Selective deposition method and deposition equipment for metal molybdenum film

Abstract

The invention relates to a selective deposition method and deposition equipment of a metal molybdenum film. The method comprises the following steps: a treatment piece is provided with an exposed active surface and an inert surface, and a deposition selection ratio exists between the active surface and the inert surface; the treated part is placed in a reaction chamber for multiple deposition treatment steps, and the deposition treatment steps comprise the steps that carrier gas carries a molybdenum halide precursor containing no oxygen element to enter the reaction chamber, and the carrier gas and the active surface are adsorbed; after the molybdenum halide precursor and the active surface are adsorbed, carrying out first purging treatment on the treated part; after carrying out the first purging treatment, introducing a reductive co-reactant into the reaction chamber, and reducing the molybdenum halide precursor adsorbed on the active surface into a metal molybdenum layer; after the metal molybdenum layer is reduced, carrying out second purging treatment on the reaction chamber and the treatment piece; and after the multiple deposition treatment steps are carried out, the multiple metal molybdenum layers formed in the multiple deposition treatment steps are used as metal molybdenum films. And the conductivity and the forming quality of the metal molybdenum film are improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of semiconductor manufacturing, and in particular, to a method for selective deposition of a metal molybdenum film and a deposition apparatus. BACKGROUND

[0002] As semiconductor manufacturing technology continues to advance towards 10 nanometer and beyond, the size of interconnect and via structures is continuously scaled down, leading to a dramatic increase in contact resistance for traditional conductive materials such as copper (Cu) and tungsten (W), which in turn severely impacts device performance and power consumption. Metal molybdenum (Mo) is considered as a key candidate material for gate electrodes, interconnect lines and via fill in next generation integrated circuits due to its intrinsic properties of low resistivity, high melting point and excellent thermal stability. The industry is actively exploring effective methods for depositing high quality molybdenum films on various substrate structures to meet the stringent requirements for conductive material performance in advanced processes.

[0003] Among existing molybdenum film deposition techniques, chemical vapor deposition and physical vapor deposition are two commonly used processes. However, when faced with mixed surfaces that have alternating exposure of metal and dielectric regions, these conventional techniques generally struggle to achieve regionally selective self-aligned deposition, often accompanied by serious problems of parasitic deposition on dielectric surfaces. In addition, while atomic layer deposition techniques can provide excellent step coverage, reported molybdenum deposition processes rely on molybdenum oxyhalide precursors, which can introduce oxygen impurities after deposition, leading to increased film resistivity, and their relatively high deposition temperatures can also cause damage to heat-sensitive materials in the underlying layers.

[0004] At present, the formation quality of the metal molybdenum film still needs to be improved. SUMMARY

[0005] The problem solved by embodiments of the present application is to provide a method for selective deposition of a metal molybdenum film and a deposition apparatus, which can improve the conductivity and formation quality of the metal molybdenum film while reducing the process steps for forming the metal molybdenum film.

[0006] To solve the above problems, the embodiment of the present application provides a selective deposition method of a metal molybdenum film, comprising: providing a processing piece, the processing piece having an exposed active surface and an inert surface, and the active surface and the inert surface having a deposition selectivity ratio therebetween; placing the processing piece in a reaction chamber, and performing a plurality of deposition processing steps to deposit a metal molybdenum film on the active surface of the processing piece, the deposition processing step comprising: carrying a molybdenum halide precursor containing no oxygen element by a carrier gas into the reaction chamber to be adsorbed on the active surface; after the molybdenum halide precursor is adsorbed on the active surface, performing a first purging treatment on the processing piece; after the first purging treatment, introducing a reducing co-reactant into the reaction chamber to reduce the molybdenum halide precursor adsorbed on the active surface into a metal molybdenum layer; after the reduction into the metal molybdenum layer, performing a second purging treatment on the reaction chamber and the processing piece; and taking the multi-layer metal molybdenum layer formed by the plurality of deposition processing steps as the metal molybdenum film.

[0007] Optionally, the molybdenum halide precursor has a general formula MoXa a wherein X includes one or more of F, Cl, Br and I; and a is an integer greater than zero.

