Substrate surface modifier for atomic layer deposition and chemical vapor deposition and method for modifying substrate surface using the same

Abstract

The present invention discloses a surface modifier for uniformly modifying the surface of a substrate, such as an inorganic thin film, using atomic layer deposition or chemical vapor deposition, and a method for modifying a substrate surface using the same.

Description

[Technical field]

[0001] Cross-reference to related application(s) This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0143703 filed on November 11, 2019 and Korean Patent Application No. 10-2020-0145671 filed on November 4, 2020, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a substrate surface modifier and a method for modifying a substrate surface using the same, and more particularly to a surface modifier for modifying a substrate surface such as an inorganic thin film using atomic layer deposition or chemical vapor deposition, and a method for modifying a substrate surface using the same. [Background technology]

[0003] Highly developed semiconductor manufacturing processes involve numerous operations to form thin films with various physical properties and shapes and to remove the formed thin films partially or entirely. Many characteristics must be considered when forming thin films. For example, ensuring the bonding strength between thin films made of different materials is essential in manufacturing semiconductor devices. Specifically, when sufficient bonding strength between adjacent organic and inorganic films is required, such as in photolithography processes, the surface of the inorganic film must be coated with a bonding promoter such as hexamethyldisilazane (HMDS) to increase the bonding strength between the inorganic film and the organic film. In the process of modifying such inorganic films, a modifier is generally applied to the surface of the inorganic film by a spin coating method. However, if a modifier is applied to the surface of the inorganic film using a conventional coating process, there is a limitation in that it is difficult to obtain a modified thin film with a uniform thickness and high density due to the characteristics of the process. Recently, as semiconductor processes continue to be miniaturized, the standards for the processes and materials used are becoming stricter, and therefore it is necessary to develop a new process that can ensure the process margin.

[0004] Meanwhile, in recent thin film deposition processes, atomic layer deposition (ALD) or chemical vapor deposition (CVD) are increasingly being introduced as high-quality thin film deposition is required to precisely adjust the thickness of the thin film and accommodate complex shapes. When surface modification is required for a thin film deposited by atomic layer deposition or chemical vapor deposition, a process is performed in which the substrate on which the thin film has been deposited is transferred to a separate modification layer deposition equipment (track process) to deposit a modification layer. This process is complicated and requires the substrate to be moved from the ALD or CVD equipment to the modification layer deposition equipment, which can result in problems such as time consumption and substrate contamination.

[0005] In addition, to modify the substrate, a track process such as spin coating is performed to form an organic polymer film on the substrate. However, since the existing organic polymer film for surface modification is a physical surface modification method, there are limitations to the surface modification and fine tuning is difficult.

[0006] In addition, liquid polymer compounds are mainly used as compounds for surface modification in conventional CVD / ALD processes, but the liquid polymer compounds have low volatility and high viscosity, which not only makes it impossible to carry out the CVD / ALD process, but also damages the equipment, making it impossible to carry out the process itself. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a substrate surface modifier for atomic layer deposition and chemical vapor deposition, which can modify the surface of a substrate more uniformly and can more easily control the substrate surface modification process, and a method for modifying a substrate surface using the same.

[0008] Another object of the present invention is to provide a substrate surface modifier for atomic layer deposition or chemical vapor deposition, which allows a thin film deposition process by atomic layer deposition or chemical vapor deposition and a subsequent surface modification process to be performed in one step using the same equipment, and a method for modifying a substrate surface using the same. [Means for solving the problem]

[0009] The present specification provides a substrate surface modifier for atomic layer deposition or chemical vapor deposition, represented by the following Chemical Formula 1: [Chemical formula 1] JPEG0007614215000001.jpg32170

[0010] In the above Chemical Formula 1, X is Si, Ge, Ti, W, Co, Al, Ni, Ru, Cu, Ta, Sn, Hf, La, Mn, Ga, In, or Zr; L1, L2, L3 and L4 are each independently a ligand of X, at least one of L1, L2, L3 and L4 includes a functional group that modifies the surface of the substrate, and at least another of L1, L2, L3 and L4 includes a functional group that binds to the surface of the substrate.

[0011] The present invention also provides a method for forming a surface-modified layer on a surface of a substrate by disposing a substrate in a deposition chamber and supplying a gaseous substrate surface modifier to the deposition chamber; and supplying a purge gas to the deposition chamber to remove excess of the substrate surface modifier. Effect of the Invention

[0012] According to the substrate surface modifier for atomic layer deposition or chemical vapor deposition and the method for modifying a substrate surface using the same, the substrate surface can be modified more uniformly and the substrate surface modification process can be more easily controlled.

[0013] In addition, the present invention can easily form a surface modification layer on an inorganic film instead of an organic polymer film for surface modification implemented by the existing spin coating, etc. Furthermore, the present invention can improve processability by applying a half cycle process instead of the conventional full cycle process during atomic layer deposition and chemical vapor deposition processes by using a highly volatile monomolecular compound as a surface modification agent.

