Method for forming metal nitride film

Abstract

Embodiments of the present disclosure include a method of forming a film, comprising: conformally depositing a first film on a substrate; treating the first film with a first plasma to form a second film; treating the second film with a second plasma to form a third film; and selectively removing the first film, a portion of the second film, and the third film.

Description

Technical Field

[0001] This disclosure generally relates to methods for depositing films. Specifically, this disclosure relates to processes for selectively depositing ALD films.

[0002] background

[0003] Film deposition on substrates is a crucial process in various industries, including semiconductor processing, diffusion barrier coatings, and dielectrics for magnetic read / write heads. Particularly in the semiconductor industry, miniaturization necessitates atomic-level control over film deposition to create conformal coatings on high aspect ratio structures. One method for controlling and conformally depositing films is atomic layer deposition (ALD), which employs sequential surface reactions to form layers of uniformly precise thickness across all parts of the structure. Most ALD processes are based on a binary reaction sequence for depositing binary compound films. Because the surface reactions are sequential, the two gaseous reactants do not come into contact, limiting the possible gaseous reactions that can form and deposit particles.

[0004] Due to a lack of continuity, poor conformality, inadequate thickness control, and poor compositional control—such as hydrogen contamination and / or varying carbon bonding states within the film—most film properties fail to meet practical requirements. Traditionally, films formed via chemical vapor deposition (CVD) and physical vapor deposition (PVD) processes are often discontinuous and non-conformal. Furthermore, CVD processes typically offer less thickness control than ALD processes and / or may introduce vapor-phase particles, potentially leading to defects in the final device.

[0005] Selective deposition of materials can be accomplished in various ways. For example, some processes can exhibit inherent selectivity for a surface based on its surface chemistry. These processes are rare and typically specific to the reactants used, the materials formed, and the substrate surface. However, selective deposition processes face the same challenges in meeting practical requirements.

[0006] Therefore, a process is needed for the selective deposition of ALD films.

[0007] Overview

[0008] One or more embodiments of this disclosure relate to a method of forming a film. The method includes conformally depositing a first film having a horizontal surface and a vertical surface on a substrate. The substrate includes at least one feature having a top surface, a bottom surface, and sidewalls. The horizontal surface of the first film is treated with a first plasma to form a second film on the horizontal surface. After treatment with the first plasma, the second film has a lower wet etch rate than the first film. The second film on the horizontal surface is treated with a second plasma to form a third film on the horizontal surface. After treatment with the second plasma, the third film has a higher wet etch rate than the second film. The method further includes selectively removing a portion of the first film, the second film, and the third film.

[0009] Further embodiments of this disclosure relate to a processing method, including exposing a substrate to a deposition environment comprising at least one deposition cycle. The at least one deposition cycle includes sequentially exposing the substrate to a silicon precursor and a nitrogen-containing reactant to form a first silicon nitride film on the substrate. The substrate has at least one feature comprising a top surface, a bottom surface, and sidewalls. The first silicon nitride film is treated with a first directional plasma to form a second silicon nitride film. After treatment with the first directional plasma, the second silicon nitride film has a lower wet etch rate than the first silicon nitride film. The second silicon nitride film is treated with a second directional plasma to form a third silicon nitride film. After treatment with the second directional plasma, the third silicon nitride film has a higher wet etch rate than the second silicon nitride film. The processing method further includes removing the third silicon nitride film, a portion of the second silicon nitride film, and the first silicon nitride film.

[0010] Brief description of the attached figures

[0011] To enable a more detailed understanding of the features described above in this disclosure, a more specific description of the disclosure, which has been briefly summarized above, can be obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only typical embodiments of this disclosure and should not be construed as limiting the scope of this disclosure, as other equivalent embodiments are permissible.

[0012] Figure 1A A substrate is illustrated according to one or more embodiments of the present disclosure;

[0013] Figure 1B A substrate is illustrated according to one or more embodiments of the present disclosure;

[0014] Figure 1C A substrate is illustrated according to one or more embodiments of the present disclosure;

[0015] Figure 1D A substrate is illustrated according to one or more embodiments of the present disclosure;

[0016] Figure 1E A substrate is illustrated according to one or more embodiments of the present disclosure;

[0017] Figure 2 A process flow diagram illustrating a method for forming a film according to one or more embodiments of this disclosure; and

[0018] Figure 3 The figure shows a schematic diagram of a capacitively coupled plasma (CCP) chamber according to one or more embodiments of the present disclosure.

[0019] Detailed description

[0020] Before describing several exemplary embodiments of this disclosure, it should be understood that this disclosure is not limited to the details of the construction or process steps set forth in the following description. This disclosure can be implemented in other ways and can be practiced or performed in various manner.

