A thin film for a semiconductor device and a method of manufacturing the same, and a semiconductor device

Abstract

This invention discloses a thin film for semiconductor devices and a method for manufacturing the same, relating to the field of semiconductor fabrication technology. It utilizes a first antireflective film with a first roughness to optimize patterned photoresist, while simultaneously utilizing a second antireflective film with a second roughness to optimize the patterned structure. In other words, it employs a double-layer antireflective layer to improve the pattern quality of the patterned structure, thereby optimizing the performance of the semiconductor device and the electronic devices using it. The method includes providing a substrate; forming a first antireflective film on the substrate, the first antireflective film having a first roughness; forming a second antireflective film on the first antireflective film, the second antireflective film having a second roughness; the second roughness being less than the first roughness; forming a patterned photoresist on the second antireflective film; and using the patterned photoresist as a mask to pattern the substrate, the first antireflective film, and the second antireflective film to obtain a patterned structure.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a thin film for semiconductor devices, a method for manufacturing the same, and semiconductor devices. Background Technology

[0002] Semiconductor devices are electronic devices whose conductivity lies between that of a good conductor and an insulator. They utilize the special electrical properties of semiconductor materials to perform specific functions and can be used to generate, control, receive, transform, amplify signals, and perform energy conversion.

[0003] In the fabrication of semiconductor devices, patterned photoresist needs to be formed on a substrate. Under the protection of the patterned photoresist, the substrate is then processed to form a patterned structure. During the formation of the patterned photoresist, an anti-reflection layer is typically formed between the photoresist material layer and the substrate to prevent the influence of reflected light. While the anti-reflection layer can optimize the patterned photoresist to conform to a predetermined pattern, it can lead to inconsistencies between the subsequently formed patterned structure and the patterned photoresist. Summary of the Invention

[0004] The purpose of this invention is to provide a thin film for semiconductor devices and a method for manufacturing the same, as well as a semiconductor device, to improve the pattern quality of patterned structures and optimize the performance of semiconductor devices by utilizing a double-layer anti-reflection layer.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing a thin film for a semiconductor device, comprising: providing a substrate; forming a first antireflective film on the substrate, the first antireflective film having a first roughness; forming a second antireflective film on the first antireflective film, the second antireflective film having a second roughness; the second roughness being less than the first roughness; forming a patterned photoresist on the second antireflective film; and using the patterned photoresist as a mask to perform patterning processing on the substrate, the first antireflective film, and the second antireflective film to obtain a patterned structure.

[0006] Compared with existing technologies, the thin film fabrication method for semiconductor devices provided by this invention involves forming a first antireflective film on a substrate, the first antireflective film having a first roughness; and forming a second antireflective film on the first antireflective film, the second antireflective film having a second roughness; the second roughness is smaller than the first roughness. In practical applications, when a photoresist material layer is formed on the second antireflective film, and the photoresist material layer is processed to form a patterned photoresist, the low-roughness second antireflective film can effectively suppress the adverse effects of reflected light on the patterned photoresist, ensuring that the final patterned photoresist conforms to a predetermined pattern. A high-roughness first antireflective film can cover the substrate. When the second antireflective film, the first antireflective film, and the substrate are processed using a wet etching process under the cover of the patterned photoresist to form a patterned structure, the high-roughness first antireflective film can reduce the etching rate, thereby suppressing the isotropy of the wet etching. Therefore, it can ensure that the final patterned structure has good consistency with the patterned photoresist. In summary, the method for preparing thin films for semiconductor devices of the present invention can optimize the anti-reflection effect to ensure that the patterned photoresist conforms to the preset pattern when actually applied to patterned photoresist, and can also optimize the etching effect to ensure that the patterned structure and the patterned photoresist have good consistency when actually applied to patterned structures.

[0007] In a second aspect, the present invention also provides a thin film for a semiconductor device, comprising a patterned structure, the patterned structure comprising a first patterned antireflective film and a second patterned antireflective film stacked from bottom to top;

[0008] The first patterned antireflective film has a first roughness; the second patterned antireflective film has a second roughness; the second roughness is less than the first roughness.

