Materials, methods and apparatus for forming patterned layers of 2D materials

Abstract

Disclosed herein is a method of forming a pattern of a 2D material on a surface (401), the method comprising: depositing a precursor material (402a) on a surface, where the precursor material comprises one or more components for forming a 2D material on the surface, and one or more components for forming cross-links in response to irradiation by radiation; irradiating the deposited precursor material with a patterned radiation such that cross-links are formed in the irradiated precursor material (402b); performing a developing process for removing the precursor material (402a) that does not include cross-links; performing one or more processes (402c, 402d) for removing the components of the precursor material such that substantially only one or more components used to form the 2D material remain; and performing a crystallization process for forming a 2D material (402e) on the surface.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to European application 22181351.2 filed on June 27, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to materials, methods and apparatus for forming patterned layers of 2D materials. Background Art

[0004] A lithographic apparatus is a machine configured to apply a desired pattern onto a substrate. For example, a lithographic apparatus may be used in the manufacture of integrated circuits (ICs). A lithographic apparatus may, for example, project a pattern at a patterning device (e.g., a mask) onto a layer of radiation-sensitive material (resist) disposed on a substrate.

[0005] To project a pattern onto a substrate, a lithographic apparatus may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features that can be formed on the substrate. A lithographic apparatus using extreme ultraviolet (EUV) radiation (having a wavelength in the range of 4 nm to 20 nm, such as 6.7 nm or 13.5 nm) can be used to form smaller features on a substrate than a lithographic apparatus using radiation having, for example, a 193 nm wavelength.

[0006] It is generally desirable to use 2D materials in ICs, and this requires improvements in known techniques for forming 2D materials. Summary of the invention

[0007] According to a first aspect of the present invention, there is provided a material for deposition on a substrate, the material comprising: a tellurium oxide, a transition metal telluride and / or a transition metal disulfide; and a ligand for forming cross-linked bonds in response to irradiation by radiation.

[0008] According to a second aspect of the present invention, a system for forming a pattern of 2D material on a surface is provided, the system comprising one or more devices configured to: deposit a precursor material on the surface, wherein the precursor material comprises one or more components for forming a 2D material on the surface, and one or more components for forming cross-linked bonds in response to irradiation by radiation; irradiate the deposited precursor material with patterned radiation so that cross-linked bonds are formed in the irradiated precursor material; perform a development process for removing the precursor material that does not include cross-linked bonds; perform one or more processes for removing components of the precursor material so that substantially only the one or more components for forming the 2D material remain; and perform a crystallization process for forming the 2D material on the surface.

[0009] According to a third aspect of the present invention, a method for forming a pattern of 2D material on a surface is provided, the method comprising: depositing a precursor material on the surface, wherein the precursor material comprises one or more components for forming the 2D material on the surface, and one or more components for forming cross-linked bonds in response to irradiation by radiation; irradiating the deposited precursor material with patterned radiation so that cross-linked bonds are formed in the irradiated precursor material; performing a development process for removing the precursor material that does not include cross-linked bonds; performing one or more processes for removing the components of the precursor material so that substantially only the one or more components for forming the 2D material remain; and performing a crystallization process for forming the 2D material on the surface.

[0010] According to a fourth aspect of the present invention, there is provided a device comprising one or more layers of 2D material, wherein the device is manufactured according to the method of the third aspect.

[0011] According to a fifth aspect of the present invention, there is provided a substrate at least partially coated with a material according to the first aspect.

[0012] According to a sixth aspect of the present invention, there is provided a substrate having a 2D material formed thereon, wherein the 2D material is formed according to the method of the third aspect.

[0013] According to a seventh aspect of the present invention, there is provided a substrate having a 2D material formed thereon, wherein the 2D material comprises tellurium.

[0014] According to an eighth aspect of the present invention, a substrate having a 2D material formed thereon is provided, wherein the 2D material includes one or more atoms M of tellurium or a transition metal, and the atoms M of the transition metal are covalently bonded to the atoms Q of a chalcogen element in the form of MQ2, such as MoTe2, MoS2, PtTe2, WTe2, WS2 or WSe2. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which:

[0016] Figure 1 A lithography system including a lithography apparatus and a radiation source is depicted;

[0017] Figure 2A Metal oxide nanoclusters are schematically shown;

[0018] Figure 2B Schematically illustrates metal oxide nanoclusters during or shortly after an EUV exposure process;

[0019] Figure 2C schematically illustrates a plurality of metal oxide nanoparticles and ligands after a plurality of exposed metal oxide nanoclusters have condensed;

[0020] Figure 3 A MOSFET having a channel of the MOSFET made of a 2D material is schematically shown;

[0021] Figure 4A schematically shows a substrate having a patterned structural arrangement which has been coated with a precursor material;

[0022] Figure 4B schematically shows an EUV exposure process being performed;

[0023] Figure 4C schematically illustrates remaining precursor material after a development process has been performed;

[0024] Figure 4D schematically illustrates the remaining components after the precursor material has been stripped;

[0025] Figure 4E schematically illustrates the composition of a 2D material after an insertion and / or replacement process has been performed;

[0026] Figure 4F A crystalline 2D material is schematically shown;

[0027] Figure 5 schematically illustrates an exposure process arrangement for performing a crystallization process using a moving plasma; and

[0028] FIG. 6A to FIG. 6C A number of different waveforms that may be applied during the crystallization process are schematically shown. DETAILED DESCRIPTION

[0029] Figure 1 A lithographic system is shown comprising a radiation source SO and a lithographic apparatus LA. The radiation source SO is configured to generate an EUV radiation beam B and for supplying the EUV radiation beam B to the lithographic apparatus LA. The lithographic apparatus LA comprises an illumination system IL, a support structure MT configured to support a patterning device MA (e.g. a mask), a projection system PS, and a substrate table WT configured to support a substrate W.

