Methods of area-selective deposition

Abstract

The application belongs to the technical field of semiconductors, and provides a method for regionally selective deposition, comprising the following steps: obtaining a semiconductor substrate; constructing a liquid sealing layer on one side of a mask plate, placing one end of the mask plate with the liquid sealing layer on the semiconductor substrate; and depositing a specified material to the liquid sealing mask plate. The application fills the gap between the substrate and the mask plate with the liquid sealing layer, prevents the problem of atomic layer deposition growing in an unnecessary area, effectively fills all the gaps between the mask plate and the substrate until the molecular level, and thus realizes the effect of sealing the gap between the substrate and the mask plate, so as to solve the technical problem of atomic layer deposition growing in an unnecessary area.

Description

Technical Field

[0001] This application belongs to the technical field of semiconductors, and particularly relates to a method for region-selective deposition. Background Technology

[0002] The miniaturization of integrated circuits in semiconductor technology currently relies almost entirely on top-down processing, characterized by a complex combination of many material deposition, extreme ultraviolet lithography, and etching steps.

[0003] There are many methods for preparing nanomaterials, such as atomic layer deposition (ALD), chemical vapor deposition (CVD), and physical vapor deposition (PVD). However, during deposition, the gap between the mask and the substrate can lead to long-term weaknesses with blurred boundaries, causing the intended material to grow in unwanted areas. Current methods for addressing this gap problem mainly focus on applying forces to the mask surface using mechanical or magnetic devices to reduce the gap space. These methods offer some improvement, but cannot reduce the gap to the molecular level.

[0004] Therefore, developing a masking method that can effectively improve the barrier performance of mask plates and is convenient to apply to most scenarios is of great practical significance. Summary of the Invention

[0005] This application provides a method for region-selective deposition to solve the technical problem of atomic layer deposition growing in unwanted regions.

[0006] This application provides a method for region-selective deposition, comprising: hydrophilic hydroxylation treatment of the semiconductor substrate; constructing a liquid sealing layer on one end of the mask, placing the end with the liquid sealing layer on the semiconductor substrate to form a liquid-sealed mask; and depositing a specified material onto the liquid-sealed mask.

[0007] In one possible implementation, the liquid sealing layer comprises a long straight-chain alkane oil obtained from crude oil fractionation and / or dearomatization, wherein the long straight-chain alkane oil has six or more carbon atoms.

[0008] In one possible implementation, the long-chain alkane oil is a perfluoropolyether.

[0009] In one possible implementation, the thickness of the liquid sealing layer is not less than the maximum gap between the mask and the semiconductor substrate.

[0010] In one possible implementation, the hydrophilic hydroxylation treatment includes: cleaning the semiconductor substrate with a plasma treatment gas; the plasma treatment gas is an argon-oxygen mixture, the excitation frequency is 13-15MHz, and the treatment time is 3-5min.

[0011] In one possible implementation, the step of depositing the specified material onto the liquid-sealed mask includes: placing the liquid-sealed mask and the semiconductor substrate within a chamber of an atomic layer deposition apparatus; sequentially introducing a first precursor gas and a second precursor gas into the chamber, wherein the first precursor gas comprises water and a hydrophilic reactant, and the second precursor gas comprises water and a hydrophilic reactant; purging an inert gas into the chamber; and returning the first and second precursor gases to the chamber sequentially until a specified material film of a predetermined thickness is obtained, wherein the film comprises at least a metal oxide, a metal nitride, and an organic film.

[0012] In one possible implementation, the deposition includes atomic layer deposition, magnetron sputtering deposition, physical vapor deposition, or chemical vapor deposition.

[0013] In one possible implementation, after depositing the specified material onto the liquid-sealed mask, the process further includes ultrasonically cleaning and immersing the deposited liquid-sealed mask and the semiconductor substrate in a perfluorohexane solution to obtain a substrate with atomic layer deposition film patterning.

[0014] In one possible implementation, the liquid sealing layer is constructed using a scraping or spin coating method.

[0015] In one possible implementation, the process before the hydrophilic hydroxylation treatment of the semiconductor substrate further includes cleaning the semiconductor substrate and the mask in different solutions.

[0016] The beneficial effects of this application embodiment compared with the prior art are: by filling the gap between the substrate and the mask with a liquid sealing layer, the problem of atomic layer deposition and growth in unwanted areas is prevented, and all gaps between the mask and the substrate are effectively filled down to the molecular level, thereby achieving the effect of sealing the gap between the substrate and the mask. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram showing a gap between the substrate and the mask during deposition in the prior art;

[0019] Figure 2 A schematic flowchart of the regional selective deposition method provided in this application;

[0020] Figure 3 A schematic diagram of the substrate and mask plate in the region-selective deposition method provided in this application;

[0021] Figure 4 The images show substrate maps and XPS spectra of corresponding regions on the substrates after atomic layer deposition, respectively, for Comparative Example 1 and Example 1, the prior art, and the region-selective deposition method provided in this application.

