Laminated structure, preparation method thereof and semiconductor device

Abstract

The invention relates to a laminated structure, a preparation method thereof and a semiconductor device. The laminated structure comprises a substrate, a dielectric layer located on the substrate, and a first metal layer, an insulating protection layer and a second metal layer which are located on the first surface of the dielectric layer and are sequentially laminated in the direction away from the dielectric layer, wherein the longitudinal section of the first metal layer is in the shape of a right trapezoid with a target acute angle, and the insulating protection layer is located on the outer surface of the first metal layer and extends to the first surface; the second metal layer covers the insulating protection layer and a part of the top surface of the first metal layer and extends to the first surface. The structure can effectively relieve and reduce the cracking of the insulating protection layer, and can enhance the stability and reliability of the whole device in an extreme environment.

Description

Technical Field

[0001] The present application relates to the field of integrated circuit technology, and in particular to a stacked structure and a preparation method thereof, and a semiconductor device. Background Art

[0002] Semiconductor power devices are widely used in power conversion, automotive electronics, aerospace and other fields due to their excellent electrical properties. These devices usually need to work in high temperature, high humidity and high voltage environments, which pose severe challenges to the performance and life of the devices. Among them, the insulating protective layer, as a commonly used insulating and protective material, is widely used in surface coatings in semiconductor power devices. However, the insulating protective layer is prone to microcracks when exposed to high temperature and humidity for a long time. The presence of these cracks will become a channel for water vapor intrusion, which will in turn cause corrosion problems in the internal metallization layer. The corrosion of the metal layer not only reduces the conductivity of the device, but may also cause early failure of the device in high-voltage applications. In addition, under the working conditions of high temperature and high pressure, the thermal stress and electric field stress inside the semiconductor power device will work together to accelerate the destruction process of the insulating protective layer, thereby exacerbating the aging problem of the device. Therefore, developing new technical solutions to enhance the protective layer on the surface of semiconductor power devices, prevent water vapor penetration and inhibit metal corrosion is of great significance to improving the overall performance and reliability of the device.

[0003] In summary, there is an urgent need to develop a new semiconductor power device manufacturing technology, especially an improved surface treatment technology, to improve the reliability and life of the device in high temperature, high humidity and high pressure environments. Summary of the invention

[0004] Based on this, it is necessary to provide a laminated structure and a preparation method thereof, and a semiconductor device to address the technical problems in the prior art, which can at least help reduce the cracking of the insulating protective layer.

[0005] In the first aspect, the present application provides a stacked structure, comprising: a substrate, a dielectric layer located on the substrate, and a first metal layer, an insulating protective layer, and a second metal layer located on the first surface of the dielectric layer and stacked in sequence in a direction away from the dielectric layer; wherein the longitudinal section of the first metal layer is a "right-angled trapezoid" with a target acute angle, the insulating protective layer is located on the outer surface of the first metal layer and extends to the first surface; the second metal layer covers a portion of the top surface of the first metal layer and the insulating protective layer, and extends to the first surface.

[0006] The laminated structure in the above embodiment is provided with a climbing angle by setting the longitudinal section of the first metal layer to be a "right-angle trapezoid" with a target acute angle, and then the insulating protective layer is provided on the outer surface of the first metal layer and extends to the first surface of the dielectric layer, and the second metal layer is provided to cover the insulating protective layer and part of the top surface of the first metal layer and extend to the first surface of the dielectric layer, so that the climbing angles of the insulating protective layer and the second metal layer can be adjusted by adjusting the thickness of the first metal layer and the angle of the target acute angle, so as to more effectively and reasonably distribute and alleviate the internal stress caused by the difference in thermal expansion coefficient between the insulating protective layer and the dielectric layer. An appropriate climbing angle can reduce the stress concentration caused by uneven material shrinkage while ensuring the uniformity of the coating, thereby achieving the purpose of reducing the risk of cracking. It is also possible to choose to add an appropriate intermediate layer material to optimize the adhesion between the first metal layer or the second metal layer and the insulating protective layer, and further prevent interlayer peeling; the first metal layer or the second metal layer can also serve as a buffer layer to prevent the insulating protective layer from breaking when it is impacted or vibrated by external forces.

