Method of manufacturing a semiconductor element with an etch-resistant nitride layer

Abstract

A method for fabricating a semiconductor device is provided, including: providing a substrate in a reaction chamber; forming an untreated silicon nitride film on the substrate; and forming a treated silicon nitride film on the untreated silicon nitride film. Forming the untreated silicon nitride film includes: (a) supplying a first silicon precursor into the reaction chamber; and (b) supplying a nitrogen precursor into the reaction chamber. (a) and (b) are performed sequentially and repeatedly to form the untreated silicon nitride film. Forming the treated silicon nitride film includes: (c) supplying a second silicon precursor into the reaction chamber; (d) performing a first hydrogen radical purge by supplying a plurality of hydrogen radicals into the reaction chamber to reduce impurities in chemical species from the second silicon precursor; and (e) supplying a second nitrogen precursor into the reaction chamber. (c), (d), and (e) are performed sequentially and repeatedly to form the treated silicon nitride film. The untreated silicon nitride film and the treated silicon nitride film together form a silicon nitride layer.

Description

Technical Field

[0001] This disclosure claims priority to and the benefit of U.S. regular application No. 17 / 077,685, filed on October 22, 2020, the contents of which are incorporated herein by reference in their entirety.

[0002] The present disclosure relates to a method for preparing a semiconductor element, and more particularly to a method for preparing a semiconductor element having an etching-resistant nitride layer. Background Art

[0003] Semiconductor devices are used in a variety of electronic applications, such as personal computers, mobile phones, digital cameras, and other electronic devices. Semiconductor device sizes are steadily decreasing to meet the increasing demand for computing power. However, during this process of size reduction, various challenges arise, and these challenges continue to increase in number and complexity. Consequently, achieving improvements in quality, yield, performance, and reliability, while reducing complexity, remains a constant challenge.

[0004] The above description of “prior art” is merely to provide background technology, and does not admit that the above description of “prior art” discloses the subject matter of the present disclosure, does not constitute the prior art of the present disclosure, and any description of the above “prior art” should not be regarded as any part of the present disclosure. Summary of the Invention

[0005] One embodiment of the present disclosure provides a method for fabricating a semiconductor device, comprising: providing a substrate in a reaction chamber; forming an untreated silicon nitride film on the substrate; and forming a treated silicon nitride film on the untreated silicon nitride film. Forming the untreated silicon nitride film includes the following steps: (a) supplying a first silicon precursor into the reaction chamber, thereby allowing multiple chemical species from the first silicon precursor to be absorbed on the substrate; and (b) supplying a first nitrogen precursor into the reaction chamber, thereby nitriding the chemical species to deposit the resulting silicon nitride on the substrate. Steps (a) and (b) are performed sequentially and repeatedly to form the untreated silicon nitride film. Forming the treated silicon nitride film includes the following steps: (c) supplying a second silicon precursor into the reaction chamber, thereby allowing multiple chemical species from the second silicon precursor to be absorbed onto the untreated silicon nitride film; (d) performing a first hydrogen radical scavenging step by supplying multiple hydrogen radicals into the reaction chamber to reduce impurities in the chemical species from the second silicon precursor; and (e) supplying a second nitrogen precursor into the reaction chamber, thereby nitriding the chemical species from the second silicon precursor to deposit the resulting silicon nitride on the untreated silicon nitride film. Steps (c), (d), and (e) are sequentially and repeatedly performed to form the treated silicon nitride film. The untreated silicon nitride film and the treated silicon nitride film together form a silicon nitride layer.

[0006] In some embodiments, the first silicon precursor and the second silicon precursor include dichlorosilane.

[0007] In some embodiments, the first nitrogen precursor and the second nitrogen precursor include ammonia gas.

[0008] In some embodiments, the hydrogen radicals in step (d) are generated in a plasma generating unit by supplying hydrogen gas through the plasma generating unit.

[0009] In some embodiments, the step (d) includes a stabilizing stage, a flowing stage, and a vacuuming stage.

[0010] In some embodiments, during the flow phase of step (d), a process pressure in the reaction chamber is between about 40 Pa and about 100 Pa.

[0011] In some embodiments, during the flow phase of step (d), a process pressure in the plasma generating unit is between about 70 Pa and about 400 Pa.

[0012] In some embodiments, during the flowing phase of step (d), a flow rate of the hydrogen radicals is between about 0.5 slm and about 5 slm.

[0013] In some embodiments, during the flow phase of step (d), a process frequency of the plasma generating unit is between about 10.00 MHz and about 15.00 MHz.

[0014] In some embodiments, forming the treated silicon nitride film further includes a step (f) of performing a second hydrogen radical scavenging step by supplying a plurality of hydrogen radicals into the reaction chamber.

[0015] Another embodiment of the present disclosure provides a method for preparing a semiconductor device, comprising: providing a substrate in a reaction chamber; and forming a silicon nitride layer on the substrate by repeatedly forming an untreated silicon nitride film and a treated silicon nitride film. Forming the untreated silicon nitride film comprises the following steps: (a) supplying a first silicon precursor into the reaction chamber, thereby allowing a plurality of chemical species from the first silicon precursor to be absorbed on the substrate; (b) supplying a first nitrogen precursor into the reaction chamber, thereby nitriding the chemical species to deposit the resulting silicon nitride on the substrate; (c) sequentially and repeatedly performing steps (a) and (b) to form the untreated silicon nitride film; (d) supplying a second silicon precursor into the reaction chamber, thereby allowing a plurality of chemical species from the second silicon precursor to be absorbed on the substrate; (e) supplying a second silicon precursor into the reaction chamber, thereby allowing a plurality of chemical species from the second silicon precursor to be absorbed on the substrate; (f) supplying a second silicon precursor into the reaction chamber, thereby allowing a plurality of chemical species from the second silicon precursor to be absorbed on the substrate; (g) supplying a second silicon precursor into the reaction chamber, thereby allowing a plurality of chemical species from the second silicon precursor to be absorbed on the substrate; (h) supplying a first silicon precursor into the reaction chamber, thereby nitriding the chemical species to deposit the resulting silicon nitride on the substrate; (h) supplying a second silicon precursor into the reaction chamber, thereby allowing a plurality of chemical species from the second silicon precursor to be absorbed on the substrate; (h) supplying a first silicon precursor into the reaction chamber, thereby allowing a plurality of chemical species from the first ... (e) performing a first hydrogen radical scavenging step by providing a plurality of hydrogen radicals into the reaction chamber to reduce impurities in the chemical species from the second silicon precursor; (f) supplying a second nitrogen precursor into the reaction chamber to nitride the chemical species from the second silicon precursor to deposit the resulting silicon nitride on the untreated silicon nitride film; and (g) sequentially and repeatedly performing the steps (c), (d), and (e) to form the treated silicon nitride film.

[0016] In some embodiments, the first silicon precursor and the second silicon precursor include dichlorosilane.

[0017] In some embodiments, the first nitrogen precursor and the second nitrogen precursor include ammonia.

[0018] In some embodiments, the hydrogen radicals in step (e) are generated in a plasma generating unit by supplying hydrogen gas through the plasma generating unit.

[0019] In some embodiments, step (a) includes a stabilization stage, a flow stage, and a purging and vacuuming stage.

[0020] In some embodiments, during the flow phase of step (a), a process temperature is between about 200°C and about 550°C.

[0021] In some embodiments, during the flow phase of step (a), a flow rate of the first silicon precursor is between about 1 slm and about 5 slm.

[0022] In some embodiments, during the flow phase of step (a), a process pressure is between about 400 Pa and about 1200 Pa.

