Hafnium-containing structure and related method and system

Abstract

To provide a hafnium-containing structure, and related method and system.SOLUTION: There are provided a method, a system, and a structure for lithography, particularly EUV lithography. An embodiment of a structure disclosed herein includes a hafnium oxide secondary electron generating layer that can advantageously reduce the amount of light exposure required to fully develop an EUV resist.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to the field of integrated circuit manufacturing, particularly to the field of substrate process patterning, and more particularly to the field of extreme ultraviolet (EUV) patterning. [Background technology]

[0002] Semiconductor device patterning is often designed around the characteristics of expensive lithography equipment. Reducing the time required per wafer during a lithography step can greatly improve the throughput and cost of device manufacturing, and this time can be expressed in terms of lithography exposure dose.

[0003] Exposure dose is equal to the energy over a unit space, or in other words, the photon flux (the number of photons per unit space per unit time) multiplied by the photon energy and exposure time. In the emerging field of extreme ultraviolet (EUV) lithography, which improves resolution through reduced wavelength, the energy per photon is greatly increased. To reduce the exposure dose, either the photon flux or the exposure time must be reduced, both of which reduce the total number of photons hitting the lithographic resist to a very small amount. Furthermore, high energy EUV photons are more difficult to absorb by most materials, exaggerating the problem of low photon counts. With such a small number of photons absorbed by the resist, it is difficult to obtain good quality lithographic structures due to photon shot noise effects, especially when small feature sizes are pursued. Therefore, the key to actually reducing the exposure dose is to increase the useful effect of each photon.

[0004] The usefulness of each photon is generally improved through two methods: by increasing the absorption of each photon, and by increasing the number of electrons generated per photon. Absorption is often improved by simply inserting an EUV absorbing material into the lithographic structure. This absorption produces photoelectrons that can drive reactions in the resist, but one electron per photon conversion still produces high shot noise. This problem is solved if the high energy photoelectrons are converted into multiple secondary electrons (SEs) through multiple possible paths.

[0005] There are two main known solutions for incorporating EUV absorbing and SE generating materials into the lithography stack. One is to add the materials directly to the resist, such as by adding a sensitizer to a chemically amplified resist (CAR) or by using a highly absorbing metal oxide resist (MOR). However, these new resists have drawbacks. The resist becomes a complex structure where SE generation is difficult to control, and too high absorption in the resist can prevent further photons from traveling to the bottom of the resist, as needed. An excessively long electron path in the resist is also undesirable, because this impairs resolution and causes roughness. If the absorption is balanced so that the photons are absorbed at the bottom of the resist, the SEs are still often lost to the substrate.

[0006] A second solution, which complements the above solutions, is to deposit EUV absorbing and SE generating materials into the secondary electron generating layer. These layers can be directly designed to generate many electrons and help deliver SEs to the bottom of the resist. However, many of the materials are heavy metals that have a self-limiting effect, since electrons from deeper levels cannot easily travel to the resist. For example, tin is a popular candidate for high EUV absorption, but it suffers from the limitations mentioned above and has so far not reached the ideal dose reduction level. Therefore, there is still a need for alternative materials that have higher absorption and can improve the electron path to the resist. Summary of the Invention [Means for solving the problem]

[0007] Described herein is a structure that includes a substrate, a secondary electron generating layer, and an extreme ultraviolet (EUV) resist. The secondary electron generating layer is disposed between the substrate and the EUV resist. The secondary electron generating layer includes hafnium. In some embodiments, the secondary electron generating layer includes hafnium oxide (HfO2).

[0008] In some embodiments, the secondary electron generating layer has a thickness of at least 1 nm and up to 5 nm.

[0009] In some embodiments, the secondary electron generating layer further comprises one or more EUV absorbing elements selected from the group consisting of iodine (I), tellurium (Te), cesium (Cs), antimony (Sb), tin (Sn), indium (In), bismuth (Bi), silver (Ag), lead (Pb), gold (Au), platinum (Pt), iridium (Ir), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), and arsenic (As).

[0010] In some embodiments, the secondary electron generating layer contains at least 15 atomic percent hafnium.

[0011] In some embodiments, the structure further includes an adhesive layer positioned between the secondary electron generating layer and the EUV resist.

[0012] In some embodiments, the adhesive layer comprises silicon, carbon, oxygen, and hydrogen.

[0013] In some embodiments, the adhesive layer further comprises nitrogen.

[0014] Further described herein is a method of forming a structure, the method including providing a substrate to a reaction chamber and performing a deposition process including exposing the substrate to a hafnium precursor comprising hafnium, the deposition process further including exposing the substrate to a reactant thereby forming a hafnium-containing secondary electron generating layer on the substrate, and forming an EUV resist on the substrate.

[0015] In some embodiments, the deposition process comprises a cyclic deposition process, the cyclic deposition process comprising a plurality of cycles, one from the plurality of cycles comprising a hafnium precursor pulse and a reactant pulse, the hafnium precursor pulse comprising exposing the substrate to a hafnium precursor, and the reactant pulse comprising exposing the substrate to a reactant, thereby forming a hafnium-containing secondary electron generating layer on the substrate.

[0016] In some embodiments, the method further includes forming an adhesive layer on the substrate, the adhesive layer being formed on the hafnium-containing secondary electron generating layer, and the EUV resist being formed on the adhesive layer.

[0017] In some embodiments, the hafnium precursor comprises one or more alkylamine ligands.

