Peelable nitride structure and methods of making and peeling thereof

Abstract

This invention discloses a peelable nitride structure, its preparation method, and its peeling method. The peelable nitride structure includes a substrate, a buffer layer, a sacrificial layer, an etching layer, and a target nitride structure arranged sequentially. The sacrificial layer has through-cracks. Because a sacrificial layer with through-cracks is introduced into the buffer layer and the target nitride structure, the through-cracks provide flow channels for the solution, allowing for rapid etching of the etching layer via electrochemical etching to achieve peeling of the target nitride structure from the substrate and the buffer layer.

Description

Technical Field

[0001] This invention relates to a peelable semiconductor chip structure, specifically to a peelable nitride structure and its preparation and peeling methods. Background Technology

[0002] Nitride semiconductor materials have significant applications in light emission, detection, power electronics, and microwave radio frequency. To meet the demands of high-power, high-detectivity, and high-frequency, high-voltage devices, it is typically necessary to strip away substrate and buffer layer materials with low thermal conductivity and light transmittance.

[0003] However, traditional laser ablation technology is limited by factors such as laser wavelength, and cannot achieve stable, repeatable, large-area, and non-destructive ablation in many scenarios.

[0004] Therefore, there is an urgent need to develop a new stripping method to overcome the above problems. Summary of the Invention

[0005] To address at least one of the problems of the current laser ablation technology being unable to stably, repeatedly, over a large area, and non-destructively ablate nitride structures, according to one aspect of the present invention, a peelable nitride structure is provided.

[0006] The peelable nitride structure includes a substrate, a buffer layer, a sacrificial layer, an etched layer, and a target nitride structure arranged sequentially; wherein the sacrificial layer has a through-crack.

[0007] By introducing a sacrificial layer with through-cracks into the buffer layer and the target nitride structure, the through-cracks can provide flow channels for the solution, allowing the corrosion layer to be rapidly corroded by electrochemical etching, thereby achieving the separation of the target nitride structure from the substrate and the buffer layer.

[0008] In some embodiments, the etched layer is a heavily doped etched layer. This can improve the conductivity of the etched layer, and when the etched layer is etched by electrochemical etching, the etching rate of the etched layer can be further accelerated to achieve non-destructive separation of the target nitride structure from the substrate and buffer layer.

[0009] In some implementations, the buffer layer comprises Al x Ga y In 1-x-y N layers, where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ 1 - xy ≤ 1; and / or the sacrificial layer contains Al. m Ga n In 1-m-n N layers, where 0 ≤ m ≤ 1, 0 ≤ n ≤ 1, 0 ≤ 1 - mn ≤ 1; and / or the etched layer contains Al. a Ga b In1-a-b N layers, where 0≤a≤1, 0≤b≤1, 0≤1-ab≤1. Thus, while ensuring the quality of the target nitride structure generated on the corrosion layer, it is possible to adjust the composition of the buffer layer and the sacrificial layer to create a lattice mismatch, thereby causing the sacrificial layer to develop through-cracks due to the stress caused by the lattice mismatch.

[0010] In some implementations, the top layer of the buffer layer is Al. x Ga y In 1-x-y N layers, with the bottom layer of the sacrificial layer being Al. m Ga n In 1-m-n N layers (i.e., the bottom layer of the sacrificial layer grows on the upper surface of the top layer in the buffer layer), and the top layer in the buffer layer and the bottom layer of the sacrificial layer satisfy [x·L AlN +y·L GaN +(1-xy)·L InN [m·L] AlN +n·L GaN +(1-mn)·L InN ], where L AlN L GaN L InN Here, represents the in-plane lattice constants of AlN, GaN, and InN, respectively. Therefore, when the sacrificial layer is stretched on the upper surface of the buffer layer, the lattice mismatch caused by the difference in composition leads to tensile stress in the sacrificial layer, resulting in through-cracks.