[0014] In addition, according to the present invention, a thin film deposition process using atomic layer deposition or chemical vapor deposition and a subsequent surface modification process can be continuously performed in one step using the same equipment. [Brief description of the drawings]

[0015] [Figure 1] 1 is a view illustrating a state in which a substrate is modified using a substrate surface modifier according to the present invention; [Diagram 2] 1 is a view illustrating a method for modifying a substrate surface using a substrate surface modifier according to the present invention. [Diagram 3] 1 is a photograph showing experimental results of water contact angle with respect to a silicon substrate. [Figure 4] 1 is a graph showing experimental results of water contact angle depending on the number of depositions of a substrate surface modifier according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the surface modifier and the method for modifying a substrate surface using the same of the present invention will be described in detail with reference to the accompanying drawings.

[0017] The terms used in this specification are merely used to describe exemplary embodiments and are not intended to limit the present invention. A singular expression includes a plural expression unless otherwise clearly indicated in the context.

[0018] In this specification, the terms "comprise", "include", "comprise" or "have" are intended to specify the presence of embodied features, numbers, steps, components, or combinations thereof, and should be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, components, or combinations thereof.

[0019] The present invention can be modified in various ways and can have various forms, and will be described in detail below by taking specific examples as examples. However, this is not intended to limit the present invention to the specific disclosed form, but it should be understood that the present invention includes all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention.

[0020] In addition, in this specification, the contact angle means the contact angle of the substrate surface with water. That is, the contact angle can be measured by the static contact angle method using an image digital contact angle analyzer (DSA100 by KRUSS) to measure the contact angle of 3 μl of water (ultrapure water) on the outermost surface of the substrate or thin film to be measured.

[0021] In addition, in this specification, a full cycle may mean performing a four-step process of precursor supply, purging, reactant supply, and purging in a deposition chamber during an atomic layer deposition or chemical vapor deposition process (CVD / ALD process).

[0022] In addition, in this specification, a half cycle may mean performing a two-step process of supplying a substrate surface modifier to form a surface modification layer in a deposition chamber containing a thin film (substrate) to be surface modified; and supplying a purge gas to remove excess substrate surface modifier.

[0023] First, the present specification provides a substrate surface modifier for atomic layer deposition or chemical vapor deposition represented by Chemical Formula 1. [Chemical formula 1] JPEG0007614215000002.jpg32170

[0024] In the above Chemical Formula 1, X is Si, Ge, Ti, W, Co, Al, Ni, Ru, Cu, Ta, Sn, Hf, La, Mn, Ga, In, or Zr; L1, L2, L3 and L4 are each independently a ligand of X, at least one of L1, L2, L3 and L4 includes a functional group that modifies the surface of the substrate, and at least another of L1, L2, L3 and L4 includes a functional group that binds to the surface of the substrate.

[0025] When using existing organic polymer films for surface modification, there are limitations to the physical surface modification method.

[0026] Therefore, the present invention provides a monomolecular compound (precursor) represented by the above formula 1, which can be easily realized as an inorganic film, as a surface modifier for a substrate. In addition, the surface modifier of the present invention is used not only for the existing simple thin film application, but also for the application of modifying the substrate surface to be hydrophobic or hydrophilic.

[0027] Another feature of the present invention is to provide a novel surface modification method that utilizes a half-cycle process during atomic layer deposition or chemical vapor deposition (CVD / ALD) process rather than a spin coating process.

[0028] That is, in semiconductor manufacturing, CVD / ALD processes are generally full cycles, and such full cycle processes are not used for surface modification but for simple thin film deposition processes such as SiO2 or SiN.

[0029] However, the present invention has an advantage that the surface modification can be easily applied to an inorganic film by using the surface modifier of Formula 1 and performing the surface modification through a half cycle process that is a partial modification of the CVD / ALD process, rather than a simple thin film deposition.

[0030] The substrate surface modifier for atomic layer deposition or chemical vapor deposition of Formula 1 according to the present invention is a compound that is deposited on the surface of a substrate by atomic layer deposition (ALD) or chemical vapor deposition (CVD) to change the surface properties of the substrate. In addition, the substrate surface modifier of Formula 1 is a monomolecular compound in the form of a gas phase, and can be used in atomic layer deposition or chemical vapor deposition applications as described above.

[0031] In addition, the substrate surface modifier can adjust the surface contact angle (°) including the surface modification layer depending on the degree of hydrophilicity or hydrophobicity of the surface modification target. Specifically, the substrate surface modifier can adjust the surface contact angle of the substrate including the surface modification layer to be 50° or more depending on the degree of hydrophilicity or hydrophobicity of the surface modification target. In addition, the substrate surface modifier can adjust the surface contact angle of the substrate including the surface modification layer to be less than 50°. In other words, the substrate surface modifier can variably adjust the surface contact angle depending on the properties of the substrate, and can adjust the degree of hydrophobicity of the substrate.

[0032] Specifically, when the substrate surface modifier is used to make the surface contact angle of a substrate including a surface modification layer less than 50°, the contact angle can be adjusted to be less than 50°, or between 15° and 50°, or less than 15°, or between 5° and 15°.

