Step structure, manufacturing method thereof and semiconductor structure

Abstract

The embodiment of the invention relates to the technical field of semiconductors, and provides a step structure and a manufacturing method thereof, and a semiconductor structure, the step structure comprises a plurality of conductive layers which are arranged at intervals along a first direction, each conductive layer comprises at least two sub-conductive layers which are arranged at intervals along a second direction, and the conductive layers extend along a third direction; the plurality of step structures are arranged at intervals along the second direction, and one column of sub-conductive layers arranged at intervals along the first direction are at least in contact connection with one step structure; wherein each step structure comprises a plurality of conductive columns which are electrically insulated from one another, one conductive column is in contact connection with one sub-conductive layer, and the conductive column which is in contact connection with one sub-conductive layer is electrically insulated from other sub-conductive layers; and in a row of conductive layers arranged at intervals along the first direction, the conductive layers are in contact connection with the conductive columns one by one. The embodiment of the invention is at least beneficial to reducing the horizontal area occupied by the whole stepped structure and improving the integration density of the conductive columns in the stepped structure.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to the field of semiconductor technology, and particularly to a stepped structure, a manufacturing method thereof, and a semiconductor structure. Background Art

[0002] With the continuous development of semiconductor structures, their critical dimensions are continuously reduced. However, due to the limitations of lithography machines, there is a limit to the reduction of their critical dimensions. Therefore, how to fabricate chips with higher storage density on a single wafer is the research direction of many scientific researchers and semiconductor practitioners. On this basis, the development of semiconductor devices has moved towards three-dimensional semiconductor devices.

[0003] However, as the number of stacked layers of signal transmission layers, such as bit lines or word lines, in three-dimensional semiconductor devices increases, how to design an extraction structure that occupies less layout space to transmit the electrical signals on multiple signal transmission layers has become an urgent problem to be solved. Summary of the Invention

[0004] Embodiments of the present disclosure provide a stepped structure, a manufacturing method thereof, and a semiconductor structure, which are at least beneficial to reducing the overall horizontal area occupied by the stepped structure and increasing the integration density of conductive pillars in the stepped structure.

[0005] According to some embodiments of the present disclosure, on the one hand, a stepped structure is provided, which is characterized in that it includes: a plurality of conductive layers arranged at intervals along a first direction, the conductive layer includes at least two sub-conductive layers arranged at intervals along a second direction, the conductive layer extends along a third direction, and the first direction, the second direction, and the third direction intersect pairwise; a plurality of stepped structures arranged at intervals along the second direction, and a column of the sub-conductive layers arranged at intervals along the first direction is at least in contact connection with one of the stepped structures; wherein, each of the stepped structures includes a plurality of mutually electrically insulated conductive pillars, one of the conductive pillars is in contact connection with one of the sub-conductive layers, and the conductive pillar in contact connection with one of the sub-conductive layers is electrically insulated from the other sub-conductive layers; and in a column of the conductive layers arranged at intervals along the first direction, the conductive layers are in contact connection with the conductive pillars one by one.

[0006] In some embodiments, the conductive pillar includes a main body portion and an epitaxial portion, the main body portion extends along the first direction, the epitaxial portion is located on a side wall of the main body portion extending along the first direction with a partial thickness, the epitaxial portion is in contact connection with the sub-conductive layer, and the epitaxial portion in contact connection with the sub-conductive layer is in the same layer; and, the main body portions of the plurality of conductive pillars in the same stepped structure are arranged at intervals along the third direction, and the plurality of epitaxial portions in the same stepped structure are respectively located in different layers.

[0007] In some embodiments, the conductive pillar further includes at least one extension portion, which is also located on the side wall extending along the first direction of a partial thickness of the main body portion, and the extension portion and the epitaxial portion in contact connection with the same conductive pillar are arranged at intervals along the first direction, and the extension portion is electrically insulated from the sub-conductive layer.

[0008] In some embodiments, among at least one extension portion in contact connection with the same conductive pillar, one extension portion is in the same layer as one sub-conductive layer; or, all of the at least one extension portion in contact connection with the same conductive pillar are located on one side of the epitaxial portion along the first direction.

[0009] In some embodiments, the second direction and the third direction together form a reference plane, and the orthographic projection area of the extension portion on the reference plane is smaller than the orthographic projection area of the epitaxial portion on the reference plane.

[0010] In some embodiments, the main body portion has opposite first and second surfaces in the first direction. In the same step structure, along the third direction, the distances between different epitaxial portions and the first surface in the first direction increase or decrease successively.

[0011] In some embodiments, a column of sub-conductive layers arranged at intervals along the first direction is in contact connection with one step structure, and two adjacent sub-conductive layers along the second direction are respectively used as a first sub-conductive layer and a second sub-conductive layer; wherein, the step structure in contact connection with the first sub-conductive layer is located on the side of the first sub-conductive layer away from the second sub-conductive layer along the second direction, or, the step structure in contact connection with the first sub-conductive layer is located between the first sub-conductive layer and the second sub-conductive layer; the step structure in contact connection with the second sub-conductive layer is located on the side of the second sub-conductive layer away from the first sub-conductive layer along the second direction, or, the step structure in contact connection with the second sub-conductive layer is located between the second sub-conductive layer and the first sub-conductive layer.

[0012] In some embodiments, a column of sub-conductive layers arranged at intervals along the first direction is in contact connection with two step structures, and the two step structures in contact connection with the same column of sub-conductive layers are respectively located on opposite sides of the column of sub-conductive layers in the second direction.

[0013] According to some embodiments of the present disclosure, on the other hand, an embodiment of the present disclosure further provides a semiconductor structure, including: the stepped structure according to any one of the above; a plurality of signal transmission layers arranged at intervals along the first direction, the signal transmission layers are in one-to-one contact connection with the conductive layers, and the sub-conductive layers in the same conductive layer are all in contact connection with the same signal transmission layer; wherein, the signal transmission layer includes a word line or a bit line.

[0014] According to some embodiments of the present disclosure, on the other hand, an embodiment of the present disclosure further provides a manufacturing method of a stepped structure, including: forming a plurality of conductive layers arranged at intervals along the first direction, the conductive layer includes at least two sub-conductive layers arranged at intervals along the second direction, the conductive layer extends along the third direction, and the first direction, the second direction and the third direction intersect pairwise; forming a plurality of stepped structures arranged at intervals along the second direction, and at least one of the sub-conductive layers arranged in a column along the first direction is in contact connection with one of the stepped structures; wherein, each of the stepped structures includes a plurality of electrically insulated conductive columns, one of the conductive columns is in contact connection with one of the sub-conductive layers, and the conductive column in contact connection with one of the sub-conductive layers is electrically insulated from the other sub-conductive layers; and in a column of the conductive layers arranged at intervals along the first direction, the conductive layers are in one-to-one contact connection with the conductive columns.

[0015] In some embodiments, the step of forming the conductive layer includes: forming a stacked structure, the stacked structure includes a first dielectric layer and a second dielectric layer stacked alternately along the first direction; performing a first patterning process on the stacked structure to form a trench penetrating the stacked structure; performing a lateral etching on the second dielectric layer exposed by the trench to form a groove between adjacent first dielectric layers, and both sides of the trench in the second direction are respectively communicated with one of the grooves; forming one of the sub-conductive layers in one of the grooves; forming a third dielectric layer in the trench, and a plurality of the sub-conductive layers in contact connection with the same third dielectric layer constitute one of the conductive layers.

[0016] In some embodiments, the step of forming the stepped structure includes: performing a second patterning process on the stacked structure to form a plurality of through-holes that penetrate the stacked structure and are arranged at intervals along the third direction, wherein a plurality of the through-holes arranged at intervals along the third direction form a through-hole group, and a column of the sub-conductive layers arranged at intervals along the first direction corresponds to at least one through-hole group; forming a first sacrificial layer in the through-holes, among the plurality of through-holes corresponding to the same column of the conductive layers arranged at intervals along the first direction, the thicknesses of the first sacrificial layers in different through-holes are different in the first direction, and the first sacrificial layer with the smallest thickness is in contact connection with one layer of the first dielectric layer and one layer of the second dielectric layer; forming a fourth dielectric layer that conformally covers the remaining sidewalls of the through-holes; using the fourth dielectric layer as a protective layer to remove the first sacrificial layer that is in contact connection with one layer of the second dielectric layer, and the remaining through-holes not filled with the first sacrificial layer are used as sub-through-holes, so that each sub-through-hole exposes one layer of the second dielectric layer; performing a lateral etching on the second dielectric layer exposed by the sub-through-holes to form an epitaxial groove between adjacent first dielectric layers, and the epitaxial groove exposes the sub-conductive layers, and the epitaxial groove communicates with the sub-through-holes; removing the remaining first sacrificial layer, and forming the conductive pillars in the through-holes and the epitaxial grooves, and a plurality of the conductive pillars formed in the same through-hole group form a stepped structure.

[0017] In some embodiments, before forming the fourth dielectric layer and after forming the first sacrificial layer, it further includes: performing a lateral etching on the second dielectric layer exposed by the through-holes to form an extended groove between adjacent first dielectric layers, and the extended groove exposes the remaining second dielectric layer, and the extended groove communicates with the through-holes; the step of forming the fourth dielectric layer further includes: forming the fourth dielectric layer that conformally covers the surface of the extended groove; the step of forming the conductive pillars includes: forming the conductive pillars in the extended groove.

[0018] In some embodiments, one layer of the first dielectric layer and one layer of the second dielectric layer adjacent to each other in the first direction form a sub-stacked structure, among the plurality of through-holes corresponding to the same column of the conductive layers arranged at intervals along the first direction, the number of layers of the sub-stacked structures in contact connection with the first sacrificial layers in different through-holes is different.

[0019] In some embodiments, among at least two through-hole groups corresponding to a column of the conductive layers arranged at intervals along the first direction, any one of the through-hole groups is located at one of the opposite sides of the conductive layer in the second direction, or any one of the through-hole groups is located between adjacent sub-conductive layers.