[0008] Optionally, the molybdenum halide precursor includes one or more of MoCl5, MoF5 and MoF6.

[0009] Optionally, during the deposition processing step, the temperature of the reaction chamber is between 300°C and 600°C.

[0010] Optionally, in the step of carrying the molybdenum halide precursor into the reaction chamber by the carrier gas, the carrier gas includes one or more of argon and nitrogen.

[0011] Optionally, the purging gas used in the first purging treatment includes an inert gas; and the purging gas used in the second purging treatment includes an inert gas.

[0012] Optionally, the inert gas includes one or both of nitrogen and argon.

[0013] Optionally, the reducing co-reactant includes one or more of hydrogen, hydrogen plasma and atomic hydrogen.

[0014] Optionally, in the deposition processing step, the deposition selectivity ratio between the active surface and the inert surface is greater than 50:1.

[0015] Optionally, the material of the active surface includes one or more of metal, metal nitride, metal silicide, silicon and germanium silicon.

[0016] Optionally, the material of the inert surface includes a dielectric material.

[0017] Optionally, before performing the one or more deposition processing steps, the selective deposition method further comprises: performing an in-situ pre-cleaning on the processing piece.

[0018] Optionally, the in-situ pre-cleaning uses hydrogen plasma, metal reducing agent or dry chemical etching gas.

[0019] Optionally, the processing piece includes a two-dimensional planar structure or a three-dimensional solid structure.

[0020] Correspondingly, the embodiment of the present application also provides a deposition device for performing the selective deposition method provided by the present application, comprising: a reaction chamber; a precursor source supply system for providing a molybdenum halide precursor; a reducing co-reactant supply system for introducing a reducing co-reactant into the reaction chamber; a purge system for purging the processing piece and the reaction chamber; and a control system configured to control the reaction chamber, the precursor source supply system, the reducing co-reactant supply system and the purge system to perform the deposition processing steps.

[0021] Compared with the prior art, the technical scheme of the embodiment of the present application has the following advantages: The selective deposition method of the metal molybdenum film provided by the embodiment of the present application places the processing piece in the reaction chamber and performs multiple deposition processing steps to deposit a metal molybdenum film on the active surface of the processing piece. The deposition processing steps include: carrying the molybdenum halide precursor without oxygen elements into the reaction chamber by the carrier gas to adsorb on the active surface; after the molybdenum halide precursor is adsorbed on the active surface, the processing piece is subjected to first purging treatment; after the first purging treatment, the reducing co-reactant is introduced into the reaction chamber to reduce the molybdenum halide precursor adsorbed on the active surface into a metal molybdenum layer; after the reduction into the metal molybdenum layer, the reaction chamber and the processing piece are subjected to second purging treatment; and the multiple metal molybdenum layers formed by the multiple deposition processing steps are used as the metal molybdenum film. That is, by using the molybdenum halide precursor without oxygen elements, it is impossible to generate molybdenum oxide or cause oxygen doping in the subsequent reaction with the reducing co-reactant, which directly ensures that the metal molybdenum film formed finally has extremely low impurity content and high electrical conductivity, so that the resistivity of the metal molybdenum film can be significantly reduced. By using the principle that the chemical adsorption of the molybdenum halide precursor on the active surface and the inert surface is different, self-aligned deposition with high selectivity is realized, so that the molybdenum halide precursor without oxygen elements only effectively chemically adsorbs and nucleates on the active surface, while only physically adsorbs on the inert surface and can be completely removed by the subsequent first purging treatment and second purging treatment. The mask and etching steps necessary for realizing selective area deposition in the traditional process are omitted, the process steps are simplified, and the process cost is reduced. Moreover, by multiple deposition processing steps, uniform, conformal and pore-free film deposition can be realized on the active surface. One layer of metal molybdenum layer is deposited each time, and the thickness of the metal molybdenum film can be accurately controlled through multiple deposition processing steps. In summary, the electrical conductivity and formation quality of the metal molybdenum film can be improved while reducing the process steps for forming the metal molybdenum film.