[0023] In some embodiments, step (b) includes a stabilization phase, a flow phase, and a purge and vacuum phase.

[0024] In some embodiments, during the flow phase of step (b), a process frequency of the plasma generating unit is between about 10.00 MHz and about 15.00 MHz.

[0025] Due to the design of the semiconductor device disclosed herein, the impurity concentration of the resulting silicon nitride layer can be reduced, thereby improving the wet etch resistance of the silicon nitride layer and thereby improving the yield, quality, and reliability of the semiconductor device.

[0026] The above has been a fairly broad overview of the technical features and advantages of the present disclosure, so that the detailed description of the present disclosure below can be better understood. Other technical features and advantages that constitute the subject matter of the claims of the present disclosure will be described below. It should be understood by those skilled in the art of the present disclosure that the concepts and specific embodiments disclosed below can be used to modify or design other structures or processes to achieve the same purpose as the present disclosure. It should also be understood by those skilled in the art of the present disclosure that such equivalent constructions cannot depart from the concept and scope of the present disclosure as defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] A more complete understanding of the disclosure of the present invention may be obtained by referring to the embodiments and claims in conjunction with the accompanying drawings, in which like reference numerals refer to like elements.

[0028] Figure 1 A schematic flow chart illustrating a method for manufacturing a semiconductor device according to an embodiment of the present disclosure.

[0029] Figure 2 A schematic cross-sectional view illustrating a portion of a process for fabricating a semiconductor device according to an embodiment of the present disclosure.

[0030] Figure 3A process chart illustrating process conditions for forming an untreated silicon nitride film according to some embodiments of the present disclosure.

[0031] Figure 4 A schematic cross-sectional view illustrating a portion of a process for fabricating a semiconductor device according to an embodiment of the present disclosure.

[0032] Figure 5 A process chart illustrating process conditions for forming a treated silicon nitride film according to some embodiments of the present disclosure.

[0033] Figure 6 A process chart illustrating process conditions for forming a treated silicon nitride film according to some embodiments of the present disclosure.

[0034] Figure 7 A schematic flow chart illustrating a method for manufacturing a semiconductor device according to another embodiment of the present disclosure.

[0035] Figure 8 and Figure 9 A schematic cross-sectional view illustrating a portion of a process for manufacturing a semiconductor device according to another embodiment of the present disclosure.

[0036] Figures 10 to 15 Schematic cross-sectional views of semiconductor devices illustrating some embodiments of the present disclosure.

[0037] Explanation of symbols

[0038] 1A: Semiconductor components

[0039] 1B: Semiconductor components

[0040] 1C: Semiconductor components

[0041] 1D: Semiconductor components

[0042] 1E: Semiconductor components

[0043] 1F: Semiconductor components

[0044] 1G: Semiconductor components

[0045] 1H: semiconductor components

[0046] 10: Preparation method

[0047] 101: Base

[0048] 20: Preparation method

[0049] 200: Silicon nitride layer

[0050] 201: Silicon nitride sub-membrane

[0051] 300: Untreated silicon nitride film

[0052] 301: Untreated silicon nitride sub-film

[0053] 400: Silicon nitride film after treatment

[0054] 401: Silicon nitride sub-film after treatment

[0055] 501: First silicon precursor supply step

[0056] 503: First nitrogen precursor supply step

[0057] 601: Second silicon precursor supply step

[0058] 603: First hydrogen radical scavenging step

[0059] 605: Second nitrogen precursor supply step

[0060] 607: Second hydrogen radical scavenging step

[0061] S11: Steps

[0062] S13: Steps

[0063] S15: Steps

[0064] S21: Steps

[0065] S23: Steps

[0066] Z: Direction DETAILED DESCRIPTION

[0067] Specific examples of components and configurations are described below to simplify the embodiments of the present disclosure. Of course, these embodiments are for illustration only and are not intended to limit the scope of the present disclosure. For example, the description of a first component formed on a second component may include embodiments in which the first and second components are in direct contact, and may also include embodiments in which additional components are formed between the first and second components so that the first and second components are not in direct contact. In addition, the embodiments of the present disclosure may repeat reference numbers and / or letters in many examples. The purpose of these repetitions is for simplicity and clarity, and unless otherwise specified in the text, they do not themselves represent a specific relationship between the various embodiments and / or configurations discussed.

[0068] Furthermore, for ease of description, spatially relative terms, such as "beneath," "below," "lower," "above," and "upper," may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different orientations of the element in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0069] It should be understood that when forming a component on, connected to, and / or coupled to another component, it may include embodiments in which these components are in direct contact, and may also include embodiments in which additional components are formed between these components so that these components do not directly contact.

[0070] It should be understood that although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, or sections, these elements, components, regions, layers, or sections are not limited by these terms. Instead, these terms are used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Therefore, without departing from the teachings of the progressive concept of the present invention, the first element, component, region, layer, or section discussed below may be referred to as a second element, component, region, layer, or section.

[0071] Unless the context indicates otherwise, as used herein, terms such as "same," "equal," "planar," or "coplanar" when referring to orientation, layout, location, shapes, sizes, amounts, or other measures do not necessarily mean an exactly identical orientation, layout, location, shape, size, amount, or other measure, but rather mean nearly identical orientation, layout, location, shape, size, amount, or other measure within acceptable variations that may occur, for example, due to manufacturing processes. The term "substantially" may be used herein to convey this meaning. For example, terms such as substantially the same, substantially equal, or substantially planar are exactly the same, equal, or planar, or they may be the same, equal, or planar within acceptable variations, such as may occur due to the manufacturing process.

[0072] It should be understood that the term "about" modifies a quantity of an ingredient, component, or reactant of the present disclosure to indicate variation in the numerical quantity that may occur, for example, through typical measurements and liquid handling procedures used to make concentrates or solutions. Furthermore, variation may arise from inadvertent error in measurement procedures used to make the compositions or perform the methods or the like, differences in manufacturing, source, or purity of the ingredients. In one aspect, the term "about" means within 10% of the reported value. In another aspect, the term "about" means within 5% of the reported value. In yet another aspect, the term "about" means within 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1% of the reported value.

[0073] In the present disclosure, a semiconductor device generally refers to a device that can operate by utilizing semiconductor characteristics, and an electro-optical device, a light-emitting display device, a semiconductor circuit, and an electronic device are all included in the scope of semiconductor devices.

[0074] It should be understood that in the description of the present disclosure, above (or up) is the direction corresponding to the Z-direction arrow, and below (or down) is the relative direction corresponding to the Z-direction arrow.

[0075] Figure 1 A schematic flow chart illustrating a method 10 for manufacturing a semiconductor device 1A according to an embodiment of the present disclosure is shown. Figure 2 A schematic cross-sectional view illustrating a portion of a manufacturing process of the semiconductor device 1A according to an embodiment of the present disclosure. Figure 3 A process chart illustrating process conditions for forming an untreated silicon nitride film 300 according to some embodiments of the present disclosure.

[0076] Please refer to Figure 1 and Figure 2 In step S11 , a substrate 101 may be provided to a reaction chamber.

[0077] Please refer to Figure 2 In some embodiments, the substrate 101 may include a semiconductor wafer, such as crystalline silicon (eg, silicon <100> or silicon <111> ), silicon oxide, strained silicon, silicon-on-insulator (SOI), silicon germanium, a doped or undoped polysilicon wafer, or the like, but are not limited thereto. In some embodiments, the top surface of the substrate 101 may include the following regions: bare silicon, a barrier material, a low-k or high-k dielectric material, a conductive material, or the like. In some embodiments, the top surface of the substrate 101 may include a plurality of trenches, a plurality of openings, a plurality of holes, a plurality of recesses, or the like.

