Anti-reflection film layer structure and forming method thereof

Abstract

The invention relates to the technical field of semiconductors, and relates to an anti-reflection film layer structure and a forming method thereof, and the anti-reflection film layer structure comprises a first hard mask layer and a second hard mask layer which are distributed in a stacked manner. Wherein the refractive indexes and / or extinction coefficients of the first hard mask layer and the second hard mask layer are different; and the thickness ratio of the first hard mask layer to the second hard mask layer is 1: 10-10: 1. The forming method can improve the uniformity of the contour of the developing region.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to an anti-reflective film layer structure and a method for forming the same. Background Art

[0002] During the exposure process of photoresist (PR), the reflected light can be reduced by the anti-reflective coating (DARC) layer underneath. However, due to the structure of the anti-reflective coating layer, the profile uniformity of the developed area formed after exposure and development is poor.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0004] In view of this, the present disclosure provides an anti-reflection film layer structure and a method for forming the same, which can improve the uniformity of the profile of the development area.

[0005] According to one aspect of the present disclosure, there is provided an anti-reflection film layer structure, comprising:

[0006] A first hard mask layer and a second hard mask layer are stacked and distributed;

[0007] The first hard mask layer and the second hard mask layer have different refractive indices and / or extinction coefficients; and a thickness ratio between the first hard mask layer and the second hard mask layer is 1:10 to 10:1.

[0008] In an exemplary embodiment of the present disclosure, the thickness of the first hard mask layer and the second hard mask layer are both 10 nm to 60 nm.

[0009] In an exemplary embodiment of the present disclosure, the number of the first hard mask layers is two, and the second hard mask layer is located between the two first hard mask layers; or, the number of the second hard mask layers is two, and the first hard mask layer is located between the two second hard mask layers.

[0010] In an exemplary embodiment of the present disclosure, the number of the first hard mask layer and the number of the second hard mask layer are both plural, and the plurality of the first hard mask layers and the plurality of the second hard mask layers are alternately distributed in sequence.

[0011] In an exemplary embodiment of the present disclosure, the total thickness of the first hard mask layers is greater than the total thickness of the second hard mask layers, and the refractive index and / or extinction coefficient of the first hard mask layers are less than the refractive index and / or extinction coefficient of the second hard mask layers.

[0012] In an exemplary embodiment of the present disclosure, the total thickness of the plurality of second hard mask layers is greater than the total thickness of the plurality of first hard mask layers, and the refractive index and / or extinction coefficient of the first hard mask layer is greater than the refractive index and / or extinction coefficient of the second hard mask layer.

[0013] According to one aspect of the present disclosure, a method for forming an anti-reflection film layer structure is provided, comprising:

[0014] forming a first hard mask layer and a second hard mask layer in a stacked arrangement;

[0015] The first hard mask layer and the second hard mask layer have different refractive indices and / or extinction coefficients; and a thickness ratio between the first hard mask layer and the second hard mask layer is 1:10 to 10:1.

[0016] In an exemplary embodiment of the present disclosure, the number of the first hard mask layers is two, and the second hard mask layer is located between the two first hard mask layers; or, the number of the second hard mask layers is two, and the first hard mask layer is located between the two second hard mask layers.

[0017] In an exemplary embodiment of the present disclosure, the number of the first hard mask layer and the number of the second hard mask layer are both plural, and the plurality of the first hard mask layers and the plurality of the second hard mask layers are alternately distributed in sequence.

[0018] In an exemplary embodiment of the present disclosure, the total thickness of the first hard mask layers is greater than the total thickness of the second hard mask layers, and the refractive index and / or extinction coefficient of the first hard mask layers are less than the refractive index and / or extinction coefficient of the second hard mask layers.

[0019] In an exemplary embodiment of the present disclosure, the total thickness of the plurality of second hard mask layers is greater than the total thickness of the plurality of first hard mask layers, and the refractive index and / or extinction coefficient of the first hard mask layer is greater than the refractive index and / or extinction coefficient of the second hard mask layer.

[0020] In an exemplary embodiment of the present disclosure, the material of the first hard mask layer is silicon oxynitride, and the material of the second hard mask layer is silicon oxycarbide.

[0021] In an exemplary embodiment of the present disclosure, forming the first hard mask layer includes:

[0022] providing a reaction chamber;

[0023] introducing silicon-containing gas and nitrogen-containing gas into the reaction chamber;

[0024] Plasma bombardment is performed on the silicon-containing gas and the nitrogen-containing gas to dissociate and recombine the silicon-containing gas and the nitrogen-containing gas to form the first hard mask layer.

[0025] In an exemplary embodiment of the present disclosure, forming the second hard mask layer includes:

[0026] introducing silicon-containing gas and carbon-containing gas into the reaction chamber;

[0027] Plasma bombardment is performed on the silicon-containing gas and the carbon-containing gas to dissociate and recombine the silicon-containing gas and the carbon-containing gas to form the second hard mask layer.

[0028] In an exemplary embodiment of the present disclosure, the silicon-containing gas is silane, the nitrogen-containing gas includes at least nitrous oxide, and the carbon-containing gas is carbon dioxide.

[0029] The anti-reflective film layer structure and the method for forming the same disclosed herein, on the one hand, by stacking a first hard mask layer and a second hard mask layer with different refractive indices and / or extinction coefficients, the refractive index of the anti-reflective film layer structure finally formed is between the refractive index of the first hard mask layer and the refractive index of the second hard mask layer; at the same time, the extinction coefficient of the anti-reflective film layer structure is between the extinction coefficient of the first hard mask layer and the extinction coefficient of the second hard mask layer, thereby broadening the value range of the extinction coefficient and / or refractive index of the anti-reflective film layer, helping to improve the propagation path and interference effect of light in the anti-reflective film layer structure, reducing the line width roughness and edge roughness of the developing area, thereby improving the exposure or development effect of the photoresist, and improving the uniformity of the profile of the developing area. On the other hand, since the ratio of the thickness of the first hard mask layer to the second hard mask layer is in the range of 1:10 to 10:1, the combination of the first hard mask layer and the second hard mask layer provides the possibility of a variety of thickness combinations. Since different thickness combinations may obtain different refractive indices or extinction coefficients, the range of the extinction coefficient and / or refractive index of the anti-reflective film structure is further broadened, and the requirements of different photolithography processes for the refractive index and / or extinction coefficient can be met. In the photolithography process, the first hard mask layer and the second hard mask layer with different thickness ratios can be selected according to the process requirements, which helps to reduce the line width roughness and edge roughness of the development area in different process processes, thereby improving the uniformity of the profile of the development area.