[0030] The illumination system IL is configured to condition the EUV radiation beam B before it is incident on the patterning device MA. Furthermore, the illumination system IL may comprise a faceted field mirror arrangement 10 and a faceted pupil mirror arrangement 11. The faceted field mirror arrangement 10 and the faceted pupil mirror arrangement 11 together provide a desired cross-sectional shape and a desired intensity distribution for the EUV radiation beam B. The illumination system IL may comprise other mirrors or arrangements in addition to or instead of the faceted field mirror arrangement 10 and the faceted pupil mirror arrangement 11.

[0031] After being so adjusted, the EUV radiation beam B interacts with the pattern forming device MA. As a result of this interaction, a patterned EUV radiation beam B' is generated. The projection system PS is configured to project the patterned EUV radiation beam B' onto the substrate W. To this end, the projection system PS may include a plurality of mirrors 13, 14, which are configured to project the patterned EUV radiation beam B' onto the substrate W held by the substrate table WT. The projection system PS may apply a reduction factor to the patterned EUV radiation beam B', thereby forming an image MA whose features are smaller than corresponding features on the pattern forming device MA. For example, a reduction factor of 4 or 8 may be applied. Although the projection system PS is Figure 1 1. Although illustrated in FIG. 1 as having only two mirrors 13, 14, the projection system PS may comprise a different number of mirrors (eg six or eight mirrors).

[0032] The substrate W may include a previously formed pattern. In this case, the lithographic apparatus LA aligns an image formed by the patterned EUV radiation beam B′ with a pattern previously formed on the substrate W.

[0033] A relative vacuum, ie a small amount of gas (eg hydrogen) at a pressure well below atmospheric pressure, may be provided in the radiation source SO in the illumination system IL and / or the projection system PS.

[0034] Figure 1The radiation source SO shown in is, for example, of a type that may be referred to as a laser produced plasma (LPP) source. A laser system 1 (which may, for example, include a CO2 laser) is arranged to deposit energy via a laser beam 2 into a fuel, such as tin (Sn) provided from, for example, a fuel emitter 3. Although tin is mentioned in the following description, any suitable fuel may be used. The fuel may be in liquid form and may, for example, be a metal or an alloy. The fuel emitter 3 may include a nozzle configured to direct tin, for example, in the form of droplets, along a trajectory toward a plasma formation region 4. The laser beam 2 is incident on the tin at the plasma formation region 4. The laser energy is deposited into the tin, generating a tin plasma 7 at the plasma formation region 4. During de-excitation and recombination of electrons with ions of the plasma, radiation including EUV radiation is emitted from the plasma 7.

[0035] EUV radiation from the plasma is collected and focused by a collector 5. The collector 5 includes, for example, a near normal incidence radiation collector 5 (sometimes more generally referred to as a normal incidence radiation collector). The collector 5 may have a multilayer mirror structure arranged to reflect EUV radiation (e.g., EUV radiation having a desired wavelength such as 13.5 nm). The collector 5 may have an elliptical configuration having two focal points. A first of the focal points may be located at the plasma formation region 4, and a second of the focal points may be located at an intermediate focus 6, as discussed below.

[0036] The laser system 1 may be spatially separated from the radiation source SO. In this case, the laser beam 2 may be transferred from the laser system 1 to the radiation source SO by means of a beam delivery system (not shown), which may include, for example, suitable directional mirrors and / or beam expanders, and / or other optical devices. The laser system 1, the radiation system SO and the beam delivery system may be considered together as a radiation system.

[0037] The radiation reflected by the collector 5 forms the EUV radiation beam B. The EUV radiation beam B is focused at an intermediate focus 6 to form an image at the intermediate focus 6 of the plasma present at the plasma formation region 4. The image at the intermediate focus 6 serves as a virtual radiation source for the illumination system IL. The radiation source SO is arranged such that the intermediate focus 6 is located at or near an opening 8 in an enclosure 9 of the radiation source SO.

[0038] Although Figure 1The radiation source SO is depicted as a laser produced plasma (LPP) source, but any suitable source, such as a discharge produced plasma (DPP) source, a free electron laser (FEL) may be used to generate EUV radiation.

[0039] A method for manufacturing a semiconductor includes coating a surface of a substrate with a resist. An exposure process may then be performed in which the surface coated with the resist is irradiated by a patterned EUV radiation beam. Photons in the patterned EUV radiation beam react with the resist to cause changes in the irradiated portions of the resist. A development process may then be performed in which only the changed portions of the resist are removed or only the unchanged portions of the resist are removed, so that the surface of the substrate is coated with a resist having a pattern that depends on the EUV radiation beam. Further processes may then be performed based on the pattern of the resist on the surface of the substrate to manufacture the semiconductor.

[0040] A known resist suitable for use with photolithography is a chemically amplified resist (CAR) and may be polymer based. Upon exposure to electromagnetic radiation, the polymer in the CAR absorbs photons and may generate secondary electrons. The generation of secondary electrons in the resist is how high energy photons lose most of their energy. The secondary electrons in the resist diffuse and may generate additional secondary electrons with lower energy until the energy of the secondary electrons is below the energy required to break the bonds in the CAR. The generated electrons excite a photoacid generator (PAG), which then decomposes and may catalyze a deblocking reaction that occurs on the polymer. This results in a change in the solubility of the CAR.

