-oxo photoresist.

Figure 7

[0015] A cross-sectional view of a processing tool that can be used to perform the process of FIGS. 2, 3, or 5 according to an embodiment of the present disclosure.

Figure 8

[0016] A block diagram of an exemplary computer system is shown according to one embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0009]

[0017] A method of depositing a photoresist on a substrate using a vapor phase process is described herein. In the following description, numerous specific details are set forth, such as chemical vapor deposition (CVD) processes and atomic layer deposition (ALD) processes, and material regimes for depositing photoresists, in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known aspects, such as the manufacture of integrated circuits, are not described in detail so as not to unnecessarily obscure embodiments of the present disclosure. Further, it should be understood that the various embodiments shown in the figures are exemplary representations and are not necessarily drawn to scale.

[0010]

[0018] To provide context, photoresist systems used in extreme ultraviolet (EUV) lithography have the drawback of being inefficient. That is, existing photoresist material systems for EUV lithography require high doses to provide the solubility switch necessary to enable development of the photoresist material. Organic-inorganic hybrid materials (e.g., metal oxo material systems) have been proposed as material systems for EUV lithography because they have improved sensitivity to EUV radiation. Such material systems typically contain a metal (e.g., Sn, Hf, Zr, etc.), oxygen, and carbon. Metal oxo molecules are sometimes referred to as nanoparticles. Metal oxo-based organic-inorganic hybrid materials have also been shown to provide lower LER and higher resolution, which are properties necessary to form narrow features.

[0011]

[0019] Metal oxo material systems are currently deposited on a substrate using a wet process. The metal oxo material system is dissolved in a solvent and distributed across the substrate (e.g., a wafer) using a wet chemical deposition method such as spin coating. There are several drawbacks to wet chemical deposition of photoresist. One minus of wet chemical deposition is that a large amount of wet by-products are generated. Wet by-products are undesirable, and the semiconductor industry is actively working to reduce wet by-products as much as possible. Further, wet chemical deposition can cause non-uniformity issues. For example, spin-on deposition can provide a photoresist layer with a non-uniform thickness or non-uniform distribution of metal oxo molecules. Further, metal oxo photoresist material systems have been shown to suffer from a decrease in thickness after exposure, which is troublesome in the lithography process. Further, in the spin-on process, the ratio of metal in the photoresist is fixed and cannot be easily adjusted.

[0012]

[0020] Accordingly, embodiments of the present disclosure provide a vacuum deposition process for providing a metal oxo photoresist layer. The vacuum deposition process addresses the drawbacks of the wet deposition process described above. In particular, the vacuum deposition process has the following advantages: 1) eliminates the production of wet by-products; 2) provides a very uniform photoresist layer; 3) resists post-exposure thickness reduction; 4) provides a mechanism for adjusting the ratio of metals in the photoresist; and 5) enables the formation of a photoresist layer with a tailored non-uniform material composition throughout the thickness of the photoresist layer.

[0013]

[0021] The ability to form a tailored non-uniform material composition throughout the thickness of the photoresist layer results in improved properties of the photoresist. For example, the bottom of the photoresist layer adjacent to the underlying substrate can be a material composition with higher adhesion strength. Additionally, the bottom of the photoresist layer can be designed to be less sensitive to radiation. In negative tone resists, it may be convenient to reduce sensitivity to prevent scum after development of the photoresist. Scum may refer to the presence of residual photoresist material that is not removed from the pattern after development. Embodiments may also include a gradient functional material composition throughout the thickness of the photoresist. The gradient of the material composition can be used to control the exposure latitude curve of the photoresist. This enables control of the development profile of the photoresist and / or can be used to provide optical proximity correction (OPC). OPC is typically implemented by changing the pattern of the mask. However, the embodiments disclosed herein enable the implementation of OPC technology by changing the composition of the photoresist. Therefore, the change in OPC can be implemented without changing the photolithography mask, providing a more economical solution.

[0014]

[0022] The embodiments disclosed herein provide various vacuum deposition processes that include the reaction of a metal precursor and an oxidizing agent. In a first embodiment, the vacuum deposition process can be a chemical vapor deposition (CVD) process. In a second embodiment, the vacuum deposition process can be an atomic layer deposition (ALD) process. The vacuum deposition process can be a thermal process in some embodiments. In other embodiments, the vacuum deposition process can be a plasma (PE) deposition process (e.g., PE-CVD or PE-ALD).

[0015]

[0023] In one embodiment, the vacuum deposition process relies on a chemical reaction between a metal precursor and an oxidizing agent. The metal precursor and the oxidizing agent are vaporized into the vacuum chamber. The metal precursor reacts with the oxidizing agent to form a photoresist layer containing metal oxo on the surface of the substrate. In some embodiments, the metal precursor and the oxidizing agent are provided to the vacuum chamber together. In other embodiments, the metal precursor and the oxidizing agent are provided to the vacuum chamber in alternating pulses. In an ALD or PE-ALD process, a purge of the vacuum chamber can be provided between pulses of the metal precursor and the oxidizing agent.