[0033] Furthermore, when the substrate surface modifier is to have a surface contact angle of 50 degrees or more on a substrate including a surface modification layer, the contact angle can be adjusted to be 50° or more, or 50° to 75°, or 75° to 90°, or 90° to 130°.

[0034] Therefore, when the substrate surface modifier is used, the substrate surface can be selectively modified to be hydrophobic, whether the substrate surface is highly hydrophilic, low hydrophobic, intermediate hydrophobic, or highly hydrophobic. In other words, the substrate can be adjusted to a desired level within the range of hydrophilicity to hydrophobicity.

[0035] The surface modifier of the present invention can also improve the adhesion between the substrate and the photoresist.

[0036] Specifically, in the substrate surface modifier represented by Chemical Formula 1, L1, L2, L3, and L4 are each independently a ligand of X, and the functional group that modifies the substrate surface may be a ligand that modifies the substrate surface to be hydrophobic or hydrophilic.

[0037] The ligands of X, L1, L2, L3 and L4, may each independently be hydrogen (H); halogen, specifically I; a hydrocarbon group having 1 to 10 carbon atoms, specifically a hydrocarbon group having 1 to 6 carbon atoms; an alkoxy group having 1 to 10 carbon atoms, specifically an alkoxy group having 1 to 6 carbon atoms; or an alkylamino group having 1 to 10 carbon atoms, specifically an alkylamino group having 1 to 6 carbon atoms.

[0038] In addition, L1, L2, L3, and L4 may be the same or different from each other. Specifically, L1, L2, L3, and L4 may be the same or at least one may be different from each other. More specifically, at least one of L1, L2, L3, and L4 may have another surface modifying functional group to further optimize the performance as a surface modifier and modify the substrate surface to be hydrophobic or hydrophilic.

[0039] The halogen may be F, Cl, Cr, I, or the like, and more specifically may be I.

[0040] The hydrocarbon group may include an aliphatic or aromatic hydrocarbon, and examples thereof include an alkyl group, an alkenyl group, a cyclopentadienyl group, an aryl group, etc. More specific examples of the hydrocarbon group include an iso-butyl group, an n-butyl group, a vinyl group, an allyl group, a phenyl group, a benzyl group, a cyclopentadienyl group, etc.

[0041] The hydrocarbon group may be substituted with a halogen atom, specifically, the hydrocarbon of an alkyl group, an alkenyl group, or an aryl group may be substituted with a halogen atom, specifically, F. In such a case, examples of the hydrocarbon group include -CF3 or pentafluorophenyl (-PhF5).

[0042] Examples of the alkoxy group include a methoxy group and an ethoxy group, and examples of the alkylamino group include a dimethylamine group, a diethylamine group, and a diisopropylamine group.

[0043] The ligand of X can be exemplified by a ligand that modifies the surface of the substrate to be hydrophobic or hydrophilic, a ligand that increases the adhesive strength between the substrate and the photoresist, and the like.

[0044] Specifically, at least one of L1, L2, L3, and L4 may be a hydrocarbon group having 1 to 10 carbon atoms, and at least one of the others may be an alkylamino group having 1 to 10 carbon atoms. In this case, the ligand of the surface modifier contains at least one hydrocarbon group and at least one alkylamino group as hydrophobic functional groups, and a substrate having high hydrophobicity, for example, a substrate having a contact angle of 50° or more, 75° to 90°, or 90° to 130°, can be provided.

[0045] At least one of L1, L2, L3, and L4 may be a hydrocarbon group having 1 to 10 carbon atoms, and at least one of the others may be a halogen. In this case, the ligand of the surface modifier may contain at least one hydrocarbon group as a hydrophobic functional group and at least one halogen as a hydrophilic functional group, thereby providing a substrate with intermediate hydrophobicity, for example, a substrate with a contact angle of 15° or more or 15° to 75°.

[0046] All of L1, L2, L3, and L4 may be a hydrocarbon group having 1 to 10 carbon atoms, or all of L1, L2, L3, and L4 may be an alkoxy group having 1 to 10 carbon atoms. In this case, the ligand of the surface modifier is contained as a hydrophobic functional group, and a highly hydrophobic substrate, for example, a substrate having a contact angle of 50° or more or 75° to 90°, can be provided.

[0047] At least one of the hydrocarbon groups may be a hydrocarbon group substituted with a halogen atom, specifically a hydrocarbon group substituted with F. In this case, a substrate with high hydrophobicity can be provided.

[0048] At least one of L1, L2, L3 and L4 may be an alkylamino group and the rest may be hydrogen. In this case, the ligand of the surface modifier may contain at least one alkylamino group or hydrogen as a hydrophobic functional group to provide a substrate with intermediate hydrophobicity, for example a substrate with a contact angle of 15° to 50° or 50° to 75°.

[0049] Also, as mentioned above, X can be Si, Ge, Ti, W, Co, Al, Ni, Ru, Cu, Ta, Sn, Hf, La, Mn, Ga, In, or Zr, and more specifically, X can be Si.

[0050] The composition of Formula 1 can further improve the effect of modifying the surface of a substrate and improving adhesion to the substrate, and can provide a desired surface contact angle with respect to the substrate as well as an excellent surface modification effect of the substrate. Furthermore, the surface modifier including the ligand of Formula 1 can maintain the durability of the modification effect even when exposed to moisture in the air for 24 hours or more.