[0022] Figure 5 The image shows the EDS energy spectrum of the hafnium oxide thin film deposited in Example 2.

[0023] Figure 6 This is the EDS energy spectrum of the titanium oxide thin film deposited in Example 3;

[0024] Figure 7 The images shown are optical micrographs of the mask in Comparative Example 2 and Example 4, electron micrographs of the substrate after thermal evaporation using existing technology, and electron micrographs of the substrate after thermal evaporation using the method of this application.

[0025] Figure 8 The images shown are optical micrographs of the mask in Comparative Example 3 and Example 5, electron micrographs of the substrate after magnetron sputtering using existing technology, and electron micrographs of the substrate after magnetron sputtering using the method of this application. Detailed Implementation

[0026] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0027] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0028] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0029] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection."

[0030] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0032] The miniaturization of integrated circuits in semiconductor technology currently relies almost entirely on top-down fabrication, characterized by a complex combination of material deposition, extreme ultraviolet lithography, and etching steps. Device scales approaching 5 nanometers make the perfect alignment of reliably processed nanopatterns extremely challenging, requiring near-atomic-scale precision. Utilizing atoms as building blocks to fabricate materials in a bottom-up manner has long been a dream in the field of nanotechnology. This contrasts sharply with the current reality: the semiconductor industry's nanoelectronics manufacturing relies almost entirely on top-down fabrication, primarily due to stringent reliability requirements. However, the industry now faces significant challenges in implementing bottom-up approaches in some of the most demanding fabrication steps to obtain the desired variety of nanopatterns.

[0033] Nanomaterials, thin films, and patterns are important in electronics, energy conversion and storage, catalysis, chemical separation, environmental protection and health, and many other technologies. Scientific and technological advancements in these fields require new capabilities to control chemical reactions. Nanowires, spatial and other complex features are often patterned on surfaces using photolithography, which uses light to transfer physical mask patterns onto photoresist. Ultimately, control over chemical synthesis is needed in the initial stages of material formation and in manipulating reactions.

[0034] There are many methods for preparing nanomaterials, such as atomic layer deposition, chemical vapor deposition, and physical vapor deposition. However, during deposition, the gap between the mask and the substrate can lead to long-term weaknesses with blurred boundaries, causing the intended material to grow in unwanted areas. For example: [reference needed] Figure 1If atomic layer deposition is used, for non-heterogeneous substrates (such as silicon wafers), bottom-up atomic layer deposition requires a shadow mask to achieve atomic layer deposition patterning. Precursor molecules for atomic layer deposition can easily penetrate into the gaps and deposit under the masked area.

[0035] Current methods for addressing the gap problem primarily focus on applying forces to the mask surface using mechanical or magnetic devices to reduce the gap space. These methods offer some improvement, but they cannot reduce the gap to the molecular level, meaning that deposits still exist within the masked area.

[0036] Therefore, this application provides a method for region-selective deposition to solve the technical problem of growing atomic layer deposition in unwanted regions.

[0037] In one embodiment of this application, a method for region-selective deposition is provided, referring to... Figure 2 The process includes: obtaining a semiconductor substrate; constructing a liquid sealing layer on one end of a mask, placing the end with the liquid sealing layer on the semiconductor substrate; and depositing a specified material onto the liquid-sealed mask.

[0038] A semiconductor substrate refers to a substrate formed by atomic layer deposition using a semiconductor material. The semiconductor material refers to a material whose conductivity at room temperature is between that of a conductor and an insulator. This substrate is the foundation of radio frequency / microwave electronic devices or integrated circuits. For example, a semiconductor substrate can be a single-crystal silicon wafer, but it is not limited to single-crystal silicon wafers; other possible implementations are not listed here.

[0039] It should be noted that the semiconductor substrate may not require further treatment. It can be treated with hydrophilic hydroxylation, RCA standard cleaning, wet cleaning, or dry cleaning; no specific limitations are made here. In this embodiment, hydrophilic hydroxylation is used as an example. Hydrophilic hydroxylation refers to plasma treatment of the semiconductor substrate. Plasma treatment involves applying sufficient energy to a gas to ionize it into plasma. The "active" components of plasma include ions, electrons, atoms, and active genes. Plasma treatment utilizes the properties of these active components to treat the sample surface, thereby improving its hydrophilicity. In this embodiment, the gas introduced for plasma treatment is an argon-oxygen mixture, the excitation frequency of the plasma cleaning equipment is 13-15 MHz, and the treatment time is 3-5 minutes.