[0007] In addition, the metal sandwich structure formed by the first metal layer and the second metal layer also has the functions of electromagnetic interference (EMI) shielding and heat dissipation. As an electromagnetic shield, it can prevent external electromagnetic interference and internal electromagnetic leakage, and improve the reliability and stability of the device. The connected metal sandwich has good thermal conductivity, which can improve the heat dissipation performance of the device.

[0008] In some embodiments, the stacked structure includes a substrate, and a dielectric layer is located on the substrate.

[0009] In some embodiments, the stacked structure includes an epitaxial layer, and the dielectric layer is located on the epitaxial layer.

[0010] In some embodiments, the stacked structure includes an epitaxial layer on a substrate, and a dielectric layer on the epitaxial layer.

[0011] In some embodiments, the materials of the first metal layer and the second metal layer are the same or different.

[0012] In some embodiments, the thickness of the second metal layer is greater than the thickness of the insulating protective layer; there is a first angle between the first metal layer and the first surface; there is a second angle between the second metal layer and the first surface; the range of the first angle and the second angle both include 30°-70°.

[0013] In some embodiments, the material of the first metal layer includes titanium, tungsten, nickel, cobalt, silver, aluminum, palladium, copper, or a combination thereof.

[0014] In some embodiments, the material of the second metal layer includes titanium, tungsten, nickel, cobalt, silver, aluminum, palladium, copper, or a combination thereof.

[0015] In some embodiments, the material of the insulating protection layer includes silicon nitride, silicon carbide nitride, silicon oxynitride, or a combination thereof.

[0016] In some embodiments, the stacked structure further includes a passivation layer; the passivation layer at least covers the inclined surface of the second metal layer having a longitudinal cross section in the shape of a "right-angled trapezoid" with a target acute angle.

[0017] In some embodiments, the base includes a substrate, and a dielectric layer is located on the substrate; the substrate includes a first-type drift region; the first-type drift region includes second-type doped regions spaced apart along a first direction parallel to a top surface of the substrate, and a channel region located between adjacent second-type doped regions along the first direction; the substrate also includes a gate located on the channel region; the dielectric layer covers the first-type drift region, the second-type doped region and the gate; the first-type drift region and the second-type doped region have different conductivity types.

[0018] In a second aspect, the present application also provides a method for preparing a laminated structure, comprising: providing a substrate, the substrate comprising a dielectric layer. Forming a first metal layer and an insulating protective layer stacked in sequence along a direction away from the dielectric layer on the first surface of the dielectric layer; wherein the longitudinal section of the first metal layer is a "right-angled trapezoid" with a target acute angle, and the insulating protective layer is located on the outer surface of the first metal layer and extends to the first surface. Forming a second metal layer, the second metal layer covers a portion of the top surface of the first metal layer and the insulating protective layer, and extends to the first surface.

[0019] The stacked structure can be optimized for specific applications. The thickness, ramp angle and process parameters of the first and second metal layers can be customized according to the electrical, mechanical and heat dissipation requirements of the power device. For example, high-power IGBT modules use thicker first and second metal layers to increase heat dissipation. The customizability of the stacked structure provides engineers with great flexibility to develop high-performance packaging solutions that meet the requirements of various power devices.

[0020] In some embodiments, forming the first metal layer includes: forming a first metal material layer on the top surface of the dielectric layer; removing a portion of the first metal material layer to obtain the first metal layer; wherein the longitudinal section of the first metal layer is a "right-angled trapezoid" with a target acute angle.

[0021] In some embodiments, the insulating protection layer and the second metal layer are prepared simultaneously in the same process step.

[0022] In a third aspect, the present application also provides a semiconductor device, comprising the above-mentioned stacked structure; or comprising a stacked structure prepared by the above-mentioned stacked structure preparation method.

