Semiconductor device and preparation method thereof

Abstract

The invention provides a semiconductor device and a preparation method thereof, and relates to the technical field of semiconductors, the semiconductor device comprises a front film layer, an oxide layer and a surface metal layer which are stacked in sequence, the oxide layer comprises a plurality of preset oxidation regions spaced by grooves, and the surface metal layer comprises preset metal layers corresponding to the preset oxidation regions. The preset metal layer wraps the preset oxidation region. The surface metal layer wraps the preset oxidation region, so that the preset oxidation region below the surface metal layer is prevented from being damaged during release, the stability of the surface metal layer is enhanced, isolation protection of the surface metal layer on the preset oxidation region below the surface metal layer is realized, and the surface metal layer is completely presented on the surface of the device after the release process. And the conditions of falling, insufficient support, fracture and the like are avoided.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a semiconductor device and a preparation method thereof. Background Art

[0002] During the preparation process of piezoelectric MEMS (Micro-Electro-Mechanical System) devices, as Figure 1 shown, Figure 1 Figure 2 shows a schematic diagram of the surface metal layer 2 on the device surface, where the enclosed part represents the sealing ring, which is the metal solder ring for ball planting and sealing during packaging. The central area represents some electrical connection structures and wire parts. These parts will all be affected by the release process. In the part of the surface metal 2, the following problems are likely to occur: When the device undergoes the release process to remove the silicon oxide 1 on the surface, as Figure 2 shown, since part of the surface metal 2 is directly deposited on the silicon oxide 1, and the release process will cause serious side etching of the silicon oxide 1 used as the support in this part. As Figure 3 shown, the contact area between part of the surface metal 2 and the underlying silicon oxide 1 is greatly reduced, ultimately resulting in warping or breaking of the surface metal 2. Because the release process is a complete chemical reaction and isotropic process, while removing a certain thickness of silicon oxide 1, the area under the surface metal 2 will also be affected to a certain extent as Figure 3 shown, which will affect various properties of the surface metal 2. Summary of the Invention

[0003] The purpose of the present invention is to provide a semiconductor device and a preparation method thereof, which can avoid damage to the oxide layer under the surface metal layer and enhance the stability of the surface metal layer.

[0004] On the one hand, the present invention provides a semiconductor device, including a pre-film layer, an oxide layer, and a surface metal layer stacked in sequence. The oxide layer includes a plurality of preset oxide regions spaced by trenches. The surface metal layer includes a preset metal layer corresponding to the preset oxide regions, and the preset metal layer wraps the preset oxide regions.

[0005] Optionally, the preset metal layer further forms a first folded edge at the bottom end of the side wall of the preset oxide region, and the first folded edge fits on the upper surface of the film layer below the preset oxide region.

[0006] Optionally, the trench is a U-shaped trench. The preset metal layer includes a first metal layer wrapping the preset oxide region and U-shaped metal layers connected to both sides of the first metal layer, and the U-shaped metal layers match the U-shaped trenches.

[0007] Optionally, the pre-film layer includes at least one film layer, and at least one of the film layers includes a single-layer film layer or a composite film layer.

[0008] Optionally, the pre-film layer includes a first film layer, a second film layer, and a third film layer that are stacked in sequence, and the oxide layer is located on the third film layer; the third film layer partially covers the second film layer, the preset oxidation region simultaneously covers the second film layer and the third film layer, and when the preset metal layer wraps the preset oxidation region, part of the preset metal layer adheres to the second film layer at the bottom end of the side wall of the preset oxidation region, and part of the preset metal layer adheres to the third film layer at the bottom end of the side wall of the preset oxidation region.

[0009] On the other hand, the present invention provides a method for manufacturing a semiconductor device for manufacturing the above semiconductor device, and the method includes: Form an oxide layer on the pre-film layer; Pattern-etch the oxide layer to form trenches in the oxide layer, and the trenches divide the oxide layer into multiple oxidation regions; Form a surface metal layer on the surfaces of the oxidation regions and the trenches; Pattern the surface metal layer, remove the surface metal layer on part of the oxidation regions and on the trenches adjacent to the oxidation regions, and the remaining surface metal layer serves as the preset metal layer, and the oxidation regions covered by the preset metal layer serve as the preset oxidation regions; Remove the oxidation regions other than the preset metal layer, and the remaining preset metal layer wraps the preset oxidation regions.