[0020] The technical solutions provided by the embodiments of the present disclosure have at least the following advantages:

[0021] A new stepped structure is designed, integrating the characteristics of the steps onto the conductive posts to form a new stepped structure. In the new stepped structure, the conductive posts themselves are used not only for conducting electricity to transmit electrical signals but also for achieving electrical contact with conductive layers located on different layers. Compared with the current situation where, based on separately designing multiple steps at different levels and then separately designing conductive posts corresponding one by one to the multiple steps, resulting in a relatively large horizontal area occupied by the overall steps and conductive posts, in one embodiment of the present disclosure, integrating the characteristics of the steps onto the conductive posts helps to reduce the horizontal area occupied by the overall stepped structure on the premise of ensuring that the electrical signals on each conductive layer are led out through a conductive post. In other words, it helps to improve the integration density of the conductive posts in the stepped structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not limit the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, unless otherwise stated, the drawings in the figures do not constitute a scale limitation; in order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or in the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the following-described drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 A top view structural schematic diagram of a stepped structure provided by an embodiment of the present disclosure;

[0024] Figure 2 Another top view structural schematic diagram of a stepped structure provided by an embodiment of the present disclosure;

[0025] Figure 3 is Figure 1 or Figure 2 A cross-sectional structural schematic diagram of the stepped structure shown along the first cross-sectional direction AA1;

[0026] Figure 4 is Figure 1 or Figure 2 A cross-sectional structural schematic diagram of the stepped structure shown along the second cross-sectional direction BB1;

[0027] Figure 5 is Figure 1 A partial three-dimensional structural schematic diagram of the conductive layer and the conductive posts in the stepped structure shown;

[0028] Figure 6 is Figure 1 A front projection view of the stepped structure shown on the plane of the film layer where one of its conductive layers is located;

[0029] Figure 7 is Figure 1 a front projection view of the stepped structure shown on the plane of the film layer where another conductive layer is located;

[0030] Figure 8 is Figure 1 a front projection view of the stepped structure shown on the plane of the film layer where yet another conductive layer is located;

[0031] Fig. 9 is another top view structural schematic diagram of the stepped structure provided by an embodiment of the present disclosure;

[0032] Fig.10 is Fig. 9 a cross-sectional structural schematic diagram of the stepped structure shown along the first cross-section direction AA1;

[0033] Fig.11 is Fig. 9 a cross-sectional structural schematic diagram of the stepped structure shown along the second cross-section direction BB1;

[0034] Fig.12 is a top view structural schematic diagram of a semiconductor structure provided by another embodiment of the present disclosure;

[0035] Fig.13 is Fig.12 a cross-sectional structural schematic diagram of the semiconductor structure shown along the third cross-section direction CC1;

[0036] Figures 14 to 26 is a cross-sectional structural schematic diagram corresponding to each step in the manufacturing method of the stepped structure provided by yet another embodiment of the present disclosure. Detailed implementation manners

[0037] As can be seen from the background art, the layout space occupied by the lead-out structure in three-dimensional semiconductor devices needs to be reduced.

[0038] Through analysis, it is found that as the number of stacked layers of signal transmission layers, such as bit lines or word lines, in three-dimensional semiconductor devices increases, the number of corresponding steps required for each signal transmission layer also increases accordingly, and any two different steps need to be in different layers. In the case of a large number of steps, the horizontal area occupied by arranging all the steps increases; moreover, conductive posts corresponding to the steps one by one need to be designed. Since there is almost no gap between adjacent steps in the horizontal direction, but there needs to be a gap between adjacent conductive posts to avoid interference, the horizontal layout area of a single step should not be overly restricted to avoid too close a spacing between adjacent conductive posts and thus interference, which leads to a bottleneck in the layout space reduction of the lead-out structure composed of multiple steps and multiple conductive posts.

[0039] The present disclosure provides a stepped structure, a manufacturing method thereof, and a semiconductor structure. In the stepped structure, the features of the steps are integrated on the conductive pillars to form a new stepped structure. In the new stepped structure, the conductive pillars themselves are used not only for conducting electricity to transmit electrical signals but also for achieving electrical contact with conductive layers located on different layers. Compared with the current situation where, based on separately designing multiple steps at different levels, conductive pillars corresponding to the multiple steps are separately designed, resulting in a relatively large horizontal area occupied by the overall steps and conductive pillars, in an embodiment of the present disclosure, integrating the features of the steps on the conductive pillars is beneficial to reducing the horizontal area occupied by the overall stepped structure on the premise of ensuring that the electrical signals on each conductive layer are led out through a conductive pillar. In other words, it is beneficial to increase the integration density of the conductive pillars in the stepped structure.

[0040] The following will elaborate on the embodiments of the present disclosure in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present disclosure, many technical details are presented for the readers to better understand the embodiments of the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions required to be protected by the embodiments of the present disclosure can still be implemented.

[0041] An embodiment of the present disclosure provides a stepped structure. The stepped structure provided by an embodiment of the present disclosure will be described in detail below in conjunction with the accompanying drawings.

[0042] Figure 1 is a top view structural schematic diagram of a stepped structure provided by an embodiment of the present disclosure; Figure 2 is another top view structural schematic diagram of a stepped structure provided by an embodiment of the present disclosure; Figure 3 is Figure 1 or Figure 2 is a cross-sectional structural schematic diagram of the stepped structure shown along the first cross-sectional direction AA1; Figure 4 is Figure 1 or Figure 2 is a cross-sectional structural schematic diagram of the stepped structure shown along the second cross-sectional direction BB1; Figure 5 is Figure 1 is a partial three-dimensional structural schematic diagram of the conductive layer and the conductive pillars in the stepped structure shown; Figure 6 is Figure 1 is a front projection view of the stepped structure shown on the plane of the film layer where one of its conductive layers is located; Figure 7 is Figure 1 is a front projection view of the stepped structure shown on the plane of the film layer where another of its conductive layers is located; Figure 8 is Figure 1 is a front projection view of the stepped structure shown on the plane of the film layer where yet another of its conductive layers is located; Fig. 9 is another top view structural schematic diagram of a stepped structure provided by an embodiment of the present disclosure; Fig.10 is Fig. 9 a schematic cross-sectional structure diagram of the stepped structure shown along the first cross-sectional direction AA1; Fig.11 is Fig. 9 a schematic cross-sectional structure diagram of the stepped structure shown along the second cross-sectional direction BB1.

[0043] It should be noted that, for the convenience of description and to clearly show the stepped structure, in one embodiment of the present disclosure Figures 1 to 11 are all schematic diagrams of partial structures of the stepped structure.

[0044] Referring to Figure 1 , Figure 2 or Fig. 9 , the stepped structure 100 includes: a plurality of conductive layers 101 arranged at intervals along the first direction X, the conductive layer 101 includes at least two sub-conductive layers 111 arranged at intervals along the second direction Y, the conductive layer 101 extends along the third direction Z, and the first direction X, the second direction Y, and the third direction Z intersect pairwise; a plurality of stepped structures 102 arranged at intervals along the second direction Y, and at least one stepped structure 102 is in contact connection with a column of sub-conductive layers 111 arranged at intervals along the first direction X; wherein, each stepped structure 102 includes a plurality of electrically insulated conductive columns 103, one conductive column 103 is in contact connection with one sub-conductive layer 111, and the conductive column 103 in contact connection with one sub-conductive layer 111 is electrically insulated from other sub-conductive layers 111; and in a column of conductive layers 101 arranged at intervals along the first direction X, the conductive layer 101 is in contact connection with the conductive column 103 one by one.

[0045] It should be noted that, firstly, Figure 1 , Figure 2 or Fig. 9 take the example that one conductive layer 101 includes two sub-conductive layers 111 arranged at intervals along the second direction Y. In actual applications, the number of sub-conductive layers 111 arranged at intervals along the second direction Y included in one conductive layer 101 is not limited. For example, the number is 3, 4, or 5. It can be understood that according to the number of conductive layers 101 arranged at intervals along the first direction X in actual applications, the number of sub-conductive layers 111 arranged at intervals along the second direction Y included in one conductive layer 101 can be flexibly adjusted. For example, if the number of conductive layers 101 arranged at intervals along the first direction X is large, the number of sub-conductive layers 111 arranged at intervals along the second direction Y included in one conductive layer 101 can be increased.

[0046] Secondly, Figure 1 , Figure 2 or Fig. 9In the example, a column of sub-conductive layers 111 arranged at intervals along the first direction X are in contact connection with a step structure 102. In practical applications, in another example, a column of sub-conductive layers 111 arranged at intervals along the first direction X can also be in contact connection with two step structures 102 respectively, which will be described in detail later.

[0047] With reference to Figure 1 、 Figure 3 and Figure 5 , in the stepped structure 100, one conductive column 103 only corresponds to one conductive layer 101, and the conductive column 103 only makes contact connection with one sub-conductive layer 111 in this conductive layer 101, and is electrically insulated from other sub-conductive layers 111 in this conductive layer 101, that is, there is a spacing. In this way, one-to-one contact connection between the conductive layer 101 and the conductive column 103 is realized, so that the electrical signal on any conductive layer 101 can be transmitted through a corresponding conductive column 103.

[0048] It should be noted that one conductive layer 101 includes at least two sub-conductive layers 111. Among at least two sub-conductive layers 111 belonging to the same conductive layer 101, only one sub-conductive layer 111 needs to make contact connection with one conductive column 103 to realize the contact connection between this conductive layer 101 and this conductive column 103. In other words, each conductive column 103 makes contact connection with one sub-conductive layer 111, but not all sub-conductive layers 111 are each in contact connection with a conductive column 103, that is, among at least two sub-conductive layers 111 belonging to the same conductive layer 101, only one sub-conductive layer 111 needs to make contact connection with one conductive column 103, and other sub-conductive layers 111 belonging to the same conductive layer 101 are insulated from the conductive column 103.

[0049] It should be noted that the conductive layer 101 in the stepped structure 100 will be in electrical contact with the signal transmission layer in the semiconductor structure later, so as to lead out the electrical signal in the signal transmission layer through the conductive layer 101, that is, the stepped structure 100 can be regarded as a lead-out structure. In practical applications, the signal transmission layer in the semiconductor structure includes but is not limited to bit lines or word lines. On this basis, for the sake of clarity of subsequent description, Figure 3 and Figure 4 in it, BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8 respectively indicate 8 conductive layers 101 arranged at intervals along the first direction X. It can be understood that the conductive layer 101 is not a bit line (not shown in the figure), but the conductive layer 101 is in electrical contact with the bit line to transmit the electrical signal to the bit line or transmit the electrical signal on the bit line to other electrical components, Figure 3 and Figure 4In the figure, BL is used to indicate the conductive layer 101 for the purpose of explaining the correspondence between different conductive layers 101 and different bit lines. In practical applications, the conductive layer can also be in electrical contact with the word line to transmit an electrical signal to the word line or transmit the electrical signal on the word line to other electrical components.

[0050] In addition, Figure 3 and Figure 4 Taking 8 conductive layers 101 arranged at intervals along the first direction X as an example, in practical applications, the number of conductive layers 101 arranged at intervals along the first direction X is not limited and can be determined according to the number of layers of the signal transmission layer arranged at intervals along the first direction X that corresponds one by one to the conductive layer.