[0021] As used in this specification and the appended claims, the term "substrate" refers to a surface or part thereof on which a process is performed. Those skilled in the art will also understand that reference to a substrate may also refer only to a portion of the substrate, unless the context clearly indicates otherwise. Furthermore, reference to a step of deposition on a substrate can mean both a bare substrate and a substrate having one or more films or features deposited or formed thereon.

[0022] As used herein, “substrate” refers to any substrate on which a film treatment is performed during the manufacturing process, or a material surface formed on a substrate. For example, substrate surfaces on which treatments can be performed depend on the application and include materials such as silicon, silicon oxide, strained silicon, silicon-on-insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials. Substrates include, but are not limited to, semiconductor wafers. Substrates may be exposed to pretreatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, and / or bake substrate surfaces. In addition to performing film treatments directly on the surface of the substrate itself, any film treatment steps disclosed in this disclosure may also be performed on an underlayer formed on the substrate as disclosed in more detail below, and the term “substrate surface” is intended to include this underlayer as indicated by the context. Thus, for example, when a film / layer or a portion of a film / layer has been deposited onto a substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0023] As used herein, the term "horizontal" is defined as a plane parallel to the substrate or the surface of the substrate, regardless of its orientation. In one or more embodiments, the horizontal plane extends from one side of the substrate to the other. As illustrated in the figures, the horizontal plane extends from the left side of the device (left side of the page) to the right side of the device (right side of the page). The term "vertical" refers to a direction perpendicular to the horizontal plane just defined. A vertical plane extends from a point or plane near the substrate to a point or plane away from the substrate. As illustrated in the figures, a vertical plane extends from the top of the device (top of the page) to the substrate (bottom of the page) such that the vertical plane is parallel to the sidewall of the feature. Terms such as "above," "below," "bottom," "top," "side" (e.g., "sidewall"), "higher," "lower," "upper," "above," and "below" are defined relative to the horizontal plane, as shown in the figures. Those skilled in the art will recognize directional descriptions as orientations relative to the device and are not limited to any particular substrate orientation.

[0024] The phrase "on" indicates that there is direct contact between elements. The phrase "directly on" indicates that there is direct contact between elements without any intermediate elements.

[0025] As used in this specification and the appended claims, the terms "reactive gas," "precursor," and "reactant" are used interchangeably to mean a gas containing a substance that reacts with the substrate surface. For example, a first "reactive gas" can be simply adsorbed onto the surface of the substrate and can be used to undergo a further chemical reaction with a second reactive gas.

[0026] As used herein, the term “about” means approximately or close to, and in the context of a stated value or range, means a variation of ±15% or less. For example, values ​​differing by ±14%, ±10%, ±5%, ±2%, or ±1% would satisfy the definition of about.

[0027] The methods described herein employ an atomic layer deposition (ALD) process. As used herein, “atomic layer deposition” or “cyclic deposition” refers to the sequential exposure of two or more reactive compounds to deposit a material layer on a substrate surface. The substrate or a portion of the substrate is exposed to two or more reactive compounds in a reaction zone introduced into a processing chamber. In a time-domain ALD process, the exposure of each reactive compound is separated by a time delay to allow each compound to adhere to and / or react on the substrate surface before being purged out of the processing chamber. These reactive compounds are allegedly exposed to the substrate sequentially. In a spatial ALD process, the substrate surface or different portions of the material on the substrate surface are simultaneously exposed to two or more reactive compounds such that no given point on the substrate is substantially exposed to more than one reactive compound simultaneously. As used in this specification and the appended claims, the term “substantially,” as will be understood by those skilled in the art, means that a small portion of the substrate may be simultaneously exposed to multiple reactive gases due to diffusion, and that such simultaneous exposure is unintentional.

[0028] In one aspect of the time-domain ALD process, a first reactive gas (i.e., a first precursor or compound A) is pulsed into the reaction zone, followed by a first time delay. Then, a second precursor or compound B is pulsed into the reaction zone, followed by a second delay. During each time delay, a purge gas, such as argon, is introduced into the processing chamber to purge the reaction zone or otherwise remove any residual reactive compounds or reaction byproducts from the reaction zone. Alternatively, the purge gas may flow continuously throughout the deposition process, such that only the purge gas flows during the time delay between pulses of the reactive compounds. The reactive compounds are pulsed alternately until a desired film or film thickness is formed on the substrate surface. In either case, the ALD process of pulsed compound A, purge gas, compound B, and purge gas constitutes one cycle. A cycle may begin with compound A or compound B and continue in an individual sequence until a film with a predetermined thickness is obtained.