[0011] In some implementations, Al in the etched layer a Ga b In 1-a-b Al in N layer and sacrificial layer m Ga n In 1-m-n Layer N satisfies [a·L] AlN +b·L GaN +(1-ab)·L InN [m·L] AlN +n·L GaN +(1-mn)·L InN ], where L AlN L GaN L InN These are the in-plane lattice constants of AlN, GaN, and InN, respectively. This prevents cracks from forming in the etched layer due to tensile stress, thus ensuring the quality of the target nitride structure grown on the crack-free surface of the etched layer.

[0012] In some implementations, the material selected is one capable of being doped, depending on the material of the etched layer. For example, when the etched layer contains Al... a Ga b In 1-a-b For N layers, the element doped in the etching layer can be Si or Ge; and / or when the sacrificial layer contains Al m Ga n In 1-m-n In the case of N layers, the sacrificial layer also contains doped elements Si or Ge. This allows for the introduction of tensile stress into the sacrificial layer, thereby further increasing the number of through-cracks within it.

[0013] In some embodiments, the Si or Ge doping concentration of the etched layer is not less than 5 × 10⁻⁶. 18 cm -3 .

[0014] In some implementations, the upper surface of the etched layer is free of cracks. This ensures the quality of the target nitride structure deposited on the etched layer.

[0015] In some embodiments, the strippable nitride structure further includes a passivation layer disposed between the etched layer and the target nitride structure, and / or disposed on the upper surface and sides of the target nitride structure. Thus, the passivation layer prevents damage to the target nitride structure when the etched layer is etched by electrochemical etching.

[0016] According to another aspect of the present invention, a method for preparing a peelable nitride structure is provided, wherein the peelable nitride structure is prepared by sequentially depositing a buffer layer, a sacrificial layer, an etched layer and a target nitride structure on a substrate; and controlling the sacrificial layer to bear tensile stress so that through-cracks appear on the surface of the sacrificial layer.

[0017] In some embodiments, at the sacrificial layer growth temperature, the in-plane lattice constant of the lower surface of the sacrificial layer is smaller than the in-plane lattice constant of the upper surface of the buffer layer, and the lattice mismatch between the two is not less than 5‰. Therefore, tensile stress can be introduced into the sacrificial layer through the lattice mismatch, leading to through-cracks in the sacrificial layer due to the presence of tensile stress.

[0018] According to another aspect of the present invention, a method for peeling off a peelable nitride structure is provided. This method involves electrochemically etching the aforementioned peelable nitride structure or the peelable nitride structure prepared by the aforementioned preparation method, thereby achieving non-destructive peeling off of the target nitride structure by etching the etched layer.

[0019] Because the aforementioned peelable nitride structure and the peelable nitride structure prepared by the aforementioned method introduce a sacrificial layer and an corrosion layer between the buffer layer and the target nitride structure, and the sacrificial layer, which does not directly contact the target nitride structure, has through-cracks that allow the electrochemical etching solution to flow through it; while the corrosion layer, which separates the sacrificial layer from the target nitride structure, does not have through-cracks, thus ensuring the quality of the target nitride structure grown on the corrosion layer. When the peelable nitride structure is peeled off by electrochemical etching, the solution can flow through the through-cracks, allowing the solution to fully contact the corrosion layer, greatly improving the etching efficiency of the corrosion layer. Moreover, because the sacrificial layer has a large number of through-cracks, the stress on the corrosion layer and the target nitride structure above it is relatively small, thereby avoiding the generation of stress on the target nitride structure during the etching process, which could lead to damage or breakage of the target nitride structure due to stress.

[0020] In some embodiments, during the electrochemical corrosion process, the cathode of the electrochemical corrosion circuit is placed in the electrolyte solution used for electrochemical corrosion, and the anode of the electrochemical corrosion circuit is connected to the corrosion layer.