[0023] Semiconductor devices using a new laminated structure have been significantly improved in reliability, electromagnetic compatibility and heat dissipation performance. This structure reduces the risk of device cracking and improves device reliability by reasonably distributing and alleviating the internal stress between the insulating protection layer and the first metal layer and the second metal layer. At the same time, the metal interlayer composed of the first metal layer and the second metal layer acts as an electromagnetic shield, effectively avoiding electromagnetic interference and leakage, and enhancing the electromagnetic compatibility of the device. In addition, the good thermal conductivity of metal materials helps to dissipate heat, reduce device temperature, increase power density, and reduce the device repair rate, making the semiconductor device more competitive in the market.

[0024] In a fourth aspect, the present application also provides an electronic device, comprising the above-mentioned laminated structure; or comprising a laminated structure prepared by the above-mentioned laminated structure preparation method.

[0025] The electronic device may be, for example but not limited to, suitable types of electronic products such as consumer electronic products, household electronic products, vehicle-mounted electronic products, financial terminal products, and electronic products containing the laminated structure described in any embodiment of the present application. Among them, consumer electronic products may be mobile phones, tablet computers, laptop computers, all-in-one computers, etc. Household electronic products may be air conditioners, televisions, refrigerators, stereos, etc. Vehicle-mounted electronic products may be power management, smart door control, electric sunroofs, etc. Financial terminal products may be ATM machines, self-service terminals, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 is a flow chart of a method for preparing a laminated structure provided in an embodiment;

[0028] Figure 2 It is a schematic cross-sectional view of a structure obtained after a dielectric layer is formed in step S204 in a method for preparing a laminated structure provided in an embodiment;

[0029] Figure 3 It is a schematic cross-sectional view of a structure obtained after forming a first metal material layer in step S402 in a method for preparing a laminated structure provided in an embodiment;

[0030] Figure 4 A schematic cross-sectional view of a structure obtained by forming a first metal layer in step S402 in a method for preparing a laminated structure provided in an embodiment;

[0031] Figure 5 It is a schematic cross-sectional view of a structure obtained after an insulating protective material layer is formed in step S404 in a method for preparing a laminated structure provided in an embodiment;

[0032] Figure 6 It is a schematic cross-sectional view of a structure obtained when an insulating protective layer is formed in step S404 in a method for preparing a laminated structure provided in an embodiment;

[0033] Figure 7 It is a schematic cross-sectional view of a structure obtained after forming a second metal material layer in step S60 in a method for preparing a laminated structure provided in an embodiment;

[0034] Figure 8 It is a schematic cross-sectional view of a structure obtained after forming a second metal layer in step S60 in a method for preparing a laminated structure provided in an embodiment;

[0035] Fig. 9 It is a schematic cross-sectional view of a structure obtained after a passivation layer is formed in a method for preparing a stacked structure provided in an embodiment.

[0036] Description of reference numerals:

[0037] 10. Substrate; 11. Dielectric layer; 121. First metal material layer; 12. First metal layer; 131. Insulating protection material layer; 13. Insulating protection layer; 141. Second metal material layer; 14. Second metal layer; 15. Passivation layer; 20. Laminated structure. DETAILED DESCRIPTION

[0038] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0040] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. On the contrary, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, doping types and / or parts, these elements, components, regions, layers, doping types and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, doping type or part from another element, component, region, layer, doping type or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer, doping type or portion discussed below may be represented as a second element, component, region, layer or portion; for example, the first doping type may be referred to as the second doping type, and similarly, the second doping type may be referred to as the first doping type; the first doping type and the second doping type are different doping types, for example, the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.

[0041] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0042] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that when the terms "consisting of" and / or "comprising" are used in this specification, the presence of the features, integers, steps, operations, elements and / or parts can be determined, but the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups is not excluded. At the same time, when used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0043] Embodiments of the invention are described herein with reference to cross-sectional views which are schematic diagrams of ideal embodiments (and intermediate structures) of the present application, so that variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances can be expected. Therefore, embodiments of the present application should not be limited to the specific shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing techniques. For example, an implanted region shown as a rectangle typically has rounded or curved features and / or an implant concentration gradient at its edges, rather than a binary change from an implanted region to a non-implanted region. Similarly, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation is performed. Therefore, the regions shown in the figures are schematic in nature, their shapes do not represent the actual shape of the region of the device, and do not limit the scope of the present application.