[0016]

[0024] In one embodiment, the metal precursor can have the general formula MR x L y wherein M is a metal center, R is a leaving group, and L is a ligand. In one embodiment, x can be between 0 and 6, and y can be between 0 and 6. The metal precursor can be synthesized using any chemical reaction process. For example, a general reaction is shown in FIG. 1. As shown, the compound SnR x X y (wherein X is Cl or Br) can react with various ligands to form the metal precursor SnR x L y It should be understood that the Sn metal center can be replaced with any suitable metal atom. In one embodiment, the L ligand serves to react with the oxidizing agent to form metal oxo molecules, and the R leaving group is released during exposure (e.g., EUV exposure) during the patterning process. Thus, the sensitivity of the photoresist can be affected, at least in part, by the choice of the leaving group R.

[0017]

[0025] The selection of the metal center M, the leaving group R, and the ligand L drives different material properties of the metal-oxo photoresist. For example, changes to M, R, and L can provide different sensitivities to radiation, different adhesion properties, different structural properties (i.e., to enable the formation of high aspect ratio patterns), and different etching selectivities, among many other properties. Thus, the photoresist can be specifically tailored to suit the desired purpose. Further, using a vacuum deposition process, one or more of M, R, and L can be varied across the thickness of the photoresist to provide non-uniform material properties within the photoresist, as will be described in more detail below.

[0018]

[0026] In certain embodiments, M is Sn. However, it should be understood that M can be any suitable metal element such as, but not limited to, Sn, Hf, Zr, Co, Cr, Mn, Fe, Cu, Ni, Mo, W, Ta, Os, Re, Pd, Pt, Ti, V, In, Al, Sb, Bi, Te, As, Ge, Se, Cd, Ag, Pd, Au, Er, Yb, Pr, La, Na, or Mg.

[0019]

[0027] In one embodiment, the ligand L can have many different chemical structures. In one embodiment, the ligand L can be a pseudohalide ligand. Pseudohalides include, but are not limited to, CN, CNO, SCN, N3, or SeCN.

[0020]

[0028] In one embodiment, one class of ligands L suitable for metal precursors are monodentate ligands containing an N-donor atom. The binding mode to the metal center M is shown in molecule I. Such monodentate ligands can include cyclic ligands. Examples of some such ligands L are provided in molecules II - V. TIFF0007699002000001.tif122170

[0021]

[0029] In one embodiment, ligand L can also be a bidentate or monodentate ligand containing an N, O, S, or P donor atom. The binding mode of such a ligand to the metal center is shown in molecules VI and VII. In molecules VI and VII, X and Y can be N, O, S, or P. Examples of such ligands are shown in molecules VIII to XVIII. TIFF0007699002000002.tif237170TIFF0007699002000003.tif170170

[0022]

[0030] In molecules VI and VII, X and Y can be N, O, S, or P. Examples of such ligands are shown in molecules VIII to XVIII. Examples of such ligands are shown in molecules XX to XXIV. TIFF0007699002000004.tif191170

[0023]

[0031] In one embodiment, ligand L can also contain an N donor atom donating to a plurality of metal centers. Examples of the binding mode of such a ligand are shown in molecules XXV to XXVII. TIFF0007699002000005.tif128170

[0024]

[0032] In one embodiment, ligand L can also contain an H donor atom. An example of such a ligand is shown in molecule XXVIII. TIFF0007699002000006.tif13170

[0025]

[0033] In one embodiment, the leaving group R described herein can include many different suitable molecules. For example, the leaving group can include one or more of alkyl (C1 - C10), alkenyl (internal or terminal), alkynyl (internal or terminal), aryl, or carbene. The leaving group R can be linear, branched, or cyclic. In one embodiment, the leaving group R can also include Si, Ge, or Sn as donor atoms.

[0026]

[0034] Examples of suitable alkyls are described in molecule XXIX and molecule XXX. TIFF0007699002000007.tif35170

[0027]

[0035] Examples of suitable alkenyls are provided in molecules XXXI - XXXIII. TIFF0007699002000008.tif58170

[0028]

[0036] Examples of suitable alkynyls are described in molecule XXXIV. TIFF0007699002000009.tif19170

[0029]

[0037] Examples of suitable aryls are described in molecule XXXV and molecule XXXVI. TIFF0007699002000010.tif49170

[0030]

[0038] Examples of suitable carbenes are described in molecule XXXVII and molecule XXXVIII. TIFF0007699002000011.tif62170

[0031]

[0039] Examples of leaving group R containing Si, Ge, or Sn as the donor atom are shown in molecules XXXIX - XLI, where X is Si, Ge, or Sn. TIFF0007699002000012.tif61170

[0032]

[0040] In a further embodiment, the metal precursor may also include a stannylene precursor. Molecule XLII is an example of a general stannylene precursor. The ligand L can be either the above ligand L or a general amine (NR2). The leaving group R can include any of the above leaving groups R. TIFF0007699002000013.tif26170

[0033]

[0041] In yet another embodiment, the metal precursor can also be a common metal precursor such as those shown in molecule XLIII. R can include any of the above-described leaving groups R, and the metal center M can be any metal element such as, but not limited to, Sn, Hf, Zr, Co, Cr, Mn, Fe, Cu, Ni, Mo, W, Ta, Os, Re, Pd, Pt, Ti, V, In, Al, Sb, Bi, Te, As, Ge, Se, Cd, Ag, Pd, Au, Er, Yb, Pr, La, Na, or Mg. Such common metal precursors can be used in combination with the above-described metal precursors. TIFF0007699002000014.tif29170