[0078] In some embodiments, the substrate 101 may be pre-treated by selectively performing a plurality of processes, such as polishing, annealing, baking, etching, reduction, oxidation, halogenation, hydroxylation, or the like.

[0079] Please refer to Figures 1 to 3 In step S13 , an untreated silicon nitride film 300 may be formed on the substrate 101 .

[0080] Please refer to Figure 2 and Figure 3 The fabrication technique for an untreated silicon nitride film may include a first deposition process. The first deposition process may be an atomic layer deposition process. Generally speaking, an atomic layer deposition process involves alternately supplying two (or more) different source gases to a process object under a plurality of predetermined process conditions, such that multiple chemical species from the source gases are adsorbed onto the process object at a single atomic layer level and deposited on the process object via a plurality of surface reactions. For example, a first gas and a second gas are alternately supplied to a process object to flow along its surface, whereby multiple molecules (or multiple chemical species) contained in the first source gas are adsorbed onto the surface of the process object, and multiple molecules (or multiple chemical species) contained in the second source gas react with the adsorbed molecules from the first source gas to form a film of a thickness at a single molecular level. The aforementioned process steps are repeatedly performed to form a high-quality film on the process object.

[0081] Next, the first deposition process may include a first silicon precursor supply step 501 and a first nitrogen precursor supply step 503 performed in sequence. In the first silicon precursor supply step 501, a first silicon precursor may be supplied to the reaction chamber, and multiple chemical species from the first silicon precursor may be adsorbed onto the upper surface of the substrate 101 at a single atomic layer level. In the first nitrogen precursor supply step 503, a first nitrogen precursor may be activated and supplied to the reaction chamber, and multiple chemical species contained in the first nitrogen precursor may react with the adsorbed chemical species from the first silicon precursor to form an untreated silicon nitride sub-film 301 having a thickness at a single molecular level. The untreated silicon nitride sub-film 301 may be formed on the upper surface of the substrate 101.

[0082] In some embodiments, the first silicon precursor supplying step 501 may include a stabilizing stage, a flowing stage, and a purging and vacuuming stage.

[0083] Please refer to Figure 2 and Figure 3 During the stabilization phase of the first silicon precursor supply step 501, a dilution gas (or a carrier gas), such as nitrogen, may be supplied to the reaction chamber. A flow rate of the diluent may be between approximately 0.3 slm (standard liter per minute) and approximately 0.7 slm. For example, in the embodiment described, the flow rate of the dilution gas may be 0.5 slm. A process temperature during the stabilization phase may be between approximately 25°C and approximately 700°C, between approximately 50°C and approximately 600°C, between approximately 100°C and approximately 500°C, between approximately 200°C and approximately 450°C, or between approximately 350°C and approximately 425°C. For example, in the embodiment described, the process temperature during the stabilization phase may be 400°C. A process pressure in the stable stage may be between about 200 Pa and about 600 Pa, between about 300 Pa and about 500 Pa, or between about 350 Pa and about 450 Pa. For example, in this embodiment, the process pressure in the stable stage may be 400 Pa.

[0084] Please refer to Figure 2 and Figure 3In the flow phase of the first silicon precursor supplying step 501, the first silicon precursor may be supplied to the reaction chamber while simultaneously supplying a dilution gas. The chemical species from the first silicon precursor may be adsorbed onto the upper surface of the substrate 101 at a single atomic layer level. In some embodiments, the first silicon precursor may include a halide, such as iodine (I) or chlorine (Cl). In the described embodiment, for example, the first silicon precursor may be dichlorosilane. The reaction between the first silicon precursor and the substrate 101 may be as shown in Chemical Equation 1. In some embodiments, for example, the first silicon precursor may include silicon tetrachloride, trichlorosilane, dichlorosilane, or hexachlorodisilane. In some embodiments, for example, the first silicon precursor may include silicon tetraiodide, triiodosilane, diiodosilane, iodosilane, disilicon hexaiodide, trisilicon octaiodide, H2Si2I4, H3Si2I3, H4Si2I2, H5Si2I, or HSi2I5. In some embodiments, the first silicon precursor may include one of the following: triiodosilane, diiodosilane, iodosilane, H2Si2I4, H4Si2I2, and H5Si2I. In some embodiments, the first silicon precursor may include two, three, four, five, or six of the following: triiodosilane, diiodosilane, iodosilane, H2Si2I4, H4Si2I2, and H5Si2I, including any combination thereof.

[0085]

[0086] Please refer to Figure 2 and Figure 3In the flow phase of the first silicon precursor supplying step 501, a flow rate of the first silicon precursor may be between about 1 slm and about 5 slm, or between about 3 slm and about 4.5 slm. For example, in the embodiment described, the flow rate of the first silicon precursor may be 1 slm. If the flow rate of the first silicon precursor is less than 1 slm, the amount of the first silicon precursor may not be sufficient to supply the nitrogen atoms on the upper surface of the substrate 101. If the flow rate of the first silicon precursor is greater than 5 slm, the amount of the first silicon precursor may not react with the nitrogen atoms on the upper surface of the substrate 101. A flow rate of the dilution gas may be between about 0.3 slm and about 0.7 slm. For example, in the embodiment described, the flow rate of the dilution gas may be 0.5 slm.

[0087] Please refer to Figure 2 and Figure 3 In the flow phase of the first silicon precursor supplying step 501, a process temperature of the flow phase may be between about 200°C and about 550°C. For example, in the embodiment described, the process temperature of the flow phase may be 400°C. If the process temperature is lower than 200°C, the chemical species from the first silicon precursor may not be absorbed onto the upper surface of the substrate 101. If the process temperature is greater than 550°C, the reliability of the transistors in the substrate 101 may be affected and the thickness of the resulting silicon nitride layer in region 3 may be shallower. In other words, the thickness uniformity of the resulting nitride layer may be worse. In some embodiments, the process temperature of the flow phase may be between about 390°C and about 410°C. By using the aforementioned temperature range, the deposition rate can be increased, and various characteristics of the resulting silicon nitride layer, such as thickness uniformity, wet etch resistance, and film stress, can be improved.

[0088] Please refer to Figure 2 and Figure 3 In the flow phase of the first silicon precursor supplying step 501, a process pressure in the flow phase may be between about 400 Pa and about 1200 Pa, between about 600 Pa and about 1100 Pa, or between about 800 Pa and about 1000 Pa. For example, in the present disclosure, the process pressure in the flow phase may be 850 Pa. By using the aforementioned pressure range, the reaction rate between the plurality of nitrogen atoms and the first silicon precursor can be increased, and the pressure can be continuously adjusted.

[0089] Please refer to Figure 2 and Figure 3During the purge and vacuum phase of the first silicon precursor supply step 501, the supply of the first silicon precursor may be stopped. A flow rate of a dilution gas may be increased to purge the reaction chamber. For example, the flow rate of the dilution gas may be between approximately 3 slm and approximately 7 slm. In the embodiment described, the flow rate of the dilution gas may be 5 slm.

[0090] In some embodiments, the first nitrogen precursor supply step 503 may include a stabilization phase, a flow phase, and a purge and vacuum phase.