[0044] Power devices have high requirements for pressure resistance. In high temperature and humid environments, the current mainstream silicon oxide and silicon nitride insulating protective layers accelerate oxidation due to the high electric field, which is prone to defects such as cracks and voids, and become a path for water vapor penetration, which seriously affects the performance and life of the device and greatly reduces reliability. In addition, in the traditional single-layer structure, silicon nitride is directly coated on the underlying material. Due to the large difference in thermal expansion coefficients, the material may undergo volume changes due to thermal expansion in a high-temperature working environment, and the amount of volume change is different. Large internal stress is generated between silicon nitride and the underlying material, causing it to warp or crack. This is also one of the main reasons for silicon nitride cracking.

[0045] See also Figure 1 The present application provides a method for preparing a laminated structure, including: step S20-step S40.

[0046] Step S20: providing a substrate, wherein the substrate includes a dielectric layer.

[0047] For example, a specific substrate can be selected according to the type, function and other characteristics of the power device. Common substrate materials may be, but are not limited to, silicon (Si), germanium (Ge), silicon carbide (SiC), gallium arsenide (GaAs), or gallium nitride (GaN) epitaxially grown on 4H-SiC, sapphire (Al2O3) or silicon substrates, and other wide bandgap materials. The substrate may be a single-layer structure or a multi-layer structure. For example, the substrate may also include AlGaN / GaN, Si / SiC, GaN / Si or SiGeC / Si, etc. In addition, other electrical materials may also be included in the substrate. Therefore, the type of substrate should not limit the scope of protection of the present disclosure. In this embodiment, the material of the substrate is silicon carbide.

[0048] For example, the dielectric layer includes but is not limited to silicon oxide (SiO2) and high dielectric constant (High-K) materials such as aluminum oxide (Al2O3), titanium oxide (TiO2), zirconium oxide (ZrO2), etc. Among them, silicon oxide has good electrical insulation, thermal stability and chemical stability, and High-K materials can increase the thickness of the dielectric layer film while keeping the gate capacitance unchanged, thereby reducing the dielectric layer current. In this embodiment, the material of the dielectric layer is silicon oxide.

[0049] Step S40: Form a first metal layer and an insulating protective layer stacked in sequence along a direction away from the dielectric layer on the first surface of the dielectric layer; wherein the longitudinal section of the first metal layer is a "right-angled trapezoid" with a target acute angle, and the insulating protective layer is located on the outer surface of the first metal layer and extends to the first surface.

[0050] The insulating protective layer is an insulating protective material having compactness and chemical stability, including but not limited to silicon nitride, silicon carbide, silicon nitride oxide or a combination thereof. In this embodiment, the insulating protective layer is silicon nitride.

[0051] Step S60: forming a second metal layer, wherein the second metal layer covers a portion of the top surface of the first metal layer and the protection layer, and extends to the first surface.

[0052] For example, the first metal layer and the second metal layer may be formed of the same or similar materials, or may be composed of different metal materials, including but not limited to aluminum (Al), copper (Cu) or zinc (Zn), etc. In this embodiment, the first metal layer and the second metal layer are aluminum layers.

[0053] The laminated structure obtained after steps S20-S60 can refer to 9. Of course, in order to facilitate the understanding of this application, Fig. 9 This is an example of a laminated structure prepared by the preparation method of the present application. There may be other suitable examples of laminated structures prepared by the preparation method of the laminated structure prepared by the present application, and the present application does not limit them here.

[0054] See also Figure 2 In some embodiments, step S20 includes: step S202-step S204.

[0055] Step S202: preparing a first-type drift region, a second-type doped region and a gate (not shown) in the substrate / epitaxial layer; the first-type drift region and the second-type doped region have different conductivity types, and the second-type doped regions are spaced apart along a first direction parallel to the top surface of the substrate / epitaxial layer.

