A semiconductor structure and a method of manufacturing the same

Abstract

Disclosed are a semiconductor structure and a manufacturing method thereof. The manufacturing method comprises the following steps: providing a substrate; forming a first patterned mask layer on the substrate; etching the substrate to form a first groove by taking the first patterned mask layer as a mask, wherein an unetched region of the substrate forms a protruding structure; forming a second patterned mask layer on the substrate, wherein the second patterned mask layer covers at least a sidewall and an upper surface of the protruding structure, and the second patterned mask layer has an opening formed thereon, and the opening exposes a part of a bottom surface of the first groove; and etching the substrate from the opening to form a second groove below the first groove by taking the second patterned mask layer as a mask.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of semiconductor manufacturing, and in particular, to a semiconductor structure and a manufacturing method thereof. BACKGROUND

[0002] In a semiconductor manufacturing process, it is often required to form a photoresist pattern layer with a large height on a substrate, and then etch the substrate with the photoresist pattern layer as a mask to transfer the pattern of the photoresist pattern layer to the substrate.

[0003] However, as the semiconductor structure is continuously developing towards miniaturization and high integration, when the process is scaled down, due to the large height of the photoresist pattern layer and the small contact area of the local region with the substrate, the photoresist pattern layer may collapse, fall off, break, etc. in the local region, affecting the subsequent pattern transfer accuracy, and thus reducing the performance of the semiconductor structure. SUMMARY

[0004] The present disclosure provides a manufacturing method of a semiconductor structure, comprising:

[0005] providing a substrate, forming a first patterned mask layer on the substrate, etching the substrate with the first patterned mask layer as a mask to form a first trench, and the unetched region of the substrate constituting a protruding structure;

[0006] forming a second patterned mask layer on the substrate, the second patterned mask layer covering at least the sidewall and the upper surface of the protruding structure, and an opening is formed on the second patterned mask layer, the opening exposing part of the bottom surface of the first trench;

[0007] etching the substrate from the opening with the second patterned mask layer as a mask to form a second trench below the first trench.

[0008] In some embodiments, forming a second patterned mask layer on the substrate comprises: the ratio of the height of the second patterned mask layer to the height of the protruding structure ranges between 3 and 5; and after forming the second trench, the height of the remaining second patterned mask layer is greater than the height of the protruding structure.

[0009] In some embodiments, the number of the first trench and the second trench is multiple, multiple first trenches are arranged separately on the substrate, the protruding structure is located in the peripheral region of the multiple first trenches, and multiple second trenches are formed correspondingly below the multiple first trenches.

[0010] In some embodiments, the width of the second patterned mask layer covering the sidewall of the protruding structure ranges between 1 μm and 5 μm.

[0011] In some embodiments, the number of the protruding structures and the number of the second trenches are both plural, the plural protruding structures are separately arranged on the substrate, the gaps between the plural protruding structures form the first trenches, and the plural second trenches are formed under the first trenches.

[0012] In some embodiments, before forming the second patterned mask layer on the substrate, the method further comprises:

[0013] etching the substrate to form at least one third trench on the protruding structure, the third trench extending from the top surface of the protruding structure to the interior of the protruding structure, and the depth of the third trench being less than or equal to the depth of the first trench;

[0014] forming the second patterned mask layer on the substrate, the second patterned mask layer filling the third trench.

[0015] In some embodiments, after forming the second trench, the method further comprises:

[0016] forming a layer of conductive material, the layer of conductive material filling the second trench and the first trench and covering the protruding structure;

[0017] removing the protruding structure and removing the layer of conductive material filling the first trench and covering the protruding structure to form a conductive layer, the conductive layer filling the second trench.

[0018] The present disclosure also provides a semiconductor structure, comprising:

[0019] a substrate;

[0020] a first trench formed on the substrate, the area of the substrate not forming the first trench forming a protruding structure;

[0021] a second patterned mask layer, the second patterned mask layer covering at least the sidewall and the top surface of the protruding structure, and an opening formed on the second patterned mask layer, the opening exposing part of the bottom surface of the first trench.

[0022] In some embodiments, the ratio of the height of the second patterned mask layer to the height of the protruding structure ranges from 3 to 5.

[0023] In some embodiments, the semiconductor structure further comprises: at least one third trench extending from the top surface of the protruding structure to the interior of the protruding structure, the depth of the third trench being less than or equal to the depth of the first trench, and the second patterned mask layer filling the third trench.