[0040] It should be noted that the surface of the semiconductor substrate treated with hydrophilic hydroxylation includes at least one end connected to the mask, so as to ensure that the surface of the semiconductor substrate in contact with the mask is hydrophilic.

[0041] Constructing a liquid sealing layer involves filling one end of a photomask with a liquid sealant into the gap between the photomask and the substrate. This sealant fills the gap and prevents unwanted growth during atomic layer deposition. The liquid sealing layer can be constructed on one side of the photomask or on both sides. If it is only constructed on one side, that side is the end in contact with the substrate. (See reference...) Figure 3 The dynamic characteristics of the liquid sealing layer allow the liquid sealant to easily align with the pattern geometry, regardless of the mask's flatness. That is, under the influence of flowability, the liquid sealant can fill the gap between the mask and the substrate. When the gap is irregular, the liquid sealant can fill and adapt to the pattern, forming a liquid sealing layer to achieve a seal. Even when the mask has a macroscopic unevenness relative to an ideal plane, the liquid sealant can still achieve alignment with the surface of the deposited thin film pattern based on its own flowability and gravity. Simultaneously, the mask confines the liquid within the gap between the substrate and the mask through capillary force, preventing the liquid sealing layer from flowing freely. The liquid sealing layer barrier exhibits defect-free and anti-adsorption properties before atomic layer deposition molecules, thus achieving a seal.

[0042] One side end of a photomask refers to one side end face of the photomask. For example, if a first end face and a second end face are provided sequentially along the height direction of the photomask, the one side end of the photomask can be either the first end face or the second end face, without specific limitation.

[0043] Deposition refers to the process of forming a solid film on a solid surface using gaseous substances under certain temperature and vacuum conditions. Deposition generally includes magnetron sputtering deposition, atomic layer deposition (ALD), chemical vapor deposition (CVD), and physical vapor deposition (PVD). The ALD process is roughly as follows: reactive gases diffuse to the workpiece surface and are adsorbed; various substances adsorbed on the workpiece surface undergo surface chemical reactions; the generated material points aggregate into crystals and increase in size; gaseous products generated in the surface chemical reactions detach from the workpiece surface and return to the gas phase; interdiffusion of elements occurs at the interface between the deposited layer and the substrate, forming a coating. Chemical vapor deposition (CVD) is a process that uses gaseous substances to produce chemical and transport reactions on a solid surface to generate solid deposits. It roughly includes: forming volatile substances; transferring these substances to the deposition area; and producing a chemical reaction on the solid surface to generate a solid material. Physical vapor deposition (PVD) refers to the process of vaporizing a material source (solid or liquid) into gaseous atoms or molecules, or partially ionizing them into ions, under vacuum conditions using physical methods, and then performing a low-pressure gas (or plasma) process. The basic principles may include: vaporization of the plating material; migration of plating material atoms, molecules, or ions; and deposition of plating material atoms, molecules, or ions on the substrate. To clearly illustrate the use of the method in this embodiment, atomic layer deposition will be used as an example for explanation.

[0044] Specifically, atomic layer deposition (ALD), a commonly used method for nanomaterial fabrication, enables the growth of thin films with atomically controlled thickness and angstrom-level surface smoothness within highly confined spaces, making it indispensable in microelectronics, photovoltaics, batteries, and catalyst design. Precise deposition control and high-quality films stem from ALD's unique sequential self-limiting reaction mechanism, where two gaseous precursors are introduced sequentially and bonded layer by layer to the substrate surface. The side effect of this delicate reaction mechanism—preventing ALD from growing in unwanted areas—is extremely challenging. Currently, the main method for patterning ALD films is to remove excess material through photolithography and etching (a top-down process). With the miniaturization and three-dimensional device architecture requirements of microelectronics, capping layer alignment is becoming increasingly difficult. If ALD film patterning can be achieved through regioselective deposition with the help of simple shadow masks (a bottom-up process), the complexity of the process will be greatly reduced. For substrates with multiple regions of different surface chemistry, ALD can achieve regioselectivity by utilizing the regio-dependent characteristics of precursor adsorption / desorption properties. This feature allows for nucleation delays between unwanted and target regions. Therefore, in order to amplify surface differences, additional chemical treatments (e.g., self-assembled monolayers) are often introduced to modulate the affinity of local molecules.