[0051] For example, when a highly hydrophilic oxide film, nitride film, or oxynitride film is to be modified to be hydrophobic, a ligand can be selected depending on the required degree of hydrophobicity of the substrate surface.

[0052] If a substrate with low hydrophobicity is required (contact angle with water less than 15°, see examples for method of measuring contact angle), the surface modification ligand can contain halogens such as Cl, Br, or I as hydrophilic functional groups.

[0053] If a substrate with intermediate hydrophobicity is desired (i.e., a contact angle with respect to water of 15° or more and less than 75°), the surface modification ligand can include a functional group such as hydrogen (H); an alkoxy group having 1 to 6 carbon atoms; or an alkylamino group having 1 to 6 carbon atoms.

[0054] In this case, the alkoxy group having 1 to 6 carbon atoms includes methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, t-butoxy, sec-butoxy, cyclopentyloxy, cyclohexyloxy, etc. The alkylamino group having 1 to 6 carbon atoms includes dimethylamino, diethylamino, methylethylamino, di-n-propylamino, di-isopropylamino, di-t-butylamino, di-sec-butylamino, di-n-butylamino, methylamino, ethylamino, n-propylamino, isopropylamino, n-butylamino, sec-butylamino, t-butylamino, etc.

[0055] In addition, when a highly hydrophobic substrate is required (i.e., a contact angle with respect to water of 75° or more), the surface modifying ligand can contain a hydrophobic functional group such as F (halogen); an alkyl group having 1 to 10 carbon atoms, specifically 1 to 6 carbon atoms; an alkenyl group having 1 to 10 carbon atoms, specifically 1 to 6 carbon atoms; a cyclopentadienyl group; or an aryl group having 6 to 10 carbon atoms. The alkyl group having 1 to 10 carbon atoms includes methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, sec-butyl, t-butyl, n-pentyl, sec-pentyl, iso-pentyl, cyclohexyl, and the like. The alkenyl group having 1 to 10 carbon atoms includes vinyl, allyl, and the like. The aryl group having 6 to 10 carbon atoms includes phenyl, benzyl, and the like.

[0056] An example of the surface modifier represented by the above formula 1 is (dimethylamino)trimethylsilane (DMA-Si(Me)3). 、( Diethylamino)dimethyl ( ethyl ) Silane (( diethylamino)dimethyl (ethyl) silane, Et-Si(N Et 2)(Me)2) (Chemical formula 1c) , (diethylamino)trimethylsilane (DEA-Si(Me)3), tris(dimethylamino)phenylsilane (Ph-Si(N(Me)2)3), (dimethylamino)dimethoylphenylsilane (Ph-Si(OMe)2(NMe2)), di(isobutyl)(dimethylamino)phenylsilane (Ph-Si(sBu)2(NMe2)), dibutyl(dimethylamino)vinylsilane (Vinyl-Si( nBu)2(NMe2), vinyl(dimethylamino)dimethoxysilane, Vinyl-Si(OMe)2(NMe2), n-Butyl Ru ( Dimethylamino) Dimethoxy Silane (n-buty l( dimethylamino) Dimethoxy Silane , nBu- Si(OMe)2(NMe2), methyltriiodosilane (CH3-Si-I3), vinyltriiodosilane (CH2=CH-Si-I3), trimethyl(trifluoromethyl)silane (CF3-Si-(Me)3), trimethyl(pentafluorophenyl)silane (F5Ph-SiMe3), tris(dimethylamino)(cyclopentafluorophenyl)silane (F5Ph-SiMe3), Examples include tris(dimethylamino)(cyclopentadienyl)zirconium (Zr(C5H5)(N(Me)2)3), tetrakis(dimethylamino)hafnium(IV) (Hf(N(Me)2)4), tetramethylorthosilicate (Si(OMe)4), and tetraethylorthosilicate (Si(OCH2CH3)4).

[0057] More specifically, the surface modifier represented by the chemical formula 1 includes (diethylamino)trimethylsilane (DEA-Si(Me)3), tris(dimethylamino)phenylsilane (Ph-Si(N(Me)2)3), (dimethylamino)dimethoxyphenylsilane (Ph-Si(OMe)2(NMe2)), di(isobutyl)(dimethylamino)phenylsilane (Ph-Si(sBu)2(NMe2)), dibutyl(dimethylamino)vinylsilane (dibutyl(dimethylamino)vinylsilane, Vinyl-Si( nBu )2(NMe2), vinyl(dimethylamino)dimethoxysilane, Vinyl-Si(OMe)2(NMe2), n-Butyl Ru ( Dimethylamino) Dimethoxy Silane (n-buty l( dimethylamino) Dimethoxy Silane , nBu -Si(OMe)2(NMe2), methyltriiodosilane (CH3-Si-I3), vinyltriiodosilane (CH2=CH-Si-I3), trimethyl(trifluoromethyl)silane (CF3-Si-(Me)3), or trimethyl(pentafluorophenyl)silane (F5Ph-SiMe3).