[0091] Please refer to Figure 2 and Figure 3 During the stabilization phase of the first nitrogen precursor supply step 503, a dilution gas, such as nitrogen, may be supplied to the reaction chamber. A flow rate of the dilution gas may be between approximately 0.3 slm and approximately 0.7 slm. For example, in the embodiment described, the flow rate of the dilution gas may be 0.5 slm. A process temperature during the stabilization phase may be between approximately 25°C and approximately 700°C, between approximately 50°C and approximately 600°C, between approximately 100°C and approximately 500°C, between approximately 200°C and approximately 450°C, or between approximately 350°C and approximately 425°C. For example, in the embodiment described, the process temperature during the stabilization phase may be 400°C. A process pressure during the stabilization phase may be between approximately 10 Pa and approximately 70 Pa, between approximately 20 Pa and approximately 60 Pa, or between approximately 30 Pa and approximately 50 Pa. For example, in the embodiment of the present disclosure, the process pressure during the stabilization phase may be 50 Pa.

[0092] Please refer to Figure 2 and Figure 3 During the flow phase of the first nitrogen precursor supplying step 503, while supplying the diluent gas, the first nitrogen precursor may be activated in a plasma generating unit and then supplied to the reaction chamber. The chemical species contained in the activated first nitrogen precursor may react with the adsorbed chemical species from the first silicon precursor to form the untreated silicon nitride sub-film 301 on the upper surface of the substrate 101. For example, the first nitrogen precursor may be aqueous ammonia.

[0093] Please refer to Figure 2 and Figure 3During the flow phase of the first nitrogen precursor supply step 503, a radio frequency (RF) in the plasma generating unit may be turned on to activate the first nitrogen precursor. The RF power during the flow phase may be between about 50 W and about 1000 W, or between about 100 W and about 300 W. If the RF power during the flow phase is greater than 1000 W, the quartz walls of the plasma generating unit may be damaged. The RF power density during the flow phase may be between about 0.02 W / cm 2 To about 2.0W / cm 2 or between approximately 0.05W / cm 2 To about 1.5W / cm 2 The process frequency of the plasma generating unit may be between approximately 10.00 MHz and approximately 15.00 MHz. For example, in the embodiment described above, the process frequency of the plasma generating unit during the flow phase may be 13.56 MHz. In the embodiment described above, the activated first nitrogen precursors may be a plurality of ammonia radicals (NH3*). The activated first nitrogen precursors may be supplied to the reaction chamber in a plasma form.

[0094] Please refer to Figure 2 and Figure 3 During the flow phase of the first nitrogen precursor supply step 503, the flow rate of the activated first nitrogen precursor may be between approximately 0.5 slm and approximately 5 slm, or between approximately 3 slm and approximately 5 slm. By using the aforementioned flow rate ranges, a plasma of the activated first nitrogen precursor can be continuously generated, and the amount of the activated first nitrogen precursor is sufficient to react with the adsorbed chemical species from the first silicon precursor. In the described embodiment, for example, the flow rate of the activated first nitrogen precursor may be 3 slm. It should be understood that a dilution gas may still be supplied during the flow phase, and the flow rate of the dilution gas may be between approximately 0.3 slm and approximately 0.7 slm. For example, in the described embodiment, the flow rate of the dilution gas may still be 0.5 slm.

[0095] Please refer to Figure 2 and Figure 3During the flow phase of the first nitrogen precursor supplying step 503, a process pressure in the reaction chamber may be between about 40 Pa and about 100 Pa, or between about 50 Pa and about 70 Pa. For example, in the embodiment described, the process pressure in the reaction chamber may be 50 Pa. A process pressure in the plasma generating unit may be between about 70 Pa and about 600 Pa, or between about 280 Pa and about 330 Pa. By using the aforementioned process pressure range in the plasma generating unit, plasma of the activated first nitrogen precursor can be continuously generated, and the amount of the activated first nitrogen precursor can be sufficient to react with the adsorbed chemical species from the first silicon precursor.

[0096] Please refer to Figure 2 and Figure 3 During the flow phase of the first nitrogen precursor supply step 503, the reaction between the activated first nitrogen precursor and the chemical species derived from the absorbed first silicon precursor can be shown as shown in Chemical Reaction Formulas 2 and 3. An untreated silicon nitride sub-film 301 containing —NH—SiH2(NH2) and —NH—SiHCl(NH2) can be formed after the surface reaction. It should be understood that the presence of impurities such as chlorine in the untreated silicon nitride sub-film 301 may adversely affect certain properties of the resulting untreated silicon nitride film 300, such as film stress and wet etch resistance, as will be described below.

[0097]

[0098] Please refer to Figure 2 and Figure 3 During the purge and vacuum phase of the first nitrogen precursor supply step 503 , the supply of the first nitrogen precursor may be stopped, and the radio frequency of the plasma generation unit may be turned off. A flow rate of a dilution gas may be increased to purge the reaction chamber. For example, the flow rate of the dilution gas may be between approximately 3 slm and approximately 7 slm. In the embodiment described, the flow rate of the dilution gas may be 5 slm.

[0099] After the first deposition process, an untreated silicon nitride sub-film 301 may be formed. The first deposition process may be repeated multiple times (for simplicity, only four times are shown in the example) to form multiple layers of untreated silicon nitride sub-films 301 of a desired thickness. The multiple layers of untreated silicon nitride sub-films 301 together form the untreated silicon nitride film 300. In some embodiments, the number of repetitions of the first deposition process may be between about 20 and about 60, between about 30 and about 50, or between about 34 and about 40.

[0100] Figure 4A cross-sectional schematic diagram illustrating a portion of a process for manufacturing the semiconductor device 1A according to an embodiment of the present disclosure. Figure 5 A process chart illustrating process conditions for forming a treated silicon nitride film 400 according to some embodiments of the present disclosure.

[0101] Please refer to Figure 1 、 Figure 4 and Figure 5 In step S15 , a treated silicon nitride film 400 may be formed on the untreated silicon nitride film 300 , and the untreated silicon nitride film 300 and the treated silicon nitride film 400 together form a silicon nitride layer 200 .

[0102] Please refer to Figure 4 and Figure 5 , the manufacturing technology of the treated silicon nitride film 400 may include a second deposition process. The second deposition process may be an atomic layer deposition process. The second deposition process may include a second silicon precursor supplying step 601, a first hydrogen radical scavenging step 603, and a second nitrogen precursor supplying step 605, which are performed in sequence. In the second silicon precursor supplying step 601, a second silicon precursor may be supplied to the reaction chamber, and a plurality of chemical species from the second silicon precursor may be absorbed onto the upper surface of the untreated silicon nitride film 300 at a single atomic layer level. In the first hydrogen radical scavenging step 603, a plurality of hydrogen radicals may be supplied to the reaction chamber to replace a plurality of impurities, such as chlorine, contained in the absorbed chemical species originating from the second silicon precursor. Accordingly, the amount of the impurities contained in the absorbed chemical species originating from the second silicon precursor may be reduced. In the second nitrogen precursor supply step 605, a second nitrogen precursor may be activated and supplied to the reaction chamber, and a plurality of chemical species contained in the second nitrogen precursor may react with the adsorbed chemical species from the second silicon precursor to form a treated silicon nitride sub-film 401 having a thickness of a single molecular level. The treated silicon nitride sub-film 401 may be formed on the upper surface of the untreated silicon nitride film 300.

[0103] In some embodiments, the second silicon precursor supply step 601 may include a stabilization phase, a flow phase, and a purge and vacuum phase.

[0104] Please refer to Figure 4 and Figure 5During the stabilization phase of the second silicon precursor supplying step 601, a dilution gas, such as nitrogen, may be supplied to the reaction chamber. The dilution gas may have a flow rate between approximately 0.3 slm and approximately 0.7 slm. For example, in the described embodiment, the flow rate of the dilution gas may be 0.5 slm. A process temperature during the stabilization phase may be between approximately 25°C and approximately 700°C, between approximately 50°C and approximately 600°C, between approximately 100°C and approximately 500°C, between approximately 200°C and approximately 450°C, or between approximately 350°C and approximately 425°C. For example, in the described embodiment, the process temperature during the stabilization phase may be 400°C. A process pressure during the stabilization phase may be between approximately 200 Pa and approximately 600 Pa, between approximately 300 Pa and approximately 500 Pa, or between approximately 350 Pa and approximately 450 Pa. For example, in the described embodiment, the process pressure during the stabilization phase may be 400 Pa.