[0010] Optionally, the patterning of the surface metal layer, removing the surface metal layer on part of the oxidation regions and on the trenches adjacent to the oxidation regions, and the remaining surface metal layer serves as the preset metal layer, and the oxidation regions covered by the preset metal layer serve as the preset oxidation regions, includes: The remaining preset metal layer covers the preset oxidation regions and extends into the trenches adjacent to the preset oxidation regions.

[0011] Optionally, the patterning of the surface metal layer, removing the surface metal layer on part of the oxidation regions and on the trenches adjacent to the oxidation regions, and the remaining surface metal layer serves as the preset metal layer, and the oxidation regions covered by the preset metal layer serve as the preset oxidation regions, includes: Retain the metal layer in the preset oxidation regions and the trenches as the preset metal layer, and make the preset metal layer extend through the trenches adjacent to the preset oxidation regions to the end of the upper surface of the oxidation regions adjacent to the preset oxidation regions.

[0012] Optionally, removing the oxidation regions outside the preset metal layer and retaining the preset metal layer to wrap the preset oxidation region includes: The preset metal layer is disposed along the upper surface and sidewalls of the preset oxidation region, and in the stacking direction, a hem is further formed at the bottom end of the sidewall of the preset oxidation region of the preset metal layer, and the hem fits the upper surface of the film layer below the preset oxidation region.

[0013] Optionally, removing the oxidation regions outside the preset metal layer and retaining the preset metal layer to wrap the preset oxidation region includes: The preset metal layer is disposed along the upper surface and sidewalls of the preset oxidation region, and metal layer structures matching the trenches are further formed on both sides of the sidewall of the preset oxidation region of the preset metal layer.

[0014] The semiconductor device and its manufacturing method provided by the present invention include a pre-film layer, an oxidation layer, and a surface metal layer stacked in sequence. The oxidation layer includes a plurality of preset oxidation regions spaced by trenches. The surface metal layer includes a preset metal layer corresponding to the preset oxidation region, and the preset metal layer wraps the preset oxidation region. The surface metal layer wraps the preset oxidation region, preventing the preset oxidation region below the surface metal layer from being damaged during release, enhancing the stability of the surface metal layer, achieving isolation and protection of the preset oxidation region below the surface metal layer by the surface metal layer. After the release process, the surface metal layer is completely presented on the device surface without situations such as peeling off, insufficient support, and fracture. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for the present invention will be briefly introduced below. It should be understood that the following drawings only show some examples of the present invention, so they should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0016] Figure 1 is a schematic diagram of the surface metal layer of an existing semiconductor device; Figure 2 is one of the cross-sectional schematic diagrams of the surface metal layer of an existing semiconductor device; Figure 3 is another cross-sectional schematic diagram of the surface metal layer of an existing semiconductor device; Figure 4 is a schematic diagram of the structure of the semiconductor device provided by the present invention; Figure 5 is one of the manufacturing process diagrams of the semiconductor device provided by the present invention; Figure 6 is another manufacturing process diagram of the semiconductor device provided by the present invention; Figure 7 is Figure 6 the top view of Figure 8 Figure 3 in the semiconductor device manufacturing process diagrams provided by the present invention; Figure 9 Figure 4 in the semiconductor device manufacturing process diagrams provided by the present invention; Figure 10 Figure 5 in the semiconductor device manufacturing process diagrams provided by the present invention; Figure 11 is Figure 10 the top view of Figure 12 the defect diagram of the semiconductor device manufacturing process provided by the present invention; Figure 13 is Figure 12 the defect diagram after forming; Figure 14 is Figure 13 the top view of Figure 15 the layout schematic diagram of the semiconductor device manufacturing process provided by the present invention; Figure 16 Figure 6 in the semiconductor device manufacturing process diagrams provided by the present invention; Figure 17 Figure 7 in the semiconductor device manufacturing process diagrams provided by the present invention.