[0022] The deposition device provided by the embodiment of the present application is used for performing the selective deposition method provided by the foregoing embodiment, and comprises a reaction chamber, a precursor source supply system for providing a molybdenum halide precursor, a reducing co-reactant supply system for supplying a reducing co-reactant to the reaction chamber, a purge system for purging the processing piece and the reaction chamber, and a control system configured to control the reaction chamber, the precursor source supply system, the reducing co-reactant supply system and the purge system to perform a deposition processing step. By providing the molybdenum halide precursor containing no oxygen element, it is impossible to generate molybdenum oxide or cause oxygen doping in the subsequent reaction with the reducing co-reactant, thereby directly ensuring that the finally formed metal molybdenum film has extremely low impurity content and high electrical conductivity, so that the resistivity of the metal molybdenum film can be significantly reduced. By utilizing the principle that the chemical adsorption difference of the molybdenum halide precursor exists on the active surface and the inert surface, self-aligned deposition with a high selectivity ratio is realized, so that the molybdenum halide precursor containing no oxygen element is only effectively chemically adsorbed and nucleated on the active surface, while only physically adsorbed on the inert surface and can be completely removed by the subsequent first and second purge processes. The mask and etching steps necessary for realizing selective area deposition in the conventional process are omitted, the process steps are simplified, and the process cost is reduced. Moreover, by multiple deposition processing steps, uniform, conformal and pore-free film deposition can be realized on the active surface. One layer of metal molybdenum layer is accurately deposited in each deposition processing step, and the thickness of the metal molybdenum film can be accurately controlled through multiple deposition processing steps. In summary, the electrical conductivity and formation quality of the metal molybdenum film can be improved while reducing the process steps for forming the metal molybdenum film. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A step flow chart corresponding to an embodiment of the selective deposition method of the metal molybdenum film of the present application is shown. Figures 2 to 5 The structural schematic diagram corresponding to each step in an embodiment of the selective deposition method of the metal molybdenum film of the present application is shown. DETAILED DESCRIPTION

[0024] At present, the formation quality of the metal molybdenum film still needs to be improved.

[0025] Specifically, the existing metal molybdenum film is based on the atomic layer deposition technology of molybdenum oxygen halogen group precursor, and oxygen elements will be inevitably introduced into the molybdenum film during the deposition process to form oxygen doping, because the Mo-O bond contained in the precursor molecule itself is difficult to be completely removed in the reduction process. Oxygen impurities as scattering centers can significantly increase the resistivity of the metal film, making it much higher than the theoretical resistance value of molybdenum, which cannot meet the demand of low resistance interconnection, and the oxide is a key factor affecting the formation quality of the metal molybdenum film. Before the deposition process, the oxide remaining on the surface will hinder the molybdenum precursor and the surface material to form a firm chemical bond, so that the adhesion of the formed metal molybdenum film is poor, and the nucleation density is low, thereby resulting in poor formation quality of the metal molybdenum film and low conductivity.

[0026] To solve the above technical problems, an embodiment of the present application provides a selective deposition method of a metal molybdenum film. Figure 1 The step flow chart corresponding to an embodiment of the selective deposition method of the metal molybdenum film of the present application is shown.

[0027] Step S1: providing a processing piece, the processing piece has an exposed active surface and an inert surface, and the active surface and the inert surface have a deposition selectivity ratio.

[0028] Step S2: placing the processing piece in the reaction chamber, and performing multiple deposition processing steps to deposit a metal molybdenum film on the active surface of the processing piece, the deposition processing steps comprising: carrying the halogenated molybdenum precursor without oxygen elements into the reaction chamber by the carrier gas, and adsorbing the active surface; after the halogenated molybdenum precursor is adsorbed on the active surface, the processing piece is subjected to a first purging treatment; after the first purging treatment, a reducing co-reactant is introduced into the reaction chamber to reduce the halogenated molybdenum precursor adsorbed on the active surface into a metal molybdenum layer; after the metal molybdenum layer is formed, the reaction chamber and the processing piece are subjected to a second purging treatment; and the multiple metal molybdenum layers formed by the multiple deposition processing steps are used as the metal molybdenum film.