[0034]

[0042] Referring now to FIG. 2, a flowchart illustrating a process 220 for depositing a metal oxo photoresist on a substrate surface in accordance with an embodiment of the present disclosure is provided. Process 220 can be described as a CVD or PE-CVD process. In a CVD process, the chemical reaction is thermally driven, while in a PE-CVD process, the chemical reaction can be facilitated by the presence of plasma. In a PE-CVD process, hydrocarbons can also be flowed into the chamber during plasma-assisted deposition to incorporate more carbon into the film. When the plasma is on during deposition and there are hydrocarbon molecules in the chamber, more carbon can thereby be added to the film. The form of the carbon can be M-C (M = metal). M-C (such as Sn-C) can be functional for exposure. The hydrocarbon can be a carbon-containing molecule such as, for example, CH2=CH2, acetylene, CH4, propylene, and the like.

[0035]

[0043] In one embodiment, process 220 can begin with an operation 221 that includes providing metal precursor vapor to a vacuum chamber containing a substrate. The metal precursor vapor can include a metal precursor such as those described in more detail above. For example, the metal precursor can have the general formula MR x L y where x and y are each between 0 and 6.

[0036]

[0044] In one embodiment, the metal center M can include one or more of Sn, Hf, Zr, Co, Cr, Mn, Fe, Cu, Ni, Mo, W, Ta, Os, Re, Pd, Pt, Ti, V, In, Sb, Al, Bi, Te, As, Ge, Se, Cd, Ag, Pb, Au, Er, Yb, Pr, La, Na, and Mg. The leaving group R can include one or more of alkyl, alkenyl (internal or terminal), alkynyl (internal or terminal), aryl, or carbene. The leaving group R can also include a Si donor atom, a Ge donor atom, or a Sn donor atom. In one embodiment, the leaving group R can be linear, branched, or cyclic. In one embodiment, the ligand L can include a pseudohalide, a monodentate ligand having N donor atoms, a monodentate or bidentate ligand having N, O, S, and / or P donor atoms, a bidentate ligand having one N donor atom and one O donor atom, or a ligand having an N donor atom or a hydrogen atom that donates to a plurality of metal centers M.

[0037]

[0045] In other embodiments, the metal precursor can include a stannylene precursor or a general metal precursor as shown in molecule XLIII. Furthermore, it should be understood that a plurality of metal precursor vapors can be provided to the vacuum chamber. For example, the first metal precursor can include Sn and the second metal precursor can include Hf. In such embodiments, the resulting metal oxo photoresist can include two or more different types of metal atoms. In one embodiment, the metal precursor vapor can be diluted by a carrier gas. The carrier gas can be an inert gas such as Ar, N2, or He.

[0038]

[0046] In one embodiment, process 220 can continue with operation 222 that includes providing oxidant vapor to the vacuum chamber. In one embodiment, the oxidant vapor can include a carbon skeleton having reactive groups at both ends of the carbon skeleton. The reactive groups initiate a reaction with the metal precursor, resulting in the formation of a metal oxo photoresist on the substrate. In one embodiment, the oxidant vapor can include water or ethylene glycol. In one embodiment, the oxidant vapor can be diluted by a carrier gas. The carrier gas may be an inert gas such as Ar, N2, or He.

[0039]

[0047] In one embodiment, process 220 can continue with an optional operation 223 that includes treating the metal oxo photoresist layer with plasma. In one embodiment, the plasma treatment can include plasma generated from one or more inert gases such as Ar, N2, He, etc. In one embodiment, the one or more inert gases can also be mixed with one or more oxygen-containing gases such as O2, CO2, CO, NO, NO2, H2O, etc. In one embodiment, the vacuum chamber can be purged prior to operation 223. The purge can include pulses of an inert gas such as Ar, N2, He, etc.

[0040]

[0048] In one embodiment, process 220 can be executed in a state where operations 221 and 222 are executed simultaneously. That is, providing the metal precursor vapor to the vacuum chamber and providing the oxidant vapor to the vacuum chamber can be performed simultaneously. After a metal oxo photoresist film of a desired thickness is formed, process 220 can be stopped. In one embodiment, any plasma treatment operation 223 can be executed after a metal oxo photoresist film having a desired thickness is formed.

[0041]

[0049] In other embodiments, process 220 may be performed in a pulsed manner. That is, pulses of metal precursor vapor may be provided to the vacuum chamber, followed by pulses of oxidant vapor. In one embodiment, a cycle including pulses of metal precursor vapor and pulses of oxidant vapor may be repeated multiple times to provide a metal oxophotoresist film of a desired thickness. In one embodiment, the order of the cycles can be switched. For example, the oxidant vapor can be pulsed first and then the metal precursor vapor can be pulsed.

[0042]

[0050] In one embodiment, the pulse duration of the metal precursor vapor can be substantially the same as the pulse duration of the oxidant vapor. In other embodiments, the pulse duration of the metal precursor vapor can be different from the pulse duration of the oxidant vapor. In one embodiment, the pulse duration can be between 0 seconds and 1 minute. In certain embodiments, the pulse duration can be between 1 second and 5 seconds.