[0024] The semiconductor structure and the manufacturing method thereof provided by the embodiments of the present disclosure, wherein the manufacturing method comprises the following steps: providing a substrate, forming a first patterned mask layer on the substrate, etching the substrate to form a first groove by taking the first patterned mask layer as a mask, and the unetched area of the substrate constitutes a protruding structure; forming a second patterned mask layer on the substrate, the second patterned mask layer covers at least the sidewall and the upper surface of the protruding structure, and the second patterned mask layer is provided with an opening, and the opening exposes part of the bottom surface of the first groove; etching the substrate from the opening by taking the second patterned mask layer as a mask to form a second groove below the first groove. The embodiments of the present disclosure first form a protruding structure on the substrate, and then form a second patterned mask layer, and the second patterned mask layer covers the sidewall of the protruding structure, which on one hand increases the contact area between the second patterned mask layer and the substrate, and on the other hand, due to the existence of the protruding structure, the height of the part of the upper surface of the protruding structure covered by the second patterned mask layer is reduced, and at the same time, the protruding structure provides good support for the second patterned mask layer, so that the mechanical stability of the second patterned mask layer is improved, and the collapse, falling or fracture of the second patterned mask layer is avoided or alleviated.

[0025] The details of one or more embodiments of the present disclosure are presented in the following drawings and description. Other features and advantages of the present disclosure will become apparent from the description and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art without creative labor.

[0027] Figure 1 The flow chart of the manufacturing method of the semiconductor structure provided by the embodiments of the present disclosure is shown in the figure;

[0028] Figures 2 to 9 The process flow chart of the manufacturing method of the semiconductor structure provided by the embodiments of the present disclosure is shown in the figure;

[0029] Figures 10a to 12b The process flow chart of the manufacturing method of the semiconductor structure provided by another embodiment of the present disclosure is shown in the figure;

[0030] Figures 13 to 15 The process flow chart of the manufacturing method of the semiconductor structure provided by another embodiment of the present disclosure is shown in the figure. DETAILED DESCRIPTION

[0031] Exemplary embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the present disclosure are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0032] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that the present disclosure can be practiced without one or more of these specific details. In other instances, well-known features have not been described in detail so as not to unnecessarily complicate the present disclosure. In addition, it is to be understood that the terminology used herein is for the purpose of describing the particular embodiments only and is not intended to be limiting.

[0033] In the drawings, the size of layers, regions, elements, and the like can be exaggerated for clarity. Like reference numerals refer to like elements throughout.

[0034] It will be understood that when an element or layer is referred to as being "on" or "connected to" another element or layer, it can be directly on or connected to the other element or layer or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element or layer, there are no intervening elements or layers present. It will also be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms since such terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section.

[0035] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and / or operation in addition to the orientations depicted in the figures. For example, if a device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial descriptions used herein interpreted accordingly.

[0036] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] In a semiconductor manufacturing process, it is usually required to form a photoresist pattern layer with a large height on a substrate, and then etch the substrate with the photoresist pattern layer as a mask to transfer the pattern of the photoresist pattern layer to the substrate.

[0038] However, as the semiconductor structure is continuously developing towards miniaturization and high integration, when the process is scaled down, due to the large height of the photoresist pattern layer and the small contact area of the local region (such as the pattern region) with the substrate, the photoresist pattern layer may collapse, fall off, break, and the like in the local region, affecting the subsequent pattern transfer accuracy, and thus reducing the performance of the semiconductor structure.

[0039] Based on this, the following technical scheme of the embodiments of the disclosure is proposed. The specific embodiments of the disclosure will be described in detail below with reference to the accompanying drawings. In the detailed description of the embodiments of the disclosure, the schematic diagram will be partially enlarged without general proportion, and the schematic diagram is only an example, which should not limit the protection scope of the disclosure herein.

[0040] The embodiments of the disclosure provide a manufacturing method of a semiconductor structure, as shown in the figure, the method comprises the following steps: Figure 1 As shown in the figure, the method comprises the following steps:

[0041] Step S101, providing a substrate, forming a first patterned mask layer on the substrate, etching the substrate with the first patterned mask layer as a mask to form a first trench, the unetched region of the substrate constituting a protruding structure;

[0042] Step S102, forming a second patterned mask layer on the substrate, the second patterned mask layer covering at least the sidewall and the upper surface of the protruding structure, the second patterned mask layer having an opening formed thereon, the opening exposing part of the bottom surface of the first trench;

[0043] Step S103, etching the substrate from the opening with the second patterned mask layer as a mask to form a second trench below the first trench.