[0030] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0032] Figure 1 Schematic diagram of the working mechanism of the anti-reflection layer.

[0033] Figure 2 Schematic diagram of an anti-reflection film layer structure in an embodiment of the present disclosure.

[0034] Figure 3 Schematic diagram of the extinction coefficient and refractive index of the anti-reflection film layer structure in the embodiment of the present disclosure.

[0035] Figure 4 Schematic diagram of an anti-reflection film layer structure in an embodiment of the present disclosure.

[0036] Figure 5 Schematic diagram of a reaction chamber in an embodiment of the present disclosure.

[0037] Figure 6 Schematic diagram of sample 1 in the embodiment of the present disclosure.

[0038] Figure 7 It is a schematic diagram of sample 2 in the embodiment of the present disclosure.

[0039] Figure 8 Schematic diagram of a photoresist layer in an embodiment of the present disclosure.

[0040] Description of reference numerals:

[0041] 100. photoresist; 200. anti-reflective layer; 1. first hard mask layer; 2. second hard mask layer; 3. reaction chamber; 4. first mask layer; 5. second mask layer; 6. third mask layer; 7. fourth mask layer; 8. anti-reflective film layer structure; 9. photoresist layer; 10. substrate; 11. photoresist. DETAILED DESCRIPTION

[0042] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0043] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0044] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0045] like Figure 1 As shown, during the photolithography process, light from the light source is irradiated to the surface of the photoresist 100, and part of the light will be reflected back by the surface of the photoresist 100, causing interference, affecting the uniformity and resolution of exposure. The function of the anti-reflection layer 200 is to reduce this reflection and improve the exposure effect of the photoresist 100.

[0046] The extinction coefficient and refractive index of the anti-reflection layer 200 have a certain influence on the exposure or development of the photoresist 100. The larger the extinction coefficient, the stronger the light absorption capacity of the anti-reflection layer 200, and the more effectively the light reflection can be reduced. The refractive index will also affect the propagation path and interference effect of the light in the anti-reflection layer 200. Therefore, selecting a suitable anti-reflection layer 200 material so that its extinction coefficient and refractive index can adapt to the exposure requirements of the photoresist 100 is an important factor in ensuring the quality of the photolithography process.

[0047] The embodiment of the present disclosure provides an anti-reflection film layer structure, Figure 2 A schematic diagram showing the structure of the anti-reflective film layer of the present invention is shown in FIG. Figure 2 As shown, the anti-reflective film layer structure includes a first hard mask layer 1 and a second hard mask layer 2 which are stacked and distributed; wherein the refractive index and / or extinction coefficient of the first hard mask layer 1 and the second hard mask layer 2 are different; and the thickness ratio of the first hard mask layer 1 to the second hard mask layer 2 is 1:10 to 10:1.

[0048] The anti-reflective film layer structure disclosed in the present invention, on the one hand, is stacked by a first hard mask layer 1 and a second hard mask layer 2 having different refractive indices and / or extinction coefficients, so that the refractive index of the anti-reflective film layer structure finally formed is between the refractive index of the first hard mask layer 1 and the refractive index of the second hard mask layer 2; at the same time, the extinction coefficient of the anti-reflective film layer structure is between the extinction coefficient of the first hard mask layer 1 and the extinction coefficient of the second hard mask layer 2, thereby broadening the value range of the extinction coefficient and / or refractive index of the anti-reflective film layer, helping to improve the propagation path and interference effect of light in the anti-reflective film layer structure, reducing the line width roughness and edge roughness of the developing area, thereby improving the exposure or development effect of the photoresist, and improving the uniformity of the profile of the developing area. On the other hand, since the thickness ratio of the first hard mask layer 1 to the second hard mask layer 2 is in the range of 1:10 to 10:1, when the extinction coefficients of the first hard mask layer 1 and the second hard mask layer 2 are close, the refractive index range is adjusted by changing the thickness ratio of the first hard mask layer 1 and the second hard mask layer 2. When the thickness ratio of the first hard mask layer 1 to the second hard mask layer 2 is 10:1, the refractive index is close to the refractive index of the first hard mask layer 1. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is 1:10, the refractive index is close to the refractive index of the second hard mask layer 2. As the thickness ratio of the two approaches, the refractive index gradually moves to the middle. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is greater than 10:1, the refractive index is still close to the refractive index of the first hard mask layer 1, but its specific value is very different from the result of 10:1, so it is meaningless to exceed 10:1. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is less than 1:10, the refractive index is still close to the refractive index of the second hard mask layer 2, but its specific value is very close to the result of 1:10, so it is meaningless to be less than 1:10. The present disclosure provides a variety of thickness combinations for the combination of the first hard mask layer 1 and the second hard mask layer 2. Since different thickness combinations may obtain different refractive indices or extinction coefficients, the range of values ​​of the extinction coefficient and / or refractive index of the anti-reflective film structure is further broadened, and the requirements of different photolithography processes for the refractive index and / or extinction coefficient can be met. In the photolithography process, the first hard mask layer 1 and the second hard mask layer 2 with different thickness ratios can be selected according to the process requirements, which helps to reduce the line width roughness and edge roughness of the development area in different process processes, thereby improving the uniformity of the profile of the development area.

[0049] The following is a detailed description of the various parts of the anti-reflective film layer structure disclosed in the present invention and their specific details:

[0050] A first hard mask layer 1 may be formed on a substrate. The first hard mask layer 1 may be a thin film formed on the substrate or a coating formed on the substrate. The specific form of the first hard mask layer 1 is not particularly limited. The thickness of the first hard mask layer 1 may be 10 nm to 60 nm. For example, the thickness of the first hard mask layer 1 may be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm or 60 nm. Of course, the first hard mask layer 1 may also be other thicknesses, which are not listed here.

[0051] In some embodiments of the present disclosure, the substrate may be a structure before any etching process in the semiconductor manufacturing process. For example, it may be a structure before etching to form a bit line groove; or, it may be a structure before etching to form a word line groove; or, it may be a structure before etching to form a capacitor hole. No special limitation is made to the substrate herein.

[0052] For example, the first hard mask layer 1 can be formed on the substrate by chemical vapor deposition, physical vapor deposition or atomic layer deposition. Of course, the first hard mask layer 1 can also be formed by other methods. The formation method of the first hard mask layer 1 is not particularly limited here.