[0041] Alternative resists for lithography, especially EUV lithography, include metal oxide nanoclusters. These resists include metal oxide nanoparticles, each of which is prevented from aggregating together by a metal oxide nanoparticle having a ligand shell. During EUV exposure, photons are absorbed by the nanoparticles and secondary electrons are generated, which causes the metal oxide nanoparticles to aggregate together. This changes the solubility of the exposed portion of the resist. The development process can then remove only the unexposed portion of the resist, or only the exposed portion of the resist. Metal oxide nanoparticles have a higher EUV absorption cross-section than carbon atoms in CAR, and therefore the probability that EUV photons are absorbed is greater. Therefore, metal oxide-based resists require a lower intensity EUV beam and / or a shorter exposure time. In addition, the different conversion mechanisms have potentially lower chemical noise than CAR resist systems.

[0042] refer to FIG. 2A to FIG. 2C The exposure process of the metal oxide resist is explained in more detail.

[0043] Figure 2AA metal oxide nanocluster is schematically shown. The metal oxide cluster comprises a metal oxide nanoparticle 201 surrounded by a ligand 202. The ligand 202 forms a shell around the metal oxide nanoparticle 201. The metal oxide nanoparticle 201 may be, for example, tin oxide. Each ligand may be a polymer structure.

[0044] Figure 2B The metal oxide nanocluster 201 is schematically shown during or shortly after an EUV exposure process. The metal oxide nanoparticle 201 has absorbed EUV photons, and this has resulted in the generation of photoelectrons. The photoelectrons have further collided with atoms and secondary electrons have been generated. The secondary electrons have caused the dissociation of at least one of the ligands 202 of the metal oxide nanoparticle 201, and active sites 203 are formed due to the dissociation.

[0045] Figure 2C A plurality of metal oxide nanoparticles 201 and ligands 202 are schematically shown after the plurality of exposed metal oxide nanoclusters have condensed. Oxygen bonds 204 may be formed between active sites 203 to bond the plurality of metal oxide nanoclusters together. Figure 2C The plurality of metal oxide nanoclusters bonded together may have Figure 2A The different solubilities of the unexposed metal nanoclusters are shown in FIG. Figure 2C The plurality of metal oxide nanoclusters bonded together shown in FIG. 4 may not be dissolved in the developing fluid and thus remain during a subsequently performed developing process. However, the unexposed metal nanoclusters may be dissolved in the developing fluid and thus be removed during the developing process.

[0046] To achieve the overall goal of further scaling down the size of fabricated structures and components, 2D materials can be used. 2D materials are atomically thin flat layers and therefore have very low heights above the surface they are formed on. A single layer of a 2D material typically has a sub-nanometer thickness.

[0047] A potential use of 2D materials is as the channel of a MOSFET. The problem with standard non-2D materials used for the channel of a MOSFET is that short channel effects, such as leakage due to tunneling, impose a limit on the minimum channel length. Forming a MOSFET channel from 2D materials enables the channel length to be smaller than the limit imposed by conventional semiconductors such as silicon.

[0048] Figure 3A MOSFET having a channel of a MOSFET made of 2D material is schematically shown. The MOSFET includes substrates 301, 302. The substrate may include a silicon dioxide (SiO2) layer 302 on a silicon layer 301. Formed on the substrates 301, 302 may be a source 303 and a drain 306 of the MOSFET, both of which may be metal layers. A channel 307 of the MOSFET is also formed on the substrates 301, 302 between the source 303 and the drain 306. The channel 307 of the MOSFET is a 2D material layer. An oxide layer 304 may be formed on the channel 307. The oxide layer 304 may be, for example, hafnium dioxide HfO2. Formed on the oxide layer 304 may be a gate 305 of the MOSFET, which is typically polysilicon or any conductive material. There are many other designs of MOSFETs that may also use 2D materials. For example, a dielectric may be provided on both sides of the channel, and the dielectric may also be a 2D material, such as hBN.

[0049] The 2D material used for the channel of the MOSFET can be, for example, molybdenum disulfide, MoS2. A monolayer MoS2 is a crystal structure having a monolayer of molybdenum atoms arranged between two monolayers of sulfur atoms. The height of a monolayer MoS2 can be about 0.65 nm to 1 nm. Such a 2D material has semiconductor properties, a low relative dielectric constant, and other properties that make it suitable for use as a channel of a MOSFET. When the channel of a MOSFET is made of a 2D material, the channel can be shorter than if a standard non-2D material is used. Many other 2D materials can be used for the channel due to their semiconductor band gaps. For example, the 2D material can be WS2, WSe2, MoTe2 or other 2D materials.

[0050] In such Figure 3 The problem with using 2D materials in the structures shown in is that it is difficult to correctly form patterned layers of 2D materials. 2D materials are very sensitive and can be damaged by standard patterning processes such as resist coating, photolithography, etching, and resist stripping.

[0051] WO2019166318A1 discloses EUV deposition of resist-free direct patterning of 2D materials. However, a problem with the technology described therein is that a very high EUV dose is required. The required EUV dose may be higher than 100mJ / cm 2 Much bigger.

[0052] While 2D materials can be grown using chemical vapor deposition (CVD), the temperatures required are too high to be compatible with other material processing steps in CMOS technology.

[0053] It is known to grow a crystalline structure of a 2D material on a first substrate at high temperature and then perform a lift-off process so that the 2D material layer is transferred to the surface of a second substrate. However, the lift-off and transfer process is slow, the chemicals required are expensive, the yield is low, and many defects are introduced due to the low maturity level of the technology.