[0029] In an embodiment of the space ALD process, a first reactive gas and a second reactive gas (e.g., nitrogen) are simultaneously delivered to the reaction zone, but separated by an inert gas curtain and / or a vacuum curtain. The substrate is moved relative to the gas delivery equipment such that any given point on the substrate is exposed to both the first and second reactive gases.

[0030] Some embodiments of this disclosure relate to selective deposition methods that allow for different film properties based on deposition locations on a 3D structure. For example, films deposited on the top and bottom of a structure can be processed to have different film properties than films deposited on the sidewalls of the structure. Some embodiments of this disclosure advantageously provide methods for forming films in which wet etching selectively removes a first and a third film while leaving other portions (e.g., at least a portion of a second film).

[0031] Reference Figures 1A to 1E The illustration shows the substrate 102 during the selective deposition stage of the film. Figure 1A The illustration depicts a substrate 102 including at least one feature 100, which has a top surface 110, a bottom surface 130, and sidewalls 120. For illustrative purposes, the figures illustrate a substrate 102 with a single feature 100; however, those skilled in the art will understand that more than one feature may be present. The shape of feature 102 may be any suitable shape, including, but not limited to, trenches, cylindrical through-holes (for example, for transmitting current between films when filled with metal), and electrodes (which transmit energy within the same film). As used herein, the term "feature" implies any intentional surface irregularity. Features may have any suitable aspect ratio (the ratio of the depth of a feature to the width of a feature). In some embodiments, the aspect ratio is greater than or equal to about 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, or 40:1.

[0032] Figure 1B The illustration depicts a first film 140 conformally deposited on a substrate 102, having both horizontal and vertical surfaces. As used herein, the term "conformal" or "conformally" means a film adhered to and uniformly covering an exposed surface, with a thickness variation of less than 1% relative to the average thickness of the film. For example, The thickness variation of a thicker film will be less than... This thickness and variation at least includes the edges, corners, sides, and bottom of the groove. For example, in various embodiments of this disclosure, a conformal film deposited by ALD will provide coverage over a deposition area of ​​substantially uniform thickness on a complex surface. In one or more embodiments, the conformally deposited first film 140 has a layer of thickness that extends from the edge of the groove. to The thickness is within the range of [specific thickness]. In one or more embodiments, the conformally deposited first film 140 has [a thickness within the range of [specific thickness] from [specific thickness] to The thickness within the range.

[0033] Some embodiments of this disclosure relate to the wet etching rate of the film, as well as other film properties. Without being bound by theory, the wet etching rate of the film can be determined based on a specific chemical process and the amount of time the film spends in the etching solution. In one or more embodiments, the first film 140 is exposed to air, such that a thin layer of native oxide is formed on the first film 140. In one or more embodiments, the first film 140 has a high wet etching rate in a diluted HF 100:1 etching solution. In one or more embodiments, the wet etching rate of the first film 140 on the top surface 110 and bottom surface 130 is at least twice as high as the wet etching rate of the first film 140 on the sidewall 120. In one or more embodiments, the wet etching rate of the first film 140 on the top surface 110 and bottom surface 130 in the diluted HF 100:1 etching solution is... to Within the range.

[0034] Figure 1C Drawing for Figure 1B The first film 140 formed in the process is treated to form a second film 150. In one or more embodiments, the horizontal surface (or top surface) 152 of the first film 140 is treated with a first plasma 160 having a high ion concentration to form the second film 150 on the top surface 110 and bottom surface 130 of feature 100. In one or more embodiments, the plasma having a high ion concentration has a concentration greater than or equal to about 10. 10 / cm 3 The ion concentration. In one or more embodiments, the plasma with a high ion concentration has a concentration greater than or equal to about 10. 9 / cm 3 10 11 / cm 3 10 12 / cm 3 10 13 / cm 3 Or 10 14 / cm 3 The ion concentration. The plasma used in the treatment can be any suitable plasma capable of modifying membrane properties (e.g., direct or remote).

[0035] In one or more embodiments, the first plasma 160 is a directional plasma. As used in this specification and the appended claims, the term "directional plasma" means that the high-energy substances (ions and free radicals) present in the plasma move in a specific direction. For example, in Figure 1CIn the diagram, the first plasma 160 is depicted moving downwards, allowing the high-energy material to contact the first membrane 140 on the top surface 110 and the bottom surface 130, but with minimal contact with the membrane 140 on the sidewall 120. In other words, the first plasma 160 substantially does not affect the membrane 140 on the sidewall 120.