[0105] Please refer to Figure 4 and Figure 5 During the flow phase of the second silicon precursor supplying step 601, the second silicon precursor may be supplied to the reaction chamber, along with a dilution gas. The chemical species from the second silicon precursor may be adsorbed onto the upper surface of the untreated silicon nitride film 300 at a single atomic layer level. In some embodiments, the second silicon precursor may include a halide, such as iodine (I) or chlorine (Cl). In the depicted embodiment, for example, the second silicon precursor may be dichlorosilane. The reaction between the second silicon precursor and the untreated silicon nitride film 300 may be similar to the reaction between the first silicon precursor and the substrate 101. In some embodiments, for example, the second silicon precursor may include silicon tetrachloride, trichlorosilane, dichlorosilane, or hexachlorodisilane. In some embodiments, for example, the second silicon precursor may include silicon tetraiodide, triiodosilane, diiodosilane, iodosilane, disilium hexaiodide, silicon oxide, H2Si2I4, H3Si2I3, H4Si2I2, H5Si2I, or HSi2I5. In some embodiments, the second silicon precursor may include one of the following: triiodosilane, diiodosilane, iodosilane, H2Si2I4, H4Si2I2, and H5Si2I. In some embodiments, the second silicon precursor may include two, three, four, five, or six of the following: triiodosilane, diiodosilane, iodosilane, H2Si2I4, H4Si2I2, and H5Si2I, including any combination thereof.

[0106] Please refer to Figure 4 and Figure 5In the flow phase of the second silicon precursor supplying step 601, a flow rate of the second silicon precursor may be between about 1 slm and about 5 slm, or between about 3 slm and about 4.5 slm. For example, in the embodiment described, the flow rate of the second silicon precursor may be 1 slm. If the flow rate of the second silicon precursor is less than 1 slm, the amount of the second silicon precursor may not be sufficient to supply the nitrogen atoms on the upper surface of the untreated silicon nitride film 300. If the flow rate of the second silicon precursor is greater than 5 slm, the amount of the second silicon precursor may not react with the nitrogen atoms on the upper surface of the untreated silicon nitride film 300. A flow rate of the dilution gas may be between about 0.3 slm and about 0.7 slm. For example, in the embodiment described, the flow rate of the dilution gas may be 0.5 slm.

[0107] Please refer to Figure 4 and Figure 5 In the flow phase of the second silicon precursor supplying step 601, a process temperature of the flow phase may be between about 200°C and about 550°C. For example, in the embodiment described, the process temperature of the flow phase may be 400°C. If the process temperature is lower than 200°C, the chemical species from the second silicon precursor may not be absorbed onto the upper surface of the untreated silicon nitride film 300. If the process temperature is greater than 550°C, the reliability of the transistor in the substrate 101 may be affected and the thickness of the resulting silicon nitride layer in the region 3 may be shallower. That is, the thickness uniformity of the resulting nitride layer may be worse. In some embodiments, the process temperature of the flow phase may be between about 390°C and about 410°C. By using the aforementioned temperature range, the deposition rate can be increased, and various characteristics of the resulting silicon nitride layer, such as thickness uniformity, wet etch resistance, and film stress, can be improved.

[0108] Please refer to Figure 4 and Figure 5 In the flow phase of the second silicon precursor supplying step 601, a process pressure in the flow phase may be between about 400 Pa and about 1200 Pa, between about 600 Pa and about 1100 Pa, or between about 800 Pa and about 1000 Pa. For example, in the present disclosure, the process pressure in the flow phase may be 850 Pa. By using the aforementioned pressure range, the reaction rate between the plurality of nitrogen atoms and the first silicon precursor can be increased, and the pressure can be continuously adjusted.

[0109] Please refer to Figure 4 and Figure 5During the purge and vacuum phase of the second silicon precursor supply step 601, the supply of the second silicon precursor may be stopped. A flow rate of a dilution gas may be increased to purge the reaction chamber. For example, the flow rate of the dilution gas may be between approximately 3 slm and approximately 7 slm. In the embodiment described, the flow rate of the dilution gas may be 5 slm.

[0110] In some embodiments, the first hydrogen radical scavenging step 603 may include a stabilization phase, a flow phase, and a purge and vacuum phase.

[0111] Please refer to Figure 4 and Figure 5 During the stabilization phase of the first hydrogen radical scavenging step 603, a dilution gas, such as nitrogen, may be supplied to the reaction chamber. The dilution gas may have a flow rate between approximately 0.3 slm and approximately 0.7 slm. For example, in the described embodiment, the flow rate of the dilution gas may be 0.5 slm. A process temperature during the stabilization phase may be between approximately 25°C and approximately 700°C, between approximately 50°C and approximately 600°C, between approximately 100°C and approximately 500°C, between approximately 200°C and approximately 450°C, or between approximately 350°C and approximately 425°C. For example, in the described embodiment, the process temperature during the stabilization phase may be 400°C. A process pressure during the stabilization phase may be between approximately 10 Pa and approximately 70 Pa, between approximately 20 Pa and approximately 60 Pa, or between approximately 30 Pa and approximately 50 Pa. For example, in the embodiment of the present disclosure, the process pressure during the stabilization phase may be 50 Pa.

[0112] Please refer to Figure 4 and Figure 5 During the flow phase of the first hydrogen radical scavenging step 603, while supplying the diluent gas, the first radical source can be activated in the plasma generating unit and then supplied to the reaction chamber. The activated first radical source can be supplied to the reaction chamber to replace impurities, such as chlorine, contained in the chemical species derived from the second silicon precursor. This can reduce the amount of impurities contained in the adsorbed chemical species derived from the second silicon precursor. For example, the first radical source can be hydrogen gas.

[0113] Please refer to Figure 4 and Figure 5During the flow phase of the first hydrogen radical scavenging step 603, a radio frequency (RF) in the plasma generating unit may be turned on to activate the first radical source. The RF power during the flow phase may be between about 50 W and about 1000 W, or between about 100 W and about 300 W. If the RF power during the flow phase is greater than 1000 W, the quartz walls of the plasma generating unit may be damaged. The RF power density during the flow phase may be between about 0.02 W / cm 2 To about 2.0W / cm 2 or between approximately 0.05W / cm 2 To about 1.5W / cm 2 The process frequency of the plasma generating unit may be between approximately 10.00 MHz and approximately 15.00 MHz. For example, in the embodiment described above, the process frequency of the plasma generating unit during the flow phase may be 13.56 MHz. In the embodiment described above, the activated first radical source may be a plurality of hydrogen radicals (H2*, H*). The activated first radical source may be supplied to the reaction chamber in a plasma form.

[0114] Please refer to Figure 4 and Figure 5 During the flow phase of the first hydrogen radical scavenging step 603, the flow rate of the activated first radical source may be between approximately 0.5 slm and approximately 5 slm, or between approximately 1.5 slm and approximately 2.3 slm. By using the aforementioned flow rate ranges, a plasma of the activated first radical source can be continuously generated, and the amount of the activated first radical source is sufficient to displace impurities contained in the adsorbed chemical species from the second silicon precursor, such as chlorine. In the described embodiment, for example, the flow rate of the activated first nitrogen precursor may be 2 slm. It should be understood that a dilution gas may still be supplied during the flow phase, and the flow rate of the dilution gas may be between approximately 0.3 slm and approximately 0.7 slm. For example, in the described embodiment, the flow rate of the dilution gas may still be 0.5 slm.