[0058] Such exemplary compounds can effectively form a surface modification layer on the substrate, modifying the required substrate to be hydrophobic or hydrophilic, realizing an excellent surface contact angle on the substrate, and improving the adhesive strength between the substrate and the photoresist. In addition, the compounds can easily modify the substrate surface for inorganic films.

[0059] The substrate surface modifier and the substrate surface modifying method using the same of the present invention will be described in more detail below with reference to the drawings.

[0060] FIG. 1 is a diagram illustrating a state in which a substrate is modified using a substrate surface modifier according to the present invention.

[0061] As shown in Fig. 1, a modified layer 12 may be located on the surface of a substrate 10 as required, and a surface modification layer 14 may be located on the upper surface of the substrate 10 or the modified layer 12. That is, the surface-modified substrate of the present invention may include a surface modification layer formed on a substrate; or a surface modification layer may be included on the upper surface of a modified layer formed on the substrate, and more preferably, a surface modification layer may be formed on a modified layer as in the configuration of Fig. 1.

[0062] The substrate 10 is any underlying material on which a device, circuit, or film may be formed. The modified layer 12 may be formed on the substrate 10 for various applications in semiconductor processing, and may be formed by deposition using atomic layer deposition or chemical vapor deposition, for example. In the present invention, the substrate or modified layer may be a thin film that requires surface modification.

[0063] Specifically, the surface modification layer 14 is a monolayer deposited by atomic layer deposition or chemical vapor deposition to impart a modification effect to the surface of the underlying modified layer 12, and is formed of a substrate surface modifier represented by Chemical Formula 1.

[0064] The substrate 10 or the modified layer 12 may be bonded to the substrate surface modifier by a chemical reaction or physical adsorption. In Fig. 1, X is as defined in Chemical Formula 1, L is a ligand L1, L2, L3 or L4 in Chemical Formula 1, and M is as defined for X in Chemical Formula 1. In Fig. 1, the modified layer 12 is shown as an oxide film, but the modified layer 12 is not limited thereto and may be a nitride film, an oxynitride film, or the like formed by an atomic layer deposition method. Next, a method for modifying a substrate surface using the substrate surface modifier according to the present invention will be described.

[0065] According to another embodiment of the present invention, there may be provided a method for modifying a substrate surface, comprising the steps of: placing a substrate in a deposition chamber, supplying a substrate surface modifier in gas form to the deposition chamber to form a surface modification layer formed of the substrate surface modifier on a surface of the substrate; and supplying a purge gas to the deposition chamber to remove excess substrate surface modifier.

[0066] In order to modify the surface of a substrate 10 according to the present invention, the steps of placing the substrate 10 in an atomic layer deposition or chemical vapor deposition chamber and then supplying the substrate surface modifier according to the present invention in gas form to the deposition chamber to form a surface modification layer 14 formed of the substrate surface modifier on the surface of the substrate 10 are included.

[0067] If necessary, a modified layer 12 such as an oxide layer, a nitride layer, or an oxynitride layer may be further formed on the substrate 10 by a conventional atomic layer deposition or chemical vapor deposition method.

[0068] The modified layer may be any one inorganic film selected from the group consisting of an oxide film, a nitride film, and an oxynitride film. Specifically, the modified layer may be an inorganic film such as SiO2, SiN, SiON, SnO2, HfO2, ZrO2, etc., and various other inorganic films may be used as the modified layer.

[0069] At this time, the step of forming the surface modification layer may include performing a deposition process at least once. Specifically, the deposition process of the surface modification agent may be repeated at least once so that the surface modification layer can completely cover the surface of the substrate or the layer to be modified. Specifically, the deposition process of the surface modification agent may be repeated 1 to 10 times. More specifically, the deposition process of the surface modification agent may be repeated 2 to 10 times or 3 to 10 times.

[0070] In addition, after the surface modification layer is formed, since the surface modification agent may remain after the surface modification reaction is completed, it is advisable to remove the excess substrate surface modification agent contained in the deposition chamber, for example, by injecting a purging inert gas into the deposition chamber to remove the excess substrate surface modification agent.

[0071] The modified layer may be formed on the substrate prior to forming the surface modification layer by well known methods.

[0072] FIG. 2 is a diagram illustrating a method for modifying a substrate surface using a substrate surface modifier according to the present invention.

[0073] Specifically, FIG. 2 shows a method for modifying a surface using the substrate on which the modification layer of FIG. 1 is formed.

[0074] Therefore, the method for modifying a substrate surface of the present invention includes the steps of forming a modified layer on a substrate; and forming a surface-modified layer on the modified layer by the above-mentioned method.

[0075] The method of forming the modified layer on the substrate prior to the substrate surface modification can be an atomic layer deposition method well known in the art, or the surface modification layer can be formed by the chemical vapor deposition method.

[0076] For example, in a typical atomic layer deposition method, a four-step process of precursor supply, purging, reactant supply, and purging (referred to as a full cycle in this specification) is performed to form a modified layer 12 in molecular layer units on a substrate 10. The thickness of the modified layer 12 can be adjusted by the number of times that the full cycle process is repeated.

