Semiconductor device and mask structure
By using T-shaped anchor columns and composite film hard masks in the MEMS microbridge structure, the anchor column size control problem and empty plating phenomenon are solved, and the stability and conductivity of the conductive structure are improved, and the product yield is improved.
Patent Information
- Application Number
- CN202422627696.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-09-05
- Estimated Expiration
- 2034-10-30
AI Technical Summary
In the prior art, the size of the anchor column of the MEMS microbridge structure is difficult to control, and the hollow plating often occurs in the middle of the anchor column, which affects the stability and conductivity of the conductive structure and leads to a decrease in product yield.
The T-shaped anchor column structure is adopted, and the composite film layer is used as a hard mask. The opening of the first hard mask layer defines the etching position on the top surface of the anchor column. The groove of the second hard mask layer defines the etching position on the bottom surface of the anchor column to avoid undercutting the contact hole structure, ensuring that the contact hole is a step shape with a wide upper and narrow upper bottom, which is convenient for the filling of conductive materials.
The conductive structure stability and conductivity of the anchor column are improved, the product yield is enhanced, and miniaturization requirements are met.
Smart Images
Figure CN223304165U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of MEMS devices, in particular to a semiconductor device and a mask structure. Background Art
[0002] Micro-Electro-Mechanical System (MEMS) technology has numerous advantages, including miniaturization, scalability, integration, good process compatibility, and low cost, leading to its widespread application in numerous fields. The MEMS microbridge structure is a widely used structure in the MEMS field. It utilizes a sacrificial layer release process to form the bridge structure and can be widely used in products such as detectors and sensors. In a MEMS microbridge structure, anchor posts play a crucial role in the electrical connection of the microbridge structure, making them crucial to the entire detector. In existing techniques, the fabrication of MEMS microbridge anchor posts involves first photolithographically etching a support hole pattern on a sacrificial layer. Then, chemical vapor deposition (CVD) is used to sequentially deposit dielectric materials, including a release layer and a support layer, within the support hole. The dielectric at the bottom of the support hole is then photolithographically etched to form a contact hole. A metal thin film is then deposited to achieve electrical connection.
[0003] Unlike traditional IC (Integrated Circuit) processes, MEMS processes require contact holes to be made on a sacrificial layer. This method has the following problems:
[0004] 1) Without using a hard mask for etching, the contact holes formed after etching the sacrificial layer are straight holes. However, the size of the contact holes formed in this way is difficult to control, which makes it difficult to control the size of the final anchor pillars, and thus fails to meet the requirements of device miniaturization.
[0005] 2) Using a hard mask for etching creates an undercut between the sacrificial layer and the hard mask, resulting in a contact hole that is narrow at the top and wide at the bottom. When filling the contact hole with conductive material, existing semiconductor coating equipment such as PVD (Physical Vapor Deposition) and CVD cannot effectively achieve a solid hole fill. This often results in a void in the center of the resulting anchor column, resulting in poor stability and conductivity of the conductive structure, affecting product yield. Utility Model Content
[0006] In view of this, the purpose of the present invention is to provide a semiconductor device and a mask structure for solving the problems of difficulty in controlling the size of anchor posts and the frequent occurrence of empty plating in the middle of the anchor posts.
[0007] In order to solve the above technical problems, the utility model provides a semiconductor device, including: a readout circuit wafer, an electrode, an anchor column and a MEMS device; the MEMS device includes a sensing layer; the readout circuit on the surface of the readout circuit wafer is electrically connected to the electrode; the electrode is electrically connected to the anchor column; the anchor column is electrically connected to the sensing layer; and the anchor column is T-shaped.
[0008] Optionally, the semiconductor device further includes: a first dielectric film; the electrode is located on the surface of the readout circuit wafer; and the first dielectric film covers the readout circuit wafer and the electrode.
[0009] Optionally, the semiconductor device further includes: a protective layer; the protective layer covers the bottom surface and side surfaces of the anchor column; the electrode is electrically connected to the protective layer; and the protective layer is electrically connected to the anchor column.
[0010] Optionally, the anchor column is a tungsten column; the protective layer includes a titanium layer and a titanium nitride layer; the titanium nitride layer covers the bottom surface and side surfaces of the anchor column; and the titanium layer covers the titanium nitride layer.