[0044] Figures 2 to 9 Process flow chart of the manufacturing method of the semiconductor structure provided by the embodiment of the present disclosure; Figures 10a to 12b Process flow chart of the manufacturing method of the semiconductor structure provided by another embodiment of the present disclosure; Figures 13 to 15 Process flow chart of the manufacturing method of the semiconductor structure provided by still another embodiment of the present disclosure; wherein, Figure 3a 、 Figure 5a 、 Figure 7a 、 Figure 10a 、 Figure 11a 、 Figure 12a is a top view schematic diagram of the semiconductor structure in the manufacturing process, Figure 3b 、 Figure 5b 、 Figure 7b 、 Figure 10b 、 Figure 11b 、 Figure 12b are schematic diagrams of the cross-sectional structure taken along the line AA' in Figure 3a 、 Figure 5a 、 Figure 7a 、 Figure 10a 、 Figure 11a 、 Figure 12a , respectively. Hereinafter, the manufacturing method of the semiconductor structure of the embodiment of the present disclosure will be further described in detail in conjunction with Figures 2 to 15 .

[0045] First, step S101 is performed. As shown in Figure 2 and Figures 3a to 3b , a substrate 10 is provided, a first patterned mask layer 11 is formed on the substrate 10, the substrate 10 is etched with the first patterned mask layer 11 as a mask to form a first trench T1, and the unetched region of the substrate 10 constitutes a protruding structure 12.

[0046] The substrate 10 can be a semiconductor substrate and can include at least one elemental semiconductor material (e.g., a silicon (Si) substrate, a germanium (Ge) substrate), at least one III-V compound semiconductor material, at least one II- VI compound semiconductor material, at least one organic semiconductor material, or other semiconductor materials known in the art. The substrate 10 can have structures such as word lines, bit lines, active areas, isolation structures, and contact layers formed therein. In one embodiment, the substrate 10 is a silicon substrate, which can be doped or undoped. In some embodiments, the substrate 10 further includes device structures formed on the substrate 10, interlayer dielectric layers, interconnect layers located within the interlayer dielectric layers, and the like.

[0047] The material of the first patterned mask layer 11 can be photoresist. However, the material of the first patterned mask layer 11 can also be other materials capable of being used for pattern transfer, such as a spin-on hard mask layer, for example, an amorphous carbon layer or an amorphous silicon layer, and the like.

[0048] As shown in FIG. 1A, in one embodiment, the first trenches T1 are arranged in an array along a first direction and a second direction, and the first direction and the second direction are perpendicular or oblique to each other. However, the first trenches T1 can also have other arrangements, such as linear arrangement along any direction or irregular arrangement. Figure 3a As shown in FIG. 1A, in one embodiment, the first trenches T1 are arranged in an array along a first direction and a second direction, and the first direction and the second direction are perpendicular or oblique to each other. However, the first trenches T1 can also have other arrangements, such as linear arrangement along any direction or irregular arrangement.

[0049] As shown in FIG. 1A, in one embodiment, the first trenches T1 are arranged in an array along a first direction and a second direction, and the first direction and the second direction are perpendicular or oblique to each other. However, the first trenches T1 can also have other arrangements, such as linear arrangement along any direction or irregular arrangement. Figure 6 As shown in FIG. 1A, in one embodiment, the first trenches T1 are arranged in an array along a first direction and a second direction, and the first direction and the second direction are perpendicular or oblique to each other. However, the first trenches T1 can also have other arrangements, such as linear arrangement along any direction or irregular arrangement. Figure 6 As shown in FIG. 1A, in one embodiment, the first trenches T1 are arranged in an array along a first direction and a second direction, and the first direction and the second direction are perpendicular or oblique to each other. However, the first trenches T1 can also have other arrangements, such as linear arrangement along any direction or irregular arrangement. Figure 3a As shown in FIG. 1A, in one embodiment, the first trenches T1 are arranged in an array along a first direction and a second direction, and the first direction and the second direction are perpendicular or oblique to each other. However, the first trenches T1 can also have other arrangements, such as linear arrangement along any direction or irregular arrangement.

[0050] Figure 3a As shown in FIG. 1A, in one embodiment, the first trenches T1 are arranged in an array along a first direction and a second direction, and the first direction and the second direction are perpendicular or oblique to each other. However, the first trenches T1 can also have other arrangements, such as linear arrangement along any direction or irregular arrangement.

[0051] Next, step S102 is performed, as shown in FIG. 1B, a second patterned mask layer 13 is formed on the substrate 10, the second patterned mask layer 13 at least covers the sidewall and the upper surface of the protruding structure 12, and the second patterned mask layer 13 has an opening S formed thereon, the opening S exposes part of the bottom surface of the first trench T1. Figure 4 、 Figures 5a to 5b As shown in FIG. 1B, a second patterned mask layer 13 is formed on the substrate 10, the second patterned mask layer 13 at least covers the sidewall and the upper surface of the protruding structure 12, and the second patterned mask layer 13 has an opening S formed thereon, the opening S exposes part of the bottom surface of the first trench T1.

[0052] Specifically, the second patterned mask layer 13 is formed on the substrate 10, including:

[0053] A first film layer 13' is formed, covering the sidewalls and the upper surface of the protruding structure 12 and filling the first trench T1;

[0054] The first film layer 13' is etched to form openings S penetrating through the first film layer 13', so as to form a second patterned mask layer 13.

