Composite film and method for producing the same

Abstract

The embodiment of the present application provides a kind of composite film and its preparation method, first isolation layer is prepared on the surface of first substrate layer to obtain first composite structure;Defect layer is prepared on the surface of second substrate layer to obtain second composite structure;Functional film layer and third substrate layer are sequentially prepared on the surface of first isolation layer in first composite structure, to obtain third composite structure;First substrate layer in third composite structure is removed, to obtain fourth composite structure;The surface of first isolation layer in fourth composite structure and the surface of defect layer in second composite structure are bonded, to obtain first composite film;Third substrate layer in first composite film is removed, to obtain second composite film.Through the setting of the embodiment of the present application, the preparation time length of composite film can be shortened, and production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, and in particular to a composite film and a preparation method thereof. BACKGROUND

[0002] The composite film can meet the requirements of miniaturization, low power consumption and high performance of electronic components, and therefore, the composite film becomes an increasingly important material in the semiconductor industry. The composite film at least includes a defect layer and an isolation layer which are sequentially stacked. The isolation layer with a thickness of more than 7 μm can block signal crosstalk between the film layers on both sides of the isolation layer, and the defect layer can further optimize the performance of the electronic component.

[0003] In the related art, the composite film is usually prepared by a conventional stacking preparation method, that is, the isolation layer is prepared on the surface of the defect layer.

[0004] However, due to the requirement of the defect layer for the process temperature, it takes a long time to directly prepare the isolation layer with a thickness of more than 7 μm on the surface of the defect layer, and the production efficiency is low. SUMMARY

[0005] Embodiments of the present application provide a composite film and a preparation method thereof, to solve the technical problem of long time consumption and low production efficiency in preparing the isolation layer with a thickness of more than 7 μm on the surface of the defect layer due to the requirement of the defect layer for the process temperature in the related art.

[0006] Embodiments of the present application provide a preparation method of a composite film, including the following steps:

[0007] Preparation of a first isolation layer on the surface of a first substrate layer to obtain a first composite structure;

[0008] Preparation of a defect layer on the surface of a second substrate layer to obtain a second composite structure;

[0009] Preparation of a functional film layer and a third substrate layer on the surface of the first isolation layer in the first composite structure in sequence to obtain a third composite structure;

[0010] Removal of the first substrate layer in the third composite structure to obtain a fourth composite structure;

[0011] Bonding of the surface of the first isolation layer in the fourth composite structure and the surface of the defect layer in the second composite structure to obtain a first composite film;

[0012] Removal of the third substrate layer in the first composite film to obtain a second composite film; wherein an isolation layer is formed between the defect layer and the functional film layer, and the isolation layer at least includes the first isolation layer.

[0013] In a feasible implementation, the functional thin film layer is prepared on the surface of the third substrate layer, and then the surface of the functional thin film layer is bonded with the surface of the first isolation layer in the first composite structure to obtain the third composite structure; or the functional thin film layer is prepared on the surface of the first isolation layer in the first composite structure, and then the surface of the third substrate layer is bonded with the surface of the functional thin film layer to obtain the third composite structure.

[0014] In a feasible implementation, the functional thin film layer is prepared on the surface of the third substrate layer, and then the surface of the functional thin film layer is bonded with the surface of the first isolation layer in the first composite structure to obtain the third composite structure; or the functional thin film layer is prepared on the surface of the first isolation layer in the first composite structure, and then the surface of the third substrate layer is bonded with the surface of the functional thin film layer to obtain the third composite structure.

[0015] In a feasible implementation, the functional thin film layer is prepared on the surface of the third substrate layer, and then the surface of the functional thin film layer is bonded with the surface of the first isolation layer in the first composite structure to obtain the third composite structure; or the functional thin film layer is prepared on the surface of the first isolation layer in the first composite structure, and then the surface of the third substrate layer is bonded with the surface of the functional thin film layer to obtain the third composite structure.