[0045] The specified materials include metal oxides, metal nitrides, organic thin films, or other types of thin films. Metal nitrides include aluminum oxide, titanium oxide, zinc oxide, zirconium oxide, and hafnium oxide. Metal nitrides also include aluminum nitride, titanium nitride, and tantalum nitride. Organic thin films include, but are not limited to, novel aluminum-based organic-inorganic composite thin films, polyurea, polyamide, and polyimide. Other types of thin films may include strontium carbonate, strontium titanate, barium titanate, etc.

[0046] In this embodiment, the advantage of the region-selective deposition method provided in this application over the prior art is that by filling the gap between the substrate and the mask with a liquid sealing layer, the problem of atomic layer deposition in unwanted areas is prevented, and all gaps between the mask and the substrate are effectively filled down to the molecular level, thereby achieving the effect of sealing the gap between the substrate and the mask.

[0047] In one possible implementation provided in this application, the process further includes cleaning the semiconductor substrate and the mask in different solutions before hydrophilic hydroxylation treatment of the semiconductor substrate.

[0048] The process for cleaning the semiconductor substrate uses the RCA method, specifically:

[0049] Using a mixed solution of sulfuric acid and hydrogen peroxide (H₂SO₄:H₂O₂ = 3:1), labeled as solution one, the semiconductor substrate is boiled for 10-20 minutes at 200-250℃, followed by rinsing with deionized water for 10-20 minutes. Then, solution two (ammonia:H₂O₂:H₂O = 1:1:5-1:1:7) is prepared. The semiconductor substrate is poured into the second solution and heated to 75-85℃ for 10-20 minutes (the time should not be too long, as ammonia corrodes silicon; the complexation process removes heavy metal impurities). The substrate is then removed and placed in a hydrofluoric acid solution (1:20) for 10-15 minutes. After rinsing, it is placed in hot water and rinsed with deionized water for 10-20 minutes. Finally, a third solution (HCl:H₂O₂:H₂O = 1:1:5) is prepared. The semiconductor substrate is poured into the third solution for 10-15 minutes. After rinsing, it is placed in hot water and rinsed with deionized water for 10-20 minutes. Finally, soak the substrate in 10% hydrofluoric acid for 5-10 seconds to remove the oxide layer on the silicon surface, and then rinse with deionized water for 10-15 minutes.

[0050] When cleaning the photomask, both ends need to be cleaned. To clean the photomask, use ethanol, acetone, or similar solvents to ultrasonically clean it 2-3 times, 10-15 minutes each time. After cleaning, one end of the semiconductor substrate should be in contact with the photomask.

[0051] In one possible implementation method provided in this application, the liquid sealing layer is constructed by scraping or spin coating.

[0052] To illustrate the process steps of the blade coating or spin coating method, in this embodiment, the liquid sealant used in the liquid sealing layer is perfluoropolyether as an example, but the liquid sealant is not limited to this.

[0053] The process steps for the scraping method are as follows: First, use a syringe to drop an appropriate amount of liquid sealant such as perfluoropolyether onto one edge of the mask. Then, set the appropriate height on the applicator, which is the required thickness of the liquid sealant layer. Then, use the applicator to scrape the droplet multiple times until a uniform liquid layer exists on the mask.

[0054] The process steps for spin coating are as follows: Place the mask on a benchtop spin coater, use a syringe to drop an appropriate amount of liquid sealant such as perfluoropolyether onto the center of the mask, set the rotation time to 10-60 seconds, and adjust the rotation speed to obtain liquid sealant layers of different thicknesses, thus completing the construction of the liquid sealant layer on the mask.

[0055] In one possible implementation provided in this application, the liquid sealing layer comprises a long straight-chain alkane oil obtained from crude oil fractionation and / or dearomatization, wherein the long straight-chain alkane oil has six or more carbon atoms.

[0056] The liquid sealant used in the liquid sealing layer includes a mixture of long straight-chain alkane oils (≥6 carbon atoms) obtained from crude oil fractionation and / or dearomatization.

[0057] Long-chain alkane oils are liquids used in liquid sealants and can be kerosene, white oil, mineral oil, light paraffin oil, heavy paraffin oil, perfluoropolyether, n-dodecane, n-hexadecane, n-eicosane, etc. The choice of liquid sealant depends on its adhesion to the mask and its stability and shape retention at the corresponding material deposition temperature.

[0058] It should be noted that chain alkanes are a type of saturated hydrocarbon. When the number of carbon atoms is less than or equal to 4, alkanes are gaseous at room temperature; when the number of carbon atoms is between 5 and 16, they are liquid; and when the number of carbon atoms is greater than or equal to 17, they are solid. In order to ensure that the long straight-chain alkane oils used in this embodiment are all liquids, the number of carbon atoms in the long straight-chain alkane oils is greater than or equal to sixteen and less than sixteen.