[0055] In some embodiments, the material of the first film layer 13' includes photoresist, and the second patterned mask layer 13 is formed by performing an exposure and development process on the first film layer 13'. However, the material of the first film layer 13' can also be other materials capable of being used for pattern transfer, such as a spin-on hard mask layer, for example, an amorphous carbon layer or an amorphous silicon layer, etc.

[0056] Figure 5a The shape of the horizontal cross section of the opening S shown in FIG. 2 is circular, but the shape of the horizontal cross section of the opening S can also be other shapes, such as rectangular, elliptical, etc.

[0057] In subsequent processes, the substrate 10 can be etched from the openings S with the second patterned mask layer 13 as a mask, so as to transfer the pattern of the second patterned mask layer 13 to the substrate 10. The embodiments of the present disclosure first form the protruding structure 12 on the substrate 10, and then form the second patterned mask layer 13 covering the sidewalls and the upper surface of the protruding structure 12. On the one hand, the contact area between the second patterned mask layer 13 and the substrate 10 is increased, and on the other hand, due to the presence of the protruding structure 12, the height of the portion of the second patterned mask layer 13 covering the upper surface of the protruding structure 12 is reduced, and at the same time, the protruding structure 12 provides good support for the second patterned mask layer 13. In this way, the mechanical stability of the second patterned mask layer 13 is improved, and the collapse, falling or fracture of the second patterned mask layer 13 is avoided or alleviated, and the precision of subsequent pattern transfer is improved.

[0058] It can be understood that the higher the height of the protruding structure 12, the better the support of the protruding structure 12 to the second patterned mask layer 13, and the better the effect of improving the mechanical stability of the second patterned mask layer 13. However, the height of the protruding structure 12 cannot be too high. If the height of the protruding structure 12 is too high, the height of the portion of the second patterned mask layer 13 covering the upper surface of the protruding structure 12 is low, and in the process of etching the substrate 10 with the second patterned mask layer 13 as a mask, the upper surface of the protruding structure 12 is easily exposed, and the protruding structure 12 can be over-etched and damaged, thereby reducing the precision of pattern transfer. In an embodiment, the ratio of the height H1 of the second patterned mask layer 13 to the height H2 of the protruding structure 12 is in the range of 3 to 5 (including the end point value), for example, 3.5, 4, 4.5, etc.

[0059] like Figure 5a As shown, in one embodiment, there are multiple first trenches T1 and multiple openings S, with each opening S corresponding to the bottom surface of multiple first trenches T1. In this embodiment, the protrusion structure 12 is a structure that extends continuously on the substrate 10. The protrusion structure 12 has strong mechanical stability, thus providing better support for the second patterned mask layer 13 and increasing the mechanical stability of the second patterned mask layer 13.

[0060] See also Figure 5a and Figure 5b In one embodiment, the width L of the second patterned mask layer 13 covering the sidewall of the protruding structure 12 should not be too small or too large. If the width L is too small, the bonding strength between the second patterned mask layer 13 and the sidewall of the protruding structure 12 is poor, and the second patterned mask layer 13 located on the sidewall of the protruding structure 12 is prone to detachment or breakage. If the width L is too large, the width of the protruding structure 12 located between adjacent first grooves T1 is small, affecting the mechanical stability of the protruding structure 12 and the supporting effect of the protruding structure 12 on the second patterned mask layer 13. In a specific embodiment, the width of the second patterned mask layer 13 covering the sidewall of the protruding structure 12 is in the range of 1 μm to 5 μm (including the endpoint value), such as 2 μm, 3 μm, 4 μm, etc.

[0061] Next, proceed to step S103, as follows: Figure 6 As shown, using the second patterned mask layer 13 as a mask, the substrate 10 is etched from the opening S to form a second trench T2 below the first trench T1.

[0062] See you again Figure 6 In some embodiments, using the second patterned mask layer 13 as a mask, during the etching of the substrate 10 from the opening S, a portion of the second patterned mask layer 13 is simultaneously etched away, and the remaining second patterned mask layer 13 is defined as the second film layer 13″. In this embodiment of the present disclosure, before forming the second trench T2, the ratio of the height H1 of the second patterned mask layer 13 to the height H2 of the protrusion structure 12 is set to be between 3 and 5, so that after forming the second trench T2, the height of the remaining second patterned mask layer 13 (second film layer 13″) is greater than the height of the protrusion structure 12. That is, during the etching of the substrate 10 to form the second trench T2, the second patterned mask layer 13 always covers the surface of the protrusion structure 12 and the surface of the substrate 10 located on both sides of the protrusion structure 12, thereby providing good protection for the protrusion structure 12 and the substrate 10.