[0054] WO2020207759A1 discloses a technique for direct EUV-induced deposition. However, a large EUV exposure dose is still required. The EUV exposure dose can be at least 1.5 to 2 J / cm 2 , to deposit a monolayer of 2D material.

[0055] Embodiments address at least some of the above-mentioned issues by providing new methods for forming 2D materials on a surface such as a substrate.

[0056] Embodiments include: including one or more components of the 2D material in a solid precursor material. The precursor material may be referred to as a resist matrix. The precursor material is a resist-type material and absorbs EUV photons within its bulk. The precursor material may be deposited on a surface (such as a surface of a substrate) in a manner similar to known techniques using resists. The precursor material may then be patterned using EUV radiation. A development process may then be performed to remove areas of the precursor material that are not irradiated by the EUV radiation. This leaves a patterned arrangement of the remaining precursor material. An etching process may then be performed to remove components of the remaining precursor material other than the desired one or more components for forming the 2D material. An insertion and / or replacement process may then be performed to provide all desired components of the 2D material. A process for crystallizing the components of the 2D material may then be performed. A pattern of the 2D material is thereby formed on the surface.

[0057] Advantageously, the required EUV dose may not exceed the dose required for patterning of standard EUV resists. That is, the required EUV dose may be similar to the dose required for patterning metal oxide based resists. The required EUV dose may be less than or equal to about 100 mJ / cm 2 .

[0058] Reference below 4A to 4F The embodiments are described in more detail.

[0059] Figure 4A Schematically illustrated is a substrate 401, or W, that has a patterned arrangement of structures 403 formed thereon according to known techniques. The structures 403, as well as unpatterned areas of the substrate 401, or W, have been coated with a precursor material 402a. The precursor material 402a may have been deposited by, for example, chemical vapor deposition CVD, ALD, spin coating, or other known techniques for depositing resists.

[0060] The precursor material 402a may be a material having the same FIG. 2A to FIG. 2C The precursor material 402a may be a nanocluster of similar or identical structure to the metal oxide nanocluster described above. That is, the precursor material 402a may have a core 201, which may be a metal including the core 201 (which is surrounded by ligands 202). The ligands 202 form a shell around the core 201. Each ligand may be a polymer structure.

[0061] The core 201 may include, for example, one or more of an oxide of tellurium (such as tellurium oxide, tellurium trioxide or preferably tellurium dioxide), a transition metal telluride, or a transition metal disulfide. Advantageously, tellurium has a relatively high absorption of EUV photons. An additional advantage of using tellurium in the core 201 is that tellurium may form part of the ultimately produced 2D material. The 2D material may be, for example, MoTe2, WTe2, PtTe2 or tellurium.

[0062] Figure 4B The EUV exposure process being performed is schematically shown. During the EUV exposure process, the precursor material 402a is irradiated by patterned EUV radiation 404. The irradiated precursor material 402a absorbs EUV photons. This results in the generation of photoelectrons, and collisions between the photoelectrons and atoms result in the generation of secondary electrons. The secondary electrons cause the dissociation of the ligand 202, so that Figure 2B The active site 203 is formed in a process similar to or the same as that shown in FIG.

[0063] The plurality of nanoclusters may then condense to form condensed precursor material 402b. The condensation process may be similar to Figure 2C The condensation process may include forming bonds 204 between active sites 203 to bond the plurality of nanoclusters together. Each bond may be, for example, an oxygen bond or a tellurium bond.

[0064] The development process may then be performed. The condensed precursor material 402b may have a different solubility than the unexposed regions of the precursor material 402a. In particular, the condensed precursor material 402b may not dissolve in the development fluid and therefore not be removed by the development process. The unexposed precursor material 402a may dissolve in the development fluid and therefore be removed during the development process. Figure 4C Remaining precursor material 402b is schematically shown after a development process has been performed. The development process may be a wet development process.

[0065] Therefore, the EUV-induced deposition process can be used to form a pattern of the precursor material 402b. The content of each core 201 and / or the element that bonds the nanoclusters together after the condensation process can be substantially the same as the content of the patterned precursor material 402b according to the embodiment. FIG. 2A to FIG. 2C The only difference between the resist patterning techniques described.

[0066] A process for stripping the precursor material 402c may then be performed such that substantially only components required by further processes for forming a 2D material remain. Figure 4D The remaining component 402c after the precursor material 402b has been stripped is schematically shown. The remaining component 402c can be a transition metal precursor or a transition metal disulfide precursor. The process for stripping the precursor material 402b can be an etching process, and preferably a selective dry etching process. The etching process can be free radical based and only includes chemical etching. No bias voltage can be applied during the etching process so that there is no ion-based etching.

[0067] Then one or more processes may be performed to provide all the components required for forming the 2D material. In particular, one or more processes for inserting chalcogens may be performed. Each process for inserting chalcogens may be a CVD process. The inserted chalcogens may be any element in Group 16 of the periodic table. For example, the inserted chalcogens may be sulfur, selenium, or tellurium. If the desired chalcogen of the 2D material is a component of the precursor material 402a, the chalcogen insertion process may not be required. Additionally or alternatively, one or more processes may be performed to replace the components of the remaining precursor material 402c. Each process for replacing the components may be a CVD process. The metal inserted by the replacement process may be, for example, any one of molybdenum, tungsten, palladium, platinum, zirconium, or tin. For example, if the remaining precursor material 402c includes tin that may be in the form of tin oxide, a process for replacing tin with molybdenum may be performed.