[0115] Please refer to Figure 4 and Figure 5During the flow phase of the first hydrogen radical scavenging step 603, a process pressure in the plasma generating unit may be between approximately 70 Pa and approximately 400 Pa, or between approximately 350 Pa and approximately 4000 Pa. By using the aforementioned process pressure range in the plasma generating unit, plasma of the activated first radical source can be continuously generated, and the amount of the activated first radical source can be sufficient to replace a plurality of impurities contained in the adsorbed chemical species originating from the second silicon precursor. A process pressure in the reaction chamber may be between approximately 40 Pa and approximately 100 Pa, or between approximately 50 Pa and approximately 70 Pa. For example, in the described embodiment, the process pressure in the reaction chamber may be 50 Pa.

[0116] Please refer to Figure 4 and Figure 5 During the flow phase of the first hydrogen radical scavenging step 603, a substitution reaction occurs between the activated first radical source and the impurities contained in the absorbed chemicals from the second silicon precursor, as shown in Chemical Equation 4. In the embodiment described, a plurality of hydrogen radicals (represented by H2 in Chemical Equation 4) can replace chlorine contained in the chemical species, and chlorine can combine with the hydrogen radicals to form hydrogen chloride, which can be removed. Therefore, by removing the chlorine in the first hydrogen radical scavenging step 603, the chlorine concentration in the resulting silicon nitride layer can be reduced. Accordingly, the wet etching rate of the resulting silicon nitride layer can be reduced. In other words, the etching resistance of the resulting silicon nitride layer can be improved.

[0117]

[0118] Please refer to Figure 4 and Figure 5 During the vacuum phase of the first hydrogen radical scavenging step 603, the supply of the first radical source may be stopped, and the radio frequency of the plasma generating unit may be turned off. A dilution gas may still be supplied to the reaction chamber. A flow rate of the dilution gas may be between approximately 0.3 slm and approximately 0.7 slm. In the embodiment described, the flow rate of the dilution gas may be 0.5 slm.

[0119] In some embodiments, the second nitrogen precursor supply step 605 may include a stabilization phase, a flow phase, and a purge and vacuum phase.

[0120] Please refer to Figure 4 and Figure 5During the stabilization phase of the second nitrogen precursor supply step 605, a dilution gas, such as nitrogen, may be supplied to the reaction chamber. A flow rate of the dilution gas may be between approximately 0.3 slm and approximately 0.7 slm. For example, in the described embodiment, the flow rate of the dilution gas may be 0.5 slm. A process temperature during the stabilization phase may be between approximately 25°C and approximately 700°C, between approximately 50°C and approximately 600°C, between approximately 100°C and approximately 500°C, between approximately 200°C and approximately 450°C, or between approximately 350°C and approximately 425°C. For example, in the described embodiment, the process temperature during the stabilization phase may be 400°C. A process pressure during the stabilization phase may be between approximately 10 Pa and approximately 70 Pa, between approximately 20 Pa and approximately 60 Pa, or between approximately 30 Pa and approximately 50 Pa. For example, in the embodiment of the present disclosure, the process pressure during the stabilization phase may be 50 Pa.

[0121] In some embodiments, the two phases of the second deposition process may overlap or be combined. For example, the vacuum phase of the first hydrogen radical scavenging step 603 and the stabilization phase of the second nitrogen precursor supplying step 605 may partially or completely overlap.

[0122] Please refer to Figure 4 and Figure 5 During the flow phase of the second nitrogen precursor supplying step 605, while supplying the diluent gas, the second nitrogen precursor may be activated in the plasma generating unit and then supplied to the reaction chamber. The chemical species contained in the activated second nitrogen precursor may react with the adsorbed chemical species from the second silicon precursor to form the treated silicon nitride sub-film 401 on the upper surface of the untreated silicon nitride film 300. For example, the second nitrogen precursor may be aqueous ammonia.

[0123] Please refer to Figure 4 and Figure 5 During the flow phase of the second nitrogen precursor supplying step 605, a radio frequency (RF) in the plasma generating unit may be turned on to activate the second nitrogen precursor. The RF power during the flow phase may be between about 50 W and about 1000 W, or between about 100 W and about 300 W. If the RF power during the flow phase is greater than 1000 W, the quartz walls of the plasma generating unit may be damaged. The RF power density during the flow phase may be between about 0.02 W / cm 2 To about 2.0W / cm 2 or between approximately 0.05W / cm 2 To about 1.5W / cm 2The process frequency of the plasma generating unit may be between approximately 10.00 MHz and approximately 15.00 MHz. For example, in the embodiment described above, the process frequency of the plasma generating unit during the flow phase may be 13.56 MHz. In the embodiment described above, the activated second nitrogen precursors may be a plurality of ammonia radicals (NH3*). The activated second nitrogen precursor may be supplied to the reaction chamber in a plasma form.

[0124] Please refer to Figure 4 and Figure 5 During the flow phase of the second nitrogen precursor supply step 605, the flow rate of the activated second nitrogen precursor may be between approximately 0.5 slm and approximately 5 slm, or between approximately 3 slm and approximately 5 slm. By using the aforementioned flow rate ranges, a plasma of the activated second nitrogen precursor can be continuously generated, and the amount of the activated second nitrogen precursor is sufficient to react with the adsorbed chemical species from the second silicon precursor. In the illustrated embodiment, for example, the flow rate of the activated second nitrogen precursor may be 3 slm. It should be understood that a dilution gas may still be supplied during the flow phase, and the flow rate of the dilution gas may be between approximately 0.3 slm and approximately 0.7 slm. For example, in the illustrated embodiment, the flow rate of the dilution gas may still be 0.5 slm.

[0125] Please refer to Figure 4 and Figure 5 During the flow phase of the second nitrogen precursor supplying step 605, a process pressure in the reaction chamber may be between about 40 Pa and about 100 Pa, or between about 50 Pa and about 70 Pa. For example, in the embodiment described, the process pressure in the reaction chamber may be 50 Pa. A process pressure in the plasma generating unit may be between about 70 Pa and about 600 Pa, or between about 280 Pa and about 330 Pa. By using the aforementioned process pressure range in the plasma generating unit, plasma of the activated second nitrogen precursor can be continuously generated, and the amount of the activated second nitrogen precursor can be sufficient to react with the adsorbed chemical species from the second silicon precursor.

[0126] Please refer to Figure 4 and Figure 5 During the flow phase of the second nitrogen precursor supply step 605, the surface reaction between the activated second nitrogen precursor and the adsorbed chemical species from the second silicon precursor can be expressed as shown in Chemical Equation 5. A treated silicon nitride sub-film 401 including —NH—SiH2(NH2) can be formed after the surface reaction.

[0127]

[0128] Please refer to Figure 4 and Figure 5 During the purge and vacuum phase of the second nitrogen precursor supply step 605 , the supply of the second nitrogen precursor may be stopped, and the radio frequency of the plasma generation unit may be turned off. A dilution gas flow rate may be increased to purge the reaction chamber. For example, the dilution gas flow rate may be between approximately 3 slm and approximately 7 slm. In the embodiment described, the dilution gas flow rate may be 5 slm.

[0129] After the first deposition process, a treated silicon nitride sub-film 401 may be formed. The second deposition process may be repeated multiple times (only four times are shown for clarity) to form multiple layers of treated silicon nitride sub-films 401 of a desired thickness. These multiple layers of treated silicon nitride sub-films 401 together form a treated silicon nitride film 400. In some embodiments, the number of repetitions of the second deposition process may be between about 5 and about 35, between about 10 and about 30, or between about 13 and about 20. The untreated silicon nitride film 300 and the treated silicon nitride film 400 together form a silicon nitride layer 200 on the substrate 101.