[0036] Directional plasmas can be formed in a variety of other ways. In one or more embodiments, the horizontal surface of the first membrane 140 is exposed to at least one RF frequency. In one or more embodiments, the horizontal surface of the first membrane 140 is exposed to a first RF frequency in the range of 13.56 MHz to 60 MHz to generate directional plasmas and a second RF frequency in the range of 350 kHz to 13.56 MHz to modulate the energy and directionality of the first plasma 160. Directional plasmas can be formed as remote plasmas, wherein plasma material is excited remotely from the substrate surface and flows toward the substrate surface. The substrate may not be part of the electrical path used to generate the plasma. Directional plasmas can also be formed as direct plasmas, wherein the substrate or a substrate support serves as an electrode in plasma formation. Remote plasmas are typically diffused plasmas and can be directionalized by applying a bias voltage to the substrate, causing ions to be attracted to the substrate and move toward the substrate. In one or more embodiments, the directional plasma includes one or more of hydrogen, argon, nitrogen, ammonia, oxygen, and helium. In one or more embodiments, the directional plasma is a capacitively coupled plasma.

[0037] The amount of time used for processing can affect the amount of damage caused to the film on the top and bottom of the feature. The plasma material and power can affect the depth of damage to the film. Processes that cause deeper damage to the film can be repeated fewer times compared to processes that cause shallower damage. For example, He / NH3 plasma can cause deeper damage than Ar / NH3 plasma, allowing for a thicker film deposited prior to He / NH3 plasma treatment.

[0038] In some embodiments, as part of a conformal deposition step in an ALD cycle, the first film 140 is exposed to the first plasma 160 for a duration ranging from 0.5 seconds to 5 seconds. In other embodiments, after a predetermined number of ALD cycles, the first film 140 is exposed to the first plasma 160 for a duration ranging from 1 second to 10 seconds. In other embodiments, after depositing a first film 140 of a predetermined thickness, the first film 140 is exposed to the first plasma 160 for a duration ranging from 1 second to 10 seconds. In a further embodiment, the first film 140 is exposed to the first plasma 160 as part of a post-processing step. In a further embodiment, the post-processing step includes exposing the first film 140 to the first plasma 160 for a duration ranging from 2 seconds to 60 seconds.

[0039] In one or more embodiments, a second film 150 is formed on a horizontal surface on a top surface 110 and a horizontal surface on a bottom surface 130. In one or more embodiments, the second film 150 has a lower wet etching rate than the first film 140. In one or more embodiments, the wet etching rate of the second film 150 in a diluted HF 100:1 etching solution is lower than that of the first film 140. to Within the range. In one or more embodiments, the wet etching rate of the second film 150 in a diluted HF 100:1 etching solution is within the range of... to Within the range.

[0040] Figure 1D Drawing for Figure 1C The second membrane 150 formed in the process is treated to form a third membrane 170. In one or more embodiments, the horizontal surface 172 of the second membrane 150 is treated with a second plasma 165 to form the third membrane 170 on the top surface 110. Figure 1D In this configuration, the second membrane 150 is located on the bottom surface 130. In one or more embodiments, the first plasma 160 and the second plasma 165 are identical. Figure 1D In the diagram, the second plasma 165 is depicted moving downwards, allowing high-energy matter to contact the second membrane 150 on the top surface 110 and the bottom surface 130, but with minimal contact with the first membrane 140 on the sidewall 120. In other words, the second plasma 165 substantially does not affect the membrane 140 on the sidewall 120.

[0041] In one or more embodiments, the third film 170 has a higher wet etching rate than the second film 150. In some embodiments, during the treatment of the second film 150, the wet etching rate of the third film 170 on the top surface 110 increases at a faster rate than the wet etching rate of the second film 150 on the bottom surface 130. In one or more embodiments, the third film 170 has a wet etching rate greater than or equal to that of the second film 150 in a diluted HF 100:1 etching solution. to The range of wet etching rates.

[0042] Figure 1E The illustration depicts the selective removal of a portion of the first film 140, the second film 150, and the third film 170 from the vertical surface and sidewall 120 of feature 100. In one or more embodiments, the first film 140 and the third film 170 are selectively removed by etching with diluted hydrofluoric acid (HF). In one or more embodiments, after the selective removal of a portion of the second film 150, the second film 150 has... to The thickness is within the range. The thickness of the second membrane 150 after selective removal is less than that in the range. Figure 1C The thickness of the second film formed in the middle is 150.

[0043] Refer again Figure 1E The remaining portion of the second film 150 can be used for front-end process (FEOL) dielectric applications, such as gate spacers. In one or more embodiments, the remaining portion of the second film 150 serves as a barrier layer.