[0051] From the above description, it can be seen that an embodiment of the present disclosure designs a new stepped structure 100, fuses the characteristics of the steps on the conductive column 103 to form a new stepped structure 102. In the new stepped structure 102, the conductive column 103 itself is used for both conducting electricity to transmit electrical signals and for making electrical contact with conductive layers located on different layers. Compared with the current situation where multiple steps at different levels are designed separately and conductive columns corresponding one by one to the multiple steps are designed separately, resulting in a relatively large horizontal area occupied by the overall steps and conductive columns, in an embodiment of the present disclosure, fusing the characteristics of the steps on the conductive column 103 is beneficial to reducing the horizontal area occupied by the overall stepped structure 102 on the premise of ensuring that the electrical signal on each conductive layer 101 is led out through a conductive column 103. In other words, it is beneficial to improve the integration density of the conductive columns 103 in the stepped structure 102.

[0052] In some cases, the distances between the multiple conductive columns 103 in a stepped structure 102 and the conductive layer 101 in the second direction Y are all equal, that is, the multiple conductive columns 103 are concentratedly arranged around the conductive layer 101, which is beneficial to ensuring that the transmission path of the electrical signal between each conductive layer 101 and the conductive column 103 in contact connection with it is relatively short.

[0053] The stepped structure provided by an embodiment of the present disclosure will be described in detail below.

[0054] In some embodiments, referring to Figure 1 、 Figures 3 to 5 , or Figure 2 、 Figure 3 and Figure 4, the conductive post 103 includes a main body portion 113 and an extension portion 123. The main body portion 113 extends along the first direction X. The extension portion 123 is located on the side wall of the main body portion 113 that extends along the first direction X with a partial thickness. The extension portion 123 is in contact connection with the sub-conductive layer 111, and the extension portion 123 in contact connection with the sub-conductive layer 111 is in the same layer; moreover, the multiple main body portions 113 in the same step structure 102 are arranged at intervals along the third direction Z, and the multiple extension portions 123 in the same step structure 102 are respectively located in different layers.

[0055] It should be noted that only one extension portion 123 is provided on one main body portion 113 to ensure that one conductive post 103 is in contact connection with one sub-conductive layer 111 only through one extension portion 123. Figure 3 To distinguish different extension portions 123 that are in contact connection with different sub-conductive layers 111, that is, different conductive layers 101, the extension portion 123 in contact connection with the conductive layer BL1 is labeled as WY1, the extension portion 123 in contact connection with the conductive layer BL2 is labeled as WY2, the extension portion 123 in contact connection with the conductive layer BL3 is labeled as WY3, and the extension portion 123 in contact connection with the conductive layer BL4 is labeled as WY4. Similarly, Figure 4 To distinguish different extension portions 123 that are in contact connection with different sub-conductive layers 111, that is, different conductive layers 101, the extension portion 123 in contact connection with the conductive layer BL5 is labeled as WY5, the extension portion 123 in contact connection with the conductive layer BL6 is labeled as WY6, the extension portion 123 in contact connection with the conductive layer BL7 is labeled as WY7, and the extension portion 123 in contact connection with the conductive layer BL8 is labeled as WY8.

[0056] Continue to refer to Figure 1 、 Figures 3 to 5 or Figure 2 、 Figure 3 and Figure 4 , the conductive post 103 may further include at least one extension part 133. The extension part 133 is also located on the side wall of the main body portion 113 that extends along the first direction X with a partial thickness, and the extension part 133 and the extension portion 123 in contact connection with the same conductive post 103 are arranged at intervals along the first direction X, and there is electrical insulation between the extension part 133 and the sub-conductive layer 111.

[0057] It can be understood that, on the one hand, the length of the main body portion 113 along the first direction X is relatively long, and this length will penetrate multiple conductive layers 101 arranged at intervals along the first direction X. Then, the ratio of the length of the main body portion 113 in the first direction X to its length in the third direction Z is relatively large, which makes the main body portion 113 prone to intermediate fracture due to excessive length. Based on this, at least one extension portion 133 is designed on the side wall of the main body portion 113 extending along the first direction X, which is beneficial to reducing the probability of intermediate fracture of the main body portion 113 through the supporting effect of the extension portion 133 on the main body portion 113, thereby being beneficial to improving the structural stability of the main body portion 113 itself and improving the structural stability of the conductive column 103.

[0058] On the other hand, designing at least one extension portion 133 on the side wall of the main body portion 113 extending along the first direction X is beneficial to increasing the cross-sectional area of the conductive column 103 to reduce the resistance of the conductive column 103 itself, thereby being beneficial to improving the electrical performance of the conductive column 103.

[0059] It should be noted that, for clearly showing the three-dimensional structure of the conductive column 103, Figure 5 only two conductive columns 103 and two conductive layers 101 in contact connection with the conductive columns 103 are shown. Moreover, for clearly showing the positional relationship among the main body portion 113, the extension portion 123, and the extension portion 133 in the conductive column 103, Figure 5 only half of the three-dimensional structure of the conductive column 103 is shown.

[0060] It is worth noting that, first, in some embodiments, referring to Figure 4 , the conductive column 103 in contact connection with the topmost conductive layer 101, that is, BL8, only has the extension portion 123 and does not have the extension portion 133. Second, in some embodiments, referring to Figures 3 to 5 , among at least one extension portion 133 in contact connection with the same conductive column 103, one extension portion 133 is in the same layer as a sub-conductive layer 111. In other words, for the same conductive column 103, the extension portion 123 and the extension portion 133 on the side wall extending along the first direction X thereof are respectively in the same layer as a conductive layer 101. Third, in some embodiments, referring to Figures 3 to 5 , all at least one extension portion 133 in contact connection with the same conductive column 103 are located on one side of the extension portion 123 along the first direction X. It should be noted that, along the first direction X, a base for supporting the stepped structure 100 (not shown in the figure) can also be arranged below the stepped structure 100, and the base is located on the side of the conductive layer BL1 away from the conductive layer BL2. Based on this, all at least one extension portion 133 in contact connection with the same conductive column 103 being located on one side of the extension portion 123 along the first direction X means that all at least one extension portion 133 in contact connection with the same conductive column 103 are located on the side of the extension portion 123 away from the base.

[0061] It can be understood that the existence of the above various situations is related to the technological process of manufacturing the stepped structure 100, which will be described in detail later. In practical applications, when using some technological methods to manufacture the stepped structure 100, the stepped structure 100 can have the above various situations; when using some other technological methods to manufacture the stepped structure 100, the stepped structure 100 may not have the above various situations.

[0062] It should be noted that Figures 1 to 5 In the shown example, on the one hand, there are 8 conductive layers 101 arranged at intervals along the first direction X. Based on this, 8 conductive posts 103 designed to be in contact connection with the conductive layers 101 one by one are provided; on the other hand, one conductive layer 101 includes two sub-conductive layers 111 arranged at intervals along the second direction Y, and a column of sub-conductive layers 111 arranged at intervals along the first direction X is in contact connection with one stepped structure 102. Based on this, 2 stepped structures 102 are designed, and Figures 1 to 4 in which the two stepped structures 102 are distinguished by A and B, and it is designed that one stepped structure 102 includes 4 conductive posts 103 arranged along the third direction Z. On the above premise, on the side of the epitaxial part WY1 away from the substrate, there are also 7 conductive layers 101 arranged at intervals along the first direction X. Therefore, it is designed that there are 7 extension parts 133 arranged at intervals along the first direction X on the side wall of the main body part 113 in contact connection with the epitaxial part WY1; on the side of the epitaxial part WY2 away from the substrate, there are also 6 conductive layers 101 arranged at intervals along the first direction X. Therefore, it is designed that there are 6 extension parts 133 arranged at intervals along the first direction X on the side wall of the main body part 113 in contact connection with the epitaxial part WY2... And so on, on the side of the epitaxial part WY7 away from the substrate, there is also 1 conductive layer 101 arranged at intervals along the first direction X. Therefore, it is designed that there is 1 extension part 133 arranged at intervals along the first direction X on the side wall of the main body part 113 in contact connection with the epitaxial part WY7; on the side of the epitaxial part WY8 away from the substrate, there are also 0 conductive layers 101 arranged at intervals along the first direction X. Therefore, it is designed that there are 0 extension parts 133 arranged at intervals along the first direction X on the side wall of the main body part 113 in contact connection with the epitaxial part WY8.

[0063] In some embodiments, referring to Figures 1 to 5, the stepped structure 102 may further include an insulating portion 104 that surrounds the side wall of the extending portion 133 extending along the first direction X. It can be understood that the insulating portion 104 corresponds to the extending portion 133 one by one. In this way, it is beneficial to improve the structural stability of the conductive pillar 103 through the extending portion 133 and improve the electrical performance of the conductive pillar 103. At the same time, through the insulating portion 104, it is possible to prevent the extending portion 133 from contacting and connecting with the sub-conductive layer 111 on the same layer as it, so as to achieve the contact connection between one conductive pillar 103 and one sub-conductive layer 111, and the conductive pillar 103 in contact with the sub-conductive layer 111 is electrically insulated from other sub-conductive layers 111. Moreover, it is beneficial to prevent the contact connection between the extending portion 123 of one of the adjacent conductive pillars 103 and the extending portion 133 of the other along the third direction Z through the insulating portion 104, so as to avoid the short circuit between adjacent conductive pillars 103 in the same stepped structure 102, thereby being beneficial to improving the electrical performance of the stepped structure 100.

[0064] In some embodiments, referring to Figures 1 to 5 , only the insulating portion 104 exists between the extending portion 123 and the extending portion 133 on the same layer among the adjacent conductive pillars 103 along the third direction Z. In practical applications, not only the insulating portion 104 exists between the extending portion 123 and the extending portion 133 on the same layer among the adjacent conductive pillars 103 along the third direction Z, but also other insulating dielectric layers may exist.

[0065] In some embodiments, referring to Figures 1 to 5 , there may also be a gap between the insulating portion 104 and the sub-conductive layer 111, and other insulating dielectric layers may exist in this gap.