[0059] Preferably, in one possible implementation provided in this application, the long-chain alkane oil is a perfluoropolyether.

[0060] Perfluoropolyethers (PFPE) are synthetic polymers that are liquid at room temperature. Due to the strong electron-withdrawing effect of fluorine, PFPE does not exhibit ether-like properties, thus possessing excellent heat resistance, chemical stability, oxidation stability, and complete non-flammability. PFPE has a viscosity index of 150-400 (the higher the molecular weight of the oil, the higher its viscosity index), which is significantly superior to mineral oil. This substance is non-hygroscopic and insoluble in organic solvents, exhibiting miscibility only in perfluorooils or Freon 113 (trifluoroethane). This property means it has virtually no harmful effects on plastics and rubber. Therefore, using perfluoropolyethers as a liquid sealing layer provides a better barrier effect.

[0061] In one possible implementation provided in this application, the thickness of the liquid sealing layer is not less than the maximum gap between the mask and the semiconductor substrate.

[0062] In this embodiment, the thickness of the liquid sealant layer needs to be appropriate; too much or too little will affect the final deposition. If too much liquid sealant is selected, it will adhere to the ideal growth area of ​​the film outside the masked area; if too little liquid sealant is selected, it may not completely fill the gap between the mask and the substrate, resulting in poor barrier effect. Therefore, the thickness of the liquid sealant layer is not less than the maximum gap between the mask and the semiconductor substrate, and the liquid sealant will not overflow from the gap, making the selection of liquid sealant vector-like, which helps to ensure the stability of the region selection.

[0063] In one possible implementation provided by this application, the step of depositing a specified material onto a liquid-sealed mask includes: placing the liquid-sealed mask and a semiconductor substrate within the chamber of an atomic layer deposition apparatus; sequentially supplying a first precursor gas and a second precursor gas into the chamber, the first precursor gas comprising water and a hydrophilic reactant, and the second precursor gas comprising water and a hydrophilic reactant; purging an inert gas into the chamber; and returning the first and second precursor gases to the chamber in sequence, until a specified material film of a predetermined thickness is obtained, the film comprising at least a metal oxide, a metal nitride, and an organic film.

[0064] It should be noted that "purging inert gas into the chamber" in the above steps can be replaced with: the inert gas can be continuously purged throughout the entire atomic layer deposition process.

[0065] For substrates with multiple regions possessing different surface chemical compositions, ALDs can achieve regioselectivity by leveraging the regio-dependent characteristics of precursor adsorption / desorption properties, which allows for nucleation delays between unwanted and target regions. Therefore, to amplify surface differences, additional chemical treatments (e.g., self-assembled monolayers) are typically introduced to tune the affinity of local molecules.

[0066] The first precursor gas and the second precursor refer to gases that are input through multiple pulses to delay the reaction time. These gases include water and hydrophilic reactants, such as trimethylaluminum, triethylaluminum, titanium tetrachloride, or tetra(dimethylamino)hafnium. The first and second precursor gases can deposit to form the specified material. For clarity, an example is given below, but the specific scheme and materials are not limited to those mentioned in the example. For instance, the first and second precursor gases are trimethylaluminum and water. The first and second precursor gases are alternately pulsed into the reaction chamber, and after 100 cycles, an alumina film (the specified material) approximately 11 nm thick is obtained.

[0067] Inert gases, including but not limited to nitrogen, argon, and helium, are purged into the chamber to remove any residual reaction gases or byproducts.

[0068] In this embodiment, the process cycle consists of sequential delivery of a first precursor gas and a second precursor gas, followed by purging with a passive gas. After multiple cycles, a thin film of a predetermined target thickness is obtained.

[0069] In one possible implementation provided by this application, after depositing the specified material onto the liquid-sealed mask, the process further includes ultrasonically cleaning and immersing the deposited liquid-sealed mask and semiconductor substrate in a perfluorohexane solution to obtain a substrate with atomic layer deposition film patterning.

[0070] In this embodiment, the cleaning solvents selected include toluene, acetone, tetrahydrofuran, cyclohexane, etc., with organic solvents that are compatible with the liquid barrier layer being preferred.

[0071] To make things clearer, examples are given below, but the specific methods and materials are not limited to those mentioned in the examples. For instance, after depositing an alumina film, the substrate is immersed in a perfluorohexane solution and sonicated for 15 minutes to thoroughly remove residual oil from the surface, resulting in a substrate with an ALD film pattern.

[0072] The present invention will be further illustrated by the following non-limiting specific embodiments.