[0011] Optionally, the MEMS device further includes a second dielectric film; the second dielectric film is connected to a side wall of the anchor column facing away from the electrode; and the sensing layer is located on a surface of the second dielectric film.
[0012] Optionally, the sensing layer is a thermosensitive film.
[0013] In order to solve the above technical problems, the present invention also provides a mask structure for forming the anchor pillar in the semiconductor device as described above, the mask structure comprising: a first hard mask layer and a second hard mask layer;
[0014] The first hard mask layer is provided with an opening; the second hard mask layer covers a surface of the first hard mask layer and fills the opening, and is provided with a first groove at a position corresponding to the opening; the width of the first groove is smaller than the width of the opening;
[0015] The first etching position defined by the first groove corresponds to the bottom surface of the anchor column; the second etching position defined by the opening corresponds to the top surface of the anchor column.
[0016] Optionally, the mask structure further includes: a second dielectric film; and the first hard mask layer covers a surface of the second dielectric film.
[0017] Optionally, the second dielectric film is a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer or the first composite film layer;
[0018] and / or, the first hard mask layer is a metal layer;
[0019] And / or, the second hard mask layer is a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer or a third composite film layer.
[0020] Optionally, the mask structure further includes: a third mask layer; the third mask layer covers the surface of the second hard mask layer except the bottom surface of the first groove; the third mask layer and the bottom surface of the first groove surround each other to form a second groove.
[0021] Optionally, the third mask layer is a photoresist layer.
[0022] It can be seen that the semiconductor device provided by the present invention uses a T-shaped anchor column to realize the electrical connection between the readout circuit wafer and the MEMS device. The contact hole structure corresponding to the formation of the T-shaped anchor column is a stepped shape with a width at the top and a narrowness at the bottom. The opening position of the contact hole structure of this shape does not have an undercut structure, which makes it easier to fill the contact hole structure with conductive material. Compared with traditional contact holes, the filling effect is better. Therefore, there is no empty plating phenomenon in the middle position of the formed T-shaped anchor column, which can improve the stability and conductivity of the conductive structure, and thus improve the product yield. At the same time, the T-shaped anchor column can be prepared by a hard mask, ensuring that the size of the T-shaped anchor column can meet the miniaturization requirements. The contact mask structure provided by the present invention uses a composite film layer as a hard mask, defines a first etching position corresponding to the bottom surface of the anchor column by a groove of a second hard mask layer, and defines a second etching position corresponding to the top surface of the anchor column by an opening of the first hard mask layer. In the subsequent process of forming a T-shaped anchor column, etching is performed at the first etching position and the second etching position in sequence, a first through hole is formed in the area corresponding to the first etching position, and a second through hole is formed in the area corresponding to the second etching position. This can avoid the formation of an undercut at the opening position of the contact hole structure, thereby forming a contact hole structure that is wide at the top and narrow at the bottom. Conductive material is filled in the contact hole structure of this shape, and a T-shaped anchor column is eventually formed. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0024] Figure 1 A schematic structural diagram of a readout circuit wafer provided by an embodiment of the present utility model;
[0025] Figure 2 A schematic diagram of a structure after growing a first hard mask layer provided by an embodiment of the present utility model;
[0026] Figure 3A schematic diagram of a structure after an opening is formed provided by an embodiment of the utility model;
[0027] Figure 4 A schematic diagram of a structure after a second hard mask layer is generated according to an embodiment of the present invention;
[0028] Figure 5 A schematic diagram of a structure after forming a second groove provided by an embodiment of the utility model;
[0029] Figure 6 A schematic diagram of a structure after forming a stepped circular hole provided by an embodiment of the present utility model;
[0030] Figure 7 A schematic diagram of a structure after depositing a protective layer provided by an embodiment of the present utility model;
[0031] Figure 8 A schematic diagram of a structure after depositing metal tungsten provided in an embodiment of the present utility model;
[0032] Figure 9 A schematic diagram of an anchor column provided in an embodiment of the present utility model.