[0018] In some embodiments, the hafnium precursor comprises tetrakis(ethylmethylamino)hafnium.

[0019] In some embodiments, the reactant comprises an oxygen reactant, and the oxygen reactant comprises oxygen.

[0020] In some embodiments, the oxygen reactant comprises ozone.

[0021] In some embodiments, the oxygen reactant comprises water.

[0022] In some embodiments, the deposition process further includes generating a plasma and exposing the substrate to one or more activated species generated in the plasma.

[0023] In some embodiments, exposing the substrate to one or more activated species generated in the plasma occurs at least partially simultaneously with a reactant pulse, the reactants including one or more activated species, the activated species including at least one of ions and radicals.

[0024] In some embodiments, the deposition process occurs thermally.

[0025] In some embodiments, one from the plurality of cycles further comprises an EUV absorbing element pulse, the EUV absorbing element pulse comprising exposing the substrate to an EUV absorbing element precursor, the EUV absorbing element precursor comprising an EUV absorbing element selected from the group consisting of iodine (I), tellurium (Te), cesium (Cs), antimony (Sb), tin (Sn), indium (In), bismuth (Bi), silver (Ag), lead (Pb), gold (Au), platinum (Pt), iridium (Ir), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), and arsenic (As).

[0026] In some embodiments, a controller is constructed and arranged to cause the system to perform the methods described herein.

[0027] This Summary is provided to introduce a selection of concepts in a simplified form. These concepts are described in more detail in the Detailed Description of Example Embodiments of the Disclosure below. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. [Brief description of the drawings]

[0028] [Figure 1] 1 illustrates an embodiment of a structure according to the present disclosure. [Diagram 2] 1 illustrates an embodiment of a structure according to the present disclosure. [Diagram 3] 1 illustrates an embodiment of a structure according to the present disclosure. [Figure 4] FIG. 1 illustrates an embodiment of a method according to the present disclosure. [Diagram 5] FIG. 1 illustrates an embodiment of a system according to the present disclosure. [Figure 6] FIG. 1 illustrates an embodiment of a system according to the present disclosure. [Figure 7] FIG. 1 illustrates an embodiment of a system according to the present disclosure. [Figure 8] FIG. 1 illustrates an embodiment of a system according to the present disclosure. [Figure 9] FIG. 1 illustrates an embodiment of a method according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] It will be appreciated that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale, for example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of the illustrated embodiments of the present disclosure.

[0030] Although certain specific embodiments and examples are disclosed below, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention, and obvious modifications and equivalents thereof, and therefore it is not intended that the scope of the disclosed invention should be limited by the specific disclosed embodiments described below.

[0031] As used herein, the term "substrate" may refer to any underlying material or materials, including any underlying material or materials, that may be modified or upon which a device, circuit, or film may be formed. A "substrate" may be continuous or non-continuous, rigid or flexible, solid or porous, and combinations thereof. The substrate may be in any form, such as a powder, plate, or workpiece. Substrates in the form of plates may include wafers of various shapes and sizes. Substrates may be made of semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.

[0032] The continuous substrate may extend beyond the boundaries of the process chamber in which the deposition process occurs. In some processes, the continuous substrate may move through the process chamber, such that the process continues until the end of the substrate is reached. The continuous substrate may be fed from a continuous substrate feed system to enable the production and output of the continuous substrate in any suitable form.

[0033] In this disclosure, "gas" can include materials that are gaseous at ambient temperature and pressure (NTP), vaporized solids, and / or vaporized liquids, and can be comprised of a single gas or a mixture of gases in some circumstances. Gases other than process gases, i.e., gases introduced without passing through a gas distribution assembly, other gas distribution device, or the like, can be used, for example, to seal the reaction space and can include a seal gas. Precursors and reactants can be gases. Exemplary seal gases include noble gases, nitrogen, and the like. In some cases, the term "precursor" can refer to a compound that participates in a chemical reaction to produce another compound, and specifically a compound that constitutes the membrane matrix or backbone of the membrane, and the term "reactant" can be used interchangeably with the term precursor.

[0034] As used herein, the terms "film" and / or "layer" can refer to any continuous or non-continuous structure and material, such as materials deposited by the methods disclosed herein. For example, the film and / or layer can include two-dimensional materials, three-dimensional materials, nanoparticles, partial or complete molecular layers, or partial or complete atomic layers, or clusters of atoms and / or molecules. The film or layer can include or at least partially consist of a plurality of dispersed atoms on the surface of a substrate, and / or can be embedded or become embedded within the substrate and / or within a device fabricated on the substrate. The film or layer can comprise a material or layer with pinholes and / or isolated islands. The film or layer can be at least partially continuous. The film or layer can be patterned, e.g., subdivided, and can be included within multiple semiconductor devices. The film or layer can be selectively grown on some parts of the substrate and not on other parts.

[0035] As used herein, the term "deposition process" can refer to the introduction of precursors (and / or reactants) into a reaction chamber to deposit a layer over a substrate. A "cyclic deposition process" is an example of a "deposition process."

[0036] The term "cyclic deposition process" or "cyclical deposition process" can refer to the sequential introduction of precursors (and / or reactants) into a reaction chamber to deposit layers on a substrate, and includes processing techniques such as atomic layer deposition (ALD), cyclic chemical vapor deposition (cyclic CVD), and hybrid cyclic deposition processes that include ALD and cyclical CVD components.