[0029] The selective deposition method of the metal molybdenum film provided by the embodiment of the present application directly ensures that the metal molybdenum film formed finally has extremely low impurity content and high electrical conductivity, so that the resistivity of the metal molybdenum film is significantly reduced. By using the principle that the chemical adsorption of the molybdenum halide precursor on the active surface and the inert surface is different, self-aligned deposition with a high selectivity ratio is realized, so that the molybdenum halide precursor without oxygen elements only effectively chemically adsorbs and nucleates on the active surface, and is only physically adsorbed on the inert surface and can be completely removed by subsequent first and second blowing treatment. The mask and etching steps necessary for realizing selective area deposition in the traditional process are omitted, the process steps are simplified, the process cost is reduced, and through multiple deposition treatment steps, uniform, conformal and pore-free film deposition on the active surface can be realized. One layer of metal molybdenum layer is deposited in each deposition treatment step, and the thickness of the metal molybdenum film can be accurately controlled through multiple deposition treatment steps. In summary, the electrical conductivity and formation quality of the metal molybdenum film can be improved while reducing the process steps for forming the metal molybdenum film.

[0030] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0031] Among them, Figures 2 to 5 is the structural schematic diagram corresponding to each step in the selective deposition method of the metal molybdenum film of the embodiment of the present application.

[0032] Reference Figures 2 to 3 , execute step S1: provide a processing piece 100, the processing piece 100 has an exposed active surface 102 and an inert surface 101, and the active surface 102 and the inert surface 101 have a deposition selectivity ratio.

[0033] Specifically, the processing piece 100 provides a carrier and an interface basis for the formation of the metal molybdenum film.

[0034] It should be noted that the active surface 102 and the inert surface 101 have a deposition selectivity ratio, which ensures that the molybdenum halide precursor only effectively chemically adsorbs and reacts to nucleate on the active surface 102 subsequently, and basically does not deposit on the inert surface 101, thereby avoiding the formation of a parasitic film in a non-target area, and omitting the mask and etching steps required in the traditional process, thereby reducing the process cost.

[0035] It is also necessary to point out that the active surface 102 provides chemical adsorption sites and reaction interfaces for the molybdenum halide precursor, and is a region for selective growth of the subsequent metal molybdenum film. Meanwhile, the inert surface 101 is chemically inert to the precursor and does not participate in the film formation reaction. Its role is to limit the growth region of the metal molybdenum film, thereby ensuring the accuracy of the patterned deposition.

[0036] In this embodiment, the material of the active surface 102 includes one or more of a metal, a metal nitride, a metal silicide, silicon, and germanium silicon.

[0037] Specifically, the material surfaces of the metal, the metal nitride, the metal silicide, silicon, and germanium silicon all have unsaturated bonds or dangling bonds, which can form strong chemical bonds with the halogen atoms in the molybdenum halide precursor molecules, thereby achieving effective chemical adsorption and providing stable nucleation sites for the subsequent reduction reaction and molybdenum film growth. For example, the metal atoms on the surface of the metal nitride (such as TiN) and the silicon atoms on the surface of silicon can all undergo coordination or displacement reactions with the molybdenum halide precursor.

[0038] In this embodiment, the material of the inert surface 101 includes a dielectric material.

[0039] It is necessary to point out that the surface of the dielectric material is chemically stable and lacks active sites for strong chemical reactions with the molybdenum halide precursor. The molybdenum halide precursor can only undergo weak physical adsorption on the surface of the dielectric material, and the physical adsorption force is much smaller than the chemical adsorption. This weak physical adsorption is easily removed by the subsequent first and second purge processes, thereby ensuring a high deposition selectivity and avoiding parasitic deposition on the dielectric surface.

[0040] As an example, the material of the inert surface 101 includes one or more of silicon oxide, silicon nitride, and silicon oxynitride.

[0041] In this embodiment, the processing piece 100 includes a two-dimensional planar structure or a three-dimensional solid structure.

[0042] Specifically, the processing piece 100 includes a two-dimensional planar structure or a three-dimensional solid structure, which ensures the process adaptability of the present application. For a two-dimensional planar structure, the method can achieve precise deposition self-alignment patterning. For a three-dimensional solid structure (such as a high aspect ratio via or trench), conformal filling from the bottom up can be achieved, eliminating hole and overhang defects, and meeting the requirements of three-dimensional integration of semiconductor devices.