[0021] In some embodiments, the cathode of the electrochemical corrosion circuit contains at least one of the elements graphite, Pt, and Au. Since elements such as graphite, Pt, and Au possess excellent corrosion resistance and conductivity, using these elements to prepare the cathode can prevent a violent reaction between the cathode and the electrochemical corrosion solution. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the strippable nitride structure according to one embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the strippable nitride structure according to another embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of a strippable nitride structure according to another embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the strippable nitride structure according to another embodiment of the present invention;

[0026] Figure reference numerals: 20, substrate; 30, buffer layer; 40, sacrificial layer; 41, through-crack; 50, etched layer; 60, target nitride structure; 70, passivation layer. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0028] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising" or "including" include not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The terminology used herein is generally that commonly used by those skilled in the art; in case of any discrepancy with commonly used terminology, the terminology used herein shall prevail.

[0029] In this paper, the term "lattice constant" or lattice parameter refers to the edge length of a unit cell in a crystal lattice, that is, the edge length of each parallelepiped unit. It is an important fundamental parameter of crystal structure.

[0030] In this paper, the term "lattice mismatch" refers to the mismatch phenomenon in which stress is generated near the interface between the buffer layer and the sacrificial layer due to their different lattice constants, which in turn leads to crystal defects.

[0031] In this paper, the term "lattice mismatch" is a parameter used to measure the relative magnitude of the lattice constants of the sacrificial layer and the buffer layer. Specifically, it can be expressed as the ratio of the absolute value of the difference between the lattice constants of the sacrificial layer and the buffer layer to the lattice constant of the sacrificial layer.

[0032] In this invention, the term "upper surface" refers to the surface of the layer facing away from the substrate.

[0033] In this invention, the term "lower surface" refers to the surface of the layer facing the substrate.

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Figure 1 The strippable nitride structure according to a first embodiment of the present invention is schematically shown.

[0036] like Figure 1As shown, the peelable nitride structure includes a substrate, a buffer layer, a sacrificial layer, an etched layer, and a target nitride structure arranged sequentially; wherein, the sacrificial layer has a through crack, specifically, the through crack penetrates the upper and lower surfaces of the sacrificial layer.

[0037] For example, the substrate can be a commonly used substrate in the prior art on which epitaxial growth can be performed to prepare nitride structures, such as sapphire substrate, silicon substrate, silicon carbide substrate, nitride ceramic substrate, boron nitride ceramic substrate, etc.

[0038] For example, the buffer layer can adopt a buffer layer structure commonly used in the preparation of nitride structures in the prior art. For instance, the buffer layer is a nitride layer that is the same as the nitride in the target nitride structure. For example, the buffer layer contains Al. x Ga y In 1-x-y N layers, where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, and 0 ≤ 1 - xy ≤ 1. The buffer layer can be a single-layer structure or a multi-layer structure with different compositions. When the buffer layer is a multi-layer structure, the thicknesses of the different component material layers can be the same or different. The multi-layer structure can be entirely composed of Al. x Ga y In 1-x-y The N material layer can also be in at least one set of adjacent Al layers. x Ga y In 1-x-y A graphene layer is inserted into the N material layer, as long as the top layer of the buffer layer is Al. x Ga y In 1-x-y An N-layer material is sufficient.

[0039] For example, the target nitride structure can be a nitride layer or a functional device containing a nitride material layer, such as an LED chip.

[0040] By introducing a sacrificial layer with through-cracks into the buffer layer and the target nitride structure, the through-cracks can provide flow channels for the solution, allowing the corrosion layer to be rapidly corroded by electrochemical etching, thereby achieving non-destructive peeling of the target nitride structure from the substrate and the buffer layer.

[0041] In some preferred embodiments, the sacrificial layer is selected from materials that will bear tensile stress after being grown on the buffer layer. For example, the lattice constant of the material selected for the sacrificial layer is smaller than that of the material selected for the buffer layer. For instance, the sacrificial layer contains Al. m Ga n In 1-m-nN layers, where 0 ≤ m ≤ 1, 0 ≤ n ≤ 1, 0 ≤ 1 - mn ≤ 1. For example, the sacrificial layer can be a single-layer structure or a multi-layer structure with different compositions. When the sacrificial layer is a multi-layer structure, the thicknesses of the material layers with different compositions can be the same or different, as long as the bottom layer of the sacrificial layer is Al. m Ga n In 1-m-n N layers are sufficient. Preferably, the sacrificial layer is configured to have a lattice mismatch of not less than 5‰ with the buffer layer, so as to introduce through-cracks in the sacrificial layer when it is deposited on the upper surface of the buffer layer. Preferably, the thickness of the sacrificial layer is controlled in the range of 10nm to 1000nm.