[0043]

[0051] In one embodiment, each repetition of the cycle uses the same process gas. In other embodiments, the process gas can be changed between cycles. For example, the first cycle can utilize a first metal precursor vapor, and the second cycle can utilize a second metal precursor vapor. Subsequent cycles can continue to alternate between the first metal precursor vapor and the second metal precursor vapor. In one embodiment, multiple oxidant vapors can be alternated between cycles in a similar manner.

[0044]

[0052] In one embodiment, any plasma treatment of operation 223 can be performed after all cycles. That is, each cycle can include a pulse of metal precursor vapor, a pulse of oxidant vapor, and a plasma treatment. In an alternative embodiment, any plasma treatment of operation 223 can be performed after a plurality of cycles. In yet another embodiment, any plasma treatment operation 223 can be performed after the completion of all cycles (i.e., as a post-treatment).

[0045]

[0053] In one embodiment, process 220 can be a thermal process or a plasma process. In the case of a thermal process, the reaction between the metal precursor vapor and the oxidant vapor can be thermally driven. Such embodiments may be referred to as CVD processes. In the case of a plasma process, the plasma can be struck during one or both of operations 221 and 222. In such cases, the presence of the plasma can enhance the chemical reactions used to form the metal oxo photoresist. Such embodiments may be referred to as PE-CVD processes. In one embodiment, any plasma source can be used to form the plasma. For example, the plasma source can include, but is not limited to, a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a remote plasma source, or a microwave plasma source.

[0046]

[0054] In one embodiment, the vacuum chamber utilized in process 220 can be any suitable chamber capable of providing a pressure below atmospheric pressure. In one embodiment, the vacuum chamber can include a temperature control function for controlling the temperature of the chamber walls and / or for controlling the temperature of the substrate. In one embodiment, the vacuum chamber can also include features for providing a plasma within the chamber. A more detailed description of suitable vacuum chambers is provided below with respect to FIG. 7.

[0047]

[0055] In one embodiment, the substrate can be temperature controlled during process 220. For example, the temperature of the substrate can be between about 0° C. and about 500° C. In certain embodiments, the substrate can be maintained at a temperature between room temperature and 150° C.

[0048]

[0056] Referring now to FIG. 3, a flowchart is provided showing a process 340 for depositing a metal oxo photoresist on a substrate surface, according to an additional embodiment of the present disclosure. Process 340 can be described as an ALD or PE-ALD process. In an ALD process, the chemical reaction is thermally driven, while in a PE-ALD process, the chemical reaction can be facilitated by the presence of a plasma. In a PE-ALD process, hydrocarbons can also be flowed into the chamber during plasma-assisted deposition to incorporate more carbon into the film. When the plasma is on during deposition and there are hydrocarbon molecules in the chamber, more carbon can thereby be added to the film. The form of the carbon can be M-C (M = metal). M-C (such as Sn-C) can be functional to exposure. The hydrocarbons can be carbon-containing molecules such as, for example, CH2=CH2, acetylene, CH4, propylene, and the like.

[0049]

[0057] In one embodiment, process 340 can begin with an operation 341 that includes providing a metal precursor vapor to a vacuum chamber containing a substrate. In one embodiment, the metal precursor vapor can include molecules having one or more metal atoms. The metal precursor vapor can include a metal precursor such as those described in more detail above. For example, the metal precursor can have the general formula MR x L y where x and y are each between 0 and 6.

[0050]

[0058] In one embodiment, the metal center M can include one or more of Sn, Hf, Zr, Co, Cr, Mn, Fe, Cu, Ni, Mo, W, Ta, Os, Re, Pd, Pt, Ti, V, In, Sb, Al, Bi, Te, As, Ge, Se, Cd, Ag, Pb, Au, Er, Yb, Pr, La, Na, and Mg. The leaving group R can include one or more of alkyl, alkenyl (internal or terminal), alkynyl (internal or terminal), aryl, or carbene. The leaving group R can also include an Si donor atom, a Ge donor atom, or an Sn donor atom. In one embodiment, the leaving group R can be linear, branched, or cyclic. In one embodiment, the ligand L can include a pseudo-halide, a monodentate ligand having N donor atoms, a monodentate or bidentate ligand having N, O, S, and / or P donor atoms, a bidentate ligand having one N donor atom and one O donor atom, or a ligand having an N donor atom or a hydrogen atom that donates to a plurality of metal centers M.

[0051]

[0059] In other embodiments, the metal precursor can include a stannylene precursor or a general metal precursor as shown in molecule XLIII. Furthermore, it should be understood that a plurality of metal precursor vapors can be provided to the vacuum chamber. For example, the first metal precursor can include Sn, and the second metal precursor can include Hf. In such embodiments, the resulting metal oxo photoresist can include two or more different types of metal atoms. In one embodiment, the metal precursor vapor can be diluted by a carrier gas. The carrier gas can be an inert gas such as Ar, N2, or He.

[0052]

[0060] In one embodiment, the metal precursor vapor is absorbed on the surface of the substrate. In one embodiment, a monolayer of the metal precursor can be provided substantially on the surface of the substrate. However, in other embodiments, some layers of the metal precursor vapor can be absorbed on the surface of the substrate.

[0053]

[0061] In one embodiment, process 340 can continue with operation 342, which includes purging the vacuum chamber. In one embodiment, the purge process removes residual metal precursor vapor and any by-products from the vacuum chamber. The purge process can include pulses of an inert gas such as Ar, N2, He, etc.