[0053] The second hard mask layer 2 can be stacked and distributed with the first hard mask layer 1. For example, the second hard mask layer 2 can be located on the surface of the first hard mask layer 1 away from the substrate, or the second hard mask layer 2 can be located between the first hard mask layer 1 and the substrate, and the specific position of the second hard mask layer 2 is not particularly limited here. The thickness of the second hard mask layer 2 can be 10nm to 60nm. For example, the thickness of the second hard mask layer 2 can be 10nm, 20nm, 30nm, 40nm, 50nm or 60nm. Of course, the second hard mask layer 2 can also be other thicknesses, which are not listed here one by one. It should be noted that the thickness of the second hard mask layer 2 can be equal to the thickness of the first hard mask layer 1, and can also be unequal to the thickness of the first hard mask layer 1, and is not particularly limited here.

[0054] In some embodiments of the present disclosure, the refractive index of the first hard mask layer 1 and the second hard mask layer 2 are different; for example, for light with a wavelength of 193 nm, the refractive index of the first hard mask layer 1 is greater than the refractive index of the second hard mask layer 2. In some embodiments of the present disclosure, the extinction coefficients of the first hard mask layer 1 and the second hard mask layer 2 are different; for example, for light with a wavelength of 193 nm, the extinction coefficient of the first hard mask layer 1 is greater than the extinction coefficient of the second hard mask layer 2. In some embodiments of the present disclosure, the refractive index and extinction coefficient of the first hard mask layer 1 and the second hard mask layer 2 are different; for example, for light with a wavelength of 193 nm, the refractive index of the first hard mask layer 1 is greater than the refractive index of the second hard mask layer 2; at the same time, the extinction coefficient of the first hard mask layer 1 is greater than the extinction coefficient of the second hard mask layer 2. In the disclosed embodiment, by stacking the first hard mask layer 1 and the second hard mask layer 2 with different refractive index and / or extinction coefficient, the refractive index of the anti-reflective film layer structure finally formed is between the refractive index of the first hard mask layer 1 and the refractive index of the second hard mask layer 2; at the same time, the extinction coefficient of the anti-reflective film layer structure is between the extinction coefficient of the first hard mask layer 1 and the extinction coefficient of the second hard mask layer 2, which broadens the range of the extinction coefficient and / or refractive index of the anti-reflective film layer, helps to improve the propagation path and interference effect of light in the anti-reflective film layer structure, reduces the line width roughness and edge roughness of the development area, and thus improves the exposure or development effect of the photoresist, and improves the uniformity of the profile of the development area. It should be noted that the refractive index of the hard mask layer is positively correlated with the extinction coefficient, and the extinction coefficient increases as the refractive index increases.

[0055] For example, the material of the first hard mask layer 1 may be silicon oxynitride, and the material of the second hard mask layer 2 may be silicon oxycarbide, wherein the refractive index of silicon oxynitride is greater than the refractive index of silicon oxycarbide, and at the same time, the extinction coefficient of silicon oxynitride is greater than the extinction coefficient of silicon oxycarbide. Of course, the material of the first hard mask layer 1 may be silicon oxycarbide, and the material of the second hard mask layer 2 may be silicon oxynitride, and the specific materials of the first hard mask layer 1 and the second hard mask layer 2 are not particularly limited here. Figure 3 As shown, for light with a wavelength of 193 nm, the curve of the refractive index and the extinction coefficient of the first hard mask layer 1 is shown in a, and the curve of the refractive index and the extinction coefficient of the second hard mask layer 2 is shown in b. The refractive index of the anti-reflection film layer structure formed by the combination of the first hard mask layer 1 and the second hard mask layer 2 fluctuates between 1.6 and 1.95. At the same time, the extinction coefficient of the anti-reflection film layer structure formed by the combination of the first hard mask layer 1 and the second hard mask layer 2 fluctuates between 0.05 and 0.65 (as shown in FIG. Figure 3 circled in the middle).

[0056] It should be noted that the specific values ​​of the refractive index and extinction coefficient of the anti-reflective film structure can be determined according to the ratio of the thickness of the first hard mask layer 1 to the thickness of the second hard mask layer 2; for example, in the anti-reflective film structure, if the thickness of the first hard mask layer 1 accounts for a relatively high proportion, and the refractive index and extinction coefficient of the first hard mask layer 1 are relatively large, the refractive index and extinction coefficient of the anti-reflective film structure finally formed are relatively high. Conversely, in the anti-reflective film structure, if the thickness of the second hard mask layer 2 accounts for a relatively high proportion, the refractive index and extinction coefficient of the anti-reflective film structure finally formed are relatively small.

[0057] In an exemplary embodiment of the present disclosure, the thickness ratio of the first hard mask layer 1 and the second hard mask layer 2 may be 1:10 to 10:1. For example, the thickness ratio of the first hard mask layer 1 and the second hard mask layer 2 may be 1:10, 1:5, 1:2, 1:1, 2:1, 5:1 or 10:1. Of course, the thickness ratio of the first hard mask layer 1 and the second hard mask layer 2 may also be other ratios, which are not listed here one by one. In the embodiment disclosed herein, since the ratio of the thickness of the first hard mask layer 1 to the second hard mask layer 2 is in the range of 1:10 to 10:1, when the extinction coefficients of the first hard mask layer 1 and the second hard mask layer 2 are close, the refractive index range is adjusted by changing the thickness ratio of the first hard mask layer 1 and the second hard mask layer 2. When the thickness ratio of the first hard mask layer 1 to the second hard mask layer 2 is 10:1, the refractive index is close to the refractive index of the first hard mask layer 1. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is 1:10, the refractive index is close to the refractive index of the second hard mask layer 2. As the thickness ratio of the two approaches, the refractive index gradually moves to the middle. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is greater than 10:1, the refractive index is still close to the refractive index of the first hard mask layer 1, but its specific value is very different from the result of 10:1, so it is meaningless to exceed 10:1. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is less than 1:10, the refractive index is still close to the refractive index of the second hard mask layer 2, but its specific value is very close to the result of 1:10, so it is meaningless to be less than 1:10. The present disclosure provides a variety of thickness combinations for the combination of the first hard mask layer 1 and the second hard mask layer 2. Since different thickness combinations may obtain different refractive indices or extinction coefficients, the range of values ​​of the extinction coefficient and / or refractive index of the anti-reflective film structure is further broadened, and the requirements of different photolithography processes for the refractive index and / or extinction coefficient can be met. In the photolithography process, the first hard mask layer 1 and the second hard mask layer 2 with different thickness ratios can be selected according to the process requirements, which helps to reduce the line width roughness and edge roughness of the development area in different process processes, thereby improving the uniformity of the profile of the development area.