[0044] Figures 1B to 1E The illustration shows a selectively deposited ALD film. In one or more embodiments, the first film 140, the second film 150, and the third film 170 independently comprise one or more of metal nitride, silicon nitride (SiN), silicon oxynitride (SiON), and silicon carbonitride (SiOCN).

[0045] The formation of each of the first film 140, the second film 150, and the third film 170 can be performed by any suitable method, including but not limited to atomic layer deposition (ALD), plasma-enhanced atomic layer deposition (PEALD), chemical vapor deposition (CVD), and plasma-enhanced chemical vapor deposition (PECVD). In some embodiments, each of the first film 140, the second film 150, and the third film 170 is formed by an ALD process, wherein the substrate 102 is sequentially exposed to a metal-containing precursor and a nitrogen-containing reactant. In one or more embodiments, the first film 140, the second film 150, and the third film 170 each comprise silicon nitride (SiN). In some embodiments, the silicon-containing precursor and the nitrogen-containing reactant are used to form a film comprising silicon nitride (SiN). As used in this respect, the silicon precursor reacts with the surface of the substrate such that silicon molecules are retained on the substrate 102. As used in this respect, the nitrogen-containing reactant reacts with silicon molecules on the substrate 102.

[0046] Although the following embodiments of this disclosure are described in relation to the deposition of silicon nitride (SiN) films, those skilled in the art will understand that this disclosure is not limited thereto. Other films (e.g., including metal nitride, silicon oxynitride (SiON), and silicon carbonitride (SiOCN) films) can be deposited, processed, and etched.

[0047] In some embodiments, a silicon nitride (SiN) film is formed on substrate 102 by exposing a nitrogen precursor between a silicon precursor and a nitrogen reactant. As used in this regard, a "nitrogen precursor" reacts with the substrate surface and reacts minimally with the silicon material already on substrate 102. In other words, a nitrogen precursor includes a substance that does not react with the silicon precursor molecules on substrate 102. The step of exposing the nitrogen precursor can occur before, during, or after the step of exposing the silicon precursor, because both the nitrogen precursor material and the silicon precursor material react with substrate 102 and react with each other minimally.

[0048] Suitable silicon precursors include, but are not limited to, silane, disilane, dichlorosilane (DCS), bis(diethylamino)silane (BDEAS), tetrakis(dimethylamino)silane (TDMAS), and / or bis(tertiary-butylamino)silane (BTBAS). In some embodiments, the silicon precursor includes dichlorosilane. In one or more embodiments, the silicon precursor consists essentially of dichlorosilane, meaning that the silicon content, excluding dichlorosilane, is less than 1% atomically.

[0049] Suitable nitrogen precursors include, but are not limited to, molecular nitrogen and ammonia. The process conditions employed during nitrogen precursor exposure can affect the reactivity of the nitrogen material with the silicon material on the surface. In some embodiments, the process conditions are configured such that the nitrogen precursor reacts substantially only with the substrate surface. As used herein, the term "substantially only" means that the nitrogen precursor reacts with less than about 10% of the surface silicon material.

[0050] The nitrogen reactant is a substance used to form a metal nitride film on substrate 102. In some embodiments, the nitrogen reactant provides nitrogen atoms for forming the metal nitride film (e.g., SiN). In one or more embodiments, the nitrogen reactant does not contain nitrogen-containing substances and forms the nitride film by promoting a reaction between surface substances. Suitable nitrogen reactants include, but are not limited to, nitrogen plasma, ammonia plasma, and plasmas comprising two or more of hydrogen, nitrogen, ammonia, helium, argon, or oxygen. In some embodiments, the nitrogen reactant includes plasmas of argon and ammonia, argon and nitrogen, argon and oxygen, or helium and ammonia. In some embodiments, the nitrogen reactant includes a nitrogen-free plasma that reacts with nitrogenous substances on the surface. In some embodiments, the nitrogen reactant includes plasmas of hydrogen and argon, or hydrogen and nitrogen, or hydrogen and helium, or hydrogen and ammonia, or hydrogen and oxygen.

[0051] In some embodiments, the step of forming a silicon nitride (SiN) film includes the step of forming the film by sequentially exposing a substrate surface to a silicon precursor including dichlorosilane, a nitrogen precursor including ammonia, and a nitrogen reactant including N2 / Ar plasma or H2 / Ar plasma.

[0052] Figure 2 Draw a process flow diagram illustrating the method for forming the film. Figure 2 Drawing formation Figures 1A to 1E Methods for any membrane according to one or more embodiments shown herein. In some embodiments, the method comprises two processes: membrane deposition and plasma treatment. The methods described herein can be repeated to form a membrane of desired thickness. Each step in the membrane formation process can be repeated sequentially to form a membrane for treatment. The conformally deposited membrane can then be treated and this process repeated.