[0017] Icon: 1 - silicon oxide; 2 - surface metal; 10 - first film layer; 11 - second film layer; 12 - third film layer; 13 - oxide layer; 130 - preset oxidation region; 131 - oxidation region; 14 - surface metal layer; 140 - preset metal layer; 141 - first fold; 142 - first metal layer; 143 - U-shaped metal layer; 144 - second fold; 15 - trench; 151 - first trench; 152 - second trench; A - first virtual frame; B - second virtual frame; F - stacking direction. Detailed implementation manners

[0018] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the accompanying drawings in the present invention.

[0019] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention. In addition, terms such as "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0020] It should also be noted that, unless otherwise clearly specified and limited, the terms "arrangement" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0021] The present invention provides a semiconductor device. Please refer to Figure 4 as shown, which includes a pre-layer, an oxide layer 13, and a surface metal layer 14 stacked in sequence along the stacking direction F. The oxide layer 13 includes a plurality of preset oxidation regions 130 spaced by trenches 15. The surface metal layer 14 includes preset metal layers 140 corresponding to the preset oxidation regions 130, and the preset metal layers 140 wrap the preset oxidation regions 130.

[0022] The oxide layer 13 is divided into a plurality of preset oxidation regions 130 by the trenches 15. Similarly, the surface metal layer 14 is also divided into a plurality of preset metal layers 140 by the trenches 15. Each preset metal layer 140 corresponds to a preset oxidation region 130. Moreover, the preset metal layers 140 are arranged on the upper surface and side walls of the preset oxidation regions 130 to wrap the preset oxidation regions 130. Through the protection of the preset metal layers 140, the preset oxidation regions 130 can be prevented from being damaged.

[0023] Among them, the pre-layer includes at least one layer of film, and the at least one layer of film includes a single-layer film or a composite film.

[0024] As Figure 4 shown, the pre-layer includes a first film layer 10, a second film layer 11, and a third film layer 12 stacked in sequence, and the oxide layer 13 is located on the third film layer 12.

[0025] Furthermore, the first film layer 10 can be a substrate, and the substrate can be a single-layer film such as a silicon substrate or a composite film. The second film layer 11 can be a piezoelectric layer, and the third film layer 12 can be an electrode layer.

[0026] In some examples, the third film layer 12 partially covers the second film layer 11, the preset oxidation region 130 covers the second film layer 11, and / or the preset oxidation region 130 covers the third film layer 12, and / or the preset oxidation region 130 covers both the second film layer 11 and the third film layer 12 simultaneously; Figure 4 The setting manners of three preset oxidation regions 130 are shown. Among them, one preset oxidation region 130 wrapped by a preset metal layer 140 is on the surface of the second film layer 11, one preset oxidation region 130 wrapped by a preset metal layer 140 straddles the surfaces of the second film layer 11 and the third film layer 12, and another preset oxidation region 130 wrapped by a preset metal layer 140 is on the surface of the third film layer 12.

[0027] The above three setting methods basically cover the position states of the metal wires. When the preset oxidation region 130 covers both the second film layer 11 and the third film layer 12 at the same time, the preset metal layer 140 wraps the preset oxidation region 130. Part of the preset metal layer 140 adheres to the second film layer 11 at the bottom of the side wall of the preset oxidation region 130, and part of the preset metal layer 140 adheres to the third film layer 12 at the bottom of the side wall of the preset oxidation region 130, as Figure 4 shown in the middle, the preset oxidation region 130 straddles the surfaces of the second film layer 11 and the third film layer 12.

[0028] Taking the example that the preset oxidation region 130 wrapped by the preset metal layer 140 straddles the surfaces of the second film layer 11 and the third film layer 12 as an example, the subsequent process flow diagrams of the present invention are implemented with reference to other setting methods.

[0029] Therefore, the present invention also provides a method for manufacturing a semiconductor device for manufacturing the above semiconductor device, and the method includes: As Figure 5 shown, step 200: forming an oxide layer 13 on the front film layer.