[0073] Example 1

[0074] A single-crystal silicon wafer was used as the substrate for atomic layer deposition (ALD). The single-crystal silicon (with a natural oxide layer of about 2 nm on the surface) was placed in the plasma cleaning chamber for hydroxylation treatment. The plasma gas source was oxygen, and the cleaning time was 3 minutes. The physical mask was then ultrasonically cleaned three times with acetone and isopropanol respectively. The physical mask was then dried in an oven for 5 minutes. After removal, a perfluoropolyether solution was uniformly coated onto the surface of the mask using a coater. The mask with the oil film was attached to the single-crystal silicon wafer and placed in an ALD device for deposition of alumina film. Trimethylaluminum and water were used as precursors, with a pulse time of 100 ms and a purge time of 60 s. Nitrogen was used as the purge gas at a flow rate of 150 sccm. The reaction chamber pressure was approximately 150 mTorr, and the chamber temperature was 120 °C. The precursors were alternately pulsed into the reaction chamber, and after 100 cycles, an alumina film of approximately 11 nm thickness was obtained. After the ALD process is completed, the sample is removed and rinsed with an organic solvent to separate the physical mask from the silicon substrate. The silicon wafer with deposited alumina film is then immersed in a perfluorohexane solution and ultrasonically cleaned for 15 minutes to remove residual oil stains on the surface, resulting in a silicon substrate with a clear alumina film pattern.

[0075] Comparative Example 1

[0076] A single-crystal silicon wafer was used as the substrate for atomic layer deposition (ALD). The wafer (with a natural oxide layer of approximately 2 nm on its surface) was placed in a plasma cleaning chamber for hydroxylation treatment using oxygen as the plasma gas source for 3 minutes. The physical mask was then ultrasonically cleaned three times with acetone and isopropanol. The physical mask was then dried in an oven for 5 minutes. After removal, the mask was placed directly onto the single-crystal silicon wafer and placed in an ALD apparatus for alumina film deposition. Trimethylaluminum and water were used as precursors, with pulse durations of 100 ms and purge times of 60 s. Nitrogen was used as the purge gas at a flow rate of 150 sccm. The reaction chamber pressure was approximately 150 mTorr, and the chamber temperature was 120°C. The precursors were alternately pulsed into the reaction chamber, and after 100 cycles, an alumina film approximately 11 nm thick was obtained. After the ALD process, the sample was removed, revealing the alumina film pattern on the silicon substrate.

[0077] Reference Figure 4 , Figure 4 Figure 1 shows the substrate image and XPS spectrum of the corresponding region on the substrate after atomic layer deposition using the prior art and the region-selective deposition method provided in this application, respectively. Figure 2a shows the XPS spectrum of Comparative Example 1, and Figure 3b shows the XPS spectrum of Example 1.

[0078] After characterization by photoelectron spectroscopy (XPS), no aluminum element was found on the surface coated with the liquid sealing layer, while aluminum element was found on the surface without the covering layer. The barrier rate of the liquid sealing method after growth in Example 1 can reach more than 99%, indicating that the addition of the liquid sealing layer can effectively block the atomic layer deposition in non-ideal areas.

[0079] Example 2

[0080] A single-crystal silicon wafer was used as the substrate for atomic layer deposition (ALD). The single-crystal silicon (with a natural oxide layer of about 2 nm on the surface) was placed in a plasma cleaning chamber for hydroxylation treatment. The plasma gas source was oxygen, and the cleaning time was 3 minutes. The physical mask was then ultrasonically cleaned three times with acetone and isopropanol respectively. The physical mask was then dried in an oven for 5 minutes. After removal, a vacuum pump oil solution was used to uniformly cover the surface of the mask by spin coating. The mask with the oil film was attached to the single-crystal silicon wafer and placed in an ALD device for the deposition of a hafnium oxide thin film. Tetra(dimethylamino)hafnium and water were used as precursors, with a pulse time of 100 ms and a purge time of 90 s. Nitrogen was used as the purge gas at a flow rate of 150 sccm. The reaction chamber pressure was approximately 150 mTorr, and the chamber temperature was 150 °C. The precursors were alternately pulsed into the reaction chamber, and after 100 cycles, a hafnium oxide thin film with a thickness of approximately 15 nm was obtained. After the ALD process is completed, the sample is removed and rinsed with an organic solvent to separate the physical mask from the silicon substrate. The silicon wafer after the alumina film is deposited is then immersed in a toluene solution and ultrasonically cleaned for 15 minutes to remove residual oil stains on the surface, resulting in a silicon substrate with a clear hafnium oxide film pattern.