[0130] In some embodiments, the silicon-nitrogen ratio of the silicon nitride layer 200, which does not include hydrogen or other impurities, can be expressed as SiN x x may be between about 0.5 and about 2.0, between about 0.9 and about 1.7, between about 1.0 and about 1.5, or between about 1.2 and about 1.4.

[0131] Since the first hydrogen radical scavenging step 603 can remove the impurities contained in the adsorbed chemical species originating from the second silicon precursor, the impurity concentration (e.g., chlorine concentration) of the treated silicon nitride film 400 can be lower than the impurity concentration of the untreated silicon nitride film 300. Therefore, the resulting silicon nitride layer 200 can have a high film stress and good wet etching resistance.

[0132] Furthermore, by changing the number of repetitions of the first deposition process and the second deposition process, the composition of the silicon nitride layer 200 can be continuously controlled, and thus the stress of the silicon nitride layer 200 can also be continuously controlled.

[0133] In some embodiments, for example, the stress-controlled silicon nitride layer 200 may be suitable for use in conjunction with the fabrication of field-effect transistors, dynamic random access memories, flash memories, static random access memories, advanced image sensors based on complementary metal oxide semiconductor structures, advanced light-emitting diode structures, and the like.

[0134] In some embodiments, the diluent gas may be nitrogen, argon, or helium, for example. The first silicon precursor, the first nitrogen precursor, the second silicon precursor, the second nitrogen precursor, or the first radical source may be supplied with the aid of the diluent gas. The diluent gas may also serve as a purge gas to remove excess precursors and byproducts.

[0135] Figure 6 A process chart illustrating process conditions for forming a treated silicon nitride film according to some embodiments of the present disclosure.

[0136] Please refer to Figure 6 , the fabrication techniques for the silicon nitride layer may include techniques similar to those described in Figures 1 to 5 The depicted process is performed under similar process conditions, except that after the second nitrogen precursor supply step 605, the second deposition process may further include a second hydrogen radical scavenging step 607. The second hydrogen radical scavenging step 607 may further reduce the impurity concentration of the resulting silicon nitride layer.

[0137] In some embodiments, the second hydrogen radical scavenging step 607 may include a stabilization phase, a flow phase, and a vacuum phase, each of which may have process conditions similar to those of the corresponding phases of the first hydrogen radical scavenging step 603 .

[0138] It should be understood that the same or similar element numbers used throughout the drawings are used to represent the same or similar features, elements or structures. Therefore, the same or similar features, elements or structures of each drawing will not be described in detail.

[0139] Figure 7 A schematic flow chart illustrating a method 20 for manufacturing a semiconductor device 1B according to an embodiment of the present disclosure is shown. Figure 8 and Figure 9 A cross-sectional schematic diagram illustrating a portion of a process for manufacturing the semiconductor device 1B according to an embodiment of the present disclosure.

[0140] Please refer to Figure 7 and Figure 8 In step S21 , a substrate 101 may be provided, and a silicon nitride sub-film 201 may be formed on the substrate 101 through a third deposition process.

[0141] Please refer to Figure 8 The third deposition process may include forming an untreated silicon nitride film 300 on the substrate 101 and forming a treated silicon nitride film 400 on the untreated silicon nitride film 300. The untreated silicon nitride film 300 and the treated silicon nitride film 400 together form the silicon nitride sub-film 201.

[0142] Please refer to Figure 8 , the fabrication techniques for the untreated silicon nitride film 300 may include techniques similar to those described in Figures 1 to 5 The depicted first deposition process is performed under similar process conditions and can be repeated twice to form two untreated silicon nitride sub-films 301 , which together form the untreated silicon nitride film 300 .

[0143] Please refer to Figure 8 , the fabrication techniques for the treated silicon nitride film 400 may include techniques similar to those described above. Figures 1 to 5 The depicted second deposition process is performed under similar process conditions and can be repeated three times to form three treated silicon nitride sub-films 401 , which together form the treated silicon nitride film 400 .

[0144] Please refer to Figure 7 and Figure 9 In step S23 , the silicon nitride sub-film 201 may be repeatedly formed multiple times to stack a silicon nitride layer 200 on the substrate 101 .

[0145] Please refer to Figure 9 The third process may be repeated multiple times (only four times are shown for clarity) to form a multi-layer silicon nitride sub-film 201 of a desired thickness. The multi-layer silicon nitride sub-film 201 together forms the silicon nitride layer 200.

[0146] Figures 10 to 15 Schematic cross-sectional views of semiconductor devices 1C, 1D, 1E, 1F, 1G, and 1H according to an embodiment of the present disclosure are illustrated.

[0147] Please refer to Figure 10 , the manufacturing technology of semiconductor element 1C can be similar to Figures 7 to 9 The first deposition process may be repeated twice to form two untreated silicon nitride sub-films 301, which together form the untreated silicon nitride film 300. The second deposition process may be repeated once to form a treated silicon nitride sub-film 401, which may be considered the treated silicon nitride film 400.

[0148] Please refer to Figure 11 , the manufacturing technology of semiconductor element 1D can be similar to Figures 7 to 9 The first deposition process may be repeated three times to form three untreated silicon nitride sub-films 301, which together form the untreated silicon nitride film 300. The second deposition process may be repeated once to form a treated silicon nitride sub-film 401, which may be considered the treated silicon nitride film 400.

[0149] Please refer to Figure 12 The manufacturing technology of semiconductor element 1E can be similar to Figures 7 to 9The first deposition process may be repeated once to form an untreated silicon nitride sub-film 301, which may be referred to as the untreated silicon nitride film 300. The second deposition process may be repeated twice to form two treated silicon nitride sub-films 401, which together may become the treated silicon nitride film 400.

[0150] Please refer to Figure 13 , the manufacturing technology of semiconductor element 1F can be similar to Figures 7 to 9 The first deposition process may be repeated once to form an untreated silicon nitride sub-film 301, which may be referred to as the untreated silicon nitride film 300. The second deposition process may be repeated three times to form three treated silicon nitride sub-films 401, which together form the treated silicon nitride film 400.

[0151] Please refer to Figure 14 The manufacturing technology of semiconductor element 1G can be similar to Figures 7 to 9 The first deposition process may be repeated three times to form three layers of untreated silicon nitride sub-films 301, which together form the untreated silicon nitride film 300. The second deposition process may be repeated twice to form two layers of treated silicon nitride sub-films 401, which together form the treated silicon nitride film 400.

[0152] Please refer to Figure 15 , the manufacturing technology of semiconductor element 1H can be similar to Figures 7 to 9 The first deposition process may be repeated once to form an untreated silicon nitride sub-film 301, which may be referred to as the untreated silicon nitride film 300. The second deposition process may be repeated once to form a treated silicon nitride sub-film 401, which may be referred to as the treated silicon nitride film 400.

[0153] Due to the design of the semiconductor device disclosed herein, the impurity concentration of the resulting silicon nitride layer 200 can be reduced, thereby improving the wet etching resistance of the silicon nitride layer 200. Consequently, the yield, quality, and reliability of the semiconductor device 1A can be improved.

[0154] Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and replacements can be made without departing from the concept and scope of the present disclosure as defined in the claims. For example, many of the above processes can be implemented in different ways, and many of the above processes can be replaced by other processes or combinations thereof.