[0030] Among them, in the example of the present invention, the front film layer includes a first film layer 10, a second film layer 11, and a third film layer 12.

[0031] Further, the third film layer 12 partially covers the second film layer 11, and the oxide layer 13 completely covers the third film layer 12 and the second film layer 11, so that part of the oxide layer 13 directly covers the second film layer 11, and part of the oxide layer 13 covers the third film layer 12.

[0032] Since the actual thickness of the third film layer 12 is much smaller than the thickness of the oxide layer 13, the influence on the surface topography of the oxide layer 13 is extremely small. Therefore, the surface of the oxygen-silicon layer is drawn as a plane.

[0033] As Figure 6 shown, step 201: patterning and etching the oxide layer 13 to form a trench 15 in the oxide layer 13, and the trench 15 divides the oxide layer 13 into multiple oxidation regions 131.

[0034] Figure 6 shown in the formation of a first trench 151 and a second trench 152, the first trench 151 and the second trench 152 divide the oxide layer 13 into three oxidation regions 131, as Figure 7 shown.

[0035] Since the aforementioned third film layer 12 partially covers the second film layer 11, the oxidation region 131 can be located on the second film layer 11, and / or the oxidation region 131 covers the second film layer 11 and the third film layer 12, that is, the oxidation region 131 straddles the second film layer 11 and the third film layer 12, and / or the oxidation region 131 is located on the third film layer 12.

[0036] In this invention, an example is given where the three oxidation regions 131 are respectively located on the second film layer 11, straddle the second film layer 11 and the third film layer 12, and are located on the third film layer 12.

[0037] As Figure 8 shown, step 202: Form a surface metal layer 14 on the surface of the oxidation region 131 and the trench 15.

[0038] The surface metal layer 14 can choose the sputtering deposition method. The conformal effect of the surface metal layer 14 obtained by sputtering deposition is better, which can avoid defects at the sidewalls of the trench 15, the bottom surface of the oxide layer 13, and the corners on both sides of the bottom surface.

[0039] Through experimental verification, the sealing effect of the surface metal layer 14 by the evaporation coating method is poor. During the Figures 9 to 10 release process, the encapsulated oxide layer 13 will be partially damaged. However, even if it is partially damaged, the defective morphological result obtained by this process is still better than that before the structural optimization. Therefore, the evaporation coating method can partially improve the aforementioned problems and disadvantages, but the sputtering deposition method is better.

[0040] Step 203: Pattern the surface metal layer 14, remove the surface metal layer 14 on part of the oxidation region 131 and the trench 15 adjacent to this part of the oxidation region 131. The remaining surface metal layer 14 is used as the preset metal layer 140, and the oxidation region 131 covered by the preset metal layer 140 is used as the preset oxidation region 130. After depositing the surface metal layer 14, pattern the surface metal layer 14 to block the oxidation region 131 under the relevant graphic area as the preset oxidation region 130. The preset oxidation region 130 is wrapped by the corresponding preset metal layer 140, and remove the surface metal layer 14 covering the other oxidation regions 131 to form the morphology as Figure 9 shown.

[0041] Among them, Figure 9 in, the remaining preset metal layer 140 covers the preset oxidation region 130 and extends into the trench 15 adjacent to the preset oxidation region 130 to form a first hem 141.

[0042] As Figure 10 shown, step 204: Remove the oxidation region 131 outside the preset metal layer 140, and the remaining preset metal layer 140 wraps the preset oxidation region 130.

[0043] Perform a release process to remove the oxidation regions 131 in other areas of the surface, leaving only the preset oxidation region 130 and the preset metal layer 140 that wraps the preset oxidation region 130, obtaining a schematic diagram of the device structure morphology as shown in Figure 10 the following figure.