[0066] It should be noted that in some examples, taking the plane formed by the second direction Y and the third direction Z as the projection plane, Figure 1 and Figures 5 to 8 both take the orthographic projection shape of the main body portion 113 as a circle, and the orthographic projection shapes of the extending portion 123, the extending portion 133, and the insulating portion 104 as circular rings as examples. In other examples, referring to Figure 2 , taking the plane formed by the second direction Y and the third direction Z as the projection plane, Figure 2 both take the orthographic projection shape of the main body portion 113 as a square, and the orthographic projection shapes of the extending portion 123, the extending portion 133, and the insulating portion 104 as square rings as examples. Moreover, Figure 2In the illustrated example, the extension portion 123 has four side walls extending in the first direction X, and each of the side walls is in contact connection with the sub-conductive layer 111. This is beneficial to ensuring a relatively large contact area between the extension portion 123 and the sub-conductive layer 111, so as to ensure a relatively high transfer efficiency of electrical signals between the conductive pillar 103 and the conductive layer 101. In practical applications, the orthographic projection shapes of the main body portion, the extension portion, the extension part, and the insulating portion can also be other figures, and an embodiment of the present disclosure does not limit the orthographic projection shapes of the four.

[0067] It should be noted that Figure 1 and Figures 6 to 8 In the illustrated example, the orthographic projection shape of the extension portion 123 on the plane formed by the second direction Y and the third direction Z is a quasi-circular ring shape. Specifically, the orthographic projection shape of the portion of the extension portion 123 in contact connection with the sub-conductive layer 111 is a straight line rather than an arc. This is beneficial to increasing the contact area between the extension portion 123 and the sub-conductive layer 111, so as to improve the transfer efficiency of electrical signals between the conductive pillar 103 and the conductive layer 101. In practical applications, the orthographic projection shape of the extension portion on the plane formed by the second direction and the third direction can also be a complete circular ring shape, and then the extension portion is tangent to the sub-conductive layer.

[0068] In some embodiments, referring to Figure 1 , the radius of the insulating portion 104 with an orthographic projection shape of a circular ring is less than or equal to the distance between the center of the main body portion 113 and the sub-conductive layer 111 capable of electrical signal transfer therewith in the second direction Y. In this way, it is beneficial to ensuring that there is a complete insulating portion 104 between the extension part 133 and the sub-conductive layer 111 in the same layer as it, so as to prevent the extension part 133 from being in contact connection with the sub-conductive layer 111 in the same layer as it. It should be noted that Figure 2 In the illustrated example, the spacing relationship among the insulating portion 104, the main body portion 113, and the sub-conductive layer 111 capable of electrical signal transfer therewith is similar, and details are not described herein again.

[0069] In some embodiments, referring to Figure 1 , on the plane formed by the second direction Y and the third direction Z, the maximum distance between the center of the main body portion 113 and the extension portion 123 is greater than or equal to the distance between the center of the main body portion 113 and the sub-conductive layer 111 capable of electrical signal transfer therewith in the second direction Y. In this way, it is beneficial to ensuring the contact connection between the extension portion 123 and the sub-conductive layer 111. It should be noted that Figure 2 In the illustrated example, the spacing relationship among the main body portion 113, the extension portion 123, and the sub-conductive layer 111 in contact connection therewith is similar, and details are not described herein again.

[0070] In some embodiments, referring to Figures 1 to 7, the second direction Y and the third direction Z together form a reference plane, and the orthographic projection area of the extension part 133 on the reference plane is smaller than the orthographic projection area of the extension part 123 on the reference plane.

[0071] It should be noted that Figures 1 to 8 in the examples shown, it is taken as an example that in addition to the main body part 113 and the extension part 123, the conductive column 103 further includes an extension part 133. In some other embodiments, refer to Figures 9 to 11 , the conductive column 103 only includes the main body part 113 and the extension part 123. The main body part 113 extends along the first direction X, and the extension part 123 is located on the side wall of the main body part 113 extending along the first direction X with a partial thickness. The extension part 123 is in contact connection with the sub-conductive layer 111, and the extension part 123 in contact connection with the sub-conductive layer 111 is in the same layer; moreover, multiple main body parts 113 in the same step structure 102 are arranged at intervals along the third direction Z, and multiple extension parts 123 in the same step structure 102 are respectively located in different layers.

[0072] It should be noted that Figures 9 to 11 the parts that are the same or similar in the examples shown as those in the foregoing Figures 1 to 8 shown examples will not be elaborated herein again.

[0073] It can be understood that any conductive column 103 only includes one main body part 113 extending along the first direction X and one extension part 123 located on the side wall of the main body part 113 extending along the first direction X with a partial thickness. In this way, on the premise of ensuring the contact connection between any conductive column 103 and its corresponding conductive layer 101, it is beneficial to increase the distance between other parts of other conductive columns 103 except the extension part 123 and the conductive layer 101 in the second direction Y to ensure the one-to-one contact connection between the conductive layer 101 and the conductive column 103. In addition, it is also beneficial to increase the distance between most regions of adjacent conductive columns 103 in the third direction Z, thereby being beneficial to reducing the electrical interference between adjacent conductive columns 103 in the third direction Z.

[0074] Continue to refer to Figures 9 to 11 , the step structure 102 may further include an insulating part 104, and the insulating part 104 surrounds the side wall of the main body part 113 extending along the first direction X. It can be understood that the insulating part 104 corresponds to the main body part 113 one by one. In this way, it is beneficial to improve the insulation performance between the region of the main body part 113 except for the partial region surrounded by the extension part 123 and the conductive layer 101.

[0075] In some embodiments, refer to Figures 9 to 11, the side walls of the main body portion 113 that are not surrounded by the epitaxial portion 123 are divided into upper and lower parts, and the insulating portion 104 surrounds the upper part side wall of the main body portion 113 in the corresponding conductive pillar 103. Among them, the upper part side wall of the main body portion 113 is the side wall of the main body portion 113 on the side away from the substrate of the epitaxial portion 123.

[0076] In some embodiments, referring to Figures 9 to 11 , the insulating portion 104 and the sub-conductive layer 111 may also have a gap, and other insulating dielectric layers may be provided in the gap.

[0077] In the above various embodiments, referring to Figure 3 and Figure 4 or Fig.10 and Fig.11 , the main body portion 113 has opposite first surface 113a and second surface 113b in the first direction X. In the same step structure 102, along the third direction Z, the distances between different epitaxial portions 123 and the first surface 113a in the first direction X increase or decrease successively. In this way, it is beneficial to ensure that different epitaxial portions 123 are in contact and connection with conductive layers 101 located in different layers, and it is beneficial to improve the arrangement regularity between different epitaxial portions 123 in the step structure 102.

[0078] It should be noted that the distances between the epitaxial portions 123 in different step structures 102 and the first surface 113a in the first direction X are also different. In addition, the first surface 113a may be the bottom surface of the conductive pillar 103 close to the substrate.

[0079] In the above various embodiments, taking the examples shown in Figure 1 , Figure 3 and Figure 4 as a reference, a column of sub-conductive layers 111 arranged at intervals in the first direction X is in contact and connection with a step structure 102, and two adjacent sub-conductive layers 111 in the second direction Y are respectively used as the first sub-conductive layer 121 and the second sub-conductive layer 131.

[0080] Among them, the positional relationship between the first sub-conductive layer 121 and the step structure 102 in contact and connection with it includes at least the following two cases: In some cases, referring to Figure 3 , the step structure 102 in contact and connection with the first sub-conductive layer 121 is located on the side of the first sub-conductive layer 121 away from the second sub-conductive layer 131 in the second direction Y; in other cases, the step structure in contact and connection with the first sub-conductive layer is located between the first sub-conductive layer and the second sub-conductive layer.

[0081] The positional relationship between the second sub-conductive layer 131 and the step structure 102 in contact and connection with it includes at least the following two cases: In some cases, referring to Figure 3, the step structure 102 in contact connection with the second sub-conductive layer 131 is located on the side of the second sub-conductive layer 131 away from the first sub-conductive layer 121 along the second direction Y; in some other cases, the step structure in contact connection with the second sub-conductive layer is located between the second sub-conductive layer and the first sub-conductive layer.

[0082] In this way, taking two columns of sub-conductive layers 111 adjacent along the second direction Y as a group of sub-conductive layers, for this group of sub-conductive layers, the two step structures in contact connection with this group of sub-conductive layers at least include the following four layout situations:

[0083] In some cases, referring to Figure 3 , the step structure 102 in contact connection with the first sub-conductive layer 121 is located on the side of the first sub-conductive layer 121 away from the second sub-conductive layer 131 along the second direction Y, and the step structure 102 in contact connection with the second sub-conductive layer 131 is located on the side of the second sub-conductive layer 131 away from the first sub-conductive layer 121 along the second direction Y. In this way, the distance between the first sub-conductive layer 121 and the second sub-conductive layer 131 in the same conductive layer 101 in the second direction Y can be designed to be very small.

[0084] In some other cases, the step structure in contact connection with the first sub-conductive layer is located on the side of the first sub-conductive layer away from the second sub-conductive layer along the second direction, and the step structure in contact connection with the second sub-conductive layer is located between the second sub-conductive layer and the first sub-conductive layer.

[0085] In still some other cases, the step structure in contact connection with the first sub-conductive layer is located between the first sub-conductive layer and the second sub-conductive layer, and the step structure in contact connection with the second sub-conductive layer is located on the side of the second sub-conductive layer away from the first sub-conductive layer along the second direction.

[0086] In yet some other cases, the step structure in contact connection with the first sub-conductive layer is located between the first sub-conductive layer and the second sub-conductive layer, and the step structure in contact connection with the second sub-conductive layer is located between the second sub-conductive layer and the first sub-conductive layer.

[0087] In some embodiments, different from the case in the above embodiments where "a column of sub-conductive layers 111 arranged at intervals in the first direction X are in contact connection with a step structure 102", a column of sub-conductive layers 111 arranged at intervals in the first direction X can be in contact connection with two step structures 102, and the two step structures 102 in contact connection with the same column of sub-conductive layers 111 are respectively located on the opposite sides of this column of sub-conductive layers 111 in the second direction Y. Thus, a column of sub-conductive layers 111 arranged at intervals in the first direction X are respectively in contact connection with 2 step structures 102. For example, there are 8 sub-conductive layers 111 arranged at intervals in the first direction X, and 4 of the sub-conductive layers 111 need to be respectively in contact connection with 2 step structures 102, then one step structure 102 can be in contact connection with 2 of the 4 sub-conductive layers 111, and the other step structure 102 can be in contact connection with the remaining 2 of the 4 sub-conductive layers 111.

[0088] It can be understood that when the number of conductive layers 101 arranged at intervals in the first direction X is relatively large, for example, the number of conductive layers 101 arranged at intervals in the first direction X is M, and on the premise of ensuring that each conductive layer 101 has a step structure 102 in contact connection therewith, in order to reasonably plan the layout space of the step structure 102, the length of the conductive layer 101 in the third direction Z is made to match the number of step structures 102 arranged at intervals in the third direction Z.