[0056] For example, doping techniques such as ion implantation can be used to implant dopants into the substrate / epitaxial layer in a first direction parallel to the top surface of the substrate / epitaxial layer, and heavily doped to prepare a second-type doped region, wherein the dopant has an opposite polarity to the substrate / epitaxial layer, and the doping concentration in the second-type doped region gradually decreases in the direction toward the substrate / epitaxial layer. In this embodiment, the types of N-type and P-type impurity ions are not specifically limited. For example, P-type impurity ions may include, but are not limited to, any one or more of boron (Boron, B) ions, gallium (Magnesium, Mg) ions, or indium (Indium, In) ions, etc.; N-type impurity ions may include, but are not limited to, one or more of phosphorus (Phosphorus, P) ions, arsenic (Arsenic, As) ions, or antimony (Antimony, Sb) ions.

[0057] At this time, the substrate / epitaxial layer outside the second type doping region is used to form the first type drift region. When the gate-source voltage changes, the amount of induced charge in the substrate / epitaxial layer near the dielectric layer 11 will change, and a continuous channel region will be formed between the second type doping regions adjacent to each other along the first direction. The thickness of the substrate / epitaxial layer, in addition, other special structures such as trench isolation structures can also be formed in the substrate / epitaxial layer, which are not limited in this embodiment.

[0058] The substrate / epitaxial layer, the internal first-type drift region, the second-type doping region, the channel region and other structures located in the substrate / epitaxial layer together constitute the base 10 .

[0059] Step S204 : forming a dielectric layer 11 on the substrate 10 to cover the substrate 10 .

[0060] See also Figure 2 For example, the above structure can be obtained by using a deposition process, including but not limited to one or more of a chemical vapor deposition process (CVD), an atomic layer deposition process (ALD), a high density plasma deposition (HDP), a plasma enhanced deposition process, and a spin-on dielectric layer (SOD) to form the dielectric layer 11. The dielectric layer 11 can isolate the gate and the substrate 10 to prevent direct current conduction between the two.

[0061] See also Figure 3-Figure 9 In some embodiments, step S40 further includes: step S402-step S408.

[0062] Step S402 : forming a first metal material layer 121 on the first surface 11 a of the dielectric layer 11 .

[0063] See also Figure 3 For example, a deposition method may be used to form a first metal material layer 121 on the top surface of the dielectric layer 11;

[0064] See also Figure 4 For example, photolithography combined with etching can be used to remove part of the first metal material layer 121 to obtain the first metal layer 12; wherein the longitudinal section of the first metal layer 12 is a "right-angled trapezoid" with a target acute angle.

[0065] For example, etching can be mainly divided into dry etching and wet etching. Dry etching is usually divided into three types: plasma etching (PE), sputtering etching and reactive ion etching (RIE); the etching solution of the wet etching process can be a mixed solution of hydrofluoric acid and hydrogen peroxide. The specific selection should be made according to different processing objects, requirements and actual conditions.

[0066] For example, in this embodiment, a photoresist is coated on the first metal material layer 121, and after a series of steps such as exposure and development, a patterned photoresist layer is realized by using a self-aligned double patterning (SADP) process or a self-aligned quadruple patterning (SAQP) process to form an etching window on the top surface of the substrate 10. Finally, the following is obtained: Figure 4 The longitudinal section shown is a first metal layer 12 in a "right-angle trapezoid" shape with a target acute angle. The first metal layer 12 forms a first angle with the first surface 11a, and the first angle ranges from 30° to 70°.

[0067] By way of example, the thickness of the first metal layer 12 includes, but is not limited to, 0.5 micrometers to 3 micrometers, such as 0.5 micrometers, 1 micrometer, 1.5 micrometers, 2 micrometers, 2.5 micrometers, or 3 micrometers.

[0068] Step S404 : forming an insulating protection layer 13 on the top surface of the first metal layer 12 .

[0069] See also Figure 5 , for example, an insulating protective material layer 131 is formed on the top surface of the dielectric layer 11 by also using a deposition method;

[0070] See also Figure 6For example, photolithography combined with etching can be used to remove part of the insulating protective material layer 131 to expose part of the top surface of the first metal layer 12; wherein the remaining insulating protective material layer 131 is located on the outer surface of the first metal layer 12 and extends to the first surface 11a.