[0044] Figure 10 In the figure, the preset metal layer 140 is disposed along the upper surface and the sidewalls of the preset oxidation region 130, such that the preset metal layer 140 covers the preset oxidation region 130; and in the stacking direction F, the preset metal layer 140 further forms a first folded edge 141 at the bottom end of the sidewall of the preset oxidation region 130, and the first folded edge 141 extends into the adjacent trench 15 of the preset oxidation region 130, and the first folded edge 141 adheres to the upper surface of the film layer below the preset oxidation region 130. As shown in Figure 11 the figure, the first folded edges 141 are respectively formed on both sides of the preset metal layer 140. Since the preset oxidation region 130 straddles the second film layer 11 and the third film layer 12, part of the first folded edge 141 adheres to the second film layer 11 below the preset oxidation region 130, and part of the first folded edge 141 adheres to the third film layer 12 below the preset oxidation region 130.

[0045] Although the above structure and preparation process finally achieve the stability of the surface metal layer 14, when etching to remove the surface metal layer 14 outside the first trench 151, the second trench 152 and the trench 15, the film layer at the bottom of the trench 15 (such as Figure 12 , Figure 13 the third film layer 12 in the figure) is easily affected by over-etching. Especially for the first trench 151, the thickness of the third film layer 12 in the first trench 151 region is relatively thin (generally less than 100 nm), and it is easy to etch and break the third film layer 12 when over-etching the surface metal layer 14.

[0046] Since both the surface metal layer 14 and the third film layer 12 are metal materials, when facing the etching menu for the surface metal layer 14, it is impossible to have an extremely high selectivity ratio only by adjusting the etching menu. Therefore, this shortcoming can only be solved by structural improvement.

[0047] As shown in Figure 14 the figure, a part of the third film layer 12 of the semiconductor device is connected to the surface metal layer 14 (because it is necessary to connect the circuit to achieve electrical connection). Therefore, for the connection part between the third film layer 12 and the surface metal layer 14 ( Figure 14 the part within the dotted line box in the figure), the situation shown in the dotted box in Figure 13 the figure will occur, and it is damaged, resulting in the third film layer 12 possibly breaking, so that the electrical signal on the third film layer 12 cannot be transmitted to other areas through the wire, thereby causing the device to fail.

[0048] In the above process, the above relationship between the third film layer 12 and the surface metal layer 14 of the semiconductor device necessarily exists. Although the damage problem of the surface metal layer 14 is improved by the patterned oxide layer 13, however, this results in a direct etching relationship between the etched area of the surface metal layer 14 and a partial connection area of the third film layer 12 when preparing the patterned surface metal layer 14 (in the trench 15 area, the surface metal layer 14 is directly deposited on the third film layer 12, so when etching this part of the surface metal layer 14, the third film layer 12 will inevitably be etched during the etching process).

[0049] As Figure 15 shown by the first virtual frame A and the second virtual frame B in, where the first virtual frame A represents a certain electrical connection structure area on the surface, and the second virtual frame B represents the connection area of the third film layer 12; when not using the pre-etching oxide layer 13, although the first virtual frame A and the second virtual frame B overlap, due to the barrier of the oxide layer 13, it will not cause the third film layer 12 to be directly etched when etching the surface metal layer 14. However, when preparing the trench 15 and removing this part of the oxide layer 13, the surface metal layer 14 and the third film layer 12 will directly contact in the trench 15 in the intersecting area of the first virtual frame A and the second virtual frame B. Therefore, the etching of this part of the surface metal layer 14 will inevitably damage the third film layer 12, causing damage as shown in Figure 14 which is unavoidable.

[0050] Therefore, in some other examples of the above step 203, as Figure 16 shown, step 203: Pattern the surface metal layer 14, remove a part of the oxidation region 131 and the surface metal layer 14 on the trench adjacent to this part of the oxidation region 131, and the remaining surface metal layer 14 is used as the preset metal layer 140. The oxidation region 131 covered by the preset metal layer 140 is used as the preset oxidation region 130, and further includes: The preset metal layer 140 extends to the end of the upper surface of the oxidation region 131 adjacent to the preset oxidation region 130 through the trench 15 adjacent to the preset oxidation region 130.