[0058] In some embodiments of the present disclosure, Figure 4As shown, the number of first hard mask layers 1 is two, and the second hard mask layer 2 is located between the two first hard mask layers 1. The total thickness of the two first hard mask layers 1 is greater than the thickness of the second hard mask layer 2, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is less than the refractive index and / or extinction coefficient of the second hard mask layer 2. At this time, the material of the first hard mask layer 1 may be silicon oxycarbide, and the material of the second hard mask layer 2 may be silicon oxynitride. Alternatively, the total thickness of the two first hard mask layers 1 is less than the thickness of the second hard mask layer 2, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2. At this time, the materials of the first hard mask layer 1 and the second hard mask layer 2 are different, the material of the first hard mask layer 1 may be silicon oxynitride, and the material of the second hard mask layer 2 may be silicon oxycarbide.

[0059] In some other embodiments of the present disclosure, the number of the second hard mask layers 2 is two, and the first hard mask layer 1 is located between the two second hard mask layers 2. The total thickness of the two second hard mask layers 2 is greater than the thickness of the first hard mask layer 1, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2. In this case, the material of the first hard mask layer 1 may be silicon oxynitride, and the material of the second hard mask layer 2 may be silicon oxycarbide. Alternatively, the total thickness of the two second hard mask layers 2 is less than the thickness of the first hard mask layer 1, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is less than the refractive index and / or extinction coefficient of the second hard mask layer 2. In this case, the materials of the first hard mask layer 1 and the second hard mask layer 2 are different, the material of the first hard mask layer 1 may be silicon oxycarbide, and the material of the second hard mask layer 2 may be silicon oxynitride.

[0060] In an exemplary embodiment of the present disclosure, there are multiple first hard mask layers 1 and multiple second hard mask layers 2, and the multiple first hard mask layers 1 and the multiple second hard mask layers 2 are alternately distributed in a direction perpendicular to the substrate. For example, the first hard mask layer 1 and the second hard mask layer 2 can be sequentially formed on the surface of the substrate by chemical vapor deposition, physical vapor deposition, or atomic layer deposition.

[0061] In some embodiments of the present disclosure, the total thickness of the plurality of first hard mask layers 1 is greater than the total thickness of the plurality of second hard mask layers 2, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is less than the refractive index and / or extinction coefficient of the second hard mask layer 2. The refractive index or extinction coefficient of the anti-reflective film layer structure finally obtained is close to the refractive index and / or extinction coefficient of the first hard mask layer 1, and is greater than the refractive index and / or extinction coefficient of the first hard mask layer 1 and less than the refractive index and / or extinction coefficient of the second hard mask layer 2. At this time, the material of the first hard mask layer 1 is, for example, silicon oxycarbide, and the material of the second hard mask layer 2 is, for example, silicon oxynitride.

[0062] In some embodiments of the present disclosure, the total thickness of the plurality of first hard mask layers 1 is less than the thickness of the plurality of second hard mask layers 2, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2. The refractive index or extinction coefficient of the anti-reflective film layer structure finally obtained is close to the refractive index and / or extinction coefficient of the second hard mask layer 2, and is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2 and less than the refractive index and / or extinction coefficient of the first hard mask layer 1. At this time, the material of the first hard mask layer 1 may be silicon oxynitride, and the material of the second hard mask layer 2 may be silicon oxycarbide.

[0063] In some other embodiments of the present disclosure, the total thickness of the plurality of second hard mask layers 2 is greater than the thickness of the plurality of first hard mask layers 1, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2. The refractive index or extinction coefficient of the anti-reflection film layer structure finally obtained is close to the refractive index and / or extinction coefficient of the second hard mask layer 2, and is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2 and less than the refractive index and / or extinction coefficient of the first hard mask layer 1. At this time, the material of the first hard mask layer 1 may be silicon oxynitride, and the material of the second hard mask layer 2 may be silicon oxycarbide. Alternatively, the total thickness of the plurality of second hard mask layers 2 is less than the thickness of the plurality of first hard mask layers 1, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is less than the refractive index and / or extinction coefficient of the second hard mask layer 2. The refractive index or extinction coefficient of the anti-reflective film layer structure finally obtained is close to the refractive index and / or extinction coefficient of the first hard mask layer 1, and is smaller than the refractive index and / or extinction coefficient of the first hard mask layer 1 and greater than the refractive index and / or extinction coefficient of the second hard mask layer 2. At this time, the material of the first hard mask layer 1 may be silicon oxycarbide, and the material of the second hard mask layer 2 may be silicon oxynitride.

[0064] The present disclosure also provides a method for forming an anti-reflection film layer structure, the method comprising:

[0065] Forming a first hard mask layer 1 and a second hard mask layer 2 that are stacked and distributed;

[0066] The first hard mask layer 1 and the second hard mask layer 2 have different refractive indices and / or extinction coefficients; and the thickness ratio of the first hard mask layer 1 to the second hard mask layer 2 is 1:10 to 10:1.

[0067] The method for forming an anti-reflective film layer structure disclosed in the present invention, on the one hand, is to stack a first hard mask layer 1 and a second hard mask layer 2 with different refractive indices and / or extinction coefficients so that the refractive index of the anti-reflective film layer structure finally formed is between the refractive index of the first hard mask layer 1 and the refractive index of the second hard mask layer 2; at the same time, the extinction coefficient of the anti-reflective film layer structure is between the extinction coefficient of the first hard mask layer 1 and the extinction coefficient of the second hard mask layer 2, thereby broadening the value range of the extinction coefficient and / or refractive index of the anti-reflective film layer, helping to improve the propagation path and interference effect of light in the anti-reflective film layer structure, reducing the line width roughness and edge roughness of the developing area, thereby improving the exposure or development effect of the photoresist, and improving the uniformity of the profile of the developing area. On the other hand, since the thickness ratio of the first hard mask layer 1 to the second hard mask layer 2 is in the range of 1:10 to 10:1, when the extinction coefficients of the first hard mask layer 1 and the second hard mask layer 2 are close, the refractive index range is adjusted by changing the thickness ratio of the first hard mask layer 1 and the second hard mask layer 2. When the thickness ratio of the first hard mask layer 1 to the second hard mask layer 2 is 10:1, the refractive index is close to the refractive index of the first hard mask layer 1. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is 1:10, the refractive index is close to the refractive index of the second hard mask layer 2. As the thickness ratio of the two approaches, the refractive index gradually moves to the middle. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is greater than 10:1, the refractive index is still close to the refractive index of the first hard mask layer 1, but its specific value is very different from the result of 10:1, so it is meaningless to exceed 10:1. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is less than 1:10, the refractive index is still close to the refractive index of the second hard mask layer 2, but its specific value is very close to the result of 1:10, so it is meaningless to be less than 1:10. The present disclosure provides a variety of thickness combinations for the combination of the first hard mask layer 1 and the second hard mask layer 2. Since different thickness combinations may obtain different refractive indices or extinction coefficients, the range of values ​​of the extinction coefficient and / or refractive index of the anti-reflective film structure is further broadened, and the requirements of different photolithography processes for the refractive index and / or extinction coefficient can be met. In the photolithography process, the first hard mask layer 1 and the second hard mask layer 2 with different thickness ratios can be selected according to the process requirements, which helps to reduce the line width roughness and edge roughness of the development area in different process processes, thereby improving the uniformity of the profile of the development area.