[0089] On the one hand, each conductive layer 101 can be divided into N sub-conductive layers 111 in the second direction, then M / N sub-conductive layers 111 are designed in a column of sub-conductive layers 111 arranged at intervals in the first direction X to have a contact connection relationship with at least one step structure 102, and thus M conductive layers 101 can each be in contact connection with M step structures 102. On the other hand, a column of sub-conductive layers 111 arranged at intervals in the first direction X can be in contact connection with 1 step structure 102 or 2 step structures 102. If it is 1 step structure 102, it is sufficient that this 1 step structure 102 is located on either one of the opposite sides of this column of sub-conductive layers 111 in the second direction Y, then the number of conductive columns 103 arranged in the third direction Z in 1 step structure 102 can be reduced to M / N; if it is 2 step structures 102, and these 2 step structures 102 are respectively located on the opposite sides of this column of sub-conductive layers 111 in the second direction Y, then the number of conductive columns 103 arranged in the third direction Z in 1 step structure 102 can be reduced to M / 2N.

[0090] It can be understood that if each conductive layer 101 is divided into N sub-conductive layers 111 in the second direction, and a column of sub-conductive layers 111 arranged at intervals in the first direction X is in contact connection with 1 step structure 102, then a column of conductive layers 101 arranged at intervals in the first direction X is in contact connection with N step structures; if each conductive layer 101 is divided into N sub-conductive layers 111 in the second direction, and a column of sub-conductive layers 111 arranged at intervals in the first direction X is in contact connection with 2 step structures 102, then a column of conductive layers 101 arranged at intervals in the first direction X is in contact connection with 2N step structures.

[0091] It should be noted that a column of conductive layers 101 arranged at intervals in the first direction X includes N columns of sub-conductive layers 111, both M and N are positive integers. If M / N is a non-integer, round M / N, that is, take the largest integer not exceeding the real number M / N, and call this largest integer P. Among the N columns of sub-conductive layers 111 in a column of conductive layers 101, P sub-conductive layers 111 of one of the two adjacent columns of sub-conductive layers 111 have a contact connection relationship with at least one step structure 102, and the (M - P) sub-conductive layers 111 of the other have a contact connection relationship with at least one step structure 102. Similarly, if M / 2N is a non-integer, round M / 2N and call this integer Q, so that the number of conductive posts 103 arranged in the third direction Z in 1 step structure 102 is reduced to Q, and the number of conductive posts 103 arranged in the third direction Z in the other 1 step structure 102 is reduced to (M / 2 - Q). Similarly, similar rounding operations and subsequent designs can also be performed on M / 2. It can be understood that the above is the main idea of dividing the conductive layer 101 into sub-conductive layers 111, and the main idea of the corresponding relationship between a column of sub-conductive layers 111 arranged at intervals in the first direction X and the step structure 102. In practical applications, the above various quantities can be adjusted according to the actual situation.

[0092] In addition, making the length of the conductive layer 101 in the third direction Z match the number of step structures 102 arranged at intervals in the third direction Z means that when the length of the conductive layer 101 in the third direction Z is limited, the number of conductive posts 103 arranged at intervals in the third direction Z in the step structure 102 will also be limited, so that the number of conductive layers 101 arranged at intervals in the first direction X is more than the number of conductive posts 103 that can be arranged at intervals in the third direction Z. Therefore, additional layout space needs to be considered for the extra conductive posts 103. Based on this, the measures taken include: First, each conductive layer 101 is divided into N sub-conductive layers 111 in the second direction; Second, the number of step structures 102 in contact connection with a column of sub-conductive layers 111 arranged at intervals in the first direction X is 1 or 2.

[0093] Moreover, in practical applications, the conductive layer 101 may not be divided along the second direction Y. Only the number of the step structures 102 in contact connection with a column of conductive layers 101 arranged at intervals along the first direction X is designed to be 2, and the 2 step structures 102 are respectively located on the opposite sides of the column of conductive layers 101 in the second direction Y.

[0094] The following will Figure 1 and Figures 3 to 8 give a detailed description of the one-to-one contact connection between the conductive layer 101 and the conductive posts 103. Among them, Figure 1 can be regarded as a front projection view of the stepped structure 100 on the plane of the film layer where the conductive layer BL8 is located; Figure 6 can be regarded as a front projection view of the stepped structure 100 on the plane of the film layer where the conductive layer BL7 is located; Figure 7 can be regarded as a front projection view of the stepped structure 100 on the plane of the film layer where its conductive layer BL4 is located; Figure 8 can be regarded as a front projection view of the stepped structure 100 on the plane of the film layer where its conductive layer BL1 is located.

[0095] Among the 8 conductive posts 103 of the 2 step structures 102, referring to Figure 1 and Figure 3 , on the plane of the film layer where the conductive layer BL8 is located, only the conductive posts 103 with the epitaxial part WY8 are in contact connection with the conductive layer BL8, and the other conductive posts 103 have the extension part 133 on the plane of the film layer where the conductive layer BL8 is located; referring to Figure 6 and Figure 3 , on the plane of the film layer where the conductive layer BL7 is located, only the conductive posts 103 with the epitaxial part WY7 are in contact connection with the conductive layer BL7, and the conductive posts 103 in contact connection with the conductive layer BL8 only have the main body part 113 on this plane, and the other conductive posts 103 have the extension part 133 on this plane. And so on, on the plane of the film layer where the conductive layer BL6 is located, only the conductive posts 103 with the epitaxial part WY6 are in contact connection with the conductive layer BL6, and the conductive posts 103 in contact connection with the conductive layers BL8 and BL7 only have the main body part 113 on this plane, and the other conductive posts 103 have the extension part 133 on this plane; on the plane of the film layer where the conductive layer BL5 is located, only the conductive posts 103 with the epitaxial part WY5 are in contact connection with the conductive layer BL5, and the conductive posts 103 in contact connection with the conductive layers BL8, BL7, and BL6 only have the main body part 113 on this plane, and the other conductive posts 103 have the extension part 133 on this plane. Moreover, the 4 conductive posts 103 in contact connection with the conductive layers BL8, BL7, BL6, and BL5 form a step structure B, and the conductive posts in the step structure B are all in contact connection with the second sub-conductive layer 131.

[0096] Referring to Figure 7 and Figure 4 On the plane of the film layer where the conductive layer BL4 is located, only the conductive column 103 with the epitaxial part WY4 is in contact connection with the conductive layer BL4. The conductive column 103 in contact connection with the conductive layers BL8, BL7, BL6, and BL5 only has the main body part 113 on this plane, and the other conductive columns 103 have the extension part 133 on this plane. And so on, on the plane of the film layer where the conductive layer BL3 is located, only the conductive column 103 with the epitaxial part WY3 is in contact connection with the conductive layer BL3. The conductive column 103 in contact connection with the conductive layers BL8, BL7, BL6, BL5, and BL4 only has the main body part 113 on this plane, and the other conductive columns 103 have the extension part 133 on this plane. On the plane of the film layer where the conductive layer BL2 is located, only the conductive column 103 with the epitaxial part WY2 is in contact connection with the conductive layer BL2. The conductive column 103 in contact connection with the conductive layers BL8, BL7, BL6, BL6, BL5, BL4, and BL3 only has the main body part 113 on this plane, and the other conductive columns 103 have the extension part 133 on this plane; Refer to Figure 8 and Figure 3 On the plane of the film layer where the conductive layer BL1 is located, only the conductive column 103 with the epitaxial part WY1 is in contact connection with the conductive layer BL1, and the other conductive columns 103 only have the main body part 113 on this plane. Moreover, the four conductive columns 103 in contact connection with the conductive layers BL4, BL3, BL2, and BL1 form a step structure A, and the conductive columns in the step structure A are all in contact connection with the first sub-conductive layer 121.

[0097] In summary, the characteristics of the step are integrated on the conductive column 103 to form a new step structure 102. The conductive column 103 itself in the new step structure 102 is used both for conducting electricity to transmit electrical signals and for realizing electrical contact with the conductive layers located in different layers. Compared with the current situation where multiple steps in different layers are designed separately and the conductive columns corresponding to the multiple steps are designed separately, resulting in a relatively large horizontal area occupied by the steps and the conductive columns as a whole, in an embodiment of the present disclosure, integrating the characteristics of the step on the conductive column 103 is beneficial to reducing the horizontal area occupied by the step structure 102 as a whole on the premise of ensuring that the electrical signals on each conductive layer 101 are led out through a conductive column 103. In other words, it is beneficial to improve the integration density of the conductive columns 103 in the step structure 102.

[0098] Another embodiment of the present disclosure further provides a semiconductor structure, including the stepped structure provided by an embodiment of the present disclosure. The semiconductor structure provided by another embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the same or corresponding parts as those in the foregoing embodiments will not be described in detail here.

[0099] Fig.12A top view structural schematic diagram of a semiconductor structure provided by another embodiment of the present disclosure; Fig.13 is Fig.12 A cross-sectional structural schematic diagram of the semiconductor structure shown along the third cross-sectional direction CC1. It should be noted that, for the convenience of description and to clearly illustrate the semiconductor structure, in this embodiment, Fig.12 and Fig.13 are both partial structural schematic diagrams of the semiconductor structure.

[0100] Referring to Fig.12 and Fig.13 , the semiconductor structure includes: a stepped structure 100 provided by an embodiment of the present disclosure; a plurality of signal transmission layers 105 arranged at intervals along the first direction X, the signal transmission layers 105 are in one-to-one contact connection with the conductive layers 101, and the sub-conductive layers 111 in the same conductive layer 101 are all in contact connection with the same signal transmission layer 105; wherein, the signal transmission layer 105 includes a word line or a bit line.

[0101] It should be noted that, Fig.12 uses different forms of dashed boxes to schematically show the stepped structure 100 and the stepped structure 102 in the stepped structure 100. In addition, Fig.12 the signal transmission layer 105 shown is in a simplified drawing method. In actual application, the signal transmission layer 105 has a very long extension length in the third direction Z. For example, the extension length of the signal transmission layer 105 in the third direction Z is greater than the extension length of the conductive layer 101 in the third direction Z.

[0102] In some embodiments, the semiconductor structure may further include a transistor structure (not shown in the figure). If the signal transmission layer 105 is a bit line, the signal transmission layer 105 is in contact connection with the source or drain in the transistor structure. If the signal transmission layer 105 is a word line, the signal transmission layer 105 surrounds the channel region in the transistor structure.