[0037] The term "atomic layer deposition" can refer to a deposition process in which deposition cycles, typically multiple successive deposition cycles, are performed in a process chamber. As used herein, the term atomic layer deposition is also meant to include processes designated by related terms such as atomic layer chemical vapor deposition, atomic layer epitaxy (ALE), molecular beam epitaxy (MBE), gas source MBE, metalorganic MBE, and chemical beam epitaxy, when performed with alternating pulses of precursor / reactive gases and purge (e.g., inert carrier) gas. Pulsing can include exposing the substrate to a precursor or reactant. This can be done, for example, by introducing the precursor or reactant into a reaction chamber in which the substrate is present. Additionally or alternatively, exposing the substrate to the precursor can include moving the substrate to a location in the substrate processing system where the reactant or precursor is present.

[0038] Generally, for an ALD process, during each cycle, a precursor is introduced into the reaction chamber and chemisorbed onto the deposition surface (e.g., a substrate surface, which may include previously deposited material or other materials from a previous ALD cycle) and forms a monolayer or quasi-monolayer of material that does not readily react with additional precursors (i.e., self-limiting reaction). A reactant (e.g., another precursor or reactant gas) may then be introduced into the process chamber for use in converting the chemisorbed precursor to a desired material on the deposition surface. The reactant may be capable of further reaction with the precursor. Purging steps may be utilized during one or more cycles (e.g., during each step of each cycle) to remove any excess precursor from the process chamber and / or to remove any excess reactants and / or reaction by-products from the reaction chamber.

[0039] As used herein, the term "purging" may refer to a procedure in which an inert or substantially inert gas is provided to the reaction chamber between two pulses of gases that react with each other. For example, a purge, e.g., a purge using a noble gas, may be provided between the precursor pulse and the reactant pulse, thus avoiding or at least minimizing gas phase interactions between the precursor and the reactant. Of course, purging can be accomplished temporally, or spatially, or both. For example, in the case of temporal purging, the purging step can be used in a time sequence, e.g., providing a first precursor to the reaction chamber, providing a purge gas to the reaction chamber, and providing a second precursor to the reaction chamber, without moving the substrate on which the layer is deposited. For example, in the case of spatial purging, the purging step can take the following form: moving the substrate from a first location where the first precursor is continuously supplied, through a purge gas curtain, to a second location where the second precursor is continuously supplied.

[0040] As used herein, "precursor" includes a gas or material that can be gaseous and can be represented by a chemical formula that includes elements that may be incorporated during a deposition process as described herein.

[0041] The term "oxygen reactant" can refer to a gas or material that can be gaseous and can be represented by a chemical formula that includes oxygen. In some cases, the chemical formula includes oxygen and hydrogen.

[0042] Further, in this disclosure, any two numbers for a variable can constitute a workable range for that variable, and any range stated can include or exclude the endpoints. In addition, any values ​​for a stated variable (whether they are stated with "about" or not) can refer to an exact or approximate value, and can include equivalents, and can refer to the average, median, representative value, majority, or the like.

[0043] As used herein, the term "comprising" indicates that certain features are included, but do not exclude the presence of other features unless doing so would render the claim or embodiment unworkable. In some embodiments, the term "comprising" includes "consisting of." As used herein, the term "consisting of" indicates that no other features are present in the device / method / product except for what follows the term. When the term "consisting of" is used with reference to a chemical compound, it indicates that the chemical compound contains only the recited components.

[0044] As used herein, the term "exposure dose" can refer to the amount of photon energy provided to a substrate per unit area, or in other words, the photon flux (the number of photons per unit time per unit space) multiplied by the photon energy and the exposure time.

[0045] Described herein is a structure including a substrate, a secondary electron generating layer, and an extreme ultraviolet (EUV) resist. The secondary electron generating layer is positioned between the substrate and the EUV resist. The secondary electron generating layer can include hafnium, which can advantageously reduce the required exposure dose to fully develop the EUV resist. In some embodiments, the secondary electron generating layer includes hafnium oxide (HfO2). In some embodiments, the secondary electron generating layer includes a hafnium chalcogenide, such as hafnium selenide, hafnium sulfide, or hafnium telluride. In some embodiments, the secondary electron generating layer includes a hafnium pnictogen, such as hafnium nitride, hafnium phosphide, hafnium arsenide, or hafnium antimonide. In some embodiments, the secondary electron generating layer includes hafnium boride. In some embodiments, the secondary electron generating layer includes hafnium oxide (HfO2). In some embodiments, the secondary electron generating layer consists essentially of hafnium oxide. Surprisingly and advantageously, it has been discovered that a secondary electron generating layer including hafnium oxide can reduce the required exposure dose of a chemically amplified resist by 5 percent. Although this disclosure is not limited by any particular theory or mode of operation, it is believed that hafnium oxide, although not a particularly strong EUV absorber, exhibits excellent secondary electron yield, which may explain the observed exposure dose reduction.

[0046] Exemplary structures according to embodiments of the present disclosure are shown in FIGS.

[0047] FIG. 1 shows a structure comprising a substrate 100 , a secondary electron generating layer 120 overlying the substrate 100 , and a resist 140 overlying the secondary electron generating layer 120 .

[0048] 2 shows a structure comprising a substrate 200, a secondary electron generating layer 220 on the substrate 200, an adhesive layer 230 on the secondary electron generating layer 220, and a resist 240 on the adhesive layer 230. Advantageously, the adhesive layer 230 can provide adhesion between the secondary electron generating layer 220 and the resist 240. Exemplary adhesive layers and methods for their manufacture are described in U.S. Pat. No. 1,173,5422, which is incorporated herein by reference in its entirety.