[0077] The modified layer may be formed by an atomic layer deposition method including the steps of: adsorbing a substrate surface modifier for forming the modified layer on the top of a substrate positioned in the deposition chamber; supplying an inert purge gas to the deposition chamber to remove excess substrate surface modifier not adsorbed to the substrate; supplying a reactant to the deposition chamber that reacts with the substrate surface modifier to form the modified layer to form the modified layer; and supplying a purge gas again to the deposition chamber to remove unreacted reactant.

[0078] More specifically, in order to form the modified layer 12 by atomic layer deposition, as shown in the left side of FIG. 2, a substrate 10 is placed in a deposition chamber, and a precursor for forming the modified layer 12 is supplied as a first raw material to the deposition chamber, so that the precursor is adsorbed on the substrate 10. Next, an inert purge gas such as nitrogen (N2) or argon (Ar2) is supplied to the deposition chamber to remove the excess precursor that is not adsorbed on the substrate 10. Next, a second raw material (reactant) that reacts with the first raw material to form the modified layer 12, such as an oxide film, a nitride film, or an oxynitride film, is supplied to the deposition chamber to form the modified layer 12. The reactant varies depending on the type of precursor used and the thin film to be formed, and is generally a gas containing O, N, H, or the like, or a plasma generated using the same. Next, a purge gas is supplied again to the deposition chamber to remove the unreacted second raw material (reactant).

[0079] Furthermore, the method for forming a surface-modifying layer on a substrate layer does not include the above-mentioned four-step full cycle, but includes a two-step process of injecting a gaseous surface-modifying agent and a purge gas.

[0080] That is, the method for modifying a substrate surface according to the present invention is carried out in a two-step process (referred to as a half cycle in the present specification) of placing a substrate 10 in a deposition chamber, supplying a substrate surface modifier to form a surface modification layer 14 formed of the substrate surface modifier on the surface of the substrate 10 or the layer to be modified 12 as shown on the right side of FIG. 2, and then supplying a purge gas to the deposition chamber to remove excess substrate surface modifier. The half cycle may refer to the deposition process of the surface modifier described above. Therefore, the present invention can adjust the deposition degree and thickness of the surface modification layer 14 by the number of times the half cycle process is repeated. Such a half cycle process can be repeated 2 to 10 times, specifically 3 to 7 times.

[0081] On the other hand, if the deposition process of the surface modifier is completed in a full cycle in which a reactant is injected at the end, as in the case of conventional atomic layer deposition, there is a problem that the top layer of the surface, i.e., the modified layer 12, is formed in a state of low surface energy and high polarity due to the reactant.

[0082] On the other hand, if deposition of the surface modifier is completed in a half cycle, the ligand (L) of the substrate surface modifier does not react with the reactant and remains on the surface of the substrate 10. Therefore, by selecting an appropriate ligand (L), the surface of the substrate 10 can be modified, for example, by adjusting the surface energy and polarity.

[0083] Furthermore, the formation of the modified layer and the formation of the surface modified layer according to the present invention as described above can be carried out in a continuous process.

[0084] As described above, the present invention forms the surface modification layer 14 using atomic layer deposition or chemical vapor deposition, which are considered to be the most precise of the current thin film deposition methods, and therefore not only can a very uniform and dense monolayer surface modification layer 14 be obtained, but also has a superior surface modification effect compared to the existing surface modification agent coating method. In addition, since the modification target layer 12, which is the target of modification, is often formed by atomic layer deposition these days, the surface modification layer 14 can be continuously formed using the same atomic layer deposition equipment without the need to change equipment for forming the surface modification layer 14. Therefore, unnecessary external exposure of the substrate 10 can be prevented, and the associated advantages of time, cost, and quality can be obtained.

[0085] The present invention will be described in more detail with reference to the following specific examples. The following examples are provided to illustrate the present invention, and are not intended to limit the scope of the present invention.

[0086] [Example 1] SiO 2 Surface modification of thin films Using a 4-inch traveling-type atomic layer deposition equipment (CN-1), a relatively thick modified layer (10 nm) and a molecular-layer-thick surface modification layer (thin film stack) were sequentially deposited on a silicon substrate. To prevent moisture contamination due to exposure to the atmosphere and to simplify the process, the silicon substrate was constantly maintained inside the vacuum reactor chamber of the deposition equipment, and the deposition processes of the modified layer and surface modification layer were carried out one after the other in-situ. The specific deposition process is as follows:

[0087] First, a silicon substrate was treated with a 10 wt% HF aqueous solution for 1 minute to remove the naturally occurring oxide film on the surface, and then washed with distilled water and dried with nitrogen to prepare a substrate for atomic layer deposition. In order to form a SiO2 thin film as a modified layer, the substrate was placed in a reactor, and (1) diisopropylaminosilane (diisopropylaminosilane) was added as a silicon precursor for atomic layer deposition. [(iPr) 2 N]SiH 3 )A SiO2 thin film with a total thickness of 10 nm was deposited by sequentially repeating four unit processes: (1) injection of O3 gas as a reactant material, (2) inert gas (N2) purging to remove excess precursors and by-products, (3) injection of O3 gas as a reactant material, and (4) inert gas (N2) purging to remove excess reactants and by-products. The substrate temperature was maintained at 300°C, and the duration of each step and the purge gas flow rate were set according to the optimum conditions of the experimental equipment. No plasma was used as the energy source required for the deposition reaction, and only thermal energy from substrate heating was used.