[0103] In some embodiments, continuing to refer to Fig.12 and Fig.13 , a plurality of signal transmission layers arranged at intervals along the first direction X form a signal transmission group 115, and a plurality of signal transmission groups 115 are arranged at intervals along the second direction Y. One signal transmission group 115 corresponds to one stepped structure 100. In this way, the electrical signals on all the signal transmission layers 105 in one signal transmission group 115 can be respectively led out through a plurality of conductive posts 103 in one stepped structure 100.

[0104] Another embodiment of the present disclosure further provides a manufacturing method of a stepped structure for forming the stepped structure provided by an embodiment of the present disclosure. The manufacturing method of the stepped structure provided by another embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings. Figures 14 to 26The cross-sectional structure diagrams corresponding to the steps in the manufacturing method of the stepped structure provided by another embodiment of the present disclosure. It should be noted that, for the convenience of description and to clearly illustrate the steps of the manufacturing method of the stepped structure, in this embodiment, Figures 14 to 26 are all partial structure diagrams of the stepped structure. The same or corresponding parts as those in the foregoing embodiments will not be elaborated herein.

[0105] It should be noted that another embodiment of the present disclosure takes the formation of Figure 1 、 Figure 3 and Figure 4 The shown stepped structure 102 as an example to elaborate in detail on the manufacturing method of the stepped structure provided by another embodiment of the present disclosure.

[0106] Referring to Figure 1 、 Figure 3 、 Figure 4 and Figures 14 to 26 , the manufacturing method of the stepped structure includes: forming a plurality of conductive layers 101 arranged at intervals along the first direction X, the conductive layer 101 includes at least two sub-conductive layers 111 arranged at intervals along the second direction Y, the conductive layer 101 extends along the third direction Z, and the first direction X, the second direction Y, and the third direction Z intersect pairwise; forming a plurality of stepped structures 102 arranged at intervals along the second direction Y, and a column of sub-conductive layers 111 arranged at intervals along the first direction X is at least in contact connection with one stepped structure 102. Wherein, each stepped structure 102 includes a plurality of electrically insulated conductive columns 103, one conductive column 103 is in contact connection with one sub-conductive layer 111, and the conductive column 103 in contact connection with one sub-conductive layer 111 is electrically insulated from other sub-conductive layers 111; and in a column of conductive layers 101 arranged at intervals along the first direction X, the conductive layer 101 is in contact connection with the conductive column 103 one by one.

[0107] The following will elaborate in detail on each step in the manufacturing method with reference to the drawings.

[0108] In some embodiments, referring to Figures 14 to 17 , forming the conductive layer 101 may include the following steps:

[0109] Referring to Fig.14 and Fig.15 , forming a stacked structure 106, the stacked structure 106 includes a first dielectric layer 116 and a second dielectric layer 126 stacked alternately along the first direction X.

[0110] In some embodiments, the material of the first dielectric layer 116 is different from the material of the second dielectric layer 126. For example, the material of the first dielectric layer 116 is silicon oxide, and the material of the second dielectric layer 126 is silicon nitride.

[0111] Wherein, Fig.15 is Fig.14A schematic cross-sectional structure diagram of the shown structure along the fourth cross-section direction DD1. It should be noted that, subsequently, a schematic cross-sectional structure diagram along the fourth cross-section direction DD1 will be set according to the needs of the description. In addition, Fig.14 and Fig.15 what is shown in is the stacked structure 106 after the first patterning process.

[0112] Continue to refer to Fig.14 and Fig.15 Perform a first patterning process on the stacked structure 106 to form a trench 107 that penetrates the stacked structure 106.

[0113] In some embodiments, before performing the first patterning process on the stacked structure 106, a first mask layer 119 with an opening is further formed on the top surface of the stacked structure 106. Subsequently, based on the first mask layer 119, a first patterning process is performed on the stacked structure 106. It can be understood that the first patterning process etches the first dielectric layer 116 and the second dielectric layer 126 without discrimination.

[0114] With reference to Fig.15 and Fig.16 , perform a lateral etch on the second dielectric layer 126 exposed by the trench 107 to form a groove 117 between adjacent first dielectric layers 116. The trench 107 communicates with a groove 117 on each side in the second direction Y. It can be understood that, among the 2 adjacent grooves 117 along the second direction Y, subsequently, they are respectively used to form Figure 1 the 2 sub-conductive layers 111 in the same conductive layer 101 shown.

[0115] It should be noted that the material of the first dielectric layer 116 is different from that of the second dielectric layer 126. In the step of performing a lateral etch on the second dielectric layer 126 exposed by the trench 107, the etching process only has a relatively high etching rate for the second dielectric layer 126 and hardly etches the first dielectric layer 116.

[0116] With reference to Fig.16 and Fig.17 , form a sub-conductive layer 111 in a groove 117, and form a third dielectric layer 136 in the trench 107. Multiple sub-conductive layers 111 in contact with the same third dielectric layer 136 constitute a conductive layer 101.

[0117] It should be noted that, Fig.16 and Fig.17In the illustrated example, the fact that a plurality of sub-conductive layers 111 in contact connection with the same third dielectric layer 136 constitute a conductive layer 101 means that 2 sub-conductive layers 111 in contact connection with the same third dielectric layer 136 and located in the same layer constitute a conductive layer 101. In practical applications, a plurality of grooves arranged at intervals in the second direction may be formed, and a recess may be formed on each side of any groove in the second direction to form a conductive layer including a plurality of sub-conductive layers arranged at intervals in the second direction.

[0118] In some embodiments, the material of the third dielectric layer 136 may be the same as that of the first dielectric layer 116, for example, both are silicon oxide; in other embodiments, the material of the third dielectric layer 136 may also be different from that of the first dielectric layer 116.

[0119] In some embodiments, referring to Figures 18 to 26 , forming the stepped structure 102 may include the following steps:

[0120] Referring to Fig.18 , a second patterning process is performed on the stacked structure 106 (refer to Fig.17 ) to form a plurality of through holes 127 penetrating the stacked structure 106 and arranged at intervals in the third direction Z. Among them, the plurality of through holes 127 arranged at intervals in the third direction Z form a through hole group 137, and at least one column of sub-conductive layers 111 arranged at intervals in the first direction X corresponds to at least one through hole group 137.

[0121] It should be noted that, to show the positional relationship between the through hole 127 and the conductive layer 101, Fig.18 the layout space approximately occupied by 2 sub-conductive layers 111 in the conductive layer 101 is schematically shown by relatively dense dotted lines. In addition, Fig.18 a through hole group 137 is schematically shown by a relatively thick dotted-line rectangle in

[0122] In addition, since the conductive layer 101 includes at least two sub-conductive layers 111 arranged at intervals in the second direction Y, based on this, at least one column of sub-conductive layers 111 arranged at intervals in the first direction X corresponds to at least one through hole group 137, then at least one column of conductive layers 101 arranged at intervals in the first direction X corresponds to at least two through hole groups 137.

[0123] In some embodiments, referring to Fig.18 , the top surface of the stacked structure 106 (refer to Fig.17 ) further has a first mask layer 119, and in the step of performing the second patterning process on the stacked structure 106, the first mask layer 119 is also subjected to the second patterning process. It can be understood that the second patterning process etches the first dielectric layer 116, the second dielectric layer 126, and the first mask layer 119 without distinction.

[0124] In some embodiments, referring to Fig.18 , in at least two via groups 137 corresponding to a column of conductive layers 101 spaced apart in the first direction X, any one of the via groups 137 is located at one of the opposite sides of the conductive layer 101 in the second direction Y.

[0125] It can be understood that Fig.18 , in one of the two via groups 137 corresponding to a column of conductive layers 101 spaced apart in the first direction X, one is located on one of the opposite sides of the conductive layer 101 in the second direction Y, and the other is located on the other of the opposite sides of the conductive layer 101 in the second direction Y. In practical applications, one of the two via groups corresponding to a column of conductive layers spaced apart in the first direction is located on one of the opposite sides of the conductive layer in the second direction Y, and the other can be located between adjacent sub-conductive layers; or, both of the two via groups corresponding to a column of conductive layers spaced apart in the first direction are located between adjacent sub-conductive layers.

[0126] Referring to Fig.21 and Fig. 22 , a first sacrificial layer 118 is formed in the via 127. Among the multiple vias 127 corresponding to the same column of conductive layers 101 spaced apart in the first direction X, the first sacrificial layers 118 located in different vias 127 have different thicknesses in the first direction X, and the first sacrificial layer 118 with the smallest thickness is in contact connection with one layer of the first dielectric layer 116 and one layer of the second dielectric layer 126.

[0127] It should be noted that Fig.21 FIG. Fig.18 is a schematic cross-sectional structure diagram of a structure along the fifth cross-section direction EE1 after the first sacrificial layer 118 is formed in the via 127 shown; Fig. 22 FIG. Fig.18 is a schematic cross-sectional structure diagram of a structure along the sixth cross-section direction FF1 after the first sacrificial layer 118 is formed in the via 127 shown. In addition, schematic cross-sectional structure diagrams along at least one of the fifth cross-section direction EE1 and the sixth cross-section direction FF1 will be set according to the expression needs later.

[0128] Referring to Figures 18 to 22 , the step of forming the first sacrificial layer 118 may include:

[0129] Referring to Fig.18 , an initial first sacrificial layer (not shown in the figure) that fills the via 127 is now formed in the via 127 penetrating the stacked structure 106; referring to FIGS. 19 and Fig. 20 , the initial first sacrificial layer in one of the 2 via groups 137 (referring to Fig.18 ) is etched to remove nearly half of the initial first sacrificial layer, referring to Fig.19, the via 127 is exposed again above the remaining initial first sacrificial layer 128 in one of the two via groups 137 (refer to Fig.18 ), and a part of the exposed region of the via 127 is filled with the second sacrificial layer 138. Refer to Fig. 20 . In the other of the two via groups 137, the initial first sacrificial layer 128 is not etched.

[0130] It should be noted that one layer of the first dielectric layer 116 and one layer of the second dielectric layer 126 adjacent in the first direction X form a sub-stack structure 156. The number of sub-stack structures 156 in the stack structure 106 is determined by the number of conductive layers 101 in a column of conductive layers 101 arranged at intervals in the first direction X. Refer to Fig.19 . The number of sub-stack structures 156 in the stack structure 106 is 8 layers. Removing nearly half of the initial first sacrificial layer means removing the initial first sacrificial layer corresponding to the upper 4 layers of sub-stack structures 156. In practical applications, the number of sub-stack structures 156 in the stack structure 106 is M layers, where M is a positive integer. If M is an even number, the initial first sacrificial layer corresponding to the upper M / 2 layers of sub-stack structures 156 is removed. If M is an odd number, the initial first sacrificial layer corresponding to the upper (M - 1) / 2 layers of sub-stack structures 156 is removed.