[0049] 3 shows a structure comprising a substrate 300, an electron reflecting layer 310 overlying the substrate, a secondary electron generating layer 320 overlying the electron reflecting layer 310, an adhesive layer 330 overlying the secondary electron generating layer 320, and a resist 340 overlying the adhesive layer 330. Advantageously, the electron reflecting layer 310 can reflect electrons generated in the secondary electron generating layer 320, which can provide additional exposure dose reduction. Suitable electron reflecting layers 310 and methods for their manufacture are described in U.S. Provisional Patent Application No. 63 / 484,346, which is incorporated herein by reference in its entirety.

[0050] In some embodiments, the secondary electron generating layer has a thickness of less than 10 nm, or at least 1 nm and up to 5 nm, or at least 2 nm and up to 4 nm, or about 3 nm.

[0051] In some embodiments, the secondary electron generating layer further comprises one or more EUV absorbing elements. In some embodiments, the one or more EUV absorbing elements are selected from the group consisting of iodine (I), tellurium (Te), cesium (Cs), antimony (Sb), tin (Sn), indium (In), bismuth (Bi), silver (Ag), lead (Pb), gold (Au), platinum (Pt), iridium (Ir), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), and arsenic (As). Exemplary precursors for one or more of these elements are described in one or more of U.S. Patent Application Nos. 17 / 900,065, 17 / 900,578, and 17 / 899,928, which are incorporated herein by reference in their entireties.

[0052] In some embodiments, the one or more EUV absorbing elements are selected from tin and tellurium.

[0053] In some embodiments, the secondary electron generating layer can include one or more elements selected from magnesium, tin, and aluminum. For example, the secondary electron generating layer can include one or more materials selected from the group consisting of magnesium oxide, antimony oxide, and tin oxide. Magnesium oxide can include MgO. Antimony oxide can include SbO. Tin oxide can include SnO, i.e., tin(II) oxide.

[0054] In some embodiments, the secondary electron generating layer includes a chalcogenide, such as sulfur, selenium, or tellurium. For example, the secondary electron generating layer can include a metal chalcogenide, such as one or more of MgS, SbS, SnS, MgSe, SbSe, SnSe, MgTe, SbTe, or SnTe.

[0055] In some embodiments, the secondary electron generating layer contains at least 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, or 90 atomic percent hafnium.

[0056] In some embodiments, the structure further comprises an adhesive layer. The adhesive layer can be positioned between the secondary electron generating layer and the EUV resist. In some embodiments, the adhesive layer comprises silicon, carbon, oxygen, and hydrogen. In some embodiments, the adhesive layer further comprises nitrogen. In some embodiments, the adhesive layer comprises silicon, oxygen, and carbon. In some embodiments, the adhesive layer can comprise silicon oxycarbide. In some embodiments, the adhesive layer can further comprise nitrogen. In some embodiments, the adhesive layer can comprise silicon oxynitride carbide. In some embodiments, the adhesive layer further comprises hydrogen. The adhesive layer can be formed using a thermal or plasma vapor deposition process. For example, the adhesive layer can be formed using thermal or plasma enhanced atomic layer deposition.

[0057] In some embodiments, the EUV resist is selected from metal-organic framework resists, metal oxide resists, and chemically amplified resists. The resists can be positive or negative tone.

[0058] Further described herein is a method of forming a structure. The method can include providing a substrate to a reaction chamber. The method can further include performing a deposition process including exposing the substrate to a hafnium precursor that includes hafnium. The deposition process can further include exposing the substrate to a reactant. Thus, a hafnium-containing secondary electron generating layer can be formed on the substrate. The method described herein can further include forming an EUV resist on the substrate.

[0059] In some embodiments, the deposition process includes a cyclic deposition process. Thus, an embodiment of the method described herein can be described as follows: The method can include providing a substrate to a reaction chamber. The method can further include performing a cyclic deposition process. The cyclic deposition process can include a plurality of cycles. One from the plurality of cycles includes a hafnium precursor pulse and a reactant pulse. The hafnium precursor pulse includes exposing the substrate to a hafnium precursor. The reactant pulse includes exposing the substrate to a reactant. The hafnium precursor includes hafnium. Thus, a hafnium-containing secondary electron generating layer is formed on the substrate. The method can further include forming an EUV resist on the substrate.

[0060] An exemplary ALD pulsing scheme is shown in FIG. 4. Such a pulsing scheme may be suitable for forming a two-component material, such as hafnium oxide. In particular, the embodiment of FIG. 4 includes positioning a substrate on a substrate support 411, after which a number of deposition cycles 418 are performed. One from the number of deposition cycles 418 includes a precursor pulse 412 and a reactant pulse 414. Optionally, the precursor pulse 412 may be followed by a post-precursor purge 413. Optionally, the reactant pulse 414 may be followed by a post-reactant purge 415. After a suitable amount of deposition cycles 418 have been performed, a layer is formed on the substrate and the method ends 416.

[0061] In some embodiments, the methods described herein can include forming an adhesive layer on a substrate. The adhesive layer can be formed on the hafnium-containing secondary electron generating layer. The EUV resist can be formed on the adhesive layer. Thus, the adhesive layer can enhance adhesion between the secondary electron generating layer and the EUV resist.