[0068] The specific details of the method for forming the anti-reflective film layer structure disclosed in the present invention are described in detail below:

[0069] A first hard mask layer 1 may be formed on a substrate. The first hard mask layer 1 may be a thin film formed on the substrate or a coating formed on the substrate. The specific form of the first hard mask layer 1 is not particularly limited. The thickness of the first hard mask layer 1 may be 10 nm to 60 nm. For example, the thickness of the first hard mask layer 1 may be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm or 60 nm. Of course, the first hard mask layer 1 may also be other thicknesses, which are not listed here.

[0070] In some embodiments of the present disclosure, the substrate may be a structure before any etching process in the semiconductor manufacturing process. For example, it may be a structure before etching to form a bit line groove; or, it may be a structure before etching to form a word line groove; or, it may be a structure before etching to form a capacitor hole. No special limitation is made to the substrate herein.

[0071] For example, the first hard mask layer 1 can be formed on the substrate by chemical vapor deposition, physical vapor deposition or atomic layer deposition. Of course, the first hard mask layer 1 can also be formed by other methods. The formation method of the first hard mask layer 1 is not particularly limited here.

[0072] The second hard mask layer 2 can be stacked and distributed with the first hard mask layer 1. For example, the second hard mask layer 2 can be located on the surface of the first hard mask layer 1 away from the substrate, or the second hard mask layer 2 can be located between the first hard mask layer 1 and the substrate, and the specific position of the second hard mask layer 2 is not particularly limited here. The thickness of the second hard mask layer 2 can be 10nm to 60nm. For example, the thickness of the second hard mask layer 2 can be 10nm, 20nm, 30nm, 40nm, 50nm or 60nm. Of course, the second hard mask layer 2 can also be other thicknesses, which are not listed here one by one. It should be noted that the thickness of the second hard mask layer 2 can be equal to the thickness of the first hard mask layer 1, and can also be unequal to the thickness of the first hard mask layer 1, and is not particularly limited here.

[0073] In some embodiments of the present disclosure, the refractive index of the first hard mask layer 1 and the second hard mask layer 2 are different; for example, for light with a wavelength of 193 nm, the refractive index of the first hard mask layer 1 is greater than the refractive index of the second hard mask layer 2. In some embodiments of the present disclosure, the extinction coefficients of the first hard mask layer 1 and the second hard mask layer 2 are different; for example, for light with a wavelength of 193 nm, the extinction coefficient of the first hard mask layer 1 is greater than the extinction coefficient of the second hard mask layer 2. In some embodiments of the present disclosure, the refractive index and extinction coefficient of the first hard mask layer 1 and the second hard mask layer 2 are different; for example, for light with a wavelength of 193 nm, the refractive index of the first hard mask layer 1 is greater than the refractive index of the second hard mask layer 2; at the same time, the extinction coefficient of the first hard mask layer 1 is greater than the extinction coefficient of the second hard mask layer 2. In the disclosed embodiment, by stacking the first hard mask layer 1 and the second hard mask layer 2 with different refractive index and / or extinction coefficient, the refractive index of the anti-reflective film layer structure finally formed is between the refractive index of the first hard mask layer 1 and the refractive index of the second hard mask layer 2; at the same time, the extinction coefficient of the anti-reflective film layer structure is between the extinction coefficient of the first hard mask layer 1 and the extinction coefficient of the second hard mask layer 2, which broadens the range of the extinction coefficient and / or refractive index of the anti-reflective film layer, helps to improve the propagation path and interference effect of light in the anti-reflective film layer structure, reduces the line width roughness and edge roughness of the development area, and thus improves the exposure or development effect of the photoresist, and improves the uniformity of the profile of the development area. It should be noted that the refractive index of the hard mask layer is positively correlated with the extinction coefficient, and the extinction coefficient increases as the refractive index increases.

[0074] For example, the material of the first hard mask layer 1 may be silicon oxynitride, and the material of the second hard mask layer 2 may be silicon oxycarbide, wherein the refractive index of silicon oxynitride is greater than the refractive index of silicon oxycarbide, and at the same time, the extinction coefficient of silicon oxynitride is greater than the extinction coefficient of silicon oxycarbide. Of course, the material of the first hard mask layer 1 may be silicon oxycarbide, and the material of the second hard mask layer 2 may be silicon oxynitride, and the specific materials of the first hard mask layer 1 and the second hard mask layer 2 are not particularly limited here. Figure 3 As shown, for light with a wavelength of 193 nm, the curve of the refractive index and the extinction coefficient of the first hard mask layer 1 is shown in a, and the curve of the refractive index and the extinction coefficient of the second hard mask layer 2 is shown in b. The refractive index of the anti-reflection film layer structure formed by the combination of the first hard mask layer 1 and the second hard mask layer 2 fluctuates between 1.6 and 1.95. At the same time, the extinction coefficient of the anti-reflection film layer structure formed by the combination of the first hard mask layer 1 and the second hard mask layer 2 fluctuates between 0.05 and 0.65 (as shown in FIG. Figure 3 circled in the middle).

[0075] It should be noted that the specific values ​​of the refractive index and extinction coefficient of the anti-reflective film structure can be determined according to the ratio of the thickness of the first hard mask layer 1 to the thickness of the second hard mask layer 2; for example, in the anti-reflective film structure, if the thickness of the first hard mask layer 1 accounts for a relatively high proportion, and the refractive index and extinction coefficient of the first hard mask layer 1 are relatively large, the refractive index and extinction coefficient of the anti-reflective film structure finally formed are relatively high. Conversely, in the anti-reflective film structure, if the thickness of the second hard mask layer 2 accounts for a relatively high proportion, the refractive index and extinction coefficient of the anti-reflective film structure finally formed are relatively small.