[0033] The following are the descriptions of the reference numerals:
[0034] 1-readout circuit wafer; 2-electrode; 3-first dielectric film; 4-sacrificial layer; 5-second dielectric film; 6-first hard mask layer; 7-opening; 8-second hard mask layer; 9-photoresist layer; 10-second groove; 11-stepped circular hole; 12-protective layer; 13-anchor column. DETAILED DESCRIPTION
[0035] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.
[0036] Please refer to Figures 1 to 9 A semiconductor device provided by an embodiment of the present invention may include: a readout circuit wafer 1, an electrode 2, an anchor column 13 and a MEMS device; the MEMS device includes a sensing layer; the readout circuit on the surface of the readout circuit wafer 1 is electrically connected to the electrode 2; the electrode 2 is electrically connected to the anchor column 13; the anchor column 13 is electrically connected to the sensing layer; and the anchor column 13 is T-shaped.
[0037] This embodiment does not limit the specific type of electrode 2, and the electrode 2 can be, but is not limited to, a metal electrode. It should be noted that metal is a common material in the prior art, and this embodiment does not limit the internal components of the electrode 2, but directly uses a metal electrode 2 made of existing materials.
[0038] Furthermore, the semiconductor device in this embodiment may further include: a first dielectric film 3; an electrode 2 located on a surface of the readout circuit wafer 1; and the first dielectric film 3 covering the readout circuit wafer 1 and the electrode 2. This embodiment does not limit the specific type of the first dielectric film 3; it may be any insulating dielectric film.
[0039] This embodiment does not limit the specific type of anchor post 13; anchor post 13 may be, but is not limited to, a tungsten post or a copper post. It should be noted that tungsten and copper are both common materials in the prior art. This embodiment does not limit the internal composition of anchor post 13; instead, tungsten or copper posts made from existing materials are directly used. This embodiment does not limit the specific cross-sectional shape of anchor post 13; the cross-sectional shape of anchor post 13 may be, but is not limited to, a circular shape.
[0040] This embodiment does not limit the specific type of the sensing layer, and the sensing layer can be, but is not limited to, a thermosensitive film. It should be noted that thermosensitive films are commonly used in the prior art. This embodiment does not limit the internal components of the sensing layer, but directly uses a thermosensitive film made of existing materials.
[0041] Furthermore, the MEMS device in this embodiment may further include a second dielectric film 5; the second dielectric film 5 is connected to the sidewall of the anchor pillar 13 at the end facing away from the electrode 2; and the sensing layer is located on the surface of the second dielectric film 5. It should be noted that the second dielectric film 5 provided in this embodiment can serve as a support layer for the sensing layer and also provide insulation for subsequent process flows.
[0042] This embodiment does not limit the specific type of second dielectric film 5. The second dielectric film 5 may be, but is not limited to, a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, or a first composite film layer. The first composite film layer may be, but is not limited to, a stacked structure formed by at least two of a silicon oxide layer, a silicon nitride layer, and a silicon oxynitride layer arranged sequentially along a first direction. It should be noted that silicon oxide, silicon nitride, and silicon nitride are all common materials in the prior art. This embodiment does not limit the internal composition of the second dielectric film 5; instead, a film layer made of existing materials is directly used as the second dielectric film 5.
[0043] Furthermore, in this embodiment, a protective layer 12 may be provided on the inner surface of the contact hole structure; the protective layer 12 covers the bottom and side surfaces of the anchor post 13; the electrode 2 is electrically connected to the protective layer 12; and the protective layer 12 is electrically connected to the anchor post 13. It should be noted that the protective layer 12 in this embodiment only covers the inner surface of the contact hole structure and does not completely fill the entire contact hole structure. Therefore, the provision of the protective layer 12 creates a new fill space. The conductive structure in this embodiment can be filled into the fill space formed by the protective layer 12, thereby protecting the conductive structure.
[0044] This embodiment does not limit the specific type of protective layer 12. Protective layer 12 may, but is not limited to, include a titanium layer and a titanium nitride layer; the titanium nitride layer covers the bottom and side surfaces of anchor post 13; and the titanium layer covers the titanium nitride layer. It should be noted that titanium and titanium nitride are both common materials in the prior art. This embodiment does not limit the internal components of protective layer 12, but directly adopts a laminated structure made of existing materials. Furthermore, it should be noted that when anchor post 13 is a tungsten post, the titanium layer and titanium nitride layer can serve as both a protective layer and a seed layer for growing tungsten, thereby facilitating the formation of the tungsten post.