[0062] In some embodiments, the hafnium precursor comprises one or more alkylamine ligands, hi some embodiments, the hafnium precursor comprises tetrakis(ethylmethylamino)hafnium.

[0063] In some embodiments, the hafnium precursor comprises hafnium in the +4 oxidation state.

[0064] In some embodiments, the hafnium precursor comprises one or more ligands selected from alkylamide ligands, alkoxy ligands, cyclopentadienyl ligands, β-diketonate ligands, alkyl ligands, amidinate ligands, and halide ligands.

[0065] In some embodiments, the hafnium precursor can include at least one of an alkylamide ligand and a dialkylamide ligand. Suitable hafnium alkylamines include tetrakis(dimethylamino)hafnium, tetrakis(diethylamino)hafnium, and tetrakis(ethylmethylamino)hafnium.

[0066] In some embodiments, the hafnium precursor comprises a hafnium halide, such as hafnium chloride, hafnium bromide, or hafnium iodide. Suitable hafnium chlorides include HfCl4. Suitable hafnium bromides include HfBr4. Suitable hafnium iodides include HfI4.

[0067] In some embodiments, the hafnium precursor comprises a heteroleptic hafnium precursor. In some embodiments, the heteroleptic hafnium precursor comprises an unsubstituted or alkyl-substituted hafnium cyclopentadienyl ligand. In some embodiments, the hafnium precursor comprises one or more alkylamide ligands. In some embodiments, the hafnium precursor comprises an alkylamide ligand and an unsubstituted or alkyl-substituted cyclopentadienyl ligand. Suitable hafnium precursors include HfCp(NMe2)3, i.e., tris(dimethylamino)cyclopentadienyl hafnium.

[0068] In some embodiments, the reactant comprises an oxygen reactant. The oxygen reactant comprises oxygen. In some embodiments, the oxygen reactant comprises ozone. In some embodiments, the oxygen reactant comprises water.

[0069] In some embodiments, the oxygen reactant comprises one or more of H2O, H2O2, O2, O3, N2O, NO, and NO2.

[0070] In some embodiments, the reactants include chalcogen reactants. Suitable chalcogen reactants can include sulfur reactants such as H2S, selenium reactants such as H2Se, and tellurium reactants such as H2Te.

[0071] In some embodiments, the reactants include pnictogen reactants. Suitable pnictogen reactants may include nitrogen reactants such as NH3, phosphorus reactants such as PH3, arsenic reactants such as AsH3, and antimony reactants such as SbH3.

[0072] In some embodiments, the reactants include a boron reactant. Suitable boron reactants include boron hydrides such as B2H6.

[0073] In some embodiments, one from the multiple cycles further includes generating a plasma and exposing the substrate to one or more activated species generated within the plasma.

[0074] In some embodiments, exposing the substrate to one or more activated species generated in the plasma occurs at least partially simultaneously with the reactant pulse. In some embodiments, exposing the substrate to one or more activated species generated in the plasma occurs during the reactant pulse. In such cases, the reactants can include one or more activated species. In some embodiments, the activated species includes at least one of ions and radicals, for example, at least one of oxygen ions and oxygen radicals.

[0075] In some embodiments, the deposition process, e.g., the cyclic deposition process, occurs thermally, in other words, in some embodiments, the deposition process, e.g., the cyclic deposition process, does not include exposing the substrate to active species, such as ions or radicals, that may be generated in a plasma.

[0076] In some embodiments, the one from the multiple cycles further comprises an EUV absorbing element pulse. The EUV absorbing element pulse comprises exposing the substrate to an EUV absorbing element precursor. The EUV absorbing element precursor comprises an EUV absorbing element selected from the group consisting of iodine (I), tellurium (Te), cesium (Cs), antimony (Sb), tin (Sn), indium (In), bismuth (Bi), silver (Ag), lead (Pb), gold (Au), platinum (Pt), iridium (Ir), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), and arsenic (As). In some embodiments, the EUV absorbing element is selected from tin and tellurium.

[0077] FIG. 9 illustrates an ALD pulse scheme that may be advantageously used to form a ternary material, such as a hafnium oxide-containing secondary electron generating layer that includes one or more EUV absorbing elements described herein. In particular, the embodiment of FIG. 9 includes positioning a substrate on a substrate support 911, after which a plurality of deposition cycles 919 are performed. One from the plurality of deposition cycles 918 includes a first subcycle 917 and a second subcycle 918. Optionally, the first subcycle 917 can be repeated one or more times. Optionally, the second subcycle 918 can be repeated one or more times. The first subcycle 917 includes a first precursor pulse 912 and a first reactant pulse 913. The first precursor pulse 912 includes exposing the substrate to a first precursor. The first reactant pulse 913 includes exposing the substrate to a first reactant 914. The second subcycle includes a second precursor pulse 914 and a second reactant pulse 915. A second precursor pulse 914 includes exposing the substrate to a second precursor. A second reactant pulse 915 includes exposing the substrate to a second reactant 915. After a suitable amount of deposition cycles 918 have been performed, a layer is formed on the substrate and the method ends 916. Subsequent pulses may optionally be separated by purging.

[0078] In some embodiments, the first precursor and the second precursor are different. In some embodiments, the first reactant and the second reactant are different. For example, to form magnesium aluminum oxide, the first precursor may be a magnesium precursor, and the first and second reactants may be oxygen reactants.