[0054]

[0062] In one embodiment, process 340 can continue with operation 343, which includes providing an oxidant vapor to the vacuum chamber. The oxidant vapor reacts with the metal precursor absorbed on the surface to form a metal oxo photoresist layer on the surface of the substrate. Since the metal precursor is absorbed on the surface of the substrate, the reaction can be considered self-limiting. In one embodiment, the oxidant vapor can include a carbon skeleton having reactive groups at both ends of the carbon skeleton. The reactive groups initiate the reaction with the metal precursor, resulting in the formation of a metal oxo photoresist on the substrate. In one embodiment, the oxidant vapor can include water or ethylene glycol. In one embodiment, the oxidant vapor can be diluted by a carrier gas. The carrier gas can be an inert gas such as Ar, N2, or He.

[0055]

[0063] In one embodiment, the pulse duration of the metal precursor vapor can be substantially the same as the pulse duration of the oxidant vapor. In other embodiments, the pulse duration of the metal precursor vapor can be different from the pulse duration of the oxidant vapor. In one embodiment, the pulse duration can be between 0 seconds and 1 minute. In certain embodiments, the pulse duration can be between 1 second and 5 seconds.

[0056]

[0064] In one embodiment, process 340 can continue with operation 344, which includes purging the vacuum chamber. In one embodiment, the purge process removes residual oxidant vapor and any by-products from the vacuum chamber. The purge process can include pulses of an inert gas such as Ar, N2, He, etc.

[0057]

[0065] In one embodiment, process 340 can continue with an optional operation 345 that includes treating the metal oxo photoresist layer with plasma. In one embodiment, the plasma treatment can include a plasma generated from one or more inert gases such as Ar, N2, He, etc. In one embodiment, the one or more inert gases can also be mixed with one or more oxygen-containing gases such as O2, CO2, CO, NO, NO2, H2O, etc.

[0058]

[0066] In one embodiment, process operations 341 to 344 can define the cycle of process 340. Embodiments can include repeating the cycle multiple times to provide a metal oxo photoresist film having a desired thickness. In one embodiment, any plasma treatment operation 345 can be performed after each cycle. That is, each cycle can include a pulse of metal precursor vapor, a purge, a pulse of oxidant vapor, a purge, and a plasma treatment. In other embodiments, the optional plasma treatment operation 345 can be performed after a plurality of cycles. In other embodiments, the optional plasma treatment operation 345 can be performed after a plurality of cycles.

[0059]

[0067] In one embodiment, each repetition of the cycle uses the same process gas. In other embodiments, the process gas can be changed between cycles. For example, the first cycle can utilize a first metal precursor vapor, and the second cycle can utilize a second metal precursor vapor. Subsequent cycles can continue to alternate between the first metal precursor vapor and the second metal precursor vapor. In one embodiment, a plurality of oxidant vapors can be alternated between cycles in a similar manner.

[0060]

[0068] In one embodiment, process 340 can be a thermal process or a plasma process. In the case of a thermal process, the reaction between the metal precursor vapor and the oxidant vapor can be thermally driven. Such embodiments may be referred to as ALD processes. In the case of a plasma process, the plasma can be struck during one or both of operations 341 and 343. In such cases, the presence of the plasma can enhance the chemical reactions used to form the metal oxophotoresist. Such embodiments may be referred to as PE-ALD processes. In one embodiment, any plasma source can be used to form the plasma. For example, the plasma source can include, but is not limited to, a CCP source, an ICP source, a remote plasma source, or a microwave plasma source.

[0061]

[0069] In one embodiment, the vacuum chamber utilized in process 340 can be any suitable chamber capable of providing a pressure below atmospheric pressure. In one embodiment, the vacuum chamber can include a temperature control function for controlling the temperature of the chamber walls and / or for controlling the temperature of the substrate. In one embodiment, the vacuum chamber can also include features for providing a plasma within the chamber. A more detailed description of suitable vacuum chambers is provided below with respect to FIG. 7.

[0062]

[0070] In one embodiment, the substrate can be temperature controlled during process 340. For example, the temperature of the substrate can be between about 0°C and about 500°C. In certain embodiments, the substrate can be maintained at a temperature between room temperature and 150°C.

[0063]

[0071] Referring now to FIG. 4, a cross-sectional view of a metal-oxo photoresist layer 470 on a substrate 401 is shown according to one embodiment. In one embodiment, the metal-oxo photoresist layer 470 can be disposed on the substrate 401 using a process such as process 340 or process 220. The metal-oxo photoresist layer 470 can have a substantially uniform composition throughout the thickness of the metal-oxo photoresist layer. However, it should be understood that the metal-oxo photoresist can include two or more types of metal centers M. Such embodiments can be provided by flowing multiple types of metal precursors into the vacuum chamber simultaneously or in alternating pulses.

[0064]

[0072] It should be understood that the embodiments are not limited to a substantially uniform metal-oxo photoresist layer. For example, the composition of the metal-oxo photoresist layer can be adjusted by the thickness of the metal-oxo photoresist layer. For example, among other variations, the metal center can be changed, the percentage of metal can be altered, or the carbon concentration can be varied.