[0043] As shown in Figure 2 , a processing piece 100 with a two-dimensional planar structure is shown.

[0044] As shown in Figure 3 , a processing piece 100 with a three-dimensional solid structure is shown.

[0045] Continuing to refer to Figures 2 to 3, performing step S11: before the one or more deposition processing steps, the selective deposition method further comprises: performing in-situ pre-cleaning on the workpiece 100.

[0046] It should be noted that the in-situ pre-cleaning of the workpiece 100 can remove the natural oxide layer formed on the active surface 102 due to exposure to the atmosphere, which can block the direct contact between the molybdenum halide precursor and the active surface 102, inhibit the nucleation of molybdenum, and result in a discontinuous and poorly adherent molybdenum film. Therefore, by performing in-situ pre-cleaning on the workpiece 100, the oxide layer can be removed, which is beneficial for obtaining a high-quality and low-resistance molybdenum film.

[0047] In this embodiment, the in-situ pre-cleaning uses hydrogen plasma, a metal reducing agent, or a dry chemical etching gas.

[0048] Specifically, the dry chemical etching gas includes hydrofluoric acid and ammonia.

[0049] It should be noted that the in-situ pre-cleaning can use different methods depending on the material of the surface.

[0050] Reference Figures 4 to 5 , performing step S2: placing the workpiece 100 in the reaction chamber and performing multiple deposition processing steps to deposit a molybdenum film 110 on the active surface 102 of the workpiece 100, the deposition processing steps comprising: introducing a carrier gas carrying a molybdenum halide precursor without oxygen elements into the reaction chamber to adsorb on the active surface 102; after the molybdenum halide precursor is adsorbed on the active surface 102, performing a first purge process on the workpiece 100; after the first purge process, introducing a reducing co-reactant into the reaction chamber to reduce the molybdenum halide precursor adsorbed on the active surface 102 to a molybdenum layer; after the molybdenum layer is formed, performing a second purge process on the reaction chamber and the workpiece 100; and using the multiple molybdenum layers formed by the multiple deposition processing steps as the molybdenum film 110.

[0051] Specifically, by using the molybdenum halide precursor containing no oxygen element, it is impossible to generate molybdenum oxide or cause oxygen doping in the subsequent reaction with the reducing co-reactant, directly ensuring that the finally formed metal molybdenum film 110 has extremely low impurity content and high electrical conductivity, so that the resistivity of the metal molybdenum film 110 is significantly reduced. By utilizing the principle that the chemical adsorption of the molybdenum halide precursor on the active surface 102 and the inert surface 101 is different, a high-selectivity self-aligned deposition is realized, so that the molybdenum halide precursor containing no oxygen element only effectively chemically adsorbs and nucleates on the active surface 102, while only physically adsorbing on the inert surface 101 and being completely removed by the subsequent first and second purge processes. Therefore, the mask and etching steps necessary for realizing selective area deposition in the traditional process are omitted, the process steps are simplified, and the process cost is reduced. Moreover, by multiple deposition processing steps, a uniform, conformal and pore-free thin film deposition can be realized on the active surface 102. Each deposition processing step precisely deposits a layer of metal molybdenum, and the thickness of the metal molybdenum film 110 can be accurately controlled by multiple deposition processing steps. In summary, the formation process steps of the metal molybdenum film 110 can be reduced, and the electrical conductivity and formation quality of the metal molybdenum film 110 can be improved.

[0052] It should be noted that the carrier gas can stably and uniformly transport the molybdenum halide precursor vapor containing no oxygen element in a gaseous state from the gas source area to the reaction chamber, ensuring that the precursor can fully contact the surface of the workpiece 100.

[0053] Specifically, the molybdenum atom and the halogen atom in the molybdenum halide precursor molecule containing no oxygen element can chemically interact with the unpaired electrons or dangling bonds between the metal atoms or silicon atoms of the active surface 102, causing the precursor molecules to chemically adsorb on the active surface 102 through coordination bonding or displacement reaction, forming a monolayer of adsorbed molecules and providing a reaction basis for the subsequent reduction step.