[0053] Some embodiments of this disclosure are advantageously performed in a single processing chamber. In some embodiments, selective deposition comprises two processes in a single processing chamber: film deposition and plasma treatment. These two processes constitute a single ALD cycle. Metal precursors and nitrogen reactants form a conformally deposited metal nitride film, and plasma treatment modifies the film on the top and bottom surfaces of the feature. The plasma treatment process can form NH or metal oxide bonds on the film surface and penetrate into the film to a certain depth depending on the processing time and plasma power. This has been found to produce higher wet etch rates on the top surface 110 and bottom surface 130 of feature 100. The deposited film thickness and the degree of plasma treatment can be adjusted to increase the selectivity of the wet etch rate. In some embodiments, selective deposition is performed at a substrate temperature in the range of about 200°C to about 550°C.

[0054] Reference Figure 2 Method 200 includes conformally depositing a first film on a substrate in operation 210. The substrate includes at least one feature having a top surface, a bottom surface, and sidewalls. The first film has a horizontal surface and a vertical surface. In one or more embodiments, the step of conformally depositing the first film includes exposing the substrate to a metal-containing precursor and a nitrogen-containing reactant. In one or more embodiments, the step of conformally depositing the first film includes exposing the substrate to a silicon-containing precursor and a nitrogen-containing reactant.

[0055] In operation 220, method 200 includes treating a horizontal surface of a first membrane with a first plasma to form a second membrane on the horizontal surface. In one or more embodiments, the step of treating the horizontal surface of the first membrane includes exposing the membrane to at least one RF frequency. In one or more embodiments, the step of treating the first membrane includes exposing the membrane to a first RF frequency in the range of 13.56 MHz to 60 MHz to generate directional plasma and a second RF frequency in the range of 350 kHz to 13.56 MHz to modulate the energy and directionality of the directional plasma.

[0056] In some embodiments, as part of a conformal deposition step in a single ALD cycle, the first film is exposed to the first plasma for a duration ranging from 0.5 seconds to 5 seconds. In other embodiments, after performing a predetermined number of ALD cycles, the first film is exposed to the first plasma for a duration ranging from 1 second to 10 seconds. In other embodiments, after depositing a first film of a predetermined thickness, the first film is exposed to the first plasma for a duration ranging from 1 second to 10 seconds. In a further embodiment, the first film is exposed to the first plasma as part of a post-processing step. In a further embodiment, the post-processing step includes exposing the first film 140 to the first plasma 160 for a duration ranging from 2 seconds to 60 seconds.

[0057] In operation 230, method 200 includes treating a second film on a horizontal surface with a second plasma to form a third film on the horizontal surface. In one or more embodiments, the third film has a higher wet etch rate than the second film. In operation 240, method 200 includes selectively removing a first film, a portion of the second film, and the third film. In one or more embodiments, the step of removing the third film and the first film includes etching with diluted hydrofluoric acid (HF). In one or more embodiments, the second film has a [missing information - likely a specific characteristic] after selective removal. to The thickness within the range.

[0058] Embodiments of this disclosure provide a method for forming a silicon nitride film. This method can be used to form… Figures 1A to 1E Any membrane of one or more embodiments shown above. The processing method can be described in conjunction with the above references. Figure 2 The methods described are performed under the same or similar process conditions unless otherwise stated. In one or more embodiments, the processing method includes exposing a substrate to a deposition environment comprising at least one deposition cycle. In one or more embodiments, the deposition cycle includes sequentially exposing the substrate to a silicon precursor and a nitrogen-containing reactant to form a first silicon nitride film on the substrate. The substrate has at least one feature including a top surface, a bottom surface, and sidewalls. The processing method includes treating the first silicon nitride film with a first directional plasma to form a second silicon nitride film, and treating the second silicon nitride film with a second directional plasma to form a third silicon nitride film. The processing method further includes removing the third silicon nitride film, a portion of the second silicon nitride film, and the first silicon nitride film. Embodiments of this disclosure provide repeated deposition cycles to form a film having a... to The thickness of the first silicon nitride film within the range.