[0065]

[0073] Changing the composition of the metal-oxo photoresist layer in the thickness direction is made possible by the vacuum deposition process used to form the metal-oxo photoresist. For example, the metal precursor vapor or the oxidant vapor can be varied (e.g., different molecules can be used, different flow rates of the vapor can be used, etc.) at different points in the deposition of the metal-oxo photoresist. This represents a significant improvement over existing wet-based spins in the process that are limited to having a substantially uniform material composition throughout the thickness of the photoresist layer.

[0066]

[0074] Accordingly, the embodiments disclosed herein enable enhanced tunability to optimize metal oxo photoresist layers for various applications. For example, the first few nanometers (e.g., the first 10 nm or less) of the metal oxo photoresist layer on a substrate may have a different composition than the rest of the film. This allows the rest of the metal oxo photoresist to potentially be optimized for dose, while the lower portion is adjusted to improve adhesion, sensitivity to EUV photons, or sensitivity to chemicals for developing, pattern control after lithography (such as scum), as well as to improve defects and resist collapse / lift-off. In other embodiments, a composition gradient may be provided through the thickness of the metal oxo photoresist. The gradient of the material composition can be used to control the exposure latitude curve of the photoresist. This enables control of the development profile of the photoresist and / or can be used to provide OPC. The gradient can also be optimized for the pattern type. For example, pillars may require improved adhesion, while line / space patterns may allow for lower adhesion while tuning for dose improvement.

[0067]

[0075] Referring now to FIG. 5, a flowchart is provided showing a process 550 for depositing a metal oxo photoresist on a substrate surface in accordance with an additional embodiment of the present disclosure. In process 550, the material composition of the metal oxo photoresist is non-uniform across the thickness of the metal oxo photoresist. Process 550 can begin with operation 551, which includes forming a first metal oxo film on the substrate in a first vapor phase process. In one embodiment, the first vapor phase process can include a first metal precursor vapor and a first oxidizer vapor. In one embodiment, the first vapor phase process can include a CVD or PE-CVD process similar to process 220 described above. In further embodiments, the first vapor phase process can include an ALD or PE-ALD process similar to process 340 described above. The first metal precursor vapor can include any of the metal precursor vapors described in more detail above.

[0068]

[0076] In one embodiment, process 550 can continue with operation 552 that includes forming a second metal oxo film on the first metal oxo film in a second vapor-phase process that includes a second metal precursor vapor and a second oxidant vapor. In one embodiment, the second vapor-phase process can include a CVD or PE-CVD process similar to process 220 described above. In a further embodiment, the second vapor-phase process can include an ALD or PE-ALD process similar to process 340 described above. In one embodiment, the second metal precursor vapor and / or the second oxidant vapor may be different from the first metal precursor vapor and the first oxidant vapor. Thus, the second metal oxo film can have a composition different from that of the first metal oxo film.

[0069]

[0077] In some embodiments, only two different metal oxo film layers are provided. An example of such an embodiment is shown in FIG. 6A. As shown, a photoresist layer including a first metal oxo film 671 and a second metal oxo film 672 is disposed on a substrate 601. In one embodiment, the first metal oxo film 671 is an interface layer that provides improved adhesion to the substrate 601. The first metal oxo film 671 can have a thickness of about 10 nm or less.

[0070]

[0078] In other embodiments, the photoresist layer can include a plurality of different metal oxo film layers. An example of such an embodiment is shown in FIG. 6B. As shown, the photoresist layer includes a plurality of different metal oxo film layers 671-678 having different compositions. Such embodiments can be formed using process 550 that includes an additional vapor-phase process for each layer. In the illustrated embodiment, each of layers 671-678 has a substantially uniform thickness. However, it should be understood that embodiments can include metal oxo film layers having a non-uniform thickness.

[0071]

[0079] In one embodiment, process 550 may further include optional plasma treatment of the metal oxo film(s). In one embodiment, the plasma treatment can be performed after deposition of both the first and second metal oxo films. Alternatively, the plasma treatment can be performed after deposition of each metal oxo film. That is, the first metal oxo film can be deposited and then plasma treatment can be performed before depositing the second metal oxo film. In one embodiment, the plasma treatment may include a plasma generated from one or more inert gases such as Ar, N2, He, etc. In one embodiment, the one or more inert gases can also be mixed with one or more oxygen-containing gases such as O2, CO2, CO, NO, NO2, H2O, etc.

[0072]

[0080] Providing a metal oxo photoresist film using a vapor phase process as described in the above embodiments provides important advantages over wet chemical methods. One such advantage is the removal of wet by-products. The vapor phase process eliminates liquid waste and simplifies the removal of by-products. Further, the vapor phase process provides a more uniform photoresist layer. Uniformity in this sense can refer to the uniformity of the thickness across the wafer and / or the uniformity of the distribution of the metal components of the metal oxo film. In particular, CVD processes, PE-CVD processes, ALD processes, and PE-ALD processes have been shown to provide excellent thickness uniformity and component uniformity.

[0073]

[0081] Furthermore, by using a vapor phase process, the proportion of metal in the photoresist and the composition of the metal in the photoresist can be finely adjusted. The percentage of metal can be changed by increasing / decreasing the flow rate of the metal precursor into the vacuum chamber and / or by changing the pulse length of the metal precursor / oxidant. The use of a vapor phase process also enables the inclusion of multiple different metals in the metal oxo film. For example, a single pulse flowing two different metal precursors can be used, or alternating pulses of two different metal precursors can be used. The use of a vapor phase process also enables the formation of metal oxo films with different material compositions to adjust the photoresist for a desired application.