[0009] Compared with the prior art, the thin film for semiconductor devices provided by the present invention has the same technical effect as the thin film preparation method for semiconductor devices described above, and will not be elaborated here.

[0010] Thirdly, the present invention also provides a semiconductor device comprising the thin film for semiconductor devices provided by the present invention.

[0011] Compared with the prior art, the beneficial effects of the semiconductor device provided by the present invention are the same as the beneficial effects of the thin film used in the semiconductor device in the above-mentioned technical solution, and will not be repeated here. Attached Figure Description

[0012] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0013] Figure 1 This is a schematic diagram of the structure of an antireflection layer in a semiconductor device in the prior art;

[0014] Figure 2 This is a schematic diagram of the structure of an antireflection layer in a thin film for semiconductor devices provided in an embodiment of the present invention;

[0015] Figure 3 This is a flowchart of a thin film preparation method for semiconductor devices provided in an embodiment of the present invention;

[0016] Figure 4 This is a schematic diagram of the structure of forming a first antireflection film on a substrate according to an embodiment of the present invention;

[0017] Figure 5 This is a graph showing the test results of the roughness of the first antireflection film formed using SiH4 as the silicon source and N2O and NH3 as nitrogen sources, as provided in an embodiment of the present invention.

[0018] Figure 6 This is a schematic diagram of the structure of forming a second antireflection film on a first antireflection film provided in an embodiment of the present invention;

[0019] Figure 7 This is a graph showing the test results of the roughness of the second antireflective film formed using SiH4 as the silicon source and N2O and NH3 as nitrogen sources.

[0020] Wherein: 10. Substrate, 11. Mask material layer, 12. Anti-reflection layer, 13. Photoresist material layer;

[0021] 20. First antireflective coating, 21. Second antireflective coating, 22. Substrate. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0023] Various schematic diagrams illustrating embodiments of the present invention are shown in the accompanying drawings, which are not drawn to scale. Some details have been enlarged and may have been omitted for clarity. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0024] In the following description, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0025] Furthermore, in this invention, directional terms such as "upper" and "lower" are defined relative to the positions of the components shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the position of the components in the accompanying drawings.

[0026] In this invention, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0027] Figure 1 This diagram illustrates the structure of an antireflective layer in a conventional semiconductor device. For example... Figure 1 As shown, in the process of fabricating semiconductor devices, when a patterned structure is formed on a substrate 10 using a patterned mask, a photoresist material layer 13 needs to be coated on the mask material layer 11 first, and then the photoresist material layer 13 is processed to form a patterned photoresist. In order to ensure that the formed patterned photoresist conforms to the preset pattern, an anti-reflection layer 12 is usually formed between the photoresist material layer 13 and the mask material layer 11. The anti-reflection layer 12 reduces the reflection of light that has passed through the photoresist material layer 13 back to the photoresist material layer 13, thereby avoiding the adverse effects of reflected light on the patterned photoresist.

[0028] The inventors discovered that the lower the surface roughness of the antireflection layer 12, the better it can suppress the adverse effects of reflected light on the patterned photoresist; in other words, it is more conducive to forming a patterned photoresist that conforms to the preset pattern. However, after the patterned photoresist conforms to the preset pattern, when wet etching is performed sequentially on the antireflection layer 12 and the hard mask material layer 11 under the masking effect of the patterned photoresist, the etching rate is accelerated due to the relatively low roughness of the antireflection layer 12. This exacerbates the isotropy of the wet etching, resulting in poor consistency between the final patterned mask and the patterned photoresist. In summary, while reducing the roughness of the antireflection layer 12 can ensure that the formed patterned photoresist conforms to the preset pattern, it will have an adverse effect on the subsequent patterned structure.

[0029] To address the above problems, the present invention provides a thin film for semiconductor devices. Figure 2This diagram illustrates the structure of an antireflective layer in a thin film for semiconductor devices, as provided in an embodiment of the present invention. Figure 2 As shown, the antireflection layer includes a first antireflection film 20 having a first roughness, and a second antireflection film 21 formed on the first antireflection film 20 having a second roughness. The second roughness is less than the first roughness.