[0076] In an exemplary embodiment of the present disclosure, the thickness ratio of the first hard mask layer 1 and the second hard mask layer 2 may be 1:10 to 10:1. For example, the thickness ratio of the first hard mask layer 1 and the second hard mask layer 2 may be 1:10, 1:5, 1:2, 1:1, 2:1, 5:1 or 10:1. Of course, the thickness ratio of the first hard mask layer 1 and the second hard mask layer 2 may also be other ratios, which are not listed here one by one. In the embodiment disclosed herein, since the ratio of the thickness of the first hard mask layer 1 to the second hard mask layer 2 is in the range of 1:10 to 10:1, when the extinction coefficients of the first hard mask layer 1 and the second hard mask layer 2 are close, the refractive index range is adjusted by changing the thickness ratio of the first hard mask layer 1 and the second hard mask layer 2. When the thickness ratio of the first hard mask layer 1 to the second hard mask layer 2 is 10:1, the refractive index is close to the refractive index of the first hard mask layer 1. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is 1:10, the refractive index is close to the refractive index of the second hard mask layer 2. As the thickness ratio of the two approaches, the refractive index gradually moves to the middle. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is greater than 10:1, the refractive index is still close to the refractive index of the first hard mask layer 1, but its specific value is very different from the result of 10:1, so it is meaningless to exceed 10:1. When the ratio of the first hard mask layer 1 to the second hard mask layer 2 is less than 1:10, the refractive index is still close to the refractive index of the second hard mask layer 2, but its specific value is very close to the result of 1:10, so it is meaningless to be less than 1:10. The present disclosure provides a variety of thickness combinations for the combination of the first hard mask layer 1 and the second hard mask layer 2. Since different thickness combinations may obtain different refractive indices or extinction coefficients, the range of values ​​of the extinction coefficient and / or refractive index of the anti-reflective film structure is further broadened, and the requirements of different photolithography processes for the refractive index and / or extinction coefficient can be met. In the photolithography process, the first hard mask layer 1 and the second hard mask layer 2 with different thickness ratios can be selected according to the process requirements, which helps to reduce the line width roughness and edge roughness of the development area in different process processes, thereby improving the uniformity of the profile of the development area.

[0077] In some embodiments of the present disclosure, Figure 4As shown, the number of first hard mask layers 1 is two, and the second hard mask layer 2 is located between the two first hard mask layers 1. The total thickness of the two first hard mask layers 1 is greater than the thickness of the second hard mask layer 2, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is less than the refractive index and / or extinction coefficient of the second hard mask layer 2. At this time, the material of the first hard mask layer 1 may be silicon oxycarbide, and the material of the second hard mask layer 2 may be silicon oxynitride. Alternatively, the total thickness of the two first hard mask layers 1 is less than the thickness of the second hard mask layer 2, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2. At this time, the material of the first hard mask layer 1 may be silicon oxynitride, and the material of the second hard mask layer 2 may be silicon oxycarbide.

[0078] In some other embodiments of the present disclosure, the number of the second hard mask layers 2 is two, and the first hard mask layer 1 is located between the two second hard mask layers 2. The total thickness of the two second hard mask layers 2 is greater than the thickness of the first hard mask layer 1, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2. In this case, the material of the first hard mask layer 1 may be silicon oxynitride, and the material of the second hard mask layer 2 may be silicon oxycarbide. Alternatively, the total thickness of the two second hard mask layers 2 is less than the thickness of the first hard mask layer 1, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is less than the refractive index and / or extinction coefficient of the second hard mask layer 2. In this case, the material of the first hard mask layer 1 may be silicon oxycarbide, and the material of the second hard mask layer 2 may be silicon oxynitride.

[0079] In an exemplary embodiment of the present disclosure, there are multiple first hard mask layers 1 and multiple second hard mask layers 2, and the multiple first hard mask layers 1 and the multiple second hard mask layers 2 are alternately distributed in a direction perpendicular to the substrate. For example, the first hard mask layer 1 and the second hard mask layer 2 can be sequentially formed on the surface of the substrate by chemical vapor deposition, physical vapor deposition, or atomic layer deposition.

[0080] In some embodiments of the present disclosure, the total thickness of the plurality of first hard mask layers 1 is greater than the total thickness of the plurality of second hard mask layers 2, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is less than the refractive index and / or extinction coefficient of the second hard mask layer 2. The refractive index or extinction coefficient of the anti-reflective film layer structure finally obtained is close to the refractive index and / or extinction coefficient of the first hard mask layer 1, and is greater than the refractive index and / or extinction coefficient of the first hard mask layer 1 and less than the refractive index and / or extinction coefficient of the second hard mask layer 2. At this time, the material of the first hard mask layer 1 is, for example, silicon oxycarbide, and the material of the second hard mask layer 2 is, for example, silicon oxynitride.

[0081] In some embodiments of the present disclosure, the total thickness of the plurality of first hard mask layers 1 is less than the thickness of the plurality of second hard mask layers 2, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2. The refractive index or extinction coefficient of the anti-reflective film layer structure finally obtained is close to the refractive index and / or extinction coefficient of the second hard mask layer 2, and is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2 and less than the refractive index and / or extinction coefficient of the first hard mask layer 1. At this time, the material of the first hard mask layer 1 may be silicon oxynitride, and the material of the second hard mask layer 2 may be silicon oxycarbide.

[0082] In some other embodiments of the present disclosure, the total thickness of the plurality of second hard mask layers 2 is greater than the thickness of the plurality of first hard mask layers 1, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2. The refractive index or extinction coefficient of the anti-reflection film layer structure finally obtained is close to the refractive index and / or extinction coefficient of the second hard mask layer 2, and is greater than the refractive index and / or extinction coefficient of the second hard mask layer 2 and less than the refractive index and / or extinction coefficient of the first hard mask layer 1. At this time, the material of the first hard mask layer 1 may be silicon oxynitride, and the material of the second hard mask layer 2 may be silicon oxycarbide. Alternatively, the total thickness of the plurality of second hard mask layers 2 is less than the thickness of the plurality of first hard mask layers 1, and the refractive index and / or extinction coefficient of the first hard mask layer 1 is less than the refractive index and / or extinction coefficient of the second hard mask layer 2. The refractive index or extinction coefficient of the anti-reflective film layer structure finally obtained is close to the refractive index and / or extinction coefficient of the first hard mask layer 1, and is smaller than the refractive index and / or extinction coefficient of the first hard mask layer 1 and greater than the refractive index and / or extinction coefficient of the second hard mask layer 2. At this time, the material of the first hard mask layer 1 may be silicon oxycarbide, and the material of the second hard mask layer 2 may be silicon oxynitride.