[0131] It should be noted that the material of the initial first sacrificial layer 128 is different from that of the second sacrificial layer 138. For example, the material of the initial first sacrificial layer 128 is a spin-on dielectric layer, which is different from the materials of the first dielectric layer 116 and the second dielectric layer 126. The material of the second sacrificial layer 138 is alumina, which is also different from the materials of the first dielectric layer 116 and the second dielectric layer 126.

[0132] Continue to refer to Fig.19 and Fig. 20 . A second mask layer 129 is formed on the top surface of the first mask layer 119, and the second mask layer 129 exposes two adjacent vias 127 in the second direction Y (refer to Fig.18 ). One of the two adjacent vias 127 in the second direction Y has the second sacrificial layer 138 shown in Fig.19 , and the other has the initial first sacrificial layer 128 shown in Fig. 20 . Combining references Fig.19 and Fig.21 , as well as Fig. 20 and Fig. 22 , first remove the second sacrificial layer 138 exposed by the second mask layer 129, and then etch the initial first sacrificial layer 128 in the two adjacent vias 127 in the second direction Y simultaneously to form Fig.21 and Fig. 22The first sacrificial layer 118 flush with the top surfaces of the conductive layers BL1 and BL5 as shown. In one example, the initial first sacrificial layer 128 in two adjacent vias 127 along the second direction Y is etched simultaneously, and the initial first sacrificial layer 128 in contact with the 3-layer sub-stack structure 156 is removed from the two vias 127 respectively.

[0133] It can be understood that, by analogy, the second mask layer 129 is removed, and a third mask layer (not shown in the figure) is formed on the top surface of the first mask layer 119. The third mask layer exposes two other adjacent vias 127 along the second direction Y (refer to Fig.18 ), for example, exposes the third via 127 from left to right along the third direction Z in each via group 137 in Fig.18 . With reference to Fig.19 and Fig.21 , and Fig. 20 and Fig. 22 , first, the second sacrificial layer 138 exposed by the third mask layer is removed, and then the initial first sacrificial layer 128 in two adjacent vias 127 along the second direction Y exposed by the third mask layer is etched simultaneously to form the first sacrificial layer 118 flush with the top surfaces of the conductive layers BL2 and BL6 as shown in Fig.21 and Fig. 22 . In one example, the initial first sacrificial layer 128 in two adjacent vias 127 along the second direction Y exposed by the third mask layer is etched simultaneously, and the initial first sacrificial layer 128 in contact with the 2-layer sub-stack structure 156 is removed from the two vias 127 respectively.

[0134] The third mask layer is removed, and a fourth mask layer (not shown in the figure) is formed on the top surface of the first mask layer 119. The fourth mask layer exposes two other adjacent vias 127 along the second direction Y (refer to Fig.18 ), for example, exposes the second via 127 from left to right along the third direction Z in each via group 137 in Fig.18 . With reference to Fig.19 and Fig.21 , and Fig. 20 and Fig. 22 , first, the second sacrificial layer 138 exposed by the fourth mask layer is removed, and then the initial first sacrificial layer 128 in two adjacent vias 127 along the second direction Y exposed by the fourth mask layer is etched simultaneously to form the first sacrificial layer 118 flush with the top surfaces of the conductive layers BL3 and BL7 as shown in Fig.21 and Fig. 22 . In one example, the initial first sacrificial layer 128 in two adjacent vias 127 along the second direction Y exposed by the fourth mask layer is etched simultaneously, and the initial first sacrificial layer 128 in contact with the 1-layer sub-stack structure 156 is removed from the two vias 127 respectively.

[0135] In addition, the fourth mask layer is removed, and a fifth mask layer (not shown in the figure) is formed on the top surface of the first mask layer 119. The fifth mask layer exposes two other vias 127 adjacent to each other along the second direction Y (refer to Fig.18 ), for example, exposes the first via 127 counted from left to right along the third direction Z in each via group 137 in Fig.18 . With reference to Fig.19 and Fig.21 , and Fig. 20 and Fig. 22 , first, the second sacrificial layer 138 exposed by the fifth mask layer is removed, and then the initial first sacrificial layer 128 in contact connection with the first mask layer 119 is removed to form the first sacrificial layer 118 flush with the top surfaces of the conductive layers BL4 and BL8 as shown in Fig.21 and Fig. 22 .

[0136] In some embodiments, with reference to Fig.21 and Fig. 22 , a layer of the first dielectric layer 116 and a layer of the second dielectric layer 126 adjacent to each other along the first direction X form a sub-stack structure 156. Among the multiple vias 127 corresponding to the same column of conductive layers 101 arranged at intervals along the first direction X, the number of layers of the sub-stack structure 156 in contact connection with the first sacrificial layer 118 in different vias 127 is different. In this way, it is beneficial to form conductive pillars in contact connection with conductive layers in different layers subsequently.

[0137] In some embodiments, with reference to Fig.21 and Fig. 22 , in the same via group 137 (refer to Fig.18 ), along the third direction Z, the number of layers of the sub-stack structure 156 in contact connection with the first sacrificial layer 118 in different vias 127 increases or decreases successively.

[0138] With reference to Fig.24 , a fourth dielectric layer 146 is formed; in some embodiments, to form the stepped structure 100 as shown in Figure 1 , before forming the fourth dielectric layer 146 and after forming the first sacrificial layer 118, the manufacturing method may further include: with reference to Fig.21 and Fig.23 , performing lateral etching on the second dielectric layer 126 exposed by the via 127 to form an extension groove 147 between adjacent first dielectric layers 116, and the extension groove 147 exposes the remaining second dielectric layer 126, and the extension groove 147 communicates with the via 127. It can be understood that the extension groove 147 is used to form an insulating portion and an extension portion subsequently.

[0139] It should be noted that the materials of the first dielectric layer 116, the second dielectric layer 126, and the first sacrificial layer 118 are all different. In the step of laterally etching the second dielectric layer 126 exposed by the through hole 127, the etching process only has a relatively high etching rate for the second dielectric layer 126, and hardly etches the first dielectric layer 116 and the first sacrificial layer 118.

[0140] It should be noted that Fig. 22 similar steps are also carried out in the four through holes 127 in the shown structure Fig.21 from the shown structure to Fig.23 the shown structure. They are not shown and described in detail here. Subsequently, the process steps performed on the structure shown in Fig.23 will also be carried out on the structure shown in Fig. 22 Subsequently, the subsequent steps will be described in detail with reference to the cross-sectional structure schematic diagram shown in Fig.23

[0141] In some embodiments, with reference to Fig.23 and Fig.24 , on the basis of forming the extension groove 147 between adjacent first dielectric layers 116, the step of forming the fourth dielectric layer 146 may further include: forming a conformal fourth dielectric layer 146 covering the surface of the extension groove 147.

[0142] It should be noted that Fig.24 only shows the fourth dielectric layer 146 on the side wall of the extension groove 147 extending along the first direction X. It can be understood that in actual applications, the fourth dielectric layer 146 may be formed only on the side wall of the extension groove 147 extending along the first direction X, that is, on the side wall of the second dielectric layer 126 exposed by the extension groove 147, so as to avoid etching this part of the second dielectric layer 126 in the subsequent etching process. It can be understood that Fig.24 the fourth dielectric layer 146 shown in Figure 1 is the insulating portion 104 shown in

[0143] In some cases, the step of forming the fourth dielectric layer 146 may include: forming an initial fourth dielectric layer conformally covering the surfaces of the through hole 127 and the extension groove 147, and etching the initial fourth dielectric layer. In this etching step, at least the initial fourth dielectric layer on the top surface of the first sacrificial layer 118 will be removed. Due to the difference in the etching process, at least part of the initial fourth dielectric layer on the side walls of the first mask layer 119 and the first dielectric layer 116 may also be etched, so that the remaining initial fourth dielectric layer is located on the surface of the extension groove 147.

[0144] With reference to Fig.24 and Fig.25, using the fourth dielectric layer 146 as a protective layer, the first sacrificial layer 118 in contact with one layer of the second dielectric layer 126 is removed, and the remaining through holes 127 not filled with the first sacrificial layer 118 are used as sub-through holes 157, so that each sub-through hole 157 exposes one layer of the second dielectric layer 126; continue to refer to Fig.24 and Fig.25 , perform lateral etching on the second dielectric layer 126 exposed by the sub-through holes 157 to form an epitaxial groove 167 between adjacent first dielectric layers 116, and the epitaxial groove 167 exposes the sub-conductive layer 111 (refer to Fig.18 ), and the epitaxial groove 167 communicates with the sub-through hole 157.

[0145] It should be noted that in the step of performing lateral etching on the second dielectric layer 126 exposed by the sub-through holes 157, the etching process only has a relatively high etching rate for the second dielectric layer 126, and hardly etches the first dielectric layer 116 and the first sacrificial layer 118.

[0146] Refer to Fig.25 and Fig.26 , remove the remaining first sacrificial layer 118, and form conductive posts 103 in the through holes 127 and the epitaxial grooves 167. The multiple conductive posts 103 formed in the same through hole group 137 constitute a stepped structure 102. In some embodiments, on the basis of forming the extension groove 147 between adjacent first dielectric layers 116, the step of forming the conductive posts 103 includes: forming the conductive posts 103 in the extension groove 147.

[0147] It can be understood that the conductive post 103 located in the through hole 127 (refer to Fig.18 ) is the Figure 3 shown main body portion 113, and the conductive post 103 located in the epitaxial groove 167 (refer to Fig.25 ) is the Figure 3 shown epitaxial portion 123, and the conductive post 103 located in the extension groove 147 (refer to Fig.25 ) is the Figure 3 shown extension portion 133. Refer to Fig.26 , the main body portion 113, the epitaxial portion 123 and the extension portion 133 in the conductive post 103 can be an integrally formed structure.

[0148] It should be noted that in the above embodiments, the manufacturing method of the stepped structure is described in detail by taking the formation of the conductive post 103 with the extension portion 133 as an example. In practical applications, as Figures 9 to 11 shown, the conductive post 103 in the stepped structure 102 can only include the main body portion 113 and the epitaxial portion 123.

[0149] The following briefly describes the formation of the stepped structure as Figures 9 to 11 shown, which is the same as the foregoing Figure 1The parts that are the same or similar to the manufacturing method of the shown stepped structure 102 will not be described in detail.