[0051] On the basis of Figure 9 , Figure 16 in, retain the preset oxidation region 130 and the metal layer in the trench 15 as the preset metal layer 140, and make the preset metal layer 140 extend to the end of the upper surface of the oxidation region 131 adjacent to the preset oxidation region 130 through the trench 15 adjacent to the preset oxidation region 130.

[0052] During preparation, similar to the foregoing, after depositing the surface metal layer 14, pattern the surface metal layer 14, block the preset oxidation region 130, retain the surface metal layer 14 in the first trench 151 and the second trench 152, and make the boundary of the surface metal layer 14 in the trench 15 rest on the surface of the adjacent oxidation region 131 to formFigure 16 The shown morphology. Then, other oxidation regions 131 on the surface are removed through a release process to obtain a structural morphology schematic diagram as shown in Figure 17 the figure.

[0053] Figure 17 In [description], the preset metal layer 140 is disposed along the upper surface and side walls of the preset oxidation region 130. The preset metal layer 140 further forms a metal layer structure matching the trench 15 on both sides of the side walls of the preset oxidation region 130, such as a U-shaped metal layer 143.

[0054] The preset oxidation region 130 below it is wrapped by the preset metal layer 140 to prevent this part of the preset oxidation region 130 from being affected by the release process and ensure the support and adhesion functions of this part of the preset oxidation region 130. At the same time, the actual morphologies on both sides of the preset metal layer 140 pattern should conform to the morphology of the trench 15. In the example of the present invention, there are "U-shaped" trench 15 features on both sides of the preset metal layer 140 pattern. Therefore, the preset metal layer 140 includes a first metal layer 142 (inverted U-shaped) that wraps the preset oxidation region 130 and a U-shaped metal layer 143 connected to both sides of the first metal layer 142. The U-shaped metal layer 143 matches the U-shaped trench 15, the side walls of the inverted U-shaped first metal layer 142 coincide with the side walls of the U-shaped metal layer 143, and the U-shaped metal layer 143 forms a second hem 144 at the end position on the upper surface of the corresponding adjacent oxidation region 131.

[0055] The preset metal layer 140 completely wraps the preset oxidation region 130 below it, making the preset oxidation region 130 have no contact with the outside world, ensuring the integrity and stability of the morphology and structure of the surface metal layer 14 as the surface layer metal layer 14 after the release of other oxidation regions 131. Moreover, the setting of the U-shaped metal layer 143 also ensures the integrity of the film layer below the preset oxidation region 130, solving the Figure 13 possible problems that may be faced.

[0056] In summary, the present invention patterns the underlying oxide layer 13 to prepare the trench 15, prepares the surface metal layer 14 along the morphology of the trench 15, and then wraps the oxide layer 13 with the surface metal layer 14 to prevent the oxide layer 13 below the surface metal layer 14 from being damaged during release, thereby enhancing the stability of the surface metal layer 14, realizing the isolation and protection of the surface metal layer 14 for the oxide layer 13 below it. After the release process, the surface metal layer 14 pattern is completely presented on the device surface without situations such as peeling off, insufficient support, and fracture. Further, the surface metal layer 14 also fills the trench 15, ensuring the film layer on both sides of the surface metal layer 14 pattern (such as Figure 13The third film layer 12) has a complete morphology, avoiding damage to the third film layer 12, and thus problems such as fracture and abnormal function of the third film layer 12. While protecting the top oxide layer 13, it also takes into account the protection of the underlying third film layer 12. In addition, the present invention uses PVD (physical vapor deposition) process technology to realize the preparation of the surface metal layer 14, which can avoid the protection failure of the surface metal layer 14.

[0057] It should be noted that there may be more than one second film layer 11 in the present invention, and other film layers may also be added between the second film layers 11 and the third film layer 12.

[0058] The surface metal layer 14 may not be just a single layer of metal, but may also be a composite film layer with a metal film layer on the surface.

[0059] The above are only examples of the present invention and are not intended to limit the protection scope of the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A semiconductor device, characterized in that: It includes a pre-film layer, an oxide layer and a surface metal layer stacked in sequence, wherein the oxide layer includes a plurality of preset oxidation zones separated by grooves, the surface metal layer includes a preset metal layer corresponding to the preset oxidation zones, and the preset metal layer wraps the preset oxidation zones.