[0068] Figure 4E Schematically illustrates the composition of the 2D material 402d after the insertion and / or replacement process described above has been performed. The composition of the 2D material 402d may not currently be in a crystalline form. Therefore, further processes may be performed to rearrange the composition of the 2D material 402d into a crystalline structure so as to form a Figure 4F Crystalline 2D material 402e is schematically shown in FIG.

[0069] A number of different processes can be performed to form the 2D material into a crystalline structure. For example, a temperature-based crystallization process, such as annealing, can be performed.

[0070] Preferably, the crystallization process is performed using a dynamic plasma with ion energy control provided by a customized waveform.

[0071] Figure 5 The configuration of an exposure process arrangement for performing the crystallization process using a moving plasma is schematically shown.

[0072] The exposure process arrangement comprises a substrate W. The substrate W comprises a substrate body 505. The substrate body 505 may have thereon a patterned layer 504 of a component of a 2D material 402d which is not initially in a crystalline form. The substrate body 505 may be firmly fixed to a substrate stage 507 by an electrostatic clamp 506.

[0073] The patterned layer 504 of the component of the 2D material 402d may be arranged so that at least a portion thereof may be irradiated by EUV radiation. The path of the EUV radiation may be orthogonal to the main surface of the substrate W. An irradiation zone 502 may be defined between the exposed main surface of the substrate W and the grounded wall 501. When the exposed main surface of the substrate W is irradiated, the EUV radiation may travel through one or more openings in the grounded wall 501 and through the irradiation zone 502.

[0074] The exposure process arrangement may further include a matching box 508 and a power supply arrangement 514. The power supply arrangement 514 may include a switch 509, a ground terminal 510, a sine waveform generator 511, and a flexible waveform generator 512. The switch 509 may control the type of waveform output by the power supply arrangement 514. When the switch 509 is applied to the sine waveform generator 511 or the flexible waveform generator 512, the output of the power supply arrangement 514 may be an AC voltage. The AC voltage output from the power supply arrangement 514 may generate an alternating electric field 513 in the patterned layer 504 of the component of the 2D material 402d. The direction of the alternating electric field 513 in the patterned layer 504 of the component of the 2D material 402d may be substantially orthogonal to the main surface of the substrate W. Therefore, the direction of the alternating electric field 513 in the patterned layer 504 of the component of the 2D material 402d may be substantially consistent with or parallel to the path of the EUV radiation irradiating the exposed main surface of the substrate W.

[0075] The alternating electric field 313 in the patterned layer 504 of the component of the 2D material 402d may crystallize the 2D material into a layer of crystalline 2D material 402e.

[0076] A number of different waveforms may be applied to produce the alternating electric field 313 . Fig. 6A and Figure 6B Sinusoidal waveforms with different frequencies that can be applied are shown. Preferably, an application such as Figure 6CSuch a customized waveform can be configured to apply the appropriate energy for rearranging atoms so as to properly form the crystalline 2D material 402e.

[0077] Figure 5 The exposure process arrangement described above and FIG. 6A to FIG. 6C The use of the waveforms shown in has been described in a document published by QUESTEL RESEARCH DISCLOSURE. The document published by QUESTEL RESEARCH DISCLOSURE (the entire contents of which are incorporated herein by reference) is entitled ANISOTROPIC RESISTPATTERNING, has a database number of 696059, a digital publication date of March 15, 2022, and a timestamp of 758220ea9fc74fcd8b575d26da52c3ea222304b25153c8e7c176308ceebf1c57. The link to the document is: https: / / www.researchdisclosure.com / database / RD696059 (As shown on June 13, 2022).

[0078] Thus, embodiments provide new techniques for forming a patterned layer of 2D material on a surface, such as the surface of substrate 401 ie W. Advantageously, the required EUV dose may be significantly less than that required by known EUV-based techniques for forming patterned 2D materials.

[0079] The formed 2D material may include atoms of a transition metal M and atoms of a chalcogen element Q. M may be from any of Groups IV, V or VI of the periodic table. Q may be any chalcogen element such as sulfur, selenium and tellurium. M and Q atoms may form a covalently bonded 2D layer of the MQ2 type having a hexagonal lattice.

[0080] Embodiments include many modifications and variations of the techniques described above.

[0081] Embodiments include more than one apparatus or tool used in the formation of a 2D material. In particular, the process for crystallizing components of a 2D material may be performed in an apparatus or separate tool from the apparatus or tool that irradiates the deposited precursor material with patterned radiation.

[0082] In the embodiments described above, EUV radiation is used to irradiate the deposited precursor material. Embodiments also include radiation having a wavelength different from the EUV used in forming the 2D material. For example, embodiments include irradiating the precursor material with DUV radiation. The type of precursor material used may depend on the wavelength of the radiation irradiating it. Therefore, the precursor material used with DUV radiation may be different from the precursor material used with EUV radiation, such that the bulk of the precursor material effectively absorbs the DUV radiation. Similarly, different development and / or stripping processes appropriate to the precursor material used may be performed.

[0083] In the embodiments described above, only the irradiated precursor material remains after the development process. Embodiments also include using different precursor materials such that irradiated areas of the precursor material are removed during the development process and non-irradiated areas of the precursor material are not removed by the development process.

[0084] The embodiments have described the formation of a single layer of 2D material. The embodiments also include the described techniques for forming multilayer materials and / or multiple stacked layers of 2D materials.