[0030] The materials of the first antireflective film 20 and the second antireflective film 21 can be different. For example, the first antireflective film 20 can be a silicon oxide antireflective film, and the second antireflective film 21 can be a silicon oxynitride antireflective film.

[0031] The roughness of the first antireflective coating 20 is greater than the roughness of the second antireflective coating 21. For example, the roughness of the first antireflective coating 20 can be 1.33 nm, in which case the roughness of the second antireflective coating 21 can be 0.68 nm.

[0032] The first antireflective film 20 has a higher first roughness than the second roughness of the second antireflective film 21. In practical applications, when a photoresist material layer is formed on the second antireflective film 21, and the photoresist material layer is processed to form a patterned photoresist, the low-roughness second antireflective film 21 can effectively suppress the adverse effects of reflected light on the patterned photoresist, ensuring that the final patterned photoresist conforms to the preset pattern. The high-roughness first antireflective film 20 can cover the substrate 22. When the second antireflective film 21, the first antireflective film 20, and the substrate 22 are processed using a wet etching process under the cover of the patterned photoresist to form a patterned structure, the high-roughness first antireflective film 20 can reduce the etching rate, thereby suppressing the isotropy of wet etching. Therefore, it can ensure that the final patterned structure has good consistency with the patterned photoresist. In summary, the method for manufacturing thin films for semiconductor devices according to the embodiments of the present invention can optimize the anti-reflection effect to ensure that the patterned photoresist conforms to the preset pattern when actually applied to patterned photoresist, and can also optimize the etching effect to ensure that the patterned structure and the patterned photoresist have good consistency when actually applied to patterned structures.

[0033] The thickness ratio of the first antireflective film 20 to the second antireflective film 21 can be from 1:1 to 19:1. That is, the thickness of the first antireflective film 20 can be the same as the thickness of the second antireflective film 21, or the thickness of the first antireflective film 20 can be greater than the thickness of the second antireflective film 21. When the antireflective layer of this embodiment is applied to form a pattern using a wet etching process, and the second antireflective film 21 is formed on a photoresist material layer, and the first antireflective film 20 is formed on a substrate 22, under the masking of the patterned photoresist, when the second antireflective film 21, the first antireflective film 20, and the mask substrate 22 are processed sequentially, the thickness of the second antireflective film 21 is the same as or smaller than the thickness of the first antireflective film 20. The wet etching process for the second antireflective film 21, which has lower roughness and higher etching rate, involves less material or a shorter processing time, while the process for the first antireflective film 20, which has higher roughness and lower etching rate, involves more material or a longer processing time. This effectively suppresses the adverse effects of the isotropic wet etching process on the entire antireflective layer, ultimately ensuring good consistency between the patterned structure and the patterned photoresist.

[0034] This invention also provides a method for preparing a thin film for semiconductor devices. Figure 3 The diagram shows a flowchart of a method for preparing a thin film for a semiconductor device according to an embodiment of the present invention. Figure 3 As shown, the method includes:

[0035] S10, see details Figure 4 A substrate 22 is provided. It should be understood that the substrate 22 may be a bulk silicon substrate, a silicon-on-insulator (SOI) substrate, a germanium substrate, a germanium-on-insulator (GOI) substrate, a silicon-germanium substrate, a III-V compound semiconductor substrate, or an epitaxial thin film substrate obtained by performing selective epitaxial growth (SEG). Furthermore, the substrate here can also be a broad concept, including a substrate containing a mask material layer.

[0036] S11, see details Figure 4 A first antireflective film 20 is formed on the substrate 22, and the first antireflective film 20 has a first roughness.

[0037] The first antireflective coating 20 in this embodiment of the invention can be a silicon oxide antireflective coating, which can be formed using plasma-assisted chemical vapor deposition (PCVD). The substrate 22 is placed within the cavity of the PCVD apparatus used in the PCVD process. SiH4 and N2O are introduced into the cavity within a first preset time. Here, SiH4 is the silicon source and N2O is the nitrogen source. The first preset time can be determined based on the thickness of the silicon oxide antireflective coating to be formed.