[0155] Furthermore, the scope of the present disclosure is not limited to the specific embodiments of the processes, machines, manufacture, compositions of matter, means, methods, and steps described in the specification. Persons skilled in the art will understand from the disclosure of this disclosure that existing or future developed processes, machines, manufacture, compositions of matter, means, methods, or steps that function the same as or achieve substantially the same results as the corresponding embodiments described herein may be used in accordance with the present disclosure. Accordingly, such processes, machines, manufacture, compositions of matter, means, methods, or steps are intended to be encompassed by the claims of this disclosure.

Claims

1. A method for preparing a semiconductor element, comprising: Providing a substrate in a reaction chamber; forming a silicon nitride layer, comprising: Forming a first untreated silicon nitride film on the substrate comprises the following steps: (a) supplying a first silicon precursor into the reaction chamber, thereby allowing a plurality of chemical species from the first silicon precursor to be adsorbed on the substrate; as well as (b) supplying a first nitrogen precursor into the reaction chamber to nitride the plurality of chemical species to deposit the resulting silicon nitride on the substrate; wherein the step (a) and the step (b) are sequentially and repeatedly performed to form the first untreated silicon nitride film; Forming a treated silicon nitride film on the first untreated silicon nitride film includes the following steps: (c) supplying a second silicon precursor into the reaction chamber, thereby allowing a plurality of chemical species from the second silicon precursor to be absorbed onto the first untreated silicon nitride film formed after performing the steps (a) and (b); (d) performing a first hydrogen radical scavenging step by providing a plurality of hydrogen radicals into the reaction chamber to reduce impurities in the plurality of chemical species from the second silicon precursor; and (e) supplying a second nitrogen precursor into the reaction chamber to thereby nitridate the plurality of chemical species from the second silicon precursor to deposit resulting silicon nitride on the first untreated silicon nitride film; wherein the step (c), the step (d), and the step (e) are sequentially and repeatedly performed to form the treated silicon nitride film on the first untreated silicon nitride film; forming a second untreated silicon nitride film on the treated silicon nitride film so that the treated silicon nitride film is sandwiched between the first untreated silicon nitride film and the second untreated silicon nitride film, comprising: repeating step (a) and step (b) after forming the treated silicon nitride film, The treated silicon nitride film has a first impurity concentration, the first untreated silicon nitride film has a second impurity concentration, and the second untreated silicon nitride film has a third impurity concentration. The first impurity concentration is lower than the second impurity concentration and the third impurity concentration. 2 . The method for fabricating a semiconductor device as claimed in claim 1 , wherein the first silicon precursor and the second silicon precursor comprise dichlorosilane. 3 . The method for fabricating a semiconductor device as claimed in claim 2 , wherein the first nitrogen precursor and the second nitrogen precursor comprise ammonia. 4 . The method for fabricating a semiconductor device as claimed in claim 3 , wherein the plurality of hydrogen radicals in the step (d) are generated in a plasma generating unit by supplying hydrogen gas therein.

5. The method for fabricating a semiconductor device as claimed in claim 4 , wherein the step (d) comprises a first stabilization phase, a first flow phase and a first vacuum phase; and the step (e) comprises a second stabilization phase, a second flow phase and a second vacuum phase, wherein the execution period of the first vacuum phase and the execution period of the second stabilization phase at least partially overlap. 6 . The method for fabricating a semiconductor device as claimed in claim 5 , wherein during the flow phase of step (d), a process pressure in the reaction chamber is between 40 Pa and 100 Pa. 7 . The method for fabricating a semiconductor device as claimed in claim 6 , wherein during the flow phase of step (d), a process pressure in the plasma generating unit is between 70 Pa and 400 Pa. 8 . The method for fabricating a semiconductor device as claimed in claim 7 , wherein during the flow phase of step (d), a flow rate of the plurality of hydrogen radicals is between 0.5 slm and 5 slm. 9 . The method for fabricating a semiconductor device as claimed in claim 8 , wherein during the flow phase of step (d), a process frequency of the plasma generating unit is between 10.00 MHz and 15.00 MHz.

10. The method for fabricating a semiconductor device as claimed in claim 9, wherein forming the treated silicon nitride film further comprises a step (f) of supplying a plurality of hydrogen radicals into the reaction chamber to perform a second hydrogen radical scavenging.

11. A method for preparing a semiconductor element, comprising: Providing a substrate in a reaction chamber; as well as forming a silicon nitride layer on the substrate, comprising: forming a first untreated silicon nitride film; forming a second untreated silicon nitride film; and forming a treated silicon nitride film sandwiched between the first untreated silicon nitride film and the second untreated silicon nitride film; The step of forming the silicon nitride layer includes: (a) supplying a first silicon precursor into the reaction chamber, thereby allowing a plurality of chemical species from the first silicon precursor to be adsorbed on the substrate; (b) supplying a first nitrogen precursor into the reaction chamber to nitride the chemical species to deposit the resulting silicon nitride on the substrate; (c) sequentially and repeatedly performing step (a) and step (b) to form the first untreated silicon nitride film; (d) supplying a second silicon precursor into the reaction chamber after performing step (c), thereby allowing a plurality of chemical species from the second silicon precursor to be absorbed onto the first untreated silicon nitride film; (e) performing a first hydrogen radical scavenging step by providing a plurality of hydrogen radicals into the reaction chamber to reduce impurities in the plurality of chemical species from the second silicon precursor, wherein step (e) comprises a vacuum stage; (f) supplying a second nitrogen precursor into the reaction chamber to nitride the plurality of chemical species from the second silicon precursor to deposit resulting silicon nitride on the untreated silicon nitride film, wherein step (f) includes a stabilization phase, and the vacuum phase of step (e) at least partially overlaps with the stabilization phase of step (f); (g) performing step (d), step (e), and step (f) repeatedly in sequence, forming the treated silicon nitride film on the first untreated silicon nitride film; and (h) sequentially and repeatedly performing step (a) and step (b) to form the second untreated silicon nitride film on the treated silicon nitride film, so that the treated silicon nitride film is sandwiched between the first untreated silicon nitride film and the second untreated silicon nitride film, the treated silicon nitride film having a first impurity concentration, which is lower than the impurity concentration of the untreated silicon nitride film. 12 . The method for fabricating a semiconductor device as claimed in claim 11 , wherein the first silicon precursor and the second silicon precursor comprise dichlorosilane. 13 . The method for fabricating a semiconductor device as claimed in claim 12 , wherein the first nitrogen precursor and the second nitrogen precursor comprise ammonia. 14 . The method for fabricating a semiconductor device as claimed in claim 13 , wherein the hydrogen radicals in step (e) are generated in a plasma generating unit by supplying hydrogen gas therein. 15 . The method for fabricating a semiconductor device as claimed in claim 14 , wherein the step (a) comprises a stabilization phase, a flow phase, and a purge and vacuum phase. 16 . The method for fabricating a semiconductor device as claimed in claim 15 , wherein during the flow phase of step (a), a process temperature is between 200° C. and 550° C. 17 . The method for fabricating a semiconductor device as claimed in claim 16 , wherein during the flow phase of step (a), a flow rate of the first silicon precursor is between 1 slm and 5 slm. 18 . The method for fabricating a semiconductor device as claimed in claim 17 , wherein during the flow phase of step (a), a process pressure is between 400 Pa and 1200 Pa. 19 . The method for fabricating a semiconductor device as claimed in claim 18 , wherein the step (b) comprises a stabilization phase, a flow phase, and a purge and vacuum phase. 20 . The method for fabricating a semiconductor device as claimed in claim 19 , wherein during the flow phase of step (b), a process frequency of the plasma generating unit is between 10.00 MHz and 15.00 MHz.

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