[0083] The following takes the case where the material of the first hard mask layer 1 is silicon oxynitride, the material of the second hard mask layer 2 is silicon oxycarbide, the first hard mask layer 1 is formed on the surface of the substrate, and the second hard mask layer 2 is formed on the surface of the first hard mask layer 1 away from the substrate as an example, and the specific formation process of the anti-reflective film layer structure is described in detail:

[0084] In an exemplary embodiment of the present disclosure, the first hard mask layer 1 and the second hard mask layer 2 may be formed by physical vapor deposition, wherein the forming of the first hard mask layer 1 includes steps S110 to S130, wherein:

[0085] Step S110, providing a reaction chamber 3.

[0086] like Figure 5As shown, the reaction chamber 3 can be located in a box, and the box can be a polyhedron or a cylinder, which is not particularly limited here. The material of the box can be metal or alloy, or glass or other materials. For example, the box can be a reaction furnace tube.

[0087] The reaction chamber 3 may be a vacuum chamber to provide a vacuum environment for subsequent reactions, thereby preventing impurities from entering, and thereby ensuring the deposition effect and performance of the film formed subsequently. For example, a vacuum pump may be used to evacuate the reaction chamber 3, thereby forming a vacuum environment in the reaction chamber 3.

[0088] In an exemplary embodiment of the present disclosure, the side wall of the reaction chamber 3 may be provided with a first air inlet, a second air inlet and a third air inlet, and the first air inlet, the second air inlet and the third air inlet may be arranged at intervals. The first air inlet, the second air inlet and the third air inlet may be arranged at the same end of the side wall of the reaction chamber 3, or may be respectively arranged on different sides of the side wall of the reaction chamber 3, without special limitation herein.

[0089] Step S120 , introducing silicon-containing gas and nitrogen-containing gas into the reaction chamber 3 .

[0090] A silicon-containing gas may be introduced into the reaction chamber 3 through the first gas inlet, and a nitrogen-containing gas may be introduced into the reaction chamber 3 through the second gas inlet. The flow rate of the silicon-containing gas may be 50 sccm to 150 sccm, for example, the flow rate may be 50 sccm, 70 sccm, 90 sccm, 110 sccm, 130 sccm or 150 sccm. Of course, the silicon-containing gas may also have other flow rates, which are not listed here. The flow rate of the nitrogen-containing gas may be 600 sccm to 800 sccm, for example, the flow rate may be 600 sccm, 650 sccm, 700 sccm, 750 sccm or 800 sccm. Of course, the nitrogen-containing gas may also have other flow rates, which are not listed here.

[0091] For example, the silicon-containing gas may be silane, and the nitrogen-containing gas may be nitrous oxide. In some embodiments of the present disclosure, ammonia gas may also be introduced into the reaction chamber 3. In the embodiments of the present disclosure, the flow rate of ammonia gas may be 0 sccm to 100 sccm, for example, the flow rate may be 0 sccm, 20 sccm, 40 sccm, 60 sccm, 80 sccm or 100 sccm. Of course, the ammonia gas may also be other flow rates, which are not listed here one by one.

[0092] Step S130 , performing plasma bombardment on the silicon-containing gas and the nitrogen-containing gas, so as to dissociate and recombine the silicon-containing gas and the nitrogen-containing gas to form the first hard mask layer 1 .

[0093] In the embodiment of the present disclosure, after silicon-containing gas and nitrogen-containing gas are introduced into the reaction chamber 3 and the silicon-containing gas and carbon-containing gas are stabilized, the power supply (150V-280V) of the reaction chamber 3 can be turned on, and the silicon-containing gas and the nitrogen-containing gas are subjected to plasma bombardment at 400°C. During this process, the silicon-containing gas and the nitrogen-containing gas are dissociated and recombined to form a silicon oxynitride film, which can be the first hard mask layer 1.

[0094] It should be noted that after forming the first hard mask layer 1 , vacuum may be drawn to remove the remaining gas in the reaction chamber 3 , so as to prevent the remaining gas from affecting the subsequent thin film forming process.

[0095] In an exemplary embodiment of the present disclosure, forming the second hard mask layer 2 may include steps S210 and S220, wherein:

[0096] Step S210 , introducing silicon-containing gas and carbon-containing gas into the reaction chamber 3 .

[0097] A silicon-containing gas may be introduced into the reaction chamber 3 through the first gas inlet, and a carbon-containing gas may be introduced into the reaction chamber 3 through the third gas inlet. The flow rate of the silicon-containing gas may be 50 sccm to 120 sccm, for example, the flow rate may be 50 sccm, 70 sccm, 90 sccm, 110 sccm or 120 sccm. Of course, the silicon-containing gas may also have other flow rates, which are not listed here. The flow rate of the carbon-containing gas may be 6500 sccm to 12000 sccm, for example, the flow rate may be 6500 sccm, 7000 sccm, 8000 sccm, 9000 sccm, 10000 sccm, 11000 sccm or 12000 sccm. Of course, the carbon-containing gas may also have other flow rates, which are not listed here. For example, the silicon-containing gas may be silane, and the carbon-containing gas may be carbon dioxide.

[0098] Step S220 , performing plasma bombardment on the silicon-containing gas and the carbon-containing gas, so as to dissociate and recombine the silicon-containing gas and the carbon-containing gas to form the second hard mask layer 2 .

[0099] In the embodiment of the present disclosure, after silicon-containing gas and carbon-containing gas are introduced into the reaction chamber 3 and the silicon-containing gas and carbon-containing gas are stabilized, the power supply (150V-280V) of the reaction chamber 3 can be turned on, and the silicon-containing gas and the carbon-containing gas are subjected to plasma bombardment at 400°C. During this process, the silicon-containing gas and the carbon-containing gas are dissociated and recombined to form a carbon oxide film, which can be the second hard mask layer 2.