[0085] Embodiments are not limited to forming patterns using a particular type of 2D material, or a 2D material patterned for the specific purpose of providing a channel of a MOSFET. Embodiments include the formation of patterned arrangements of multiple different types of 2D materials for any purpose. For example, embodiments include forming a patterned arrangement of 2D materials to serve as a metal cap or diffusion barrier interconnect. There are many different types of 2D materials, including electrical insulators, semiconductors, semimetals, metals, and superconductors. Embodiments include the need to form patterns of any type of 2D material depending on the purpose of the 2D material in the device being manufactured.

[0086] 4A to 4F The formation of a 2D material layer is shown on a substrate 401 that already has a patterned arrangement of multiple structures formed thereon, ie, W. Embodiments also include forming a 2D material layer on a surface of a substrate that does not yet have structures formed thereon.

[0087] Embodiments include a core 201 of a precursor material, alternatively or additionally, including one or more of molybdenum, tungsten, palladium, platinum, zirconium, tin, or oxides thereof. The core 201 may alternatively or additionally include other transition metals and / or oxides thereof.

[0088] Embodiments include the following numbered aspects:

[0089] 1. A material for deposition on a substrate, the material comprising:

[0090] Tellurium oxides, transition metal tellurides and / or transition metal disulfides; and

[0091] A ligand for forming a cross-link bond in response to irradiation with radiation.

[0092] 2. The material of aspect 1, wherein the ligand forms crosslinks in response to irradiation with extreme ultraviolet radiation (EUV radiation).

[0093] 3. The material according to aspect 1 or 2, wherein the transition metal telluride comprises one or more of molybdenum telluride, tungsten telluride or platinum telluride.

[0094] 4. A system for forming a pattern of 2D material on a surface, the system comprising one or more devices configured to:

[0095] depositing a precursor material on a surface, wherein the precursor material comprises one or more components for forming a 2D material on the surface and one or more components for forming crosslinks in response to exposure to radiation;

[0096] irradiating the deposited precursor material with patterned radiation such that crosslinks are formed in the irradiated precursor material;

[0097] performing a development process for removing the precursor material not including the cross-linking bonds;

[0098] performing one or more processes for removing components of the precursor material such that substantially only one or more components for forming the 2D material remain; and

[0099] A crystallization process is performed to form a 2D material on the surface.

[0100] 5. The system of aspect 4, wherein one or more components of the precursor material for forming crosslinks form crosslinks in response to irradiation with extreme ultraviolet radiation (EUV radiation); and

[0101] The one or more devices are configured to irradiate the deposited precursor material with patterned EUV radiation such that crosslinks are formed in the irradiated precursor material.

[0102] 6. A system according to aspect 4 or aspect 5, wherein, before performing the crystallization process, the device of the system is configured to further perform an insertion process for inserting components of the 2D material to be formed on the surface.

[0103] 7. The system according to aspect 6, wherein the system comprises a chemical vapor deposition device (CVD device) configured to perform the insertion process.

[0104] 8. A system according to any one of aspects 5 to 7, wherein, before performing the crystallization process, the equipment of the system is configured to further perform a replacement process for replacing one or more of the components used to form the 2D material.

[0105] 9. The system of aspect 8, wherein the system comprises a chemical vapor deposition (CVD) apparatus configured to perform the replacement process.

[0106] 10. The system of any one of aspects 5 to 9, wherein the system comprises a wet development process apparatus configured to remove the precursor material that does not include crosslinks.

[0107] 11. A system according to any one of aspects 5 to 10, wherein the system includes a dry etching device and / or a chemical etching device, and the dry etching device and / or the chemical etching device are configured to remove components of the precursor material so that essentially only the one or more components used to form the 2D material remain.

[0108] 12. The system of any one of aspects 5 to 11, wherein the system comprises an apparatus configured to perform temperature-based crystallization for forming the 2D material.

[0109] 13. A system according to any one of aspects 5 to 12, wherein the system includes an apparatus configured to crystallize the 2D material using a moving plasma in a manner with controlled ion energy.

[0110] 14. The system of any one of aspects 5 to 13, wherein the deposited precursor material comprises tellurium oxide, transition metal telluride and / or transition metal disulfide.

[0111] 15. The system of aspect 14, wherein the transition metal telluride is molybdenum telluride, tungsten telluride, or platinum telluride.

[0112] 16. The system of any one of aspects 5 to 15, wherein the deposited precursor material is a material according to any one of aspects 1 to 3.

[0113] 17. A system according to any one of aspects 5 to 16, wherein the formed 2D material includes atoms of a transition metal M and atoms of a chalcogen element Q.

[0114] 18. A system according to aspect 17, wherein the M and Q atoms form a covalently bonded 2D layer of MQ2 type.

[0115] 19. A method of forming a pattern of 2D material on a surface, the method comprising:

[0116] depositing a precursor material on a surface, wherein the precursor material comprises one or more components for forming a 2D material on the surface and one or more components for forming crosslinks in response to exposure to radiation;

[0117] irradiating the deposited precursor material with patterned radiation such that crosslinks are formed in the irradiated precursor material;

[0118] performing a development process for removing the precursor material not including the cross-linking bonds;

[0119] performing one or more processes for removing the components of the precursor material such that substantially only one or more components for forming the 2D material remain; and

[0120] A crystallization process is performed to form a 2D material on the surface.

[0121] 20. The method of aspect 19, wherein one or more components of the precursor material for forming crosslinks form crosslinks in response to irradiation with extreme ultraviolet radiation (EUV radiation); and

[0122] The deposited precursor material is irradiated with patterned EUV radiation such that crosslinks are formed in the irradiated precursor material.

[0123] 21. The method according to aspect 20, wherein, before performing the crystallization process, the method further comprises performing an insertion process for inserting a component of the 2D material to be formed on the surface.