[0045] Based on the above embodiments, the utility model adopts a T-shaped anchor column to realize the electrical connection between the readout circuit wafer and the MEMS device. The contact hole structure corresponding to the T-shaped anchor column is a stepped shape that is wide at the top and narrow at the bottom. There is no undercut structure at the opening position of the contact hole structure of this shape, which makes it easier to fill the contact hole structure with conductive material. Compared with the traditional contact hole, the filling effect is better, so there is no empty plating phenomenon in the middle position of the formed T-shaped anchor column, thereby improving the stability and conductivity of the conductive structure, and thus improving the product yield; at the same time, the T-shaped anchor column can be prepared by a hard mask, ensuring that the size of the T-shaped anchor column can meet the miniaturization requirements.
[0046] Please refer to Figures 1 to 9 , an embodiment of the present invention provides a mask structure, which can be used to form the anchor pillar 13 in the above-mentioned semiconductor device. The mask structure may include: a first hard mask layer 6 and a second hard mask layer 8;
[0047] The first hard mask layer 6 is provided with an opening 7; the second hard mask layer 8 covers the surface of the first hard mask layer 6 and fills the opening 7, and is provided with a first groove at a position corresponding to the opening 7; the width of the first groove is smaller than the width of the opening 7;
[0048] The first etching position defined by the first groove corresponds to the bottom surface of the anchor column 13 ; the second etching position defined by the opening 7 corresponds to the top surface of the anchor column 13 .
[0049] This embodiment does not limit the specific type of the first hard mask layer 6. The first hard mask layer 6 may be, but is not limited to, a metal layer. The metal layer may be, but is not limited to, a titanium layer, an aluminum layer, a titanium nitride layer, or a second composite film layer. The second composite film layer may be, but is not limited to, a stacked structure formed by at least two of a titanium layer, an aluminum layer, and a titanium nitride layer arranged in sequence along a first direction. It should be noted that titanium, aluminum, and titanium nitride are all common materials in the prior art. This embodiment does not limit the internal composition of the first hard mask layer 6. Instead, a film layer made of existing materials is directly used as the first hard mask layer 6.
[0050] This embodiment does not limit the specific type of the second hard mask layer. The second hard mask layer 8 may be, but is not limited to, a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, or a third composite film layer. The third composite film layer may be, but is not limited to, a stacked structure formed by at least two of a silicon oxide layer, a silicon nitride layer, and a silicon oxynitride layer arranged sequentially along the first direction. It should be noted that silicon oxide, silicon nitride, and silicon oxynitride are all common materials in the prior art. This embodiment does not limit the internal composition of the second hard mask layer 8. Instead, a film layer made of existing materials is directly used as the second hard mask layer 8.
[0051] Furthermore, the mask structure in this embodiment may further include: a second dielectric film 5; and a first hard mask layer 6 covering the surface of the second dielectric film 5. It should be noted that when the first hard mask layer 6 is a metal layer, the second dielectric film 5 provided in this embodiment can serve as an insulator for the first hard mask layer 6.
[0052] This embodiment does not limit the specific type of second dielectric film 5. The second dielectric film 5 may be, but is not limited to, a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, or a first composite film layer. The first composite film layer may be, but is not limited to, a stacked structure formed by at least two of a silicon oxide layer, a silicon nitride layer, and a silicon oxynitride layer arranged sequentially along a first direction. It should be noted that silicon oxide, silicon nitride, and silicon nitride are all common materials in the prior art. This embodiment does not limit the internal composition of the second dielectric film 5; instead, a film layer made of existing materials is directly used as the second dielectric film 5.
[0053] Furthermore, the mask structure in this embodiment may also include: a third mask layer; the third mask layer covers the surface of the second hard mask layer 8 except for the bottom surface of the first groove; the third mask layer and the bottom surface of the first groove surround each other to form a second groove 10. It should be noted that during the subsequent etching process, when etching at the first etching location, an undercut will form between the sacrificial layer 4 and the second dielectric film 5, i.e., the width of the first through hole formed will be slightly larger than the width of the first groove. If the width of the first groove is too large, the width of the first through hole formed will be larger than the width of the opening 7. As a result, when etching at the second etching location, the excess second dielectric film 5 at the opening 7 location will not be removed, resulting in the contact hole structure still having an undercut. The provision of the third mask layer in this embodiment can reduce the width of the first groove, i.e., the width of the first etching location can be reduced to ensure that the width of the first through hole formed by etching is smaller than the width of the opening 7, thereby ensuring that the undercut is eliminated.