[0054] It should be noted that the inert surface 101 is composed of strong covalent bonds, and the surface is chemically saturated, lacking active sites for the molybdenum halide precursor molecules to effectively chemically bond. There is only weak van der Waals force between the molybdenum halide precursor and the inert surface 101, which is much smaller than the chemical bonding force between the molybdenum halide precursor and the active surface 102. Therefore, it is easily removed by inert gas in the subsequent first and second purge processing steps, thereby ensuring that the molybdenum halide precursor is basically not deposited on the inert surface 101.

[0055] In this embodiment, the carrier gas includes one or both of argon and nitrogen in the step of carrying the molybdenum halide precursor into the reaction chamber by the carrier gas.

[0056] In this embodiment, the molybdenum halide precursor has the general formula MoX awherein X comprises one or more of F, Cl, Br, and I; and a is an integer greater than zero.

[0057] Specifically, fluorine (F), chlorine (Cl), bromine (Br), and iodine (I) are all halogen elements, which can form halides with molybdenum. These halides can generate corresponding volatile hydrogen halides when reacting with a reducing co-reactant in the subsequent process, and thus can be effectively removed by the subsequent purging process.

[0058] It should be noted that a represents the number of halogen atoms coordinated with the molybdenum atom, which is determined by the valence of molybdenum and the structure of the stable molecule formed. a is an integer greater than zero, which covers all possible stable molybdenum halide compounds.

[0059] In this embodiment, the molybdenum halide precursor includes one or more of MoCl5, MoF5, and MoF6.

[0060] It should be noted that during the deposition treatment step, the temperature of the reaction chamber should not be too high or too low. If the temperature of the reaction chamber is too high, the molybdenum halide precursor may be thermally decomposed, resulting in poor uniformity of the subsequently formed metal molybdenum film 110, and may also cause thermal damage to the heat-sensitive materials (such as low-k dielectric) already present on the device 100, affecting the electrical properties of the device. If the temperature of the reaction chamber is too low, the surface reaction of the molybdenum halide precursor may be too slow, resulting in a low growth rate or incomplete reaction, affecting the formation quality of the metal molybdenum film 110. Therefore, in this embodiment, the temperature of the reaction chamber during the deposition treatment step is between 300°C and 600°C.

[0061] It should also be noted that during the deposition treatment step, the deposition selectivity between the active surface 102 and the inert surface 101 should not be too small. If the deposition selectivity between the active surface 102 and the inert surface 101 is too small, the probability of parasitic deposition of the molybdenum halide precursor on the inert surface 101 increases, affecting the yield and reliability of the device. Therefore, in this embodiment, the deposition selectivity between the active surface 102 and the inert surface 101 during the deposition treatment step is greater than 50:1.

[0062] Specifically, the first purging process is used to physically remove the molybdenum halide precursor molecules that are not chemically adsorbed on the active surface 102 in the reaction chamber, and to remove the molybdenum halide precursor molecules that are desorbed from the active surface 102 and physically adsorbed on the inert surface 101, thereby preventing the residual molybdenum halide precursor in the reaction chamber and unnecessary reactions with the subsequently introduced reducing co-reactant, ensuring that the deposition only occurs on the chemically adsorbed layer of the active surface 102.

[0063] In this embodiment, the purge gas used in the first purge process includes inert gas.

[0064] It should be noted that inert gas is selected because it is chemically stable and is not prone to chemical reaction with the molybdenum halide precursor, the reducing co-reactant, the byproduct or the formed molybdenum film, thereby avoiding the introduction of new impurities.

[0065] In this embodiment, the inert gas includes one or both of nitrogen and argon.

[0066] Specifically, nitrogen and argon are the most commonly used, moderately priced and high-purity inert gases in semiconductor processes.

[0067] It should be noted that the reducing co-reactant undergoes a surface chemical reaction with the adsorbed molybdenum halide precursor, removes the halogen ligand, and reduces molybdenum from a higher valence state in its halide to a zero-valent metallic state, thereby achieving deposition of a single atomic layer of metallic molybdenum.