[0124] 22. The method according to aspect 21, wherein the insertion process is a chemical vapor deposition process (CVD process).

[0125] 23. A method according to any one of aspects 19 to 22, wherein, before performing the crystallization process, the method further comprises performing a replacement process for replacing one or more of the components used to form the 2D material.

[0126] 24. The method of clause 23, wherein the replacement process is a chemical vapor deposition (CVD) process.

[0127] 25. The method of any one of clauses 19 to 24, wherein the development process for removing the precursor material not comprising crosslinks is a wet development process.

[0128] 26. A method according to any one of aspects 19 to 25, wherein the one or more processes for removing components of the precursor material so that substantially only the one or more components used to form the 2D material remain include a dry etching process and / or a chemical etching process.

[0129] 27. The method of any one of aspects 19 to 26, wherein performing a crystallization process for forming the 2D material on the surface comprises performing a temperature-based crystallization process.

[0130] 28. A method according to any one of aspects 19 to 27, wherein the crystallization process for forming the 2D material on the surface is performed using a moving plasma in a controlled manner with ion energy.

[0131] 29. The method of any one of aspects 19 to 28, wherein the deposited precursor material comprises tellurium oxide, transition metal telluride and / or transition metal disulfide.

[0132] 30. The method of aspect 29, wherein the transition metal telluride is molybdenum telluride, tungsten telluride, or platinum telluride.

[0133] 31. The method of any one of aspects 19 to 30, wherein the deposited precursor material is a material according to any one of aspects 1 to 3.

[0134] 32. A method according to any one of aspects 19 to 31, wherein the formed 2D material comprises atoms of a transition metal M and atoms of a chalcogen element Q.

[0135] 33. A method according to aspect 32, wherein the M and Q atoms form a covalently bonded 2D layer of MQ2 type.

[0136] 34. A device comprising one or more layers of 2D material, wherein the device is manufactured according to the method of any one of aspects 19 to 33.

[0137] 35. A substrate at least partially coated with a material according to any one of aspects 1 to 3.

[0138] 36. A substrate having a 2D material formed thereon, wherein the 2D material is formed according to the method of any one of clauses 19 to 33.

[0139] 37. The substrate of clause 36, wherein the formed 2D material comprises atoms of a transition metal and atoms of a chalcogen element.

[0140] 38. A substrate according to aspect 36 or 37, wherein the formed 2D material includes one or more atoms M of tellurium or a transition metal, and the atoms M of the transition metal are covalently bonded to the atoms Q of the chalcogen element in the form of MQ2, such as MoTe2, MoS2, PtTe2, WTe2, WS2 or WSe2.

[0141] 39. A substrate having a 2D material formed thereon, wherein the 2D material comprises tellurium.

[0142] 40. The substrate of clause 39, wherein the 2D material is formed according to the method of any one of clauses 19 to 33.

[0143] 41. A substrate having a 2D material formed thereon, wherein the 2D material comprises one or more atoms M of tellurium or a transition metal, wherein the atoms M of the transition metal are covalently bonded to atoms Q of a chalcogen element in the form of MQ2, such as MoTe2, MoS2, PtTe2, WTe2, WS2 or WSe2.

[0144] 42. A substrate according to aspect 41, wherein the 2D material is formed according to the method of any one of aspects 19 to 33.

[0145] Although specific reference may be made herein to the use of lithographic apparatus in IC manufacturing, it should be understood that the lithographic apparatus described herein may have other applications. Possible other applications include the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat panel displays, liquid crystal displays (LCDs), thin film magnetic heads, etc.

[0146] Although specific embodiments of the present invention have been described above, it will be appreciated that the present invention may be practiced in a manner different from that described. The above description is intended to be exemplary and not restrictive. Therefore, it will be appreciated by those skilled in the art that modifications may be made to the present invention as described without departing from the scope of the claims set forth below.

Claims

1. A material for deposition on a substrate, the material comprising: Tellurium oxides, transition metal tellurides and / or transition metal disulfides; and A ligand for forming a cross-link bond in response to irradiation with radiation.

2. The material according to claim 1, wherein The ligands form crosslinks in response to irradiation with extreme ultraviolet radiation, EUV radiation.

3. The material according to claim 1 or 2, wherein The transition metal telluride includes one or more of molybdenum telluride, tungsten telluride or platinum telluride.

4. A system for forming a pattern of 2D material on a surface, the system comprising one or more devices configured to: depositing a precursor material on a surface, wherein the precursor material comprises one or more components for forming a 2D material on the surface and one or more components for forming crosslinks in response to exposure to radiation; irradiating the deposited precursor material with patterned radiation such that crosslinks are formed in the irradiated precursor material; performing a development process for removing the precursor material not including the cross-linking bonds; performing one or more processes for removing components of the precursor material such that substantially only one or more components for forming the 2D material remain; as well as A crystallization process is performed to form a 2D material on the surface.

5. The system according to claim 4, wherein: One or more components of the precursor material for forming crosslinks form crosslinks in response to irradiation with extreme ultraviolet radiation (EUV radiation); and The one or more devices are configured to irradiate the deposited precursor material with patterned EUV radiation such that crosslinks are formed in the irradiated precursor material.

6. A system according to claim 4 or claim 5, wherein: Before performing the crystallization process, the device of the system is configured to further perform an insertion process for inserting a component of the 2D material to be formed on the surface.

7. The system according to claim 6, wherein: The system includes a chemical vapor deposition apparatus (CVD apparatus) configured to perform the insertion process.