[0150] In some other embodiments, with reference to Fig.21 and Fig.10 , and Fig. 22 and Fig.11 , no extension groove is further formed, and a fourth dielectric layer covering the remaining sidewalls of the conformal via 127 (refer to Fig.18 ) is directly formed. It can be understood that the fourth dielectric layer covering the remaining sidewalls of the conformal via 127 (refer to Fig.18 ) is the insulating portion 104 shown in Fig.10 and Fig.11 .

[0151] Using the fourth dielectric layer as a protective layer, the first sacrificial layer 118 in contact with a layer of the second dielectric layer 126 (refer to Fig.21 ) is removed, and the remaining via 127 not filled with the first sacrificial layer 118 serves as a sub-via 157 (refer to Fig.25 ), so that each sub-via 157 exposes a layer of the second dielectric layer 126. It should be noted that in the example shown in Fig. 9 for forming the stepped structure, the extension groove may not be formed anymore in the example shown in Fig.25 .

[0152] The second dielectric layer 126 exposed by the sub-via is etched laterally to form an extension groove 167 (refer to Fig.25 ) between adjacent first dielectric layers 116, and the extension groove 167 exposes the sub-conductive layer 111 (refer to Fig.18 ), and the extension groove 167 communicates with the sub-via 157.

[0153] The remaining first sacrificial layer 118 is removed, and conductive pillars 103 are formed in the via 127 and the extension groove 167. The multiple conductive pillars 103 formed in the same via group 137 constitute a stepped structure 102.

[0154] In summary, the manufacturing method provided by another embodiment of the present disclosure is conducive to forming a novel stepped structure 100, integrating the features of the steps on the conductive column 103 to form a new stepped structure 102. In the new stepped structure 102, the conductive column 103 itself is used both for conducting electricity to transmit electrical signals and for achieving electrical contact with conductive layers located on different layers. Compared with the current situation where multiple steps at different levels are designed separately and conductive columns corresponding to the multiple steps are designed separately, resulting in a relatively large horizontal area occupied by the steps and the conductive columns as a whole, integrating the features of the steps on the conductive column 103 in an embodiment of the present disclosure is conducive to reducing the horizontal area occupied by the entire stepped structure 102 on the premise of ensuring that the electrical signals on each conductive layer 101 are led out through a conductive column 103. In other words, it is conducive to improving the integration density of the conductive columns 103 in the stepped structure 102.

[0155] Those of ordinary skill in the art can understand that the above embodiments are specific embodiments for implementing the present disclosure. In actual applications, various changes can be made in form and details without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of the present disclosure. Therefore, the protection scope of the embodiments of the present disclosure should be determined by the scope defined in the claims.

Claims

1. A stepped structure, characterized in that, Comprising: A plurality of conductive layers arranged at intervals along a first direction, wherein each conductive layer includes at least two sub-conductive layers arranged at intervals along a second direction, and the conductive layer extends along a third direction, and the first direction, the second direction and the third direction intersect pairwise; A plurality of step structures arranged at intervals along the second direction, and a column of the sub-conductive layers arranged at intervals along the first direction is at least in contact connection with one of the step structures; Wherein, each of the step structures includes a plurality of electrically insulated conductive columns, one of the conductive columns is in contact connection with one of the sub-conductive layers, and the conductive column in contact connection with one of the sub-conductive layers is electrically insulated from the other sub-conductive layers; and in a column of the conductive layers arranged at intervals along the first direction, the conductive layers are in one-to-one contact connection with the conductive columns.

2. The stepped structure according to claim 1, characterized in that, The conductive column includes a main body portion and an extension portion, the main body portion extends along the first direction, the extension portion is located on a side wall extending along the first direction of a partial thickness of the main body portion, and the extension portion is in contact connection with the sub-conductive layer, and the extension portion in contact connection with the sub-conductive layer is in the same layer as the sub-conductive layer; And, The main body portions in the same step structure are arranged at intervals along the third direction, and the extension portions in the same step structure are respectively in different layers.

3. The stepped structure according to claim 2, characterized in that, The conductive column further includes at least one extension part, the extension part is also located on a side wall extending along the first direction of a partial thickness of the main body portion, and the extension part and the extension portion in contact connection with the same conductive column are arranged at intervals along the first direction, and the extension part is electrically insulated from the sub-conductive layer.

4. The stepped structure according to claim 3, characterized in that, Among at least one of the extension parts in contact connection with the same conductive column, one of the extension parts is in the same layer as one of the sub-conductive layers; or, all of the at least one extension parts in contact connection with the same conductive column are located on one side of the extension portion along the first direction.

5. The stepped structure according to claim 3, characterized in that, The second direction and the third direction together form a reference plane, and the projected area of the extension part on the reference plane is smaller than the projected area of the extension portion on the reference plane.

6. The stepped structure according to claim 2, characterized in that, The main body portion has opposite first and second surfaces in the first direction, and in the same step structure, along the third direction, the distances between different extension portions and the first surface in the first direction increase or decrease successively.

7. The stepped structure according to any one of claims 1 to 6, characterized in that, A column of the sub-conductive layers arranged at intervals along the first direction is in contact connection with one of the step structures, and two adjacent sub-conductive layers along the second direction are respectively used as a first sub-conductive layer and a second sub-conductive layer; Wherein, the step structure in contact connection with the first sub-conductive layer is located on a side of the first sub-conductive layer away from the second sub-conductive layer along the second direction, or, the step structure in contact connection with the first sub-conductive layer is located between the first sub-conductive layer and the second sub-conductive layer; The step structure in contact connection with the second sub-conductive layer is located on a side of the second sub-conductive layer away from the first sub-conductive layer along the second direction, or the step structure in contact connection with the second sub-conductive layer is located between the second sub-conductive layer and the first sub-conductive layer.

8. The stepped structure according to any one of claims 1 to 6, characterized in that, A column of the sub-conductive layers arranged at intervals along the first direction is in contact connection with two of the step structures, and the two step structures in contact connection with the same column of the sub-conductive layers are respectively located on opposite sides of the column of the sub-conductive layers in the second direction.

9. A semiconductor structure, characterized in that, Comprising: The stepped structure according to any one of claims 1 to 8; A plurality of signal transmission layers arranged at intervals along the first direction, the signal transmission layers are in contact connection with the conductive layers one by one, and the sub-conductive layers in the same conductive layer are all in contact connection with the same signal transmission layer; Wherein, the signal transmission layer includes a word line or a bit line.

10. A manufacturing method of a stepped structure, characterized in that, Comprising: Forming a plurality of conductive layers arranged at intervals along a first direction, the conductive layer includes at least two sub-conductive layers arranged at intervals along a second direction, the conductive layer extends along a third direction, and the first direction, the second direction and the third direction intersect pairwise; Forming a plurality of step structures arranged at intervals along the second direction, and a column of the sub-conductive layers arranged at intervals along the first direction is at least in contact connection with one of the step structures; Wherein, each of the step structures includes a plurality of electrically insulated conductive posts, one of the conductive posts is in contact connection with one of the sub-conductive layers, and the conductive post in contact connection with one of the sub-conductive layers is electrically insulated from the other sub-conductive layers; and in a column of the conductive layers arranged at intervals along the first direction, the conductive layers are in contact connection with the conductive posts one by one.

11. The manufacturing method according to claim 10, characterized in that, The step of forming the conductive layer includes: Forming a stacked structure, the stacked structure includes a first dielectric layer and a second dielectric layer alternately stacked along the first direction; Performing a first patterning process on the stacked structure to form a trench penetrating the stacked structure; Performing a lateral etching on the second dielectric layer exposed by the trench to form a groove between adjacent first dielectric layers, and both sides of the trench in the second direction are respectively communicated with one of the grooves; Forming one of the sub-conductive layers in one of the grooves; Forming a third dielectric layer in the trench, and a plurality of the sub-conductive layers in contact connection with the same third dielectric layer constitute one of the conductive layers.

12. The manufacturing method according to claim 11, wherein, The step of forming the step structure includes: Performing a second patterning process on the stacked structure to form a plurality of through holes penetrating the stacked structure and arranged at intervals along the third direction, wherein, a plurality of the through holes arranged at intervals along the third direction form a through hole group, and a column of the sub-conductive layers arranged at intervals along the first direction is at least corresponding to one of the through hole groups; Forming a first sacrificial layer in the through holes, in a plurality of the through holes corresponding to the same column of the conductive layers arranged at intervals along the first direction, the first sacrificial layers in different through holes have different thicknesses in the first direction, and the first sacrificial layer with the smallest thickness is in contact connection with one layer of the first dielectric layer and one layer of the second dielectric layer; Form a fourth dielectric layer that conformally covers the remaining sidewalls of the through holes; Using the fourth dielectric layer as a protective layer, remove the first sacrificial layer that is in contact with and connected to one layer of the second dielectric layer. The remaining through holes that are not filled with the first sacrificial layer serve as sub-through holes, exposing one layer of the second dielectric layer in each sub-through hole; Perform lateral etching on the second dielectric layer exposed by the sub-through holes to form an epitaxial groove between adjacent first dielectric layers, and the epitaxial groove exposes the sub-conductive layer, and the epitaxial groove communicates with the sub-through hole; Remove the remaining first sacrificial layer, and form conductive pillars in the through holes and the epitaxial grooves. A plurality of conductive pillars formed in the same through hole group constitute a stepped structure.

13. The manufacturing method according to claim 12, wherein, Before forming the fourth dielectric layer and after forming the first sacrificial layer, it further includes: Perform lateral etching on the second dielectric layer exposed by the through holes to form an extension groove between adjacent first dielectric layers, and the extension groove exposes the remaining second dielectric layer, and the extension groove communicates with the through hole; The step of forming the fourth dielectric layer further includes: forming the fourth dielectric layer that conformally covers the surface of the extension groove; The step of forming the conductive pillar includes: forming the conductive pillar in the extension groove.

14. The manufacturing method according to claim 12 or 13, wherein, One layer of the first dielectric layer and one layer of the second dielectric layer adjacent in the first direction form a sub-stack structure. Among the plurality of through holes corresponding to the same column of conductive layers arranged at intervals in the first direction, the number of layers of the sub-stack structure in contact with the first sacrificial layer located in different through holes is different.

15. The manufacturing method according to claim 12 or 13, wherein, Among at least two through hole groups corresponding to a column of conductive layers arranged at intervals in the first direction, any one through hole group is located at one of the opposite sides of the conductive layer in the second direction, or any one through hole group is located between adjacent sub-conductive layers.

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