[0074]

[0082] Furthermore, metal oxo photoresists formed using a vapor phase process have been shown to be more resistant to post-exposure thickness reduction. Without being bound to a particular mechanism, the resistance to thickness reduction is thought to be due, at least in part, to a reduction in carbon loss during exposure.

[0075]

[0083] FIG. 7 is a schematic diagram of a vacuum chamber configured to perform vapor deposition of a metal oxo photoresist according to an embodiment of the present disclosure. The vacuum chamber 700 includes a grounded chamber 705. The substrate 710 is loaded through the opening 715 and clamped to the temperature-controlled chuck 720.

[0076]

[0084] Process gases are supplied into the interior of the chamber 705 from the gas source 744 via their respective mass flow controllers 749. In certain embodiments, the gas distribution plate 735 provides the distribution of the process gases 744 such as metal precursors, oxidants, and inert gases. The chamber 705 is evacuated via the exhaust pump 755.

[0077]

[0085] When RF power is applied during the processing of the substrate 710, a plasma is formed in the chamber processing region on the substrate 710. The bias power RF generator 725 is coupled to the temperature-controlled chuck 720. The bias power RF generator 725 provides bias power for energizing the plasma as needed. The bias power RF generator 725 can have a low frequency, for example, between about 2 mL and 60 mL, and in certain embodiments, is in the 13.56 mL band. In certain embodiments, the vacuum chamber 700 includes a third bias power RF generator 726 at a frequency in the about 2 mL band that is connected to the same RF match 727 as the bias power RF generator 725. The source power RF generator 730 is coupled via a match (not shown) to a plasma generation element (e.g., the gas distribution plate 735) to provide source power for energizing the plasma. The source RF generator 730 can have a frequency, for example, between 100 and 180 mL, and in certain embodiments, is in the 162 MHz band. Since the diameter of the substrate changes over time to 150 mm, 200 mm, 300 mm, etc., it is common in the art to normalize the source and bias power of the plasma etching system to the substrate area.

[0078]

[0086] The vacuum chamber 700 is controlled by a controller 770. The controller 770 can include a CPU 772, a memory 773, and an I / O interface 774. The CPU 772 can execute processing operations within the vacuum chamber 700 according to instructions stored in the memory 773. For example, one or more processes such as the above-described processes 220, 340, and 550 can be executed within the vacuum chamber by the controller 770.

[0079]

[0087] FIG. 8 shows a schematic diagram of an exemplary form of a machine, a computer system 800, within which a set of instructions for causing a machine to execute any one or more of the methods described herein can be executed. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a local area network (LAN), intranet, extranet, or the Internet. The machine may function as a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), tablet PC, set-top box (STB), personal digital assistant (PDA), cellular phone, web appliance, server, network router, switch or bridge, or any machine capable of executing a set (sequential or otherwise) of instructions that specify actions to be taken by that machine. Further, although a single machine is shown, the term "machine" shall also be taken to include any collection of machines (e.g., computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies described herein.

[0080]

[0088] The exemplary computer system 800 includes a processor 802, main memory 804 (e.g., dynamic random access memory (DRAM) such as read only memory (ROM), flash memory, synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM)), static memory 806 (e.g., flash memory, static random access memory (SRAM), MRAM, etc.), and secondary storage 818 (such as a data storage device), which communicate with each other via a bus 830.

[0081]

[0089] Processor 802 represents one or more general-purpose processing devices, such as a microprocessor or a central processing unit. More specifically, processor 802 can be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or a processor implementing a combination of instruction sets. Processor 802 can also be one or more special-purpose processing devices, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), or a network processor. Processor 802 is configured to execute processing logic 826 for performing the processes described herein.

[0082]

[0090] Computer system 800 may further include a network interface device 808. Computer system 800 may include a video display device 810 (e.g., a liquid crystal display (LCD), a light-emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 812 (e.g., a keyboard), a cursor control device 814 (e.g., a mouse), and a signal generation device 816 (e.g., a speaker).

[0083]

[0091] Secondary memory 818 may include a machine-accessible storage medium (or more specifically a computer-readable storage medium) 832 storing one or more instruction sets (e.g., software 822) that embody any one or more of the methodologies or functions described herein. Software 822 may reside, in whole or at least in part, within main memory 804 and / or within processor 802, which also constitutes a machine-readable storage medium while being executed by computer system 800. This software 822 may further be transmitted or received over network 820 via network interface device 808.

[0084]

[0092] In an illustrative embodiment, a machine-accessible storage medium 832 is shown as a single medium, but the term "machine-readable storage medium" should be understood to include a single medium or multiple media (e.g., a centralized database, or a distributed database, and / or associated caches and servers) that store one or more instruction sets. The term "machine-readable storage medium" should also be interpreted to include any medium that can store or encode a set of instructions that, when executed by a machine, cause the machine to perform any one or more of the methods of the present invention. Thus, the term "machine-readable storage medium" should be interpreted to include, but not be limited to, solid-state memory, optical media, and magnetic media.