8. A system according to any one of claims 5 to 7, wherein: Prior to performing the crystallization process, the apparatus of the system is configured to further perform a replacement process for replacing one or more of the components used to form the 2D material.

9. The system according to claim 8, wherein: The system includes a chemical vapor deposition apparatus (CVD apparatus) configured to perform the replacement process.

10. The system according to any one of claims 5 to 9, wherein: The system includes a wet development process apparatus configured to remove the precursor material that does not include crosslinks.

11. A system according to any one of claims 5 to 10, wherein: The system includes a dry etching device and / or a chemical etching device, which is configured to remove components of the precursor material so that substantially only the one or more components used to form the 2D material remain.

12. A system according to any one of claims 5 to 11, wherein: The system includes an apparatus configured to perform temperature-based crystallization for forming the 2D material.

13. A system according to any one of claims 5 to 12, wherein: The system includes an apparatus configured to crystallize the 2D material using a moving plasma in a manner with controlled ion energy.

14. A system according to any one of claims 5 to 13, wherein: The deposited precursor material includes tellurium oxides, transition metal tellurides, and / or transition metal disulfides.

15. The system of claim 14, wherein: The transition metal telluride is molybdenum telluride, tungsten telluride or platinum telluride.

16. A system according to any one of claims 5 to 15, wherein: The deposited precursor material is a material according to any one of claims 1 to 3.

17. A system according to any one of claims 5 to 16, wherein: The formed 2D material includes atoms of transition metal M and atoms of chalcogen element Q.

18. The system of claim 17, wherein: The M and Q atoms form a covalently bonded 2D layer of the MQ2 type.

19. A method of forming a pattern of 2D material on a surface, the method comprising: depositing a precursor material on a surface, wherein the precursor material comprises one or more components for forming a 2D material on the surface and one or more components for forming crosslinks in response to exposure to radiation; irradiating the deposited precursor material with patterned radiation such that crosslinks are formed in the irradiated precursor material; performing a development process for removing the precursor material not including the cross-linking bonds; performing one or more processes for removing the components of the precursor material such that substantially only one or more components for forming the 2D material remain; as well as A crystallization process is performed to form a 2D material on the surface.

20. The method according to claim 19, wherein: One or more components of the precursor material for forming crosslinks form crosslinks in response to irradiation with extreme ultraviolet radiation, i.e., EUV radiation; and The deposited precursor material is irradiated with patterned EUV radiation such that crosslinks are formed in the irradiated precursor material.

21. The method according to claim 20, wherein: Before performing the crystallization process, the method further includes performing an insertion process for inserting a component of the 2D material to be formed on the surface.

22. The method according to claim 21, wherein: The insertion process is a chemical vapor deposition process, namely a CVD process.

23. The method according to any one of claims 19 to 22, wherein: Prior to performing the crystallization process, the method further includes performing a replacement process for replacing one or more of the components used to form the 2D material.

24. The method according to claim 23, wherein: The replacement process is a chemical vapor deposition process, ie, a CVD process.

25. The method according to any one of claims 19 to 24, wherein: The development process for removing the precursor material not including crosslinks is a wet development process.

26. The method according to any one of claims 19 to 25, wherein: The one or more processes for removing components of the precursor material such that substantially only the one or more components for forming the 2D material remain include a dry etching process and / or a chemical etching process.

27. The method according to any one of claims 19 to 26, wherein: Performing a crystallization process for forming the 2D material on the surface includes performing a temperature-based crystallization process.

28. The method according to any one of claims 19 to 27, wherein: A crystallization process for forming the 2D material on the surface is performed using a moving plasma in a controlled manner with ion energies.

29. The method according to any one of claims 19 to 28, wherein: The deposited precursor material includes tellurium oxides, transition metal tellurides, and / or transition metal disulfides.

30. The method of claim 29, wherein: The transition metal telluride is molybdenum telluride, tungsten telluride or platinum telluride.

31. The method according to any one of claims 19 to 30, wherein: The deposited precursor material is a material according to any one of claims 1 to 3.

32. The method according to any one of claims 19 to 31, wherein: The formed 2D material includes atoms of transition metal M and atoms of chalcogen element Q.

33. The method of claim 32, wherein: The M and Q atoms form a covalently bonded 2D layer of the MQ2 type.

34. A device comprising one or more 2D material layers, wherein: The device is manufactured according to the method of any one of claims 19 to 33.

35. A substrate at least partially coated with a material according to any one of claims 1 to 3.

36. A substrate having a 2D material formed thereon, wherein: The 2D material is formed according to the method of any one of claims 19 to 33.

37. The substrate according to claim 36, wherein The formed 2D material includes atoms of transition metals and atoms of chalcogen elements.

38. The substrate according to claim 36 or 37, wherein The formed 2D material includes one or more atoms M of tellurium or a transition metal, which are covalently bonded to atoms Q of a chalcogen element in the form of MQ2, such as MoTe2, MoS2, PtTe2, WTe2, WS2 or WSe2.

39. A substrate having a 2D material formed thereon, wherein: The 2D material includes tellurium.

40. The substrate according to claim 39, wherein The 2D material is formed according to the method of any one of claims 19 to 33.

41. A substrate having a 2D material formed thereon, wherein: The 2D material includes one or more atoms M of tellurium or a transition metal, wherein the atoms M of the transition metal are covalently bonded to atoms Q of a chalcogen element in the form of MQ2, such as MoTe2, MoS2, PtTe2, WTe2, WS2 or WSe2.

42. The substrate according to claim 41, wherein The 2D material is formed according to the method of any one of claims 19 to 33.

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