[0081] Reference Figure 5 , Figure 5 The EDS energy spectrum of hafnium oxide thin films deposited using the method of this application is shown. The method in this embodiment can effectively achieve small-sized and highly accurate hafnium oxide ALD thin film patterns. Under the same conditions, the traditional mask method cannot obtain thin film patterns of this size and accuracy.

[0082] Example 3

[0083] A single-crystal silicon wafer was used as the substrate for atomic layer deposition (ALD). The single-crystal silicon (with a natural oxide layer of about 2 nm on the surface) was placed in a plasma cleaning chamber for hydroxylation treatment. The plasma gas source was oxygen, and the cleaning time was 3 minutes. The physical mask was then ultrasonically cleaned three times with acetone and isopropanol respectively. The physical mask was then dried in an oven for 5 minutes. After removal, a silicone oil solution was uniformly coated onto the mask surface using a vacuum pump and a scraping method. The mask with the oil film was attached to the single-crystal silicon wafer and placed in an ALD device for titanium dioxide film deposition. Tetra(dimethylamino)titanium and water were used as precursors, with a pulse time of 100 ms and a purge time of 80 s. Nitrogen was used as the purge gas at a flow rate of 1000 sccm. The reaction chamber pressure was approximately 150 mTorr, and the chamber temperature was 120 °C. The precursors were alternately pulsed into the reaction chamber, and after 100 cycles, a titanium dioxide film with a thickness of approximately 13 nm was obtained. After the ALD process is completed, the sample is removed and rinsed with an organic solvent to separate the physical mask from the silicon substrate. The silicon wafer with deposited titanium dioxide film is then immersed in toluene solution and ultrasonically cleaned for 15 minutes to remove residual oil stains on the surface, resulting in a silicon substrate with a clear titanium dioxide film pattern.

[0084] Reference Figure 6 , Figure 6 The EDS spectrum of the titanium dioxide thin film deposited using the method of this application is shown. The method in this embodiment can effectively achieve small-sized and highly accurate titanium dioxide ALD thin film patterns. Under the same conditions, the traditional mask method cannot obtain thin film patterns of this size and accuracy.

[0085] Example 4

[0086] A monocrystalline silicon wafer was used as the substrate for thermal evaporation. The monocrystalline silicon (with a natural oxide layer of about 2 nm on the surface) underwent standardized RCA cleaning. The physical mask was ultrasonically cleaned three times with acetone and isopropanol respectively. The physical mask was then dried in an oven for 5 minutes. After removal, a perfluoropolyether solution was uniformly applied to the surface of the mask using a coater. The mask with the oil film was attached to the monocrystalline silicon wafer and placed in a thermal evaporation apparatus for copper deposition. The reaction chamber pressure was approximately 10⁻⁶ mTorr. After 10 minutes of deposition, a copper film of approximately 30 nm thickness was obtained. After the thermal evaporation process, the sample was removed and rinsed with an organic solvent to separate the physical mask from the silicon substrate. The silicon wafer with the deposited alumina film was then immersed in a perfluorohexane solution and ultrasonically cleaned for 15 minutes to remove residual oil, resulting in a silicon substrate with a clearly patterned copper film.

[0087] Comparative Example 2

[0088] A monocrystalline silicon wafer was used as the substrate for thermal evaporation. The monocrystalline silicon (with a natural oxide layer of about 2 nm on the surface) underwent standardized RCA cleaning. The physical mask was ultrasonically cleaned three times with acetone and isopropanol respectively. The physical mask was then dried in an oven for 5 minutes. After removal, the mask was attached to the monocrystalline silicon wafer and placed in a thermal evaporation apparatus for copper deposition. The reaction chamber pressure was approximately 10⁻⁶ mTorr. After 10 minutes of deposition, a copper film of approximately 30 nm thickness was obtained. After the thermal evaporation process was completed, the sample was removed, yielding a silicon substrate with a copper film pattern.

[0089] Reference Figure 7 , Figure 7 The document includes Figure a, Figure b, and Figure c. Figure a is a photomicrograph of the photomask, Figure b is an electron microscope image of the substrate after thermal evaporation using existing technology, and Figure c is an electron microscope image of the substrate after thermal evaporation using the method of this application. By comparing Figure a, Figure b, and Figure c, the electron microscope image of the substrate obtained by the method of this application has a clearer outline.