[0063] Next, as Figures 7a to 7b As shown, the method also includes: removing the second film layer 13″.

[0064] In the embodiments of the present disclosure, the protruding structure 12 plays a good supporting role on the second patterned mask layer 13, thereby allowing the second patterned mask layer 13 with a larger height to be formed on the substrate 10, and further allowing the second trench T2 with a larger depth to be formed. As shown in FIG. 2, in an embodiment, the number of the second trenches T2 is plural, and the plural second trenches T2 are formed below the plural first trenches T1. Figure 7a

[0065] Next, as shown in FIG. 3, after the second trench T2 is formed, the method further includes: Figures 8 to 9

[0066] forming a conductive material layer 14' which fills the second trench T2 and the first trench T1 and covers the protruding structure 12;

[0067] removing the protruding structure 12, and removing the conductive material layer 14' which fills the first trench T1 and covers the protruding structure 12, to form a conductive layer 14 which fills the second trench T2.

[0068] In actual operation, the conductive layer 14 can be formed by the following method: first, a seed material layer (not shown) is formed, which covers the inner wall of the second trench T2 and the surface of the protruding structure 12; then, a bulk material layer (not shown) is formed which fills the second trench T2 and the first trench T1 and covers the protruding structure 12, the seed material layer (not shown) and the bulk material layer (not shown) constitute the conductive material layer 14'; then, the seed material layer (not shown) covering the surface of the protruding structure 12 is removed to form a seed layer (not shown), and the bulk material layer (not shown) filling the first trench T1 and covering the protruding structure 12 is removed to form a bulk layer (not shown), the seed layer (not shown) and the bulk layer (not shown) constitute the conductive layer 14.

[0069] The conductive material layer 14' can be formed by a chemical vapor deposition (CVD), a plasma enhanced chemical vapor deposition (PECVD), a physical vapor deposition (PVD), an atomic layer deposition (ALD), an electroplating, an electroless plating, a sputtering, or the like, for example, the seed material layer (not shown) is first formed by a chemical vapor deposition process, and then the bulk material layer (not shown) is formed by an electroplating process. The material of the conductive material layer 14' includes copper.

[0070] In some embodiments, before the conductive layer 14 is formed, an insulating layer (not shown) can also be formed on the inner wall of the second trench T2, for electrically isolating the substrate 10 and the conductive layer 14, and a barrier layer (not shown) is formed between the insulating layer (not shown) and the conductive layer 14, for preventing the metal in the conductive layer 14 from entering into the substrate 10.

[0071] ​​The method for forming the second trench T2 and the conductive layer 14 in the second trench T2 can be used to manufacture a through silicon via, and the conductive layer 14 can be used to transmit an electrical signal and realize signal transmission between semiconductor chips through the conductive layer 14. However, the second trench T2 can also be a capacitor hole, and a capacitor structure for storing data can be formed in the second trench, or a dielectric layer can also be filled in the second trench to form a deep trench isolation for isolating device structures in the substrate 10.

[0072] Figures 3a to 3b The protruding structure 12 shown in the middle is a structure continuously extending on the substrate 10. However, the protruding structure 12 is not limited to this, and as shown in the left and right of the middle, Figures 10a to 10b In another embodiment of the present disclosure, the number of protruding structures 12 is multiple, and the multiple protruding structures 12 are arranged separately on the substrate 10, and the gap between the multiple protruding structures 12 constitutes the first trench T1, that is, the first trench T1 continuously extends on the substrate 10 and defines multiple separate protruding structures 12 on the substrate 10.

[0073] Figure 10a The shape of the horizontal cross section of the protruding structure 12 shown in the middle is rectangular, but the shape of the horizontal cross section of the protruding structure 12 can also be other shapes, for example, circular, oval, etc.

[0074] Next, as shown in the left of the middle, Figures 11a to 11b a second patterned mask layer 13 is formed on the substrate 10, the second patterned mask layer 13 covers at least the side wall and the upper surface of the protruding structure 12, and an opening S is formed on the second patterned mask layer 13, and the opening S exposes part of the bottom surface of the first trench T1.

[0075] Specifically, the second patterned mask layer 13 covers the side wall and the upper surface of the multiple protruding structures 12, thereby increasing the contact area of the second patterned mask layer 13 and the side wall of the protruding structure 12, and improving the mechanical stability of the second patterned mask layer 13.

[0076] Subsequently, the substrate 10 will be etched from the opening S to form the second trench T2, and in actual operation, the arrangement mode of the opening S can be determined according to the arrangement mode of the second trench T2 to be formed. In some embodiments, in the arrangement direction of the opening S, at least one protruding structure 12 is arranged between two adjacent openings S, thereby increasing the mechanical stability of the second patterned mask layer 13 in the arrangement direction of the opening S, and better avoiding or alleviating the collapse, falling off or fracture of the second patterned mask layer 13. As Figure 11aAs shown, in one specific embodiment, a plurality of openings S are arranged in an array along a first direction and a second direction, and in the first direction and / or the second direction, at least one protrusion structure 12 is provided between two adjacent openings S. However, it is not limited to this, the openings S can also be arranged linearly in any direction, or in an irregular arrangement.