[0088] After the deposition of the modified layer (SiO2 thin film) is completed, the substrate is kept in the vacuum reactor without being exposed to the outside, and the following chemical formulas 1a to 1b are added to the substrate. e Represented by 5 The surface modification layer was deposited using each of the above compounds as a surface modification agent. In the case of the surface modification agent, since only a single molecular layer was deposited, a half-cycle deposition of the surface modification agent injection and subsequent purging was performed, unlike the usual full four-step atomic layer deposition. This omits steps (3) and (4) out of the four steps of the modified layer deposition process. Since the deposition process of the surface modification layer is a self-limiting reaction, only a maximum of one molecular layer is formed at the top of the stack. The deposition process using the surface modification agent was repeated N times (N = 1, 3, 5, 10) to completely cover the surface of the modified layer. [Surface modifier: Example compound of Chemical Formula 1] JPEG0007614215000003.jpg98170

[0089] [Example 2] Surface modification of SiN thin films The surface of the SiN thin film was modified in the same manner as in Example 1, except that DIPAS and HCP (Hollow Cathode Plasma) NH3 plasma were used as the precursor and reactant, respectively, to deposit a 10 nm thick SiN thin film as the modified layer, and compounds represented by Formula 1b and Formula 1d were used as the surface modifiers.

[0090] [Example 3] Surface modification of SiON thin films A 10 nm-thick SiON thin film was deposited as a modified layer using DIPAS and ICP (Inductively Coupled Plasma) NH3 plasma as a precursor and a reactant, respectively, and the surface of the SiON thin film was modified in the same manner as in Example 1, except that compounds represented by Formula 1b and Formula 1d, respectively, were used as surface modifiers.

[0091] [Example 4] SiO 2 Surface modification of thin films The surface of the SiO2 thin film was modified in the same manner as in Example 1, except that a 10 nm-thick SiO2 thin film was deposited as the modified layer using tetrakis(dimethylamino)tin(IV) (TDMA-Sn) and H2O as the precursor and reactant, respectively, and the compounds represented by Chemical Formula 1b and Chemical Formula 1d, respectively, were used as the surface modifiers.

[0092] [Example 5] HfO 2 Surface modification of thin films The surface of the HfO2 thin film was modified in the same manner as in Example 1, except that a 10 nm-thick HfO2 thin film was deposited as the modified layer using tetrakis(ethylmethylamino)hafnium(IV) (TEMA-Hf) and H2O as the precursor and reactant, respectively, and the compounds represented by Formula 1b and Formula 1d, respectively, were used as the surface modifier.

[0093] [Example 6] ZrO 2 Surface modification of thin films The surface of the ZrO2 thin film was modified in the same manner as in Example 1, except that a 10 nm-thick ZrO2 thin film was deposited as the modified layer using TEMA-Zr and H2O as the precursor and reactant, respectively, and the compounds represented by Chemical Formula 1b and Chemical Formula 1d, respectively, were used as the surface modifiers.

[0094] [Comparative Examples 1 to 6] Deposition of thin films without surface modification A modification layer was deposited on a substrate in the same manner as in Examples 1 to 6, except that the surface modification process was not performed.

[0095] [Experimental Example 1] Confirmation of surface modification effect through water contact angle measurement By measuring the angle formed by a water droplet dropped on a substrate (water contact angle), the degree of hydrophilicity of the substrate surface can be determined, and thus the surface polarity can be determined.

[0096] Therefore, the water contact angles of the thin films prepared in Examples 1 to 6 and Comparative Examples 1 to 6 were measured to determine the change in polarity due to the modification treatment, that is, the presence or absence and the degree of modification.

[0097] On the other hand, the contact angle of a silicon substrate with a naturally occurring oxide film is 47.9° (Figure 3(a)), and when the naturally occurring oxide film is completely removed by washing with hydrofluoric acid, the contact angle of the silicon substrate becomes 72.6° and the surface becomes hydrophobic (Figure 3(b)). The silicon substrate is initially non-polar (hydrophobic), but when the substrate surface is oxidized and a naturally occurring oxide film is formed, the polarity of the substrate surface increases relatively (hydrophilic).

[0098] [Table 1]

[0099] As shown in Table 1, when SiO2 is deposited by atomic layer deposition, the contact angle is reduced to about 10°, resulting in a hydrophilic surface (Figure 3(c), Comparative Example 1). In other words, if an oxide film is formed by atomic layer deposition that is denser and thicker than a naturally occurring oxide film, the polarity (hydrophilicity) of the substrate surface becomes higher than that of the substrate in its natural state. If the polarity of the substrate surface becomes higher, the adhesive strength decreases when a low-polarity thin film is applied. In general semiconductor processes, when a thin film is deposited on a silicon substrate, a bonding promoter such as hexamethyldisilazane (HMDS) is applied to the silicon substrate to increase the bonding strength of the silicon substrate. The water contact angle of a silicon substrate coated with HMDS is usually about 70° (Figure 3(d)), which is almost the same as that of a pure silicon substrate from which the naturally occurring oxide film has been removed.