[0090] Example 5

[0091] A single-crystal silicon wafer was used as the substrate for magnetron sputtering. The single-crystal silicon (with a natural oxide layer of about 2 nm on the surface) underwent standardized RCA cleaning. The physical mask was ultrasonically cleaned three times with acetone and isopropanol respectively. The physical mask was then dried in an oven for 5 minutes. After removal, a perfluoropolyether solution was uniformly coated onto the surface of the mask using a coater. The mask with the oil film was attached to the single-crystal silicon wafer and placed in a magnetron sputtering apparatus to deposit an ITO film. The RF power was 100W, the argon flow rate was 50 sccm, and the ITO film deposition rate was approximately 5.2 nm / min. After 8 minutes of deposition, an ITO film with a thickness of approximately 42 nm was obtained. After the magnetron sputtering process, the sample was removed and rinsed with an organic solvent to separate the physical mask from the silicon substrate. The silicon wafer with the deposited ITO film was immersed in a perfluorohexane solution and ultrasonically cleaned for 15 minutes to remove residual oil, resulting in a silicon substrate with a clear ITO film pattern.

[0092] Comparative Example 3

[0093] A single-crystal silicon wafer was used as the substrate for magnetron sputtering. The single-crystal silicon (with a natural oxide layer of about 2 nm on the surface) underwent standardized RCA cleaning. The physical mask was ultrasonically cleaned three times with acetone and isopropanol respectively. The physical mask was then dried in an oven for 5 minutes. After removal, the mask was attached to the single-crystal silicon wafer and placed in a magnetron sputtering apparatus for ITO film deposition. The RF power was 100W, the argon flow rate was 50 sccm, and the ITO film deposition rate was approximately 5.2 nm / min. After 8 minutes of deposition, an ITO film with a thickness of approximately 42 nm was obtained. After the magnetron sputtering process was completed, the sample was removed, resulting in a silicon substrate with an ITO film pattern.

[0094] Reference Figure 8 , Figure 8 The document includes Figures a, b, and c. Figure a is a photomicrograph of the photomask, Figure b is an electron microscope image of the substrate after magnetron sputtering using existing technology, and Figure c is an electron microscope image of the substrate after magnetron sputtering using the method of this application. By comparing Figures a, b, and c, the electron microscope image of the substrate obtained using the method of this application has a clearer outline.

[0095] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for regionally selective deposition, characterized in that, include: Obtain a semiconductor substrate; A liquid sealing layer is constructed on one side of the mask, and the end with the liquid sealing layer is placed on the semiconductor substrate to form a liquid-sealed mask. Deposit the specified material onto the liquid-sealed mask plate; The liquid sealing layer comprises long-chain alkane oil or perfluoropolyether obtained by crude oil fractionation and / or dearomatization, wherein the long-chain alkane oil has a carbon number greater than or equal to six and less than sixteen.

2. The method for regional selective deposition as described in claim 1, characterized in that, The thickness of the liquid sealing layer is not less than the maximum gap between the mask and the semiconductor substrate.

3. The method for regional selective deposition as described in claim 1 or 2, characterized in that, The semiconductor substrate is obtained by hydrophilic hydroxylation treatment, and the hydrophilic hydroxylation treatment step includes: Semiconductor substrate after plasma treatment and gas cleaning; The plasma treatment gas is an argon-oxygen mixture, the excitation frequency is 13-15 MHz, and the treatment time is 3-5 min.

4. The method for regional selective deposition as described in claim 3, characterized in that, The step of depositing the specified material onto the liquid-sealed mask includes: The liquid-sealed mask and the semiconductor substrate are placed in the chamber of the atomic layer deposition apparatus; A first precursor gas and a second precursor gas are sequentially delivered into the chamber. The first precursor gas includes water and a hydrophilic reactant, and the second precursor gas includes water and a hydrophilic reactant. Purge inert gas into the chamber; The process continues with the first precursor gas and the second precursor gas being sequentially delivered into the chamber until a specified material film of a predetermined thickness is obtained, wherein the film comprises at least metal oxides, metal nitrides, and organic films.

5. The method for regional selective deposition as described in claim 4, characterized in that, The deposition is performed using atomic layer deposition, magnetron sputtering deposition, physical vapor deposition, or chemical vapor deposition.

6. The method for regional selective deposition as described in claim 4 or 5, characterized in that, Following the step of depositing the specified material onto the liquid-sealed mask, the method further includes: The liquid-sealed mask and the semiconductor substrate after deposition are ultrasonically cleaned and immersed in a perfluorohexane solution to obtain a substrate with atomic layer deposition thin film patterning.

7. The method for regional selective deposition as described in claim 6, characterized in that, The liquid sealing layer is constructed using either a scraping or spin coating method.

8. The method for regional selective deposition as described in any one of claims 4, 5, or 7, characterized in that, Prior to the step of hydrophilic hydroxylation treatment of the semiconductor substrate, the method further includes cleaning the semiconductor substrate and the mask in different solutions respectively.

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