[0038] The radio frequency (RF) generator of the plasma-assisted chemical vapor deposition (PCVD) equipment is activated to generate an RF electric field within the cavity. Under the influence of the RF electric field, SiH4 and N2O are ionized, and the plasma can be adsorbed onto the surface of substrate 22, reacting to form a silicon oxide antireflection film (see details). Figure 4 It should be understood that during the formation of the silicon oxide antireflective film, byproducts such as H2O are also generated. H2O is vaporized at high temperatures, which creates voids on the surface of the silicon oxide antireflective film, thereby increasing the roughness of the first antireflective film 20.

[0039] Figure 5 The roughness test results of the first antireflective film formed using SiH4 as the silicon source and N2O as the nitrogen source are shown in the figure. Figure 5 As shown, the silicon oxynitride antireflective film formed on substrate 22 as the first antireflective film 20 using SiH4 as the silicon source and N2O as the nitrogen source via plasma-assisted chemical vapor deposition has a maximum peak value Rq = 1.33 nm and a contour arithmetic mean deviation Ra = 1.03 nm.

[0040] When the roughness of the first antireflection film 20 is increased, the etching rate is reduced when the first antireflection film 20 is subsequently etched by wet etching under the cover of patterned photoresist. At this time, the isotropy of wet etching is suppressed to ensure that the patterned structure finally formed on the substrate has good consistency with the patterned photolithography.

[0041] S12, see details Figure 6 A second antireflection film 21 is formed on the first antireflection film 20. The second antireflection film 21 has a second roughness, which is less than the first roughness.

[0042] In this embodiment of the invention, the second antireflective film 21 can be a silicon oxynitride antireflective film, which can also be formed using plasma-assisted chemical vapor deposition. After the first antireflective film 20 is formed on the substrate 22 housed within the cavity, it should be understood that this cavity is the same as the cavity in step S11, meaning that the second antireflective film 21 and the first antireflective film 20 are formed in the same cavity. SiH4, N2O, and NH3 are introduced into the cavity within a second preset time. The second preset time can be determined based on the thickness of the silicon oxynitride antireflective film to be formed, and is not specifically limited here. The time interval between the first preset time and the second preset time is greater than or equal to zero.

[0043] In other words, after simultaneously introducing SiH4 and N2O into the cavity within a first preset time to form the first antireflective film 20 (silicon oxide antireflective film), SiH4, N2O, and NH3 can then be introduced into the cavity. Furthermore, a radio frequency electric field can be continuously generated within the cavity. Under the action of the radio frequency electric field, SiH4, N2O, and NH3 are ionized. Similarly, the plasma can be adsorbed on the surface of the first antireflective film 20, forming a silicon oxynitride antireflective film as the second antireflective film 21 (see details). Figure 6 ).

[0044] Alternatively, after introducing SiH4 and N2O into the cavity within a first preset time to form the first antireflection film 20, the introduction of SiH4 and N2O into the cavity is stopped, and the generation of the radio frequency electric field within the cavity is also stopped. After stopping, the reaction byproducts are discharged from the cavity. After discharge, SiH4, N2O, and NH3 are introduced into the cavity within a second preset time, and the radio frequency electric field is generated in the cavity again. Under the action of the radio frequency electric field, SiH4, N2O, and NH3 are ionized. Similarly, the plasma can be adsorbed on the surface of the first antireflection film 20 and form a silicon oxynitride antireflection film as the second antireflection film 21.

[0045] When forming the silicon oxynitride antireflective film as the second antireflective film 21, the amount of NH3 introduced can be increased. At this time, the number of N atoms is increased, and the pressure inside the cavity is also increased. Based on this, the rate of reaction with SiH4 to generate SiON can be increased to compensate for the voids that appear in the silicon oxynitride antireflective film that has been formed as the second antireflective film 21, thereby reducing the roughness of the silicon oxynitride antireflective film as the second antireflective film 21.