[0059] Figure 3The illustration shows a schematic diagram of a capacitively coupled plasma (CCP) chamber 300. The CCP chamber 300 can be used as a component of a processing chamber. The CCP chamber 300 can be used to generate plasma within a processing chamber. In one or more embodiments, the CCP chamber 300 includes a top electrode 310 and a bottom electrode 320. In one or more embodiments, RF plasma 350 can be generated and fed via one or more of a first RF power source 360 ​​and a second RF power source 370. In one or more embodiments, the top electrode 310 is a nozzle. In one or more embodiments, the bottom electrode 320 is a base. In one or more embodiments, a wafer 330 is disposed on the bottom electrode 320. As used in this specification and the appended claims, the term "provided" as used in this manner means that the wafer 330 is placed or positioned in an environment for processing. In one or more embodiments, Figures 1A to 1E One or more films of the embodiments shown are deposited on wafer 330.

[0060] In one or more embodiments, RF plasma 350 is formed between the first electrode 310 and the bottom electrode 320. In one or more embodiments, a sheath 340 represents the direction of electric field flow. Figure 3 In the embodiment illustrated, shell 340 shows an electric field flowing downwards toward bottom electrode 320. In one or more embodiments, the electric field flows upwards toward top electrode 310 (not shown).

[0061] According to one or more embodiments, a substrate is processed before and / or after film formation. This processing may be performed in a single processing chamber or in one or more separate processing chambers. In some embodiments, the substrate is moved from a first chamber to a separate second chamber for further processing. The substrate may be moved directly from the first chamber to a separate processing chamber, or the substrate may be moved from the first chamber to one or more transfer chambers and then to a separate processing chamber. Thus, the processing apparatus may include multiple chambers communicating with transfer stations. Such apparatus may be referred to as a “clustering tool” or a “clustering system”, etc.

[0062] Generally, clustering tools are modular systems comprising multiple chambers that perform various functions, including substrate centering and orientation, annealing, deposition, and / or etching. According to one or more embodiments, a clustering tool includes at least a first chamber and a central transfer chamber. The central transfer chamber houses a robot that can transfer substrates between the processing chamber and the loading and locking chamber. The transfer chamber is typically maintained under vacuum conditions and provides intermediate stages for transferring substrates from one chamber to another and / or to the loading and locking chamber located at the front end of the clustering tool. Two well-known clustering tools applicable to this disclosure are... and Both are available from Applied Materials, Inc., Santa Clara, California. However, the exact arrangement and combination of the chambers can be varied to perform the specific steps of the processes described herein. Other processing chambers that can be used include, but are not limited to, circulating layer deposition (CLD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, pre-cleaning, chemical cleaning, thermal treatments such as RTP, plasma nitriding, annealing, orientation, hydroxylation, and other substrate processes. By performing the process in a chamber on a cluster tool, surface contamination of the substrate by atmospheric impurities can be avoided, and oxidation can occur before subsequent films are deposited.

[0063] According to one or more embodiments, the substrate is continuously under vacuum or "load-locked" conditions and is not exposed to ambient air while moving from one chamber to the next. The transfer chamber is therefore under vacuum and "evacuated" under vacuum pressure. An inert gas may be present in the processing chamber or the transfer chamber. In some embodiments, the inert gas is used as a purge gas to remove some or all of the reactants. According to one or more embodiments, purge gas is injected at the outlet of the deposition chamber to prevent reactants from moving from the deposition chamber to the transfer chamber and / or additional processing chambers. Thus, the flow of inert gas forms a curtain at the outlet of the chamber.

[0064] Substrates can be processed in a single-substrate deposition chamber, where a single substrate is loaded, processed, and unloaded before processing another substrate. Substrates can also be processed continuously, similar to a transport system, where multiple substrates are individually loaded into a first portion of the chamber, moved through the chamber, and unloaded from a second portion of the chamber. The shape of the chamber and the associated transport system can form a straight path or a curved path. Alternatively, the processing chamber can be a carousel, where multiple substrates move about a central axis and are exposed to processes such as deposition, etching, annealing, and cleaning throughout the rotational path.

[0065] During processing, the substrate can be heated or cooled. This heating or cooling can be accomplished by any suitable means, including, but not limited to, changing the temperature of the substrate support and flowing heating or cooling gases to the substrate surface. In some embodiments, the substrate support includes a heater / cooler that can be controlled to change the substrate temperature conductively. In one or more embodiments, the employed gas (reactive or inert gas) is heated or cooled to locally change the substrate temperature. In some embodiments, the heater / cooler is positioned in a chamber adjacent to the substrate surface to change the substrate temperature convectively.

[0066] The substrate can be stationary or rotating during processing. The rotating substrate can rotate continuously or in discrete steps. For example, the substrate can rotate throughout the entire process, or it can rotate slightly between exposures to different reactive or purge gases. Rotating the substrate during processing (continuously or in stages) can help produce more uniform deposition or etching by minimizing the effects of, for example, localized changes in airflow geometry.