[0100] In the embodiment of the present disclosure, the performance of the anti-reflection film layer structure finally formed is verified. Specifically, in the present disclosure, a single film layer in the prior art is used as the anti-reflection layer to expose and develop the photoresist 11, thereby obtaining a sample 1, such as Figure 6 At the same time, the anti-reflective film layer structure of the present invention is used as the anti-reflective layer to expose and develop the photoresist 11, thereby obtaining sample 2, as shown in FIG. Figure 7 As shown in the figure, the contour ratios of the top and bottom of the developing area in sample 1 and sample 2 were measured, and the measurement results showed that the contour ratio of the top and bottom of the developing area in sample 1 was 0.63; while the contour ratio of the top and bottom of the developing area in sample 2 was 0.73. That is, compared with the prior art, the use of the anti-reflection film layer structure disclosed in the present invention as the anti-reflection layer can improve the uniformity of the contour of the developing area by 15.9%.

[0101] In some embodiments of the present disclosure, Figure 8 As shown, the anti-reflection film layer structure disclosed in the present invention can be used as an anti-reflection layer in the process of etching the substrate 10. For example, a first mask layer 4 (the material of the first mask layer 4 can be silicon oxide) can be formed on the substrate 10; a second mask layer 5 (the material of the second mask layer 5 can be amorphous silicon) can be formed on the first mask layer 4; a third mask layer 6 (the material of the third mask layer 6 can be silicon oxynitride) can be formed on the surface of the second mask layer 5; a fourth mask layer 7 (the material of the fourth mask layer 7 can be amorphous carbon) can be formed on the surface of the third mask layer 6; an anti-reflection film layer structure 8 disclosed in the present invention is formed on the surface of the fourth mask layer 7; a photoresist layer 9 is formed on the surface of the anti-reflection film layer structure 8 disclosed in the present invention. Due to the application of the anti-reflection film layer structure 8 disclosed in the present invention, the uniformity of the profile of the development area in the photoresist layer 9 is improved, thereby improving the uniformity of the pattern transferred from the development area to each mask layer, which helps to improve the uniformity of the pattern transferred to the substrate, thereby improving the product yield.

[0102] It should be noted that since nitrogen ions will combine with hydrogen ions in the photoresist layer 9 and thus affect the subsequent removal effect of the photoresist layer 9, when the topmost film layer in the anti-reflective film layer structure disclosed in the present invention contains nitrogen ions (for example, its material is silicon oxynitride), a bottom anti-reflective coating (BARC) can be formed on the surface of the anti-reflective film layer structure disclosed in the present invention, and then a photoresist layer 9 is formed on the surface of the bottom anti-reflective film layer, so as to ensure the subsequent removal effect of the photoresist layer 9; when the topmost film layer in the anti-reflective film layer structure disclosed in the present invention does not contain nitrogen ions (for example, its material is silicon oxycarbide), a photoresist layer 9 can be directly formed on the surface of the anti-reflective film layer structure disclosed in the present invention.

[0103] It should be noted that, although the steps of the method for forming the anti-reflective film layer structure in the present disclosure are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0104] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. An anti-reflection film structure, characterized in that: include: A first hard mask layer and a second hard mask layer are stacked and distributed; Wherein, the first hard mask layer and the second hard mask layer have different refractive indices and / or extinction coefficients; The ratio of the thickness of the first hard mask layer to the thickness of the second hard mask layer is 1:10 to 10:

1.

2. The anti-reflection film layer structure according to claim 1, characterized in that: The thickness of the first hard mask layer and the second hard mask layer are both 10 nm to 60 nm.

3. The anti-reflection film layer structure according to claim 1, characterized in that: The number of the first hard mask layers is two, and the second hard mask layer is located between the two first hard mask layers; or the number of the second hard mask layers is two, and the first hard mask layer is located between the two second hard mask layers.

4. The anti-reflection film layer structure according to claim 1, characterized in that: There are multiple first hard mask layers and multiple second hard mask layers, and the multiple first hard mask layers and the multiple second hard mask layers are alternately distributed in sequence.

5. The anti-reflection film layer structure according to claim 4, characterized in that: The total thickness of the first hard mask layers is greater than the total thickness of the second hard mask layers, and the refractive index and / or extinction coefficient of the first hard mask layers are smaller than the refractive index and / or extinction coefficient of the second hard mask layers.

6. The anti-reflection film layer structure according to claim 4, characterized in that: The total thickness of the second hard mask layers is greater than the total thickness of the first hard mask layers, and the refractive index and / or extinction coefficient of the first hard mask layer is greater than the refractive index and / or extinction coefficient of the second hard mask layer.

7. A method for forming an anti-reflection film layer structure, characterized in that: include: forming a first hard mask layer and a second hard mask layer in a stacked arrangement; The first hard mask layer and the second hard mask layer have different refractive indices and / or extinction coefficients; and a thickness ratio between the first hard mask layer and the second hard mask layer is 1:10 to 10:

1.

8. The forming method according to claim 7, characterized in that: The number of the first hard mask layers is two, and the second hard mask layer is located between the two first hard mask layers; or the number of the second hard mask layers is two, and the first hard mask layer is located between the two second hard mask layers.

9. The forming method according to claim 7, characterized in that: There are multiple first hard mask layers and multiple second hard mask layers, and the multiple first hard mask layers and the multiple second hard mask layers are alternately distributed in sequence.

10. The forming method according to claim 9, characterized in that: The total thickness of the first hard mask layers is greater than the total thickness of the second hard mask layers, and the refractive index and / or extinction coefficient of the first hard mask layers are smaller than the refractive index and / or extinction coefficient of the second hard mask layers.

11. The forming method according to claim 9, characterized in that: The total thickness of the second hard mask layers is greater than the total thickness of the first hard mask layers, and the refractive index and / or extinction coefficient of the first hard mask layer is greater than the refractive index and / or extinction coefficient of the second hard mask layer.

12. The forming method according to any one of claims 7 to 11, characterized in that: The material of the first hard mask layer is silicon oxynitride, and the material of the second hard mask layer is silicon oxycarbide.

13. The forming method according to claim 12, characterized in that: Forming the first hard mask layer includes: providing a reaction chamber; introducing silicon-containing gas and nitrogen-containing gas into the reaction chamber; Plasma bombardment is performed on the silicon-containing gas and the nitrogen-containing gas to dissociate and recombine the silicon-containing gas and the nitrogen-containing gas to form the first hard mask layer.

14. The forming method according to claim 13, characterized in that: Forming the second hard mask layer includes: introducing silicon-containing gas and carbon-containing gas into the reaction chamber; Plasma bombardment is performed on the silicon-containing gas and the carbon-containing gas to dissociate and recombine the silicon-containing gas and the carbon-containing gas to form the second hard mask layer.

15. The forming method according to claim 14, characterized in that: The silicon-containing gas is silane, the nitrogen-containing gas includes at least nitrous oxide, and the carbon-containing gas is carbon dioxide.

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