[0079] In certain embodiments, the hafnium oxide layer can have a thickness of 3 nm or less, for example, a thickness of 1 nm or 2 nm. The hafnium oxide layer can be used as a secondary electron generating layer under an EUV resist. The secondary electron generating layer can absorb EUV radiation and generate secondary electrons. The secondary electron generating layer can be formed using a thermal cyclic deposition process such as atomic layer deposition (ALD). Suitable hafnium precursors include hafnium alkylamines such as tetrakis(ethylmethylamino)hafnium (TEMAH). An oxygen reactant such as ozone or water can be used as a reactant. The thermal cyclic deposition process can be carried out at a temperature range of 175-275° C. It should be understood that depositing hafnium oxide in this manner is known. Such a secondary electron generating layer can be used in any one of the configurations of FIGS. 1-3.

[0080] Further described herein is a system that includes a reaction chamber and a controller, the controller constructed and arranged to cause the system to carry out the methods described herein.

[0081] Layers formed by methods according to the present disclosure may be formed in any suitable apparatus, including in a reactor such as that shown in FIG. 5. Similarly, structures provided herein or parts thereof may be fabricated in any suitable apparatus, including in a reactor such as that shown in FIG. 5. FIG. 5 is a schematic diagram of a plasma-enhanced atomic layer deposition (PEALD) apparatus, along with a programmed control to execute the sequences described below, which may be desirably used in some embodiments of the present disclosure. In this diagram, a pair of conductive plate electrodes 502, 504 are provided parallel and facing each other in the interior 511 (reaction zone) of a reaction chamber 503, and a plasma is excited between the electrodes by applying RF power (e.g., at 13.56 MHz and / or 27 MHz) from a power source 525 to one side and electrically grounding the other side 512. A temperature regulator may be provided on the lower stage 502, i.e., the bottom electrode. A substrate 501 is placed thereon, and its temperature is held constant at a given temperature. The upper electrode 504 can also function as a shower plate and can introduce reactant gases, and / or dilution gases, if present, as well as precursor gases, into the reaction chamber 503 through gas lines 521 and 522, respectively, and through the shower plate 504. In addition, a circular duct 513 with an exhaust line 517 is provided in the reaction chamber 503, through which the gas in the interior 511 of the reaction chamber 503 is exhausted. In addition, a transfer chamber 505 is disposed below the reaction chamber 503, and is provided with a gas seal line 524 for introducing a seal gas into the interior 511 of the reaction chamber 503 through the interior 516 of the transfer chamber 505, and is provided with a separation plate 514 for separating the reaction zone and the transfer zone. A gate valve through which the wafer may be transferred into or out of the transfer chamber 505 is omitted from this figure. The transfer chamber is also provided with an exhaust line 506. In some embodiments, forming the secondary electron generating layer, optionally forming the adhesive layer, and forming the EUV resist are performed in one and the same reaction chamber.In some embodiments, the formation of one or more of these layers is performed in separate reaction chambers contained within a cluster system in which the substrate can be transferred from one reaction chamber to another without breaking vacuum or leaving the inert gas environment.

[0082] 6 illustrates a system 600 according to an exemplary embodiment of the present disclosure. System 600 can be used to perform methods as described herein and / or to form structures or device portions as described herein.

[0083] In the illustrated embodiment, the system 600 includes one or more reaction chambers 602 , a first precursor gas source 604 , a reactant gas source 606 , a purge gas source 608 , an exhaust 610 , and a controller 612 .

[0084] The reaction chamber 602 can include any suitable reaction chamber, such as an ALD or CVD reaction chamber.

[0085] The first precursor gas source 604 can include a vessel and one or more precursors as described herein, alone or mixed with one or more carrier gases (e.g., noble gases). The reactant gas source 606 can include a vessel and one or more reactants as described herein, alone or mixed with one or more carrier gases. The purge gas source 608 can include one or more noble gases as described herein. Although illustrated with four gas sources 604-608, the system 600 can include any suitable number of gas sources. The gas sources 604-608 can be coupled to the reaction chamber 602 via lines 614-618, each of which can include flow controllers, valves, heaters, and the like.

[0086] The exhaust 610 can include one or more vacuum pumps.

[0087] The controller 612 includes electronic circuitry and software for selectively operating the valves, manifolds, heaters, pumps, and other components included within the system 600. Such circuitry and components operate to introduce precursor and purge gases from their respective sources 604-608. The controller 612 can control the timing of gas pulse sequences, the temperature of the substrate and / or reaction chamber, the pressure within the reaction chamber, and various other operations to provide proper operation of the system 600. The controller 612 can include control software that electrically or pneumatically controls valves to control the flow of precursors, reactants, and purge gases into and out of the reaction chamber 602. The controller 612 can include software or hardware components, such as modules, e.g., FPGAs or ASICs, that perform certain tasks. The modules can be advantageously configured to reside on an addressable storage medium of the control system and can be configured to execute one or more processes.

[0088] Other configurations of system 600 are possible, including different numbers and types of precursor and reactant sources, and purge gas sources. Additionally, it will be appreciated that there are numerous arrangements of valves, conduits, precursor sources, and purge gas sources that may be used to achieve the goal of selectively feeding gases into reaction chamber 602. Additionally, as a schematic representation of the system, many components have been omitted for simplicity of illustration, and such components may include, for example, various valves, manifolds, purifiers, heaters, vessels, vents, and / or bypasses.