[0085]

[0093] According to one embodiment of the present disclosure, a machine-accessible storage medium stores instructions thereon that cause a data processing system to execute a method of depositing a metal oxophotoresist on a substrate. The method includes vaporizing a metal precursor into a vacuum chamber and vaporizing an oxidizing agent into the vacuum chamber. The metal precursor and the oxidizing agent may be sequentially provided to the vacuum chamber or simultaneously supplied to the vacuum chamber. The reaction between the metal precursor and the oxidizing agent results in the formation of a metal oxophotoresist on the substrate. The metal oxophotoresist can be processed by plasma treatment in some embodiments.

[0086]

[0094] In this way, a method for forming a metal oxophotoresist using a vapor-phase process has been disclosed.

Claims

1. A method of forming a photoresist layer on a substrate, comprising: forming a first metal oxo film on the substrate using a first vapor phase process including a first metal precursor vapor and a first oxidant vapor; and forming a second metal oxo film on the first metal oxo film using a second vapor phase process including a second metal precursor vapor and a second oxidant vapor. A method as described above.

2. The method according to claim 1, wherein the material composition of the first metal oxo film is different from that of the second metal oxo film.

3. The method according to claim 1, wherein the thickness of the first metal oxo film is about 5 nm or less.

4. The method according to claim 3, wherein the first metal precursor vapor is different from the second metal precursor vapor, and / or the first oxidant vapor is different from the second oxidant vapor.

5. The method according to claim 1, wherein the first vapor phase process and the second vapor phase process are a chemical vapor deposition (CVD) process, a plasma CVD (PE-CVD) process, an atomic layer deposition (ALD) process, or a plasma ALD (PE-ALD) process.

6. The method according to claim 1, wherein the sensitivity of the first metal oxo film is lower than that of the second metal oxo film.

7. The method according to claim 1, wherein the adhesion strength of the first metal oxo film is greater than that of the second metal oxo film.

8. The method according to claim 1, further comprising forming a plurality of additional metal oxo films on the second metal oxo film, wherein the first metal oxo film, the second metal oxo film, and the plurality of additional metal oxo films provide a composition gradient.

9. A method of forming a photoresist layer on a substrate in a vacuum chamber, comprising: To provide a metal precursor vapor into the vacuum chamber, wherein the metal precursor has the general formula MR ｘ L ｙ (wherein M is a metal, R is a leaving group, L is a ligand, x is between 0 and 6, and y is between 0 and 6), and the leaving group contains one or more of alkenyl, alkynyl, aryl, and carbene, or the leaving group contains silicon or germanium as a donor atom, and to provide the metal precursor vapor into the vacuum chamber; providing an oxidant vapor in the vacuum chamber, wherein the reaction between the metal precursor vapor and the oxidant vapor results in the formation of the photoresist layer on the surface of the substrate, and the photoresist layer is a metal oxo-containing material. A method as described above.

10. The method according to claim 9, further comprising striking a plasma in the vacuum chamber between one or both of providing the metal precursor vapor into the vacuum chamber and providing the oxidant vapor into the vacuum chamber.

11. The method according to claim 9, further comprising treating the photoresist layer with plasma.

12. The method according to claim 9, wherein the ligand comprises one or more of a pseudohalide, a monodentate ligand containing a nitrogen donor atom, a nitrogen donor atom, an oxygen donor atom, a sulfur donor atom, and a bidentate ligand containing one or more of a phosphorus donor atom, a ligand having a nitrogen donor atom donating to a plurality of metal centers, or a hydrogen ligand.

13. A method of forming a photoresist layer on a substrate in a vacuum chamber, comprising: Initiating a deposition cycle, comprising: To provide a metal precursor vapor to the vacuum chamber, wherein the metal precursor has the general formula MR ｘ L ｙ (wherein M is a metal, R is a leaving group, L is a ligand, x is between 0 and 6, and y is between 0 and 6), and the metal precursor vapor is absorbed on the surface on the substrate, to provide the metal precursor vapor in the vacuum chamber; Purging the vacuum chamber; Providing an oxidant vapor into the vacuum chamber, wherein a reaction between the metal precursor absorbed on the surface of the substrate and the oxidant vapor results in the formation of the photoresist layer on the surface of the substrate, and the photoresist layer is a metal oxo-containing material; Purging the vacuum chamber And initiating the deposition cycle including the above, to form the photoresist layer on the substrate in the vacuum chamber.

14. The method according to claim 13, further comprising repeating the deposition cycle a plurality of times.

15. The method according to claim 13, further comprising striking a plasma in the vacuum chamber during the deposition cycle.

16. The method according to claim 13, wherein the ligand comprises one or more of a pseudohalide, a monodentate ligand containing a nitrogen donor atom, a nitrogen donor atom, an oxygen donor atom, a sulfur donor atom, and a bidentate ligand containing one or more of a phosphorus donor atom, a ligand having a nitrogen donor atom donating to a plurality of metal centers, or a hydrogen ligand.

17. The method according to claim 13, wherein the leaving group comprises one or more of alkyl, alkenyl, alkynyl, aryl, carbene, or the leaving group comprises silicon, germanium, or tin as a donor atom.

18. The deposition cycle is: The method according to claim 13, further comprising treating the photoresist layer with plasma.

19. The method according to claim 18, further comprising, after repeating the deposition cycle a plurality of times, treating the photoresist layer with plasma.

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