[0077] Next, as Figures 12a to 12b As shown, using the second patterned mask layer 13 as a mask, the substrate 10 is etched from the opening S to form a second trench T2 below the first trench T1. In some embodiments, after forming the second trench T2, the remaining second patterned mask layer 13 is also removed.

[0078] Next, in Figure 12b Based on this, Figure 12b The structure shown is executed as follows Figures 8 to 9 The steps shown involve forming a conductive layer 14 within the second trench T2.

[0079] like Figure 13 As shown, in another embodiment of this disclosure, before forming the second patterned mask layer 13 on the substrate 10, the method further includes: etching the substrate 10 to form at least one third trench T3 on the protrusion structure 12, the third trench T3 extending from the upper surface of the protrusion structure 12 to the interior of the protrusion structure 12, and the depth of the third trench T3 being less than or equal to the depth of the first trench T1.

[0080] In one embodiment, a plurality of third grooves T3 may be formed on the protrusion structure 12. In practice, the third grooves T3 may be formed before or after the formation of the first groove T1. When the depths of the first groove T1 and the third grooves T3 are the same, the third grooves T3 and the first grooves T1 may be formed in the same step.

[0081] Next, as Figure 14 As shown, forming a second patterned mask layer 13 on the substrate 10 further includes: forming a second patterned mask layer 13, wherein the second patterned mask layer 13 fills a third trench T3. This further increases the contact area between the second patterned mask layer 13 and the protrusion structure 12, thereby further increasing the mechanical stability of the second patterned mask layer 13.

[0082] Next, as Figure 15 As shown, using the second patterned mask layer 13 as a mask, the substrate 10 is etched from the opening S to form a second trench T2 below the first trench T1.

[0083] Next, in Figure 15 Based on this, Figure 15 The structure shown is executed as shown in Figure 7 to 7. Figure 9 The steps shown involve forming a conductive layer 14 within the second trench T2.

[0084] It should be noted that the skilled person can make possible changes between the order of the above steps without departing from the scope of the present disclosure.

[0085] The present disclosure also provides a semiconductor structure, such as Figures 5a to 5b As shown, the semiconductor structure comprises: a substrate 10; a first trench T1 located on the substrate 10, the region of the substrate 10 not forming the first trench T1 constitutes a raised structure 12; a second patterned mask layer 13, the second patterned mask layer 13 covers at least the sidewall and the upper surface of the raised structure 12, and an opening S is formed on the second patterned mask layer 13, the opening S exposes part of the bottom surface of the first trench T1.

[0086] The substrate 10 can be a semiconductor substrate, and can include at least one elemental semiconductor material (e.g., a silicon (Si) substrate, a germanium (Ge) substrate), at least one III-V compound semiconductor material, at least one II-VI compound semiconductor material, at least one organic semiconductor material, or other semiconductor materials known in the art. The substrate 10 can have structures such as word lines, bit lines, active areas, isolation structures, and contact layers formed therein. In one embodiment, the substrate 10 is a silicon substrate, which can be doped or undoped. In some embodiments, the substrate 10 further includes device structures formed on the substrate 10, interlayer dielectric layers, interconnect layers located in the interlayer dielectric layers, and the like.

[0087] In actual operation, the first trench T1 can be formed by performing an etching process on the substrate 10, and the region of the substrate 10 not etched constitutes the raised structure 12. Referring to Figure 3a In one embodiment, the number of first trenches T1 is multiple, and the multiple first trenches T1 are arranged separately on the substrate 10, the raised structure 12 is located in the peripheral region of the multiple first trenches T1, and the raised structure 12 is a structure continuously extending on the substrate 10.

[0088] Figure 5a The first trenches T1 shown in FIG. 1 are arranged in an array along a first direction and a second direction, and the first direction and the second direction are perpendicular or oblique. However, the multiple first trenches T1 can also have other arrangement manners, such as linear arrangement along any direction, or irregular arrangement manner.

[0089] Figure 5a The shape of the horizontal cross section of the first trench T1 shown in FIG. 1 is circular, but the shape of the horizontal cross section of the first trench T1 can also be other shapes, such as rectangular, elliptical, and the like.