[0071] For example, in this embodiment, there is no special requirement for the etching angle of the insulating protection material layer 131 .

[0072] See also Figure 7-Figure 8 In some embodiments, step S60 further includes: forming a second metal layer 14 on the top surface of the insulating protection material layer 131 . At this time, the insulating protection material layer 131 is used to constitute the insulating protection layer 13 .

[0073] For example, in this embodiment, step S60 is consistent with the previous step S402, that is, step S402 is repeated.

[0074] For example, see Figure 7 , depositing a second metal material layer 141; see Figure 8 The second metal material layer 141 is etched at a preset angle by using a photolithography combined with etching method. At this time, the remaining second metal material layer 141 is used to form the second metal layer 14, and the insulating protection material layer 131 is used to form the insulating protection layer 13.

[0075] The second metal layer 14 covers the insulating protection layer 13 and a portion of the bottom surface of the first metal layer 12 and extends to the first surface 11a. A second angle is formed between the second metal layer 14 and the first surface 11a, and the second angle ranges from 30° to 70°.

[0076] By way of example, the thickness of the insulating protective layer 13 includes but is not limited to 0.1 micron-1 micron, such as 0.1 micron, 0.5 micron or 1 micron, etc.; the thickness of the second metal layer 14 includes but is not limited to 2 microns-6 microns, etc., such as 2 microns, 3 microns, 4 microns, 5 microns or 6 microns, etc.

[0077] The thickness of each of the first metal layer 12, the insulating protection layer 13, and the second metal layer 14 can be adjusted as needed, and these stresses can be more effectively distributed and relieved by adjusting their thickness and the angle with the first surface 11a. A smaller angle can increase the uniformity of the coating.

[0078] In addition, the adhesion between the insulating protection layer 13 and the first metal layer 12 and the second metal layer 14 in the laminated structure 30 can be optimized by selecting appropriate intermediate layer materials and process parameters. Good adhesion can further prevent interlayer delamination, which is also an important factor in reducing crack formation.

[0079] See also Fig. 9 In some embodiments, after step S60, the method further includes: forming a passivation layer 15 that at least covers the inclined surface of the second metal layer 14 having a longitudinal cross-section that is a "right-angle trapezoid" with a target acute angle.

[0080] For example, see Fig. 9 , deposited and etched to obtain a passivation layer 15. The passivation layer 15 can effectively prevent the surface of the first metal layer 12 and the second metal layer 14 from contacting with corrosive media such as oxygen and water vapor, thereby inhibiting the occurrence of oxidative corrosion, which can not only extend the service life of the metal material, but also significantly improve its physical properties such as surface hardness, wear resistance and corrosion resistance.

[0081] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of the steps, and the steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0082] See also Fig. 9 The present application provides a stacked structure 30, comprising: a substrate 10, a dielectric layer 11 located on the substrate 10, and a first metal layer 12, an insulating protection layer 13, and a second metal layer 14 located on the first surface 11a of the dielectric layer 11 and stacked in sequence along a direction away from the dielectric layer 11; wherein the longitudinal section of the first metal layer 12 is a "right-angled trapezoid" with a target acute angle, the insulating protection layer 13 is located on the outer surface of the first metal layer 12 and extends to the first surface 11a; the second metal layer 14 covers the insulating protection layer 13 and part of the top surface of the first metal layer 12, and extends to the first surface 11a.

[0083] The longitudinal section of the first metal layer 12 is a "right-angle trapezoid" with a target acute angle, so that the first metal layer 12 has a climbing angle. The insulating protection layer 13 covering the outer surface of the first metal layer 12 and extending to the first surface 11a of the dielectric layer 11 and the second metal layer 14 directly above together constitute a stacked structure 30. Compared with a single insulating protection layer 13, the stacked structure 30 can adjust the climbing angles of the insulating protection layer 13 and the second metal layer 14 by adjusting the thickness of the first metal layer 12 and the angle of the target acute angle, and more effectively and reasonably distribute and relieve the internal stress caused by the difference in thermal expansion coefficient between the insulating protection layer 13 and the dielectric layer 11. In addition, the stacked structure 30 also has electromagnetic shielding and heat dissipation functions, which can improve the reliability and performance of the device.