[0042] In some embodiments, the etched layer comprises Al a Ga b In 1-a-b N layers, where 0≤a≤1, 0≤b≤1, and 0≤1-ab≤1. Preferably, the thickness of the etched layer is controlled within the range of 500nm to 3000nm.

[0043] In some preferred embodiments, the etched layer is a heavily doped etched layer. In this invention, a heavily doped etched layer is an etched layer doped with a large number of conductive elements to significantly improve the conductivity of the etched layer. For example, the doping concentration of the etched layer is not less than 5 × 10⁻⁶. 18 cm -3 In some embodiments, the element doped in the etched layer is Si or Ge.

[0044] In some preferred embodiments, the sacrificial layer also contains doped elements Si or Ge. This allows for the further introduction of tensile stress into the sacrificial layer, thereby further increasing the number of through-cracks in the sacrificial layer.

[0045] In some preferred embodiments, the upper surface of the etched layer is free of cracks. This ensures the quality of the target nitride structure deposited on the etched layer.

[0046] Figures 2 to 4 The diagram schematically illustrates a peelable nitride structure according to other embodiments of the present invention, which differs from the peelable nitride structure of the first embodiment in that it further includes a passivation layer.

[0047] in, Figure 2 A strippable nitride structure according to a second embodiment of the invention is schematically shown. Figure 2 As shown, the peelable nitride structure of this embodiment also includes a passivation layer disposed between the etched layer and the target nitride structure.

[0048] Figure 3A strippable nitride structure according to a third embodiment of the invention is schematically shown. Figure 3 As shown, the peelable nitride structure of this embodiment also includes passivation layers disposed on the upper surface and side surfaces of the target nitride structure.

[0049] Figure 4 A strippable nitride structure according to a fourth embodiment of the present invention is schematically shown. Figure 4 As shown, the peelable nitride structure of this embodiment also includes a passivation layer disposed between the corrosion layer and the target nitride structure, and disposed on the upper surface and side surface of the target nitride structure.

[0050] Regardless of which of the second to fourth embodiments the strippable nitride structure is described above, the passivation layers on the upper surface and sides of the target nitride structure can all be passivation layers commonly used in the prior art, such as SiO2 layers, SiN layers, etc. x The passivation layer between the etched layer and the target nitride structure is unintentionally doped with Al. j Ga k In 1-j-k N layers, where 0≤j≤1, 0≤k≤1, and 0≤1-jk≤1.

[0051] According to another aspect of the present invention, a method for preparing a peelable nitride structure is provided, wherein the peelable nitride structure is prepared by sequentially depositing a buffer layer, a sacrificial layer, an etched layer and a target nitride structure on a substrate; and controlling the sacrificial layer to bear tensile stress so that through-cracks appear on the surface of the sacrificial layer.

[0052] For example, the sequential deposition of the buffer layer, sacrificial layer, etched layer, and target nitride structure on the substrate can be performed using deposition methods commonly used in the prior art, such as at least one of Metal-organic Chemical Vapor Deposition (MOCVD), Molecular Beam Epitaxy (MBE), Physical Vapor Deposition (PVD), Pulsed Laser Deposition (PLD), and Atomic Layer Deposition (ALD). The specific deposition process can be a commonly used deposition process in the prior art, and the present invention does not limit the specific deposition process.