[0090] In actual operation, the second patterned mask layer 13 can be formed in the following manner: first, a first film layer is formed, which covers the sidewalls and the upper surface of the protruding structure 12 and fills the first trenches T1; then, the first film layer is etched to form openings S penetrating the first film layer, so as to form the second patterned mask layer 13. In some embodiments, the material of the second patterned mask layer 13 includes photoresist. However, the material of the second patterned mask layer 13 can also be other materials capable of being used for pattern transfer, for example, it can also be a spin-on hard mask layer, such as an amorphous carbon layer or an amorphous silicon layer, etc.

[0091] In an embodiment, the number of openings S is a plurality, and the plurality of openings S correspond to exposing the bottom surfaces of the plurality of first trenches T1. Figure 5a The shape of the horizontal cross section of the opening S shown in the figure is circular, but the shape of the horizontal cross section of the opening S can also be other shapes, for example, rectangular, oval, etc.

[0092] In subsequent processes, the second patterned mask layer 13 can be used as a mask to etch the substrate 10 to form second trenches from the openings S, so as to transfer the pattern of the second patterned mask layer 13 to the substrate 10. The embodiments of the present disclosure first form the protruding structure 12 on the substrate 10, and then form the second patterned mask layer 13, which covers the sidewalls and the upper surface of the protruding structure 12. On the one hand, this increases the contact area between the second patterned mask layer 13 and the substrate 10. On the other hand, due to the presence of the protruding structure 12, the height of the part of the second patterned mask layer 13 covering the upper surface of the protruding structure 12 is reduced, and at the same time, the protruding structure 12 provides good support for the second patterned mask layer 13. In this way, the mechanical stability of the second patterned mask layer 13 is improved, and the collapse, falling or fracture of the second patterned mask layer 13 is avoided or alleviated, and the accuracy of subsequent pattern transfer is improved.

[0093] It can be understood that the higher the height of the protruding structure 12, the better the support of the protruding structure 12 to the second patterned mask layer 13, and the better the effect of improving the mechanical stability of the second patterned mask layer 13. However, the height of the protruding structure 12 cannot be too high. If the height of the protruding structure 12 is too high, the height of the part of the second patterned mask layer 13 covering the upper surface of the protruding structure 12 is low, and in the process of etching the substrate 10 using the second patterned mask layer 13 as a mask, the upper surface of the protruding structure 12 is easily exposed, and the protruding structure 12 can be over-etched and damaged, thereby reducing the pattern transfer accuracy. In an embodiment, the ratio of the height H1 of the second patterned mask layer 13 to the height H2 of the protruding structure 12 is in the range of 3 to 5 (including the end point value), for example, 3.5, 4, 4.5, etc.

[0094] In one embodiment, the protrusion structure 12 is a structure that extends continuously on the substrate 10. The protrusion structure 12 has strong mechanical stability, thus providing better support for the second patterned mask layer 13 and increasing the mechanical stability of the second patterned mask layer 13.

[0095] like Figure 5a As shown, in one embodiment, the width L of the second patterned mask layer 13 covering the sidewall of the protruding structure 12 should not be too small or too large. If the width L is too small, the bonding strength between the second patterned mask layer 13 and the sidewall of the protruding structure 12 is poor, and the second patterned mask layer 13 located on the sidewall of the protruding structure 12 is prone to detachment or breakage. If the width L is too large, the width of the protruding structure 12 located between adjacent first grooves T1 is small, affecting the mechanical stability of the protruding structure 12 and the supporting effect of the protruding structure 12 on the second patterned mask layer 13. In a specific embodiment, the width of the second patterned mask layer 13 covering the sidewall of the protruding structure 12 is in the range of 1 μm to 5 μm (including the endpoint value), such as 2 μm, 3 μm, 4 μm, etc.

[0096] Figures 5a to 5b The protrusion structure 12 shown is a structure that extends continuously on the substrate 10. However, it is not limited to this, such as... Figures 11a to 11b As shown, in another embodiment of this disclosure, there are multiple protrusion structures 12, which are disposed separately on the substrate 10. The gaps between the multiple protrusion structures 12 form a first trench T1, that is, the first trench T1 extends continuously on the substrate 10 and defines multiple separate protrusion structures 12 on the substrate 10.

[0097] Figure 11a The shape of the horizontal cross-section of the protrusion structure 12 shown is rectangular, but it is not limited to this. The shape of the horizontal cross-section of the protrusion structure 12 can also be other shapes, such as circular, elliptical, etc.

[0098] The second patterned mask layer 13 covers the sidewalls and top surface of the plurality of protrusions 12, thereby increasing the contact area between the second patterned mask layer 13 and the sidewalls of the protrusions 12 and improving the mechanical stability of the second patterned mask layer 13.