[0068] In this embodiment, the reducing co-reactant includes one or more of hydrogen, hydrogen plasma and atomic hydrogen.

[0069] Specifically, hydrogen is a highly efficient reducing agent, and the byproduct is only volatile hydrogen halide, while hydrogen plasma (H-plasma) can produce hydrogen atoms or ions with higher activity, enabling efficient reduction at lower temperatures or in shorter time, which is particularly advantageous for temperature-sensitive application scenarios. Atomic hydrogen is also a highly efficient reducing agent, and hydrogen, hydrogen plasma and atomic hydrogen do not introduce impurities such as carbon or oxygen, which is conducive to obtaining a high-purity metallic molybdenum film 110.

[0070] It should be noted that the second purge process is used to remove unreacted reducing co-reactant in the reaction chamber after the chemical reaction, and to remove volatile byproducts (such as HCl, HBr, etc.) generated by the reduction reaction of the active surface 102, preventing the accumulation and re-adsorption of byproducts in the reaction chamber and avoiding cross-contamination in the next deposition process step.

[0071] In this embodiment, the purge gas used in the second purge process includes inert gas.

[0072] It should be noted that inert gas is selected because it is chemically stable and is not prone to chemical reaction with the molybdenum halide precursor, the reducing co-reactant, the byproduct or the formed molybdenum film, thereby avoiding the introduction of new impurities.

[0073] In this embodiment, the inert gas includes one or both of nitrogen and argon.

[0074] Specifically, nitrogen and argon are the most commonly used, moderately priced and high-purity inert gases in semiconductor processes.

[0075] It should be noted that the thickness of the metal molybdenum layer can be precisely controlled through repeated deposition processing steps until the target film thickness is reached, and the thickness uniformity of the metal molybdenum layer is excellent.

[0076] Correspondingly, the application also provides an apparatus for performing the selective deposition method of the metal molybdenum film provided by the foregoing embodiments.

[0077] The apparatus comprises: a reaction chamber; a precursor source supply system for providing a molybdenum halide precursor; a reducing co-reactant supply system for introducing a reducing co-reactant into the reaction chamber; a purge system for purging the processing piece and the reaction chamber; and a control system configured to control the reaction chamber, the precursor source supply system, the reducing co-reactant supply system, and the purge system to perform a deposition processing step.

[0078] It should be noted that the precursor source supply system provides a molybdenum halide precursor containing no oxygen element, which is unlikely to generate molybdenum oxide or cause oxygen doping in the subsequent reaction with the reducing co-reactant, directly ensuring that the final metal molybdenum film has extremely low impurity content and high electrical conductivity, significantly reducing the resistivity of the metal molybdenum film. By utilizing the principle of the chemical adsorption difference between the active surface and the inert surface of the molybdenum halide precursor, a high-selectivity self-aligned deposition is achieved, so that the molybdenum halide precursor containing no oxygen element only effectively chemically adsorbs and nucleates on the active surface, while only physically adsorbing on the inert surface and being completely removed by the subsequent first and second purge processes. The mask and etching steps necessary for selective area deposition in traditional processes are eliminated, simplifying the process steps and reducing the process cost. Moreover, through multiple deposition processing steps, uniform, conformal, and pore-free thin film deposition on the active surface can be achieved. Each deposition processing step precisely deposits a layer of metal molybdenum, and the thickness of the metal molybdenum film can be precisely controlled through multiple deposition processing steps. In summary, the electrical conductivity and formation quality of the metal molybdenum film can be improved while reducing the metal molybdenum film formation process steps.

[0079] Specifically, the reaction chamber provides a closed reaction environment for the selective deposition process of the metal molybdenum film, ensuring that the molybdenum halide precursor and the reducing co-reactant can chemically react on the surface of the processing piece.

[0080] It should be noted that the precursor source supply system is responsible for delivering the molybdenum halide precursor containing no oxygen element to the reaction chamber, and using a carrier gas (such as argon or nitrogen) at a set flow rate and pulse time to carry and pulse-inject the molybdenum halide precursor vapor into the reaction chamber.