[0067] Throughout this specification, references to "one embodiment," "some embodiments," "one or more embodiments," or "implementation" mean that a particular feature, structure, material, or characteristic described in connection with this embodiment is included in at least one embodiment of this disclosure. Therefore, phrases appearing throughout this specification such as "in one or more embodiments," "in some embodiments," "in one embodiment," or "in an embodiment" do not necessarily refer to the same embodiment of this disclosure. Furthermore, in one or more embodiments, a particular feature, structure, material, or characteristic may be combined in any suitable manner.

[0068] Although this disclosure has been described with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of this disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatus of this disclosure without departing from the spirit and scope of this disclosure. Therefore, it is contemplated that this disclosure includes modifications and variations within the scope of the appended claims and their equivalents.

Claims

1. A method for forming a membrane, the method comprising the following steps: A first film is conformally deposited on a substrate, the substrate including at least one feature having a top surface, a bottom surface and a sidewall, and the first film having a horizontal surface and a vertical surface; The horizontal surface of the first film is treated with a first plasma to form a second film on the horizontal surface, the second film having a lower wet etching rate than the first film; The second film on the horizontal surface is treated by a second plasma to form a third film on the horizontal surface, the third film having a higher wet etching rate than the second film; and Selectively remove the first membrane, a portion of the second membrane, and the third membrane. The first film, the second film, and the third film independently include one or more of metal nitride, silicon nitride, silicon oxynitride, and silicon carbonitride.

2. The method of claim 1, further comprising the following steps: Repeat the above method.

3. The method of claim 1, wherein the step of conformally depositing the first film comprises the following steps: The substrate is exposed to silicon-containing precursors and nitrogen reactants.

4. The method of claim 1, wherein the step of conformally depositing the first film comprises the following steps: The substrate is exposed to a metal precursor and a nitrogen reactant.

5. The method of claim 1, wherein the wet etching rate of the second film is in the range of 2 Å / min to 5 Å / min, and the wet etching rate of the third film is in the range of 10 Å / min to 15 Å / min.

6. The method of claim 1, wherein the first membrane has a thickness in the range of 20 Å to 100 Å.

7. The method of claim 1, wherein the step of treating the first membrane comprises the following steps: The membrane is exposed to a first RF frequency in the range of 13.56 MHz to 60 MHz to generate directional plasma, and a second RF frequency in the range of 350 kHz to 13.56 MHz to adjust the energy and directionality of the directional plasma.

8. The method of claim 7, wherein the directional plasma comprises one or more of hydrogen, argon, nitrogen, ammonia, oxygen, and helium.

9. The method of claim 7, wherein the directional plasma is a capacitively coupled plasma.

10. The method of claim 7, wherein the first membrane is exposed to the directional plasma for a duration ranging from 0.5 seconds to 60 seconds.

11. The method of claim 1, wherein the first plasma is the same as the second plasma.

12. The method of claim 1, wherein during the treatment of the second film, the wet etching rate of the third film on the top surface increases at a rate faster than the wet etching rate of the second film on the bottom surface.

13. The method of claim 1, wherein the step of removing the third membrane and the first membrane comprises the following steps: Etching is performed using diluted hydrofluoric acid (HF).

14. A processing method, comprising the following steps: Expose a substrate to a deposition environment, the deposition environment including at least one deposition cycle, the deposition cycle including sequentially exposing the substrate to a silicon precursor and a nitrogen-containing reactant to form a first silicon nitride film on the substrate, the substrate having at least one feature, the at least one feature including a top surface, a bottom surface and a sidewall. The first silicon nitride film is treated with a first directional plasma to form a second silicon nitride film, the second silicon nitride film having a lower wet etching rate than the first silicon nitride film; The second silicon nitride film is treated with a second directional plasma to form a third silicon nitride film, the third silicon nitride film having a higher wet etching rate than the second silicon nitride film; and Remove the third silicon nitride film, a portion of the second silicon nitride film, and the first silicon nitride film.

15. The method of claim 14, further comprising the following steps: The deposition cycle is repeated to form a first silicon nitride film with a thickness ranging from 20 Å to 100 Å.

16. The method of claim 14, wherein the first directional plasma and the second directional plasma independently comprise one or more of hydrogen, argon, nitrogen, ammonia, oxygen, and helium.

17. The method of claim 16, wherein the first directional plasma and the second directional plasma are capacitively coupled plasmas.

18. The method of claim 14, wherein the first silicon nitride film is exposed to the first directional plasma for a period ranging from 0.5 seconds to 60 seconds.

19. The method of claim 14, wherein the removal step comprises the following steps: Etching is performed using diluted hydrofluoric acid (HF).

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