[0046] Figure 7 The roughness test results of the second antireflective film formed using SiH4 as the silicon source and N2O and NH3 as nitrogen sources are shown in the figure. Figure 7As shown, using SiH4 as the silicon source and N2O and NH3 as nitrogen sources, a plasma-assisted chemical vapor deposition process was employed to form a silicon oxynitride antireflective film 21 on the first antireflective film 20. The maximum peak value of the profile, Rq, is 0.68 nm, and the arithmetic mean deviation of the profile, Ra, is 0.52 nm. It can be seen that compared to the roughness of the first antireflective film 20, the maximum peak value Rq of the profile of the second antireflective film 21 is reduced by 0.65 nm, and the arithmetic mean deviation of the profile, Ra, is reduced by 0.51 nm.

[0047] When the roughness of the silicon oxynitride antireflective film 21, which serves as the second antireflective film 21, is reduced, the second antireflective film 21 can effectively avoid the adverse effects of reflected light on the patterned photoresist during the patterning process, so that the formed patterned photoresist can conform to the preset pattern.

[0048] S13. Form a patterned photoresist on the second antireflection film. Forming a patterned photoresist on the second antireflection film is a mature existing technology and will not be described in detail here.

[0049] S14. Using patterned photoresist as a mask, the substrate, the first antireflective film, and the second antireflective film are patterned to obtain a patterned structure. Patterning the substrate is a mature existing process and will not be detailed here.

[0050] This invention also provides a semiconductor device, which includes the thin film for semiconductor devices provided in this invention. The electronic device may be a communication device or a terminal device, but is not limited thereto. Further, terminal devices include mobile phones, smartphones, tablet computers, computers, artificial intelligence devices, power banks, etc. Communication devices include base stations, but are not limited thereto.

[0051] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the device embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0052] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A thin film manufacturing method for a semiconductor device, characterized by, The application relates to a method for forming a patterned structure on a substrate. The method comprises the following steps: providing a substrate; forming a first anti-reflection film on the upper surface of the substrate, the first anti-reflection film having a first roughness; forming a second anti-reflection film on the upper surface of the first anti-reflection film, and forming the first anti-reflection film and the second anti-reflection film in the same cavity; the second anti-reflection film has a second roughness; the second roughness is smaller than the first roughness; the first anti-reflection film is a silicon oxide anti-reflection film; the second anti-reflection film is a silicon oxynitride anti-reflection film; forming a patterned photoresist on the upper surface of the second anti-reflection film; using the patterned photoresist as a mask, performing a wet etching on the substrate, the first anti-reflection film and the second anti-reflection film to obtain a patterned structure; the step of forming the first anti-reflection film and the second anti-reflection film in the same cavity comprises the following steps: forming the first anti-reflection film on the upper surface of the substrate within a first preset time; forming the second anti-reflection film on the upper surface of the first anti-reflection film within a second preset time; the time interval between the second preset time and the first preset time is greater than or equal to zero; the step of forming the first anti-reflection film on the upper surface of the substrate within a first preset time comprises the following steps: introducing a silane silicon source and a dinitrogen monoxide nitrogen source into a cavity to form the first anti-reflection film on the upper surface of the substrate; the maximum peak value of the profile of the first anti-reflection film is 1.33 nanometers; the step of forming the second anti-reflection film on the upper surface of the first anti-reflection film within a second preset time comprises the following steps: introducing a silane silicon source and a dinitrogen monoxide, ammonia nitrogen source into the cavity, and increasing the amount of ammonia introduced to form the second anti-reflection film on the upper surface of the first anti-reflection film; the maximum peak value of the profile of the second anti-reflection film is 0.68 nanometers; 2. The thin film manufacturing method for a semiconductor device according to claim 1, wherein the thickness ratio of the first anti-reflection film and the second anti-reflection film is 1:1 to 19:

1. The method for forming the first anti-reflection film and the second anti-reflection film is a plasma-assisted chemical vapor deposition process.

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