[0081] The reducing co-reactant supply system is used to supply a reducing gas, such as hydrogen or hydrogen plasma, to the reaction chamber. After the molybdenum halide precursor is adsorbed and purged, the reducing gas is introduced into the reaction chamber at a specific flow rate and pulse time, and reacts with the molybdenum halide precursor molecules chemisorbed on the active surface to break the Mo-X bond (X is halogen), thereby generating an elemental molybdenum metal layer and volatile hydrogen halide byproducts (such as HCl).

[0082] Specifically, the purge system is used to introduce an inert purge gas (such as argon or nitrogen) into the reaction chamber and purge the reaction chamber and the processing piece.

[0083] It should be noted that the first purge process is intended to remove unreacted molybdenum halide precursor in the reaction chamber and physically adsorbed molybdenum halide precursor on the inert surface, preventing it from participating in subsequent reactions or causing non-selective deposition; the second purge process is intended to remove unreacted reducing co-reactant and volatile byproducts (such as hydrogen halide) generated by surface reduction reactions, to avoid cross-contamination of subsequent deposition cycles.

[0084] Specifically, the control system is used to control the entire selective deposition process to deposit a metal molybdenum layer.

[0085] It should be noted that the deposition process steps are described in the foregoing embodiments and will not be repeated here.

[0086] Although the present application is disclosed as above, the present application is not limited to this. Any person skilled in the art, without departing from the spirit and scope of the present application, can make various changes and modifications, therefore the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A method for selective deposition of a molybdenum film, characterized in that, include: A processing component is provided having an exposed active surface and an inert surface, and a deposition selectivity ratio between the active surface and the inert surface; The processing unit is placed in a reaction chamber and subjected to multiple deposition processes to deposit a molybdenum film on the active surface of the processing unit. The deposition processes include: The carrier gas carries the oxygen-free molybdenum halide precursor into the reaction chamber, where it adsorbs onto the active surface. After the molybdenum halide precursor is adsorbed onto the active surface, the treated component is subjected to a first purging treatment. After the first purging treatment, a reducing co-reactant is introduced into the reaction chamber to reduce the molybdenum halide precursor adsorbed on the active surface to a metallic molybdenum layer. After being reduced to the molybdenum metal layer, the reaction chamber and the processing unit are subjected to a second purging treatment; The multilayer molybdenum metal layer formed by the multiple deposition processes described herein is used as the molybdenum metal film.

2. The selective deposition method for a molybdenum film as described in claim 1, characterized in that, The molybdenum halide precursor has the general formula MoX. a , where X includes one or more of F, Cl, Br and I; a refers to an integer greater than zero.

3. The selective deposition method for a molybdenum film as described in claim 1 or 2, characterized in that, The molybdenum halide precursor includes one or more of MoCl5, MoF5, and MoF6.

4. The selective deposition method for a molybdenum film as described in claim 1, characterized in that, The reducing co-reactants include one or more of hydrogen gas, hydrogen plasma, and atomic hydrogen.

5. The selective deposition method for a molybdenum film as described in claim 1, characterized in that, The active surface material includes one or more of metals, metal nitrides, metal silicides, silicon, and germanium-silicon.

6. The selective deposition method for a molybdenum film as described in claim 1, characterized in that, The material of the inert surface includes a dielectric material.

7. The selective deposition method for a molybdenum film as described in claim 1, characterized in that, Before performing one or more of the deposition processing steps, the selective deposition method further includes: performing in-situ pre-cleaning of the processed part.

8. The selective deposition method for a molybdenum film as described in claim 7, characterized in that, The in-situ pre-cleaning process employs hydrogen plasma, metal reducing agents, or dry chemical etching gases.

9. The selective deposition method for a molybdenum film as described in claim 1, characterized in that, The processing component includes a two-dimensional planar structure or a three-dimensional solid structure.

10. A deposition apparatus for performing the selective deposition method as described in any one of claims 1 to 9, characterized in that, include: Reaction chamber; A precursor supply system for providing molybdenum halide precursors; A reducing co-reactant supply system for introducing reducing co-reactants into the reaction chamber; The purging system is used to purge the processing components and reaction chambers. The control system is configured to control the reaction chamber, precursor source supply system, reducing co-reactant supply system, and purging system to perform deposition processing steps.

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