[0053] In some embodiments, at the sacrificial layer growth temperature, the in-plane lattice constant of the upper surface of the buffer layer is greater than the in-plane lattice constant of the lower surface of the sacrificial layer, and the lattice mismatch between the two is not less than 5‰. For example, introducing lattice mismatch between the buffer layer and the sacrificial layer can be achieved by controlling the composition of both: for example, controlling the top layer of the buffer layer to be Al. x Ga y In 1-x-y N layers, where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ 1 - xy ≤ 1; the control sacrifice layer is Al. m Ga n In 1-m-n N layers, where 0≤m≤1, 0≤n≤1, 0≤1-mn≤1; and control [x·L] AlN +y·L GaN +(1-xy)·L InN [m·L] AlN +n·L GaN +(1-mn)·L InN ], where L AlN L GaN L InN Here, represents the in-plane lattice constants of AlN, GaN, and InN, respectively. Therefore, by creating a lattice mismatch between the buffer layer and the sacrificial layer, tensile stress can be introduced into the sacrificial layer, leading to through-cracks in the sacrificial layer due to the presence of tensile stress.

[0054] In some embodiments, the absence of cracks on the upper surface of the prepared etched layer can be achieved by controlling the Al content in the etched layer. a Ga b In 1-a-b Al in N layer and sacrificial layer m Ga n In 1-m-n Layer N satisfies [a·L] AlN +b·L GaN +(1-ab)·L InN [m·L] AlN +n·L GaN +(1-mn)·L InN Implemented in the manner of ], where L AlN L GaN L InN are the in-plane lattice constants of AlN, GaN, and InN, respectively.

[0055] In some preferred embodiments, after the etching layer is deposited and before the target nitride structure is deposited, a passivation layer is deposited on the upper surface of the etching layer, followed by the deposition of the target nitride structure on the upper surface of the passivation layer. This avoids damage to the target nitride structure when removing the etching layer using electrochemical etching, and the passivation layer allows for more precise control of the etching endpoint, enabling the operator to strip the target nitride structure through electrochemical etching.

[0056] In some preferred embodiments, after the target nitride structure is deposited, a passivation layer is also deposited on the upper surface of the target nitride structure. This avoids damage to the target nitride structure when removing the corrosion layer using electrochemical etching.

[0057] The preparation method of the strippable nitride structure of the present invention will be described exemplarily below with reference to specific embodiments.

[0058] Example 1

[0059] The first step involves depositing a 500 nm thick layer of Al on a sapphire substrate using MOCVD. x Ga y In 1-x- y An N-layer buffer layer, with the top layer controlled as Al. x Ga y In 1-x-y N layers, where Al is located at the top layer of the buffer layer. x Ga y In 1-x-y For layer N, x = 0.5 and y = 0.4.

[0060] The second step involves continuing to use MOCVD to deposit an Al material with a thickness of 200 nm on the upper surface of the buffer layer. m Ga n In 1-m- n The sacrificial layer of N, where m = 0.7 and n = 0.2.

[0061] The third step involves continuing to use MOCVD to deposit an Al material with a thickness of 1000 nm on the upper surface of the sacrificial layer. a Ga b In 1-a-b The N-etched layer has a value of a = 0.5, b = 0.5, and the Si doping concentration is 6 × 10⁻⁶. 18 cm -3 .

[0062] The fourth step involves using MOCVD to deposit a 2500 nm thick AlGaN deep ultraviolet light-emitting diode structure on the upper surface of the etched layer.

[0063] Example 2

[0064] The difference between this embodiment and Embodiment 1 lies in steps three and four, wherein,

[0065] The third step involves continuing to use MOCVD to deposit an 800 nm thick Al material on the upper surface of the sacrificial layer. a Ga b In 1-a- b An N-etched layer is formed, where a = 0.4 and b = 0.6; then, an Al material with a thickness of 100 nm and unintentionally doped is deposited on the upper surface of the etched layer. 0.4 Ga 0.6 N passivation layer.

[0066] The fourth step involves using MOCVD to deposit a 2000 nm thick AlGaN deep ultraviolet light-emitting diode structure on the upper surface of the passivation layer.

[0067] Example 3

[0068] The difference between this embodiment and Embodiment 1 is that, after the fourth step, it also includes...

[0069] The fifth step involves using MOCVD to deposit a 100 nm thick passivation layer of SiO2 on the upper surface of the AlGaN deep ultraviolet light-emitting diode structure.