[0054] This embodiment does not limit the specific type of the third mask layer, and the third mask layer can be, but is not limited to, a photoresist layer 9. It should be noted that photoresist is a common material in the prior art, and this embodiment does not limit the internal components of the third mask layer. Instead, a film layer made of existing materials is directly used as the third mask layer.
[0055] Based on the above embodiment, the present invention uses a composite film layer as a hard mask, defines a first etching position corresponding to the bottom surface of the anchor post through a groove in the second hard mask layer, and defines a second etching position corresponding to the top surface of the anchor post through an opening in the first hard mask layer. In the subsequent process of forming a T-shaped anchor post, etching is performed in sequence at the first etching position and the second etching position, forming a first through-hole in the area corresponding to the first etching position and a second through-hole in the area corresponding to the second etching position. This can avoid the formation of undercuts at the opening position of the contact hole structure, thereby forming a contact hole structure that is wide at the top and narrow at the bottom. The contact hole structure of this shape is filled with conductive material, and ultimately a T-shaped anchor post is formed.
[0056] In order to make the present invention easier to understand, the following is also provided as one of the preparation processes for realizing the above-mentioned semiconductor device. Specifically, it includes the following steps:
[0057] 1. If Figure 1 As shown, a readout circuit wafer 1 is provided, wherein an electrode 2 is provided on the surface of the readout circuit wafer 1, and a first dielectric film 3 covering the electrode 2 and the surface of the readout circuit wafer 1;
[0058] 2. If Figure 2As shown, after coating a sacrificial layer 4 on the readout circuit wafer 1, a second dielectric film 5 and a first hard mask layer 6 are sequentially grown. This embodiment does not limit the specific type of sacrificial layer 4, which may be, but is not limited to, an organic material layer. The organic material layer may be, but is not limited to, a PI layer, a PMMA layer, or an amorphous carbon layer. It should be noted that PI (Polyimide), PMMA (Polymethyl methacrylate), and amorphous carbon are all common organic materials in the prior art. This embodiment does not limit the internal components of the sacrificial layer 4, but directly uses a film layer made of existing organic materials as the sacrificial layer 4. This type of sacrificial layer 4 is a polymer sacrificial layer.
[0059] 3. If Figure 3 As shown, a photolithography method is used to etch an opening 7 on the first hard mask layer 6;
[0060] 4. If Figure 4 As shown, a second hard mask layer 8 is grown on the first hard mask layer 6 using a photolithography etching method;
[0061] 5. If Figure 5 As shown, a photoresist layer 9 is coated on the second hard mask layer 8 using a photolithography etching method, and a second groove 10 is formed using a photolithography development method. The CD (Critical Dimension) of the second groove 10 is smaller than the CD of the opening 7, mainly because the width of the second groove 10 is smaller than the width of the opening 7.
[0062] 6. If Figure 6 As shown, plasma etching is performed, using F (fluorine)-based gas to etch the second hard mask layer 8 and the second dielectric film 5, using oxygen-containing gas to etch the sacrificial layer 4, and then using F-containing gas to etch the first dielectric film 3 on the surface of the readout circuit wafer 1. During the etching of the first dielectric film 3, the second hard mask layer 8, the second dielectric film 5 in the area corresponding to the opening 7, and a portion of the thickness of the sacrificial layer 4 are simultaneously etched away, thereby opening the sacrificial layer 4 and the first dielectric film 3 on the surface of the readout circuit wafer 1, exposing the electrode 2, and forming a stepped circular hole 11 as a contact hole structure;
[0063] 7. If Figure 7 As shown, a protective layer 12 is deposited in the stepped circular hole 11;
[0064] 8. If Figure 8 As shown, metal tungsten, which is a material used to form the anchor column 13, is deposited to fill the stepped circular hole 11 after the protective layer 12 is deposited;
[0065] 9. If Figure 9As shown, the metal tungsten, the protection layer 12 and the first hard mask layer 6 covering the surface of the readout circuit wafer 1 are removed in sequence using CMP (Chemical Mechanical Polishing) or etching methods to obtain a T-shaped anchor column 13;
[0066] 10. Prepare a MEMS device, the MEMS device including a sensing layer; electrically connect the readout circuit on the surface of the readout circuit wafer 1 to the electrode 2; electrically connect the electrode 2 to the protective layer 12; electrically connect the protective layer 12 to the anchor 13; and electrically connect the anchor 13 to the sensing layer;
[0067] 11. Release the sacrificial layer 4 to obtain the final semiconductor device.