[0084] See also Fig. 9 In some embodiments, the stacked structure 30 includes a substrate, and the dielectric layer 11 is located on the substrate.

[0085] See also Fig. 9 In some embodiments, the stacked structure 30 includes an epitaxial layer, and the dielectric layer 11 is located on the epitaxial layer. The conductivity type of the epitaxial layer is consistent with that of the substrate.

[0086] See also Fig. 9 In some embodiments, the stacked structure 30 includes an epitaxial layer located on a substrate, and the dielectric layer 11 is located on the epitaxial layer.

[0087] See also Fig. 9 In some embodiments, the materials of the first metal layer 12 and the second metal layer 14 are the same or different.

[0088] See also Fig. 9 In some embodiments, the thickness of the second metal layer 14 is greater than the thickness of the insulating protection layer 13; the first metal layer 12 forms a first angle with the first surface 11a; the second metal layer 14 forms a second angle with the first surface 11a; the first angle and the second angle both range from 30° to 70°. Of course, the specific thickness and angle can be adjusted according to the application scenario and should not be limited to the range in this embodiment.

[0089] See also Fig. 9 In some embodiments, the material of the first metal layer 12 includes titanium, tungsten, nickel, cobalt, silver, aluminum, palladium, copper, or a combination thereof.

[0090] See also Fig. 9 In some embodiments, the material of the second metal layer 14 includes titanium, tungsten, nickel, cobalt, silver, aluminum, palladium, copper, or a combination thereof.

[0091] See also Fig. 9 In some embodiments, the material of the insulating protection layer 13 includes silicon nitride, silicon carbide, silicon nitride oxide, or a combination thereof.

[0092] See also Fig. 9 In some embodiments, the stacked structure 30 further includes a passivation layer 15; the passivation layer 15 at least covers the inclined surface of the second metal layer 14 whose longitudinal cross section is a "right-angled trapezoid" with a target acute angle.

[0093] In some embodiments, the base 10 includes a substrate, and the dielectric layer 11 is located on the substrate; the substrate includes a first-type drift region; the first-type drift region includes second-type doped regions spaced apart along a first direction parallel to the top surface of the substrate, and a channel region located between adjacent second-type doped regions along the first direction; the substrate also includes a gate located on the channel region; the dielectric layer 11 covers the first-type drift region, the second-type doped region and the gate; the first-type drift region and the second-type doped region have different conductivity types.

[0094] For example, if the doping type of the first type drift region is P type, the second type doping region is N type, and vice versa. When regions of different conductivity types come into contact, holes in the P type will diffuse to the N type region, and at the same time, electrons in the N type region will also diffuse to the P type region, thereby forming a depletion region in the contact region. The widening of the depletion region in each doping region is inversely proportional to its doping concentration, that is, there will be a wider depletion region on the side with a lower doping concentration. Of course, this embodiment only represents one of the ways, and the substrate / epitaxial layer can also include doping regions of multiple conductivity types and different doping concentrations, as long as the semiconductor structure can be reasonably formed.

[0095] In the above embodiments, the unexpected technical effects of the present application are:

[0096] The laminated structure achieves multiple advantages by combining the first metal layer and the second metal layer with a climbing angle on the basis of the traditional insulating protective layer. The metal interlayer composed of the first metal layer and the second metal layer has good thermal conductivity, which helps to dissipate heat, reduce device temperature, and increase power density. By adjusting the thickness and climbing angle of the metal interlayer, the internal stress caused by the difference in thermal expansion coefficient can be more effectively distributed and alleviated, reducing the risk of cracking. Selecting a suitable intermediate layer material can enhance the adhesion between the metal interlayer and the insulating protective layer, prevent interlayer peeling or act as a buffer layer to prevent the insulating protective layer from cracking. The thickness, climbing angle and process parameters of the laminated structure can be customized for specific applications to meet the electrical, mechanical and heat dissipation requirements of different power devices.

[0097] In addition to reducing stress concentration problems, this laminated structure also has electromagnetic interference (EMI) shielding function, which can prevent external electromagnetic interference and internal electromagnetic leakage, and improve the reliability and stability of the device.