[0099] The substrate 10 will then be etched from the opening S to form the second trench. In practice, the arrangement of the openings S can be determined according to the arrangement of the second trench to be formed. In some embodiments, at least one protrusion 12 is provided between two adjacent openings S in the arrangement direction of the openings S. This increases the mechanical stability of the second patterned mask layer 13 in the arrangement direction of the openings S, and better avoids or mitigates the collapse, detachment, or breakage of the second patterned mask layer 13. Figure 11aAs shown, in one specific embodiment, a plurality of openings S are arranged in an array along a first direction and a second direction, and in the first direction and / or the second direction, at least one protrusion structure 12 is provided between two adjacent openings S. However, it is not limited to this, the openings S can also be arranged linearly in any direction, or in an irregular arrangement.

[0100] like Figure 14 As shown, in another embodiment of this disclosure, the semiconductor structure further includes: at least one third trench T3 extending from the upper surface of the protrusion structure 12 to the interior of the protrusion structure 12, the depth of the third trench T3 being less than or equal to the depth of the first trench T1, and the second patterned mask layer 13 filling the third trench T3, thereby further increasing the contact area between the second patterned mask layer 13 and the protrusion structure 12, thereby further increasing the mechanical stability of the second patterned mask layer 13.

[0101] In one embodiment, a plurality of third grooves T3 may be formed on the protrusion structure 12. In practice, the third grooves T3 may be formed before or after the formation of the first groove T1. When the depths of the first groove T1 and the third grooves T3 are the same, the third grooves T3 and the first grooves T1 may be formed in the same step.

[0102] In this embodiment of the disclosure, the protrusion structure 12 provides good support for the second patterned mask layer 13, thereby allowing the formation of a second patterned mask layer 13 with a large height on the substrate 10, and further allowing the formation of a second trench with a large depth within the substrate 10.

[0103] In practice, after transferring the pattern of the second patterned mask layer 13 onto the substrate 10 to form the second trench, a conductive layer can be filled into the second trench. The conductive layer can be used to transmit electrical signals, and signal transmission between semiconductor chips can be achieved through the conductive layer. However, it is not limited to this. The second trench can also be a capacitor hole, and a capacitor structure for storing data can be formed in the second trench. Alternatively, a dielectric layer can be filled into the second trench to form a deep trench isolation for isolating device structures within the substrate 10.

[0104] It should be noted that the above description is only a preferred embodiment of this disclosure and is not intended to limit the scope of protection of this disclosure. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method of manufacturing a semiconductor structure, characterized by, The method comprises: providing a substrate, forming a first patterned mask layer on the substrate, etching the substrate with the first patterned mask layer as a mask to form a first trench, and the unetched region of the substrate constituting a protruding structure; etching the substrate to form at least one third trench on the protruding structure, the third trench extending from the upper surface of the protruding structure to the interior of the protruding structure, and the depth of the third trench being less than or equal to the depth of the first trench; forming a second patterned mask layer on the substrate, the second patterned mask layer covering at least the sidewall and the upper surface of the protruding structure and filling the third trench, and an opening being formed on the second patterned mask layer, the opening exposing part of the bottom surface of the first trench; etching the substrate from the opening with the second patterned mask layer as a mask to form a second trench below the first trench.

2. The production method according to claim 1, characterized by The ratio of the height of the second patterned mask layer to the height of the protruding structure is in the range of 3 to 5.

3. The production method according to claim 1, characterized by The number of the first trenches and the second trenches is multiple, the multiple first trenches are arranged separately on the substrate, the protruding structure is located in the peripheral region of the multiple first trenches, and the multiple second trenches are formed correspondingly below the multiple first trenches.

4. The production method according to claim 3, characterized by The width of the second patterned mask layer covering the sidewall of the protruding structure is in the range of 1 μm to 5 μm.

5. The production method according to claim 1, characterized by The number of the protruding structures and the second trenches is multiple, the multiple protruding structures are arranged separately on the substrate, the gap between the multiple protruding structures constitutes the first trench, and the multiple second trenches are formed below the first trench.

6. The production method according to claim 1, characterized by After forming the second trench, the method further comprises: forming a conductive material layer, the conductive material layer filling the second trench and the first trench and covering the protruding structure; removing the protruding structure and removing the conductive material layer filling the first trench and covering the protruding structure to form a conductive layer, the conductive layer filling the second trench.

7. A semiconductor structure, characterized by The method comprises: a substrate; a first trench on the substrate, the unetched region of the substrate constituting a protruding structure; at least one third trench extending from the upper surface of the protruding structure to the interior of the protruding structure, and the depth of the third trench being less than or equal to the depth of the first trench; a second patterned mask layer covering at least the sidewall and the upper surface of the protruding structure and filling the third trench, and an opening being formed on the second patterned mask layer, the opening exposing part of the bottom surface of the first trench.

8. The semiconductor structure of claim 7, wherein, The ratio of the height of the second patterned mask layer to the height of the protruding structure is in the range of 3 to 5.

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