2. The semiconductor device according to claim 1, wherein: The preset metal layer also forms a first folded edge at the bottom end of the side wall of the preset oxidation zone, and the first folded edge is attached to the upper surface of the film layer below the preset oxidation zone.

3. The semiconductor device according to claim 1, wherein: The groove is a U-shaped groove, the preset metal layer includes a first metal layer wrapping the preset oxidation zone and a U-shaped metal layer connected to two sides of the first metal layer, and the U-shaped metal layer matches the U-shaped groove.

4. The semiconductor device according to any one of claims 1 to 3, characterized in that: The front film layer includes at least one film layer, and the at least one film layer includes a single film layer or a composite film layer.

5. The semiconductor device according to claim 4, characterized in that The front film layer comprises a first film layer, a second film layer and a third film layer stacked in sequence, and the oxide layer is located on the third film layer; The third film layer partially covers the second film layer, the preset oxidation region covers the second film layer, and / or the preset oxidation region covers the third film layer, and / or the preset oxidation region covers both the second film layer and the third film layer; When the preset oxidation zone covers the second film layer and the third film layer at the same time, part of the preset metal layer is attached to the second film layer at the bottom end of the side wall of the preset oxidation zone, and part of the preset metal layer is attached to the third film layer at the bottom end of the side wall of the preset oxidation zone.

6. A method for preparing a semiconductor device, for preparing the semiconductor device according to any one of claims 1 to 5, characterized in that: include: An oxide layer is formed on the front film layer; Patterning and etching the oxide layer to form grooves in the oxide layer, wherein the grooves separate the oxide layer into a plurality of oxide regions; forming a surface metal layer on the surface of the oxidation region and the groove; Patterning the surface metal layer, removing part of the oxidation area and the surface metal layer on the groove adjacent to the oxidation area, and the remaining surface metal layer is used as a preset metal layer, and the oxidation area covered by the preset metal layer is used as a preset oxidation area; The oxidized region outside the preset metal layer is removed, and the preset metal layer retained wraps the preset oxidized region.

7. The method for preparing a semiconductor device according to claim 6, characterized in that: The step of patterning the surface metal layer, removing a portion of the oxidation region and the surface metal layer on the groove adjacent to the oxidation region, and using the remaining surface metal layer as a preset metal layer, and using the oxidation region covered by the preset metal layer as a preset oxidation region, comprises: The reserved predetermined metal layer covers the predetermined oxidation region and extends into the groove adjacent to the predetermined oxidation region.

8. The method for preparing a semiconductor device according to claim 6, characterized in that: The step of patterning the surface metal layer, removing a portion of the oxidation region and the surface metal layer on the groove adjacent to the oxidation region, and using the remaining surface metal layer as a preset metal layer, and using the oxidation region covered by the preset metal layer as a preset oxidation region, comprises: The metal layer in the preset oxidation region and the groove is retained as the preset metal layer, so that the preset metal layer extends to the end of the upper surface of the oxidation region adjacent to the preset oxidation region through the groove adjacent to the preset oxidation region.

9. The method for preparing a semiconductor device according to claim 7, characterized in that: The step of removing the oxidized area outside the preset metal layer and retaining the preset metal layer to wrap the preset oxidized area comprises: The preset metal layer is arranged along the upper surface and side wall of the preset oxidation zone, and in the stacking direction, the preset metal layer also forms a first folded edge at the bottom end of the side wall of the preset oxidation zone, and the first folded edge is attached to the upper surface of the film layer below the preset oxidation zone.

10. The method for preparing a semiconductor device according to claim 8, characterized in that: The step of removing the oxidized area outside the preset metal layer and retaining the preset metal layer to wrap the preset oxidized area comprises: The preset metal layer is arranged along the upper surface and sidewalls of the preset oxidation region, and the preset metal layer also forms a metal layer structure matching the groove on both sides of the sidewalls of the preset oxidation region.

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