[0098] In summary, a new type of laminated structure is proposed, which effectively reduces the cracking of the insulating protective layer and enhances the stability and reliability of the entire device in extreme environments. Semiconductor devices with laminated structures can also be significantly improved in reliability, electromagnetic compatibility and heat dissipation performance, and the device repair rate is effectively reduced, providing new opportunities for the innovation and development of semiconductor devices.

[0099] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features of the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A laminated structure, characterized in that: include: A substrate, a dielectric layer located on the substrate, and a first metal layer, an insulating protection layer, and a second metal layer located on a first surface of the dielectric layer and stacked in sequence in a direction away from the dielectric layer; Wherein, the longitudinal section of the first metal layer is a "right-angle trapezoid" with a target acute angle, and the insulating protection layer is located on the outer surface of the first metal layer and extends to the first surface; The second metal layer covers a portion of the top surface of the first metal layer and the insulating protection layer, and extends to the first surface.

2. The laminated structure according to claim 1, characterized in that: The substrate includes any one of the following features: A substrate, wherein the dielectric layer is located on the substrate; an epitaxial layer, the dielectric layer being located on the epitaxial layer; An epitaxial layer is located on a substrate, and the dielectric layer is located on the epitaxial layer.

3. The laminated structure according to claim 1, characterized in that: The materials of the first metal layer and the second metal layer are the same or different.

4. The laminated structure according to claim 1, characterized in that: The thickness of the second metal layer is greater than the thickness of the insulating protection layer; A first angle is formed between the first metal layer and the first surface; A second angle is formed between the second metal layer and the first surface; The first angle and the second angle both range from 30° to 70°.

5. The laminated structure according to any one of claims 1 to 4, characterized in that: Includes at least one of the following features: The material of the first metal layer includes titanium, tungsten, nickel, cobalt, silver, aluminum, palladium, copper or a combination thereof; The material of the second metal layer includes titanium, tungsten, nickel, cobalt, silver, aluminum, palladium, copper or a combination thereof; The material of the insulating protection layer includes silicon nitride, silicon carbide, silicon nitride oxide or a combination thereof; The stacked structure further includes a passivation layer; the passivation layer at least covers the inclined surface of the second metal layer having a longitudinal cross section in the shape of a "right-angled trapezoid" with a target acute angle.

6. The laminated structure according to any one of claims 1 to 4, characterized in that: The base comprises a substrate, and the dielectric layer is located on the substrate; The substrate includes a first type drift region; The first-type drift region includes second-type doping regions spaced apart along a first direction parallel to the top surface of the substrate, and a channel region located between adjacent second-type doping regions along the first direction; The substrate also includes a gate located on the channel region; The dielectric layer covers the first-type drift region, the second-type doped region and the gate; The first-type drift region and the second-type doping region have different conductivity types.

7. A method for preparing a laminated structure, characterized in that: include Providing a substrate, wherein the substrate comprises a dielectric layer; A first metal layer and an insulating protective layer are formed on the first surface of the dielectric layer, which are stacked in sequence in a direction away from the dielectric layer; wherein the longitudinal section of the first metal layer is a "right-angled trapezoid" with a target acute angle, and the insulating protective layer is located on the outer surface of the first metal layer and extends to the first surface; A second metal layer is formed, where the second metal layer covers a portion of the top surface of the first metal layer and the insulating protection layer and extends to the first surface.

8. The method for preparing a laminated structure according to claim 7, characterized in that: Forming the first metal layer includes: forming a first metal material layer on the top surface of the dielectric layer; A portion of the first metal material layer is removed to obtain a first metal layer; wherein the longitudinal section of the first metal layer is a "right-angled trapezoid" with a target acute angle.

9. The method for preparing a laminated structure according to claim 7, characterized in that: The insulating protection layer and the second metal layer are prepared at the same time in the same process step.

10. A semiconductor device, characterized in that: A laminate structure comprising any one of claims 1 to 6; or A laminated structure prepared by the laminated structure preparation method described in any one of claims 7 to 9.

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