[0100] On the other hand, when a 10 nm thick atomic layer deposited SiO2 thin film was modified with the surface modifier represented by formula 1a (Example 1), the contact angle was approximately 80° (FIG. 3(e)), which is approximately 10° larger than the contact angle of the HMDS coated surface. Therefore, it can be seen that the surface modifier represented by formula 1a has a surface hydrophobicity (low polarity) effect equal to or greater than that of HMDS.

[0101] In addition, to confirm the durability of the modification effect when exposed to moisture in the air, the contact angle was measured in the same manner 24 hours after the completion of modification for Example 1. As a result, the contact angle of Example 1 either remained almost unchanged (FIG. 3(f)) or changed only slightly (chemical formula 1e), indicating that the modification effect lasted for more than 24 hours.

[0102] According to Table 1, even when the modified layer was different (Examples 2 to 6, Comparative Examples 2 to 6), the results were substantially the same as those of Example 1 and Comparative Example 1. That is, when the surface modifier represented by Chemical Formula 1b was used, the surface contact angle was about 80°, and when the surface modifier represented by Chemical Formula 1d was used, the surface contact angle was about 85°, and the contact angle was maintained even after 24 hours. Therefore, it can be seen that the contact angle of the modified substrate surface varies depending on the type of surface modifier, regardless of the composition of the modified layer.

[0103] Meanwhile, the contact angle experiment results when the surface modifier was deposited N times (N=1, 3, 5, 10) for 1 second each are shown in Figure 4. As shown in Figure 4, if the surface modifier is deposited 5 times or more for 1 second each, the contact angle becomes saturated.

[0104] As a result, the present invention is capable of a half cycle process by applying a surface modifier of Formula 1 in a gaseous state, and can uniformly modify the surface of a substrate for atomic layer deposition or chemical vapor deposition. In addition, the present invention can easily apply an organic polymer film for surface modification to an inorganic film, and can prevent damage to equipment used in the process.

Claims

1. A substrate surface modifier for atomic layer deposition or chemical vapor deposition, represented by the following formula 1: The substrate surface modifier represented by the following Chemical Formula 1 is any one selected from the group consisting of (diethylamino)dimethyl(ethyl)silane, (diethylamino)trimethylsilane, (dimethylamino)dimethoxyphenylsilane, di(isobutyl)(dimethylamino)phenylsilane, dibutyl(dimethylamino)vinylsilane, vinyl(dimethylamino)dimethoxysilane, n-butyl(dimethylamino)dimethoxysilane, methyltriiodosilane, vinyltriiodosilane, trimethyl(trifluoromethyl)silane, and trimethyl(pentafluorophenyl)silane. [Chemical formula 1] (In the above Chemical Formula 1, X is Si; L1, L2, L3 and L4 are each independently a ligand of X, at least one of L1, L2, L3 and L4 includes a functional group that modifies the surface of the substrate, and at least another of L1, L2, L3 and L4 includes a functional group that binds to the surface of the substrate.

2. The substrate surface modifier according to claim 1 , wherein the functional group that modifies the surface of the substrate is a ligand that modifies the surface of the substrate to be hydrophobic or hydrophilic.

3. The substrate surface modifier according to claim 1 , wherein the substrate surface modifier adjusts the surface contact angle of the substrate including the surface modification layer to 50° or more.

4. 2. The substrate surface modifier according to claim 1, wherein L1, L2, L3 and L4 are all hydrocarbon groups having 1 to 10 carbon atoms or all alkoxy groups having 1 to 10 carbon atoms.

5. The substrate surface modifier according to claim 4 , wherein at least one of the hydrocarbon groups is a hydrocarbon group substituted with a halogen atom.

6. After placing a substrate in a deposition chamber, supplying the substrate surface modifier according to claim 1 in a gaseous form to the deposition chamber to form a surface modification layer formed of the substrate surface modifier on the surface of the substrate; and supplying a purge gas into the deposition chamber to remove excess substrate surface modifier; The substrate further includes a modified layer that is an inorganic film, The method for modifying a substrate surface, wherein the layer to be modified is any one inorganic film selected from the group consisting of an oxide film, a nitride film, and an oxynitride film.

7. 7. The method for modifying a substrate surface according to claim 6, wherein the supply of the surface modifier and the supply of the purge gas are repeated 2 to 10 times.

8. The modified layer is adsorbing a substrate surface modifier on an upper surface of the substrate disposed in the deposition chamber to form a modified layer; supplying an inert purge gas into the deposition chamber to remove excess substrate surface modifier that is not adsorbed on the substrate; supplying a reactant to the deposition chamber to react with the substrate surface modifier to form a modified layer; and Purge gas is again supplied to the deposition chamber to remove unreacted reactants. The method for modifying a substrate surface according to claim 6, which is formed by an atomic layer deposition method comprising the steps of:

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