[0068] In the semiconductor device preparation process provided by the embodiment of the present invention, a composite film layer is used as a hard mask when etching the sacrificial layer, the CD of the contact hole structure is better controlled, and the first dielectric film at the bottom can be opened at the same time; the prepared stepped circular hole with a wide top and narrow bottom is conducive to filling tungsten, thereby improving the stability and conductivity of the anchor column, and further improving the product yield.
[0069] The above is a detailed introduction to a semiconductor device and mask structure provided by the present invention. For those skilled in the art, according to the ideas of the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.
Claims
1. A semiconductor device, characterized in that: include: A readout circuit wafer (1), an electrode (2), an anchor column (13) and a MEMS device; the MEMS device includes a sensing layer; the readout circuit on the surface of the readout circuit wafer (1) is electrically connected to the electrode (2); the electrode (2) is electrically connected to the anchor column (13); the anchor column (13) is electrically connected to the sensing layer; and the anchor column (13) is T-shaped.
2. The semiconductor device according to claim 1, wherein Also includes: A first dielectric film (3); the electrode (2) is located on the surface of the readout circuit wafer (1); the first dielectric film (3) covers the readout circuit wafer (1) and the electrode (2).
3. The semiconductor device according to claim 1, wherein Also includes: A protective layer (12); the protective layer (12) covers the bottom surface and side surfaces of the anchor column (13); the electrode (2) and the protective layer (12) are electrically connected; the protective layer (12) and the anchor column (13) are electrically connected.
4. The semiconductor device according to claim 3, wherein The anchor column (13) is a tungsten column; the protective layer (12) includes a titanium layer and a titanium nitride layer; the titanium nitride layer covers the bottom surface and side surfaces of the anchor column (13); and the titanium layer covers the titanium nitride layer.
5. The semiconductor device according to claim 1, wherein The MEMS device further comprises a second dielectric film (5); the second dielectric film (5) is connected to the side wall of the anchor column (13) at one end facing away from the electrode (2); and the sensing layer is located on the surface of the second dielectric film (5). The semiconductor device according to claim 1 , wherein: The sensing layer is a heat-sensitive film.
7. A mask structure for forming an anchor column (13) in a semiconductor device according to any one of claims 1 to 6, characterized in that: The mask structure comprises: a first hard mask layer (6) and a second hard mask layer (8); The first hard mask layer (6) is provided with an opening (7); the second hard mask layer (8) covers the surface of the first hard mask layer (6) and fills the opening (7), and is provided with a first groove at a position corresponding to the opening (7); the width of the first groove is smaller than the width of the opening (7); The first etching position defined by the first groove corresponds to the bottom surface of the anchor column (13); the second etching position defined by the opening (7) corresponds to the top surface of the anchor column (13).
8. The mask structure according to claim 7, wherein: Also includes: A second dielectric film (5); the first hard mask layer (6) covers the surface of the second dielectric film (5).
9. The mask structure according to claim 8, wherein: The second dielectric film (5) is a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer or a first composite film layer; and / or, the first hard mask layer (6) is a metal layer; And / or, the second hard mask layer (8) is a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer or a third composite film layer.
10. The mask structure according to claim 7, wherein: Also includes: a third mask layer; the third mask layer covers the surface of the second hard mask layer (8) except the bottom surface of the first groove; The third mask layer and the bottom surface of the first groove surround to form a second groove (10).
11. The mask structure according to claim 10, wherein: The third mask layer is a photoresist layer (9).