[0070] Example 4

[0071] The difference between this embodiment and Embodiment 2 is that, after the fourth step, it also includes...

[0072] The fifth step involves continuing to use MOCVD to deposit a 200 nm thick SiN material on the upper surface of the AlGaN deep ultraviolet light-emitting diode structure. x The passivation layer.

[0073] Example 5

[0074] The difference between this embodiment and Embodiment 1 is that,

[0075] In the third step, the Si doping of the etched layer is not performed using MOCVD. Instead, after the deposition of the etched layer is completed, the Si is further doped with an ion implanter at a concentration of 6 × 10⁻⁶. 18 cm -3 Si doping.

[0076] Example 6

[0077] The difference between this embodiment and Embodiment 1 is that,

[0078] In the second step, the Si doping of the sacrificial layer is not performed using MOCVD. Instead, after the deposition of the sacrificial layer is completed, the sacrificial layer is also doped with Si using an ion implanter.

[0079] According to another aspect of the present invention, a method for peeling off a peelable nitride structure is provided. This method involves electrochemically etching the aforementioned peelable nitride structure or the peelable nitride structure prepared by the aforementioned preparation method, thereby achieving non-destructive peeling off of the target nitride structure by etching the etched layer.

[0080] Because the aforementioned peelable nitride structure and the peelable nitride structure prepared by the aforementioned method introduce a sacrificial layer and an corrosion layer between the buffer layer and the target nitride structure, and the sacrificial layer, which does not directly contact the target nitride structure, has through-cracks that allow the electrochemical etching solution to flow through it; while the corrosion layer, which separates the sacrificial layer from the target nitride structure, does not have cracks, thus ensuring the quality of the target nitride structure grown on the corrosion layer. When the peelable nitride structure is peeled off by electrochemical etching, the solution can flow through the through-cracks, allowing the solution to fully contact the corrosion layer, greatly improving the etching efficiency of the corrosion layer. Moreover, because the sacrificial layer has a large number of through-cracks, the stress on the corrosion layer and the target nitride structure above it is relatively small, thereby avoiding the generation of stress on the target nitride structure during the etching process, which could lead to damage or fragmentation of the target nitride structure due to stress.

[0081] In some embodiments, during electrochemical corrosion, the cathode of the electrochemical corrosion circuit is placed in the electrolyte solution used for electrochemical corrosion, and the anode of the electrochemical corrosion circuit is connected to the corrosion layer. Generally, the electrolyte solution is selected that has almost no chemical corrosion effect on the epitaxial structure when no current is applied, but has an electrochemical corrosion effect when current is applied. For example, the electrolyte solution can be oxalic acid, nitric acid, or hydrofluoric acid. In particular, when a passivation layer is provided in the peelable nitride structure, hydrofluoric acid is not used to avoid the influence of the electrolyte solution on the passivation layer. Thus, the holes provided by the anode can react with the sacrificial layer to generate nitrogen gas and metal cations, thereby achieving the corrosion of the corrosion layer.

[0082] In a preferred embodiment, the cathode of the electrochemical corrosion circuit contains at least one of the elements graphite, Pt, and Au. This results in a cathode with both good corrosion resistance and conductivity, thus preventing a violent reaction between the cathode and the electrochemical corrosion solution.

[0083] In a preferred embodiment, when the etched layer is heavily doped with Si or Ge, when the anode is connected to the etched layer with the heavily doped Si or Ge donor, the holes provided by the anode can react with the etched layer to generate nitrogen gas and metal cations, thereby achieving selective corrosion of the etched layer. That is, when the etched layer is completely corroded, the target nitride structure will hardly be corroded.

[0084] The stripping method for strippable nitride structures of the present invention will be described exemplarily below with reference to specific embodiments.

[0085] Example 7

[0086] The first step is to select oxalic acid as the electrolyte solution for electrochemical corrosion, and select an electrode containing Pt as the cathode of the electrochemical corrosion circuit, placing the cathode in oxalic acid.