[0089] During operation of reactor system 600, a substrate (not shown), such as a semiconductor wafer, is transferred, for example, from a substrate processing system to reaction chamber 602. Once the substrate is transferred to reaction chamber 602, one or more gases, such as precursors, reactants, carrier gases, and / or purge gases from gas sources 604-608, are introduced into reaction chamber 602.

[0090] 7 shows a schematic representation of an embodiment of a system 700 as described herein. It can be used, for example, to form at least one of a secondary electron reflecting layer, a secondary electron generating layer, an adhesive layer, and an EUV resist. Additionally or alternatively, it can be used to etch one or more of a gap fill fluid and a material layer. The system 700 includes a reaction chamber 710 in which a plasma 720 is generated. Specifically, the plasma 720 is generated between a showerhead injector 730 and a substrate support 740. This is a direct plasma configuration employing a capacitively coupled plasma.

[0091] In the configuration shown, system 700 includes two alternating current (AC) power sources: a high frequency power source 721 and a low frequency power source 722. In the configuration shown, the high frequency power source 721 supplies radio frequency (RF) power to the showerhead injector and the low frequency power source 722 supplies an alternating current signal to the substrate support 740. The radio frequency power can be provided, for example, at a frequency of 13.56 MHz or higher, for example, at a frequency of at least 100 kHz up to 50 MHz, or at a frequency of at least 50 MHz up to 100 MHz, or at a frequency of at least 100 MHz up to 200 MHz, or at a frequency of at least 200 MHz up to 500 MHz, or at a frequency of at least 500 MHz up to 1000 MHz, or at a frequency of at least 1000 MHz up to 2000 MHz. The low frequency alternating current signal can be provided at a frequency of 2 MHz or less, such as at a frequency of at least 100 kHz up to 200 kHz, or at a frequency of at least 200 kHz up to 500 kHz, or at a frequency of at least 500 kHz up to 1000 kHz, or at a frequency of at least 1000 kHz up to 2000 kHz. Process gases including precursors, reactants, or both are provided through gas lines 760 to the conical gas distributor 750. The process gases then pass through through holes 731 in the showerhead injector 730 into the reaction chamber 710.

[0092] While high frequency power source 721 is shown as being electrically connected to the showerhead injector and low frequency power source 722 is shown as being electrically connected to the substrate support 740, other configurations are possible as well. For example, in some embodiments (not shown), both high frequency and low frequency power sources can be electrically connected to the showerhead injector, or both high frequency and low frequency power sources can be electrically connected to the substrate support, or the high frequency power source can be electrically connected to the substrate support and the low frequency power source can be electrically connected to the showerhead injector.

[0093] FIG. 8 shows a schematic representation of another embodiment of a system 800 as described herein, which can be used, for example, to form at least one of a secondary electron generating layer, an adhesive layer, and an EUV resist. The configuration of FIG. 8 can be described as an indirect plasma system. The subsystem 800 includes a reaction chamber 810 separated from a plasma generation space 825 in which a plasma 820 is generated. In particular, the reaction chamber 810 is separated from the plasma generation space 825 by a showerhead injector, and the plasma 820 is generated between the showerhead injector 830 and a plasma generation space ceiling 826.

[0094] In the configuration shown, the subsystem 800 includes three alternating current (AC) power sources, a high frequency power source 821 and two low frequency power sources 822, 823: a first low frequency power source 822 and a second low frequency power source 823. In the configuration shown, the high frequency power source 821 provides radio frequency (RF) power to the plasma generation space ceiling, the first low frequency power source 822 provides an alternating current signal to the showerhead injector 830, and the second low frequency power source 823 provides an alternating current signal to the substrate support 840. The substrate 841 is provided on the substrate support 840. The radio frequency power can be provided at a frequency of, for example, 13.56 MHz or higher. The low frequency AC signals of the first low frequency power source 822 and the second low frequency power source 823 can be provided at a frequency of, for example, 2 MHz or lower.

[0095] Process gases including precursors, reactants, or both can be provided to the plasma generation space 825 through gas lines 860 passing through the plasma generation space ceiling 826. Active species such as ions and radicals generated by the plasma 825 from the process gases pass through through-holes 831 in the showerhead injector 830 into the reaction chamber 810.

[0096] FIG. 14 shows a schematic representation of another embodiment of a subsystem 900 as described herein, which can be used, for example, to form at least one of a secondary electron generating layer, an adhesive layer, and an EUV resist. The configuration of FIG. 9 can be described as a remote plasma system. The subsystem 900 includes a reaction chamber 910 operatively connected to a remote plasma source 925 in which a plasma 920 is generated. Any type of plasma source can be used as the remote plasma source 925, for example, an inductively coupled plasma, a capacitively coupled plasma, or a microwave plasma.

[0097] Specifically, the activated species are provided from the plasma source 925 to the reaction chamber 910 via the activated species duct 960 to the cone distributor 950 through the through-holes 931 in the shower plate injector 930 to the reaction chamber 910. Therefore, the activated species can be provided to the reaction chamber in a uniform manner.

[0098] In the configuration shown, the subsystem 900 includes three alternating current (AC) power sources, a high frequency power source 921 and two low frequency power sources 922, 1423: a first low frequency power source 922 and a second low frequency power source 923. In the configuration shown, the high frequency power source 921 provides radio frequency (RF) power to the plasma generation space ceiling, the first low frequency power source 922 provides an alternating current signal to the showerhead injector 930, and the second low frequency power source 923 provides an alternating current signal to the substrate support 940. The substrate 941 is provided on the substrate support 940. The radio frequency power can be provided at a frequency of, for example, 13.56 MHz or higher. The low frequency AC signals of the first low frequency power source 922 and the second low frequency power source 1423 can be provided at a frequency of, for example, 2 MHz or lower.