[0087] The second step involves placing the strippable nitride structure in oxalic acid and connecting the anode of the electrochemical corrosion circuit to the corrosion layer to achieve corrosion of the corrosion layer.

[0088] In this invention, the epitaxial growth achieved by deposition and the doping achieved by epitaxial growth or ion implantation can be implemented using methods commonly used in the prior art, and this invention does not impose any particular limitation on them.

[0089] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A strippable nitride structure, characterized in that, It includes a substrate, a buffer layer, a sacrificial layer, an etched layer, and a target nitride structure arranged sequentially; wherein, The sacrificial layer has through-cracks to provide channels for rapid etching of the corrosion layer, thereby achieving the separation of the target nitride structure from the substrate and the buffer layer. The upper surface of the corrosion layer is free of cracks; The etched layer is a heavily doped etched layer; The buffer layer contains Al x Ga y In 1-x-y N layers, wherein 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ 1 - xy ≤ 1; and / or the sacrificial layer contains Al. m Ga n In 1-m-n N layers, wherein 0 ≤ m ≤ 1, 0 ≤ n ≤ 1, 0 ≤ 1 - mn ≤ 1; and / or the etched layer comprises Al. a Ga b In 1-a-b N layers, where 0≤a≤1, 0≤b≤1, and 0≤1-ab≤1; The top layer of the buffer layer is Al. x Ga y In 1-x-y N layers, the bottom layer of which is Al m Ga n In 1-m-n N layers, and the top layer of the buffer layer and the bottom layer of the sacrificial layer satisfy [x·L AlN +y·L GaN +(1-xy)·L InN [m·L] AlN +n·L GaN +(1-mn)·L InN ], where L AlN L GaN L InN , respectively, are the in-plane lattice constants of AlN, GaN, and InN; Al in the corrosion layer a Ga b In 1-a-b Al in N layer and sacrificial layer m Ga n In 1-m-n Layer N satisfies [a·L] AlN +b·L GaN +(1-ab)·L InN [m·L] AlN +n·L GaN +(1-mn)·L InN ], where L AlN L GaN L InN are the in-plane lattice constants of AlN, GaN, and InN, respectively.

2. The strippable nitride structure according to claim 1, characterized in that, The etched layer is doped with Si or Ge; and / or the sacrificial layer also contains Si or Ge as dopants.

3. The strippable nitride structure according to any one of claims 1 to 2, characterized in that, It also includes a passivation layer disposed between the corrosion layer and the target nitride structure, and / or disposed on the upper surface and side surface of the target nitride structure.

4. A method for preparing a strippable nitride structure, characterized in that, A buffer layer, a sacrificial layer, an etched layer, and a target nitride structure are sequentially deposited on the substrate; The sacrificial layer is controlled to bear tensile stress so that through-cracks appear on the surface of the sacrificial layer, thereby preparing the peelable nitride structure according to any one of claims 1 to 3.

5. The method for preparing the strippable nitride structure according to claim 4, characterized in that, At the growth temperature of the sacrificial layer, the in-plane lattice constant of the lower surface of the sacrificial layer is less than the in-plane lattice constant of the upper surface of the buffer layer, and the lattice mismatch between the two is not less than 5‰.

6. A method for stripping nitride structures, characterized in that, Electrochemical corrosion method is used to remove the peelable nitride structure or as described in any one of claims 1 to 3. The strippable nitride structure prepared according to the preparation method of claim 4 or 5 is etched to separate the target nitride structure from the substrate, buffer layer and sacrificial layer by etching the etched layer.

7. The stripping method for strippable nitride structures according to claim 6, characterized in that, During the electrochemical corrosion process, the cathode of the electrochemical corrosion circuit is placed in the electrolyte solution used for electrochemical corrosion, and the anode of the electrochemical corrosion circuit is connected to the corrosion layer.

8. The stripping method for strippable nitride structures according to claim 7, characterized in that, The cathode of the electrochemical corrosion circuit contains at least one of the three elements: graphite, Pt, and Au.

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