[0099] In some embodiments (not shown), an additional RF power source can be electrically connected to the substrate support. Thus, a direct plasma can be generated within the reaction chamber.

[0100] Process gases including precursors, reactants, or both are provided to the plasma source 925 by gas lines 960. Active species such as ions and radicals generated by the plasma 925 from the process gases are guided to the reaction chamber 910.

[0101] The illustrations presented herein are not meant to be the actual appearance of any particular materials, structures, or devices, but merely idealized representations used to describe embodiments of the present disclosure.

[0102] The particular implementations shown and described are illustrative of the invention and its best mode and are not intended to otherwise limit the scope of aspects and implementations in any way. Indeed, for the sake of brevity, conventional manufacturing, association, preparation, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent example functional relationships and / or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may be present in an actual system and / or may not be present in some embodiments.

[0103] It should be understood that the configurations and / or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be construed in a limiting sense, as numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. Thus, various illustrated operations may be performed in the order illustrated, or in other orders, or may be omitted in some cases.

[0104] The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various processes, systems, and configurations, and other features, functions, operations and / or properties disclosed herein, as well as all equivalents thereof. [Explanation of symbols]

[0105] 100, 200, 300 base material 120, 220, 320 Secondary electron generation layer 140, 240, 340 Resist 230, 330 adhesive layer 310 Electron reflective layer

Claims

1. A structure including a substrate, a secondary electron generating layer, and an extreme ultraviolet (EUV) resist, the secondary electron generating layer being disposed between the substrate and the EUV resist, the secondary electron generating layer being hafnium oxide (HfO ２ ), including the structure.

2. The structure of claim 1 , wherein the secondary electron generating layer has a thickness of at least 1 nm and up to 5 nm.

3. 10. The structure of claim 1, wherein the secondary electron generating layer further comprises one or more EUV absorbing elements selected from the group consisting of iodine (I), tellurium (Te), cesium (Cs), antimony (Sb), tin (Sn), indium (In), bismuth (Bi), silver (Ag), lead (Pb), gold (Au), platinum (Pt), iridium (Ir), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), and arsenic (As).

4. 10. The structure of claim 1, wherein said secondary electron generating layer contains at least 15 atomic percent hafnium.

5. The structure of any one of claims 1 to 4, further comprising an adhesive layer positioned between the secondary electron generating layer and the EUV resist.

6. The structure of claim 5 , wherein the adhesive layer comprises silicon, carbon, oxygen, and hydrogen.

7. The structure of claim 6 , wherein the adhesive layer further comprises nitrogen.

8. 1. A method of forming a structure, the method comprising: Providing a substrate into a reaction chamber; performing a deposition process comprising exposing the substrate to a hafnium precursor comprising hafnium, the deposition process further comprising exposing the substrate to a reactant thereby forming a hafnium-containing secondary electron generating layer on the substrate; forming an EUV resist on the substrate.

9. 10. The method of claim 8, wherein the deposition process comprises a cyclic deposition process, the cyclic deposition process comprising a plurality of cycles, a cycle from the plurality of cycles comprising a hafnium precursor pulse and a reactant pulse, the hafnium precursor pulse comprising exposing the substrate to the hafnium precursor, and the reactant pulse comprising exposing the substrate to the reactant, thereby forming a hafnium-containing secondary electron generating layer on the substrate.

10. 10. The method of claim 8, further comprising forming an adhesive layer on the substrate, the adhesive layer being formed on the hafnium-containing secondary electron generating layer and the EUV resist being formed on the adhesive layer.

11. The method of claim 8 , wherein the hafnium precursor comprises one or more alkylamine ligands.

12. The method of claim 11 , wherein the hafnium precursor comprises tetrakis(ethylmethylamino)hafnium.

13. The method of claim 8 , wherein the reactants include an oxygen reactant, the oxygen reactant comprising oxygen.

14. The method of claim 13 , wherein the oxygen reactant comprises ozone.

15. The method of claim 14 , wherein the oxygen reactant comprises water.

16. 10. The method of claim 9, wherein one from the plurality of cycles further comprises generating a plasma and exposing the substrate to one or more activated species generated within the plasma.

17. 17. The method of claim 16, wherein exposing the substrate to one or more activated species generated in the plasma occurs at least partially simultaneously with the reactant pulse, the reactants comprising the one or more activated species, the activated species comprising at least one of ions and radicals.

18. The method of claim 8 , wherein the deposition process occurs thermally.

19. 10. The method of claim 9, wherein one from the plurality of cycles further comprises an EUV absorbing element pulse, the EUV absorbing element pulse comprising exposing the substrate to an EUV absorbing element precursor, the EUV absorbing element precursor comprising an EUV absorbing element selected from the group consisting of iodine (I), tellurium (Te), cesium (Cs), antimony (Sb), tin (Sn), indium (In), bismuth (Bi), silver (Ag), lead (Pb), gold (Au), platinum (Pt), iridium (Ir), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), and arsenic (As).

20. A system comprising a reaction chamber and a controller, said controller constructed and arranged to cause said system to carry out the method of any one of claims 8 to 19.

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