[0016] In a feasible implementation, the functional thin film layer is prepared on the surface of the third substrate layer, and then the surface of the functional thin film layer is bonded with the surface of the first isolation layer in the first composite structure to obtain the third composite structure; or the functional thin film layer is prepared on the surface of the first isolation layer in the first composite structure, and then the surface of the third substrate layer is bonded with the surface of the functional thin film layer to obtain the third composite structure.

[0017] In a feasible implementation, the functional thin film layer is prepared on the surface of the third substrate layer, and then the surface of the functional thin film layer is bonded with the surface of the first isolation layer in the first composite structure to obtain the third composite structure; or the functional thin film layer is prepared on the surface of the first isolation layer in the first composite structure, and then the surface of the third substrate layer is bonded with the surface of the functional thin film layer to obtain the third composite structure.

[0018] The composite layer is prepared by ion implantation, wherein the composite layer comprises a functional thin film layer, an implantation layer and a residual layer which are stacked in sequence;

[0019] The surface of the functional thin film layer in the composite layer is bonded with the surface of the third substrate layer to obtain a first transition structure;

[0020] The implantation layer and the residual layer in the first transition structure are removed to obtain a second transition structure;

[0021] The surface of the functional thin film layer in the second transition structure is bonded with the surface of the first isolation layer in the first composite structure to obtain the third composite structure.

[0022] In a feasible implementation, the implantation layer and the residual layer in the first transition structure are removed to obtain the second transition structure, and the surface of the functional thin film layer in the second transition structure is bonded with the surface of the first isolation layer in the first composite structure to obtain the third composite structure.

[0023] The first transition structure is annealed to break the injection layer, so that the excess layer is peeled off from the functional thin film layer along the injection layer, and a second transition structure is obtained.

[0024] In a possible implementation, after the functional thin film layer is prepared on the surface of the first isolation layer in the first composite structure by ion implantation, the surface of the third substrate layer is bonded to the surface of the functional thin film layer to obtain a third composite structure; and the method specifically comprises the following steps:

[0025] The composite layer is prepared by ion implantation; and the composite layer comprises the functional thin film layer, the injection layer, and the excess layer which are stacked in sequence.

[0026] The surface of the functional thin film layer in the composite layer is bonded to the surface of the first isolation layer in the first composite structure to obtain a third transition structure.

[0027] The injection layer and the excess layer in the third transition structure are removed to obtain a fourth transition structure.

[0028] The surface of the third substrate layer is bonded to the surface of the functional thin film layer in the fourth transition structure to obtain the third composite structure.

[0029] In a possible implementation, the injection layer and the excess layer in the third transition structure are removed to obtain a fourth transition structure; and the method specifically comprises the following steps:

[0030] The third transition structure is annealed to break the injection layer, so that the excess layer is peeled off from the functional thin film layer along the injection layer, and the fourth transition structure is obtained.

[0031] In a possible implementation, the third substrate layer in the first composite thin film is removed to obtain a second composite thin film; and the method specifically comprises the following steps:

[0032] The third substrate layer is removed by a CMP process or a chemical etching method.

[0033] In a possible implementation, the isolation layer comprises at least the first isolation layer.

[0034] In a possible implementation, the thickness of the isolation layer is 7 μm to 25 μm.

[0035] In a possible implementation, the thickness of the first isolation layer is equal to the thickness of the isolation layer.

[0036] In a possible implementation, the surface of the first isolation layer in the fourth composite structure is bonded to the surface of the defect layer in the second composite structure to obtain the first composite thin film; and the method specifically comprises the following steps:

[0037] The surface of the first isolation layer in the fourth composite structure and the surface of the defect layer in the second composite structure are activated respectively to bond the fourth composite structure and the second composite structure to obtain the first composite film.

[0038] In a feasible implementation, the second composite structure is prepared by preparing a defect layer on the surface of the second substrate layer; and the method specifically comprises the following steps:

[0039] After the defect layer is prepared by depositing on the surface of the second substrate layer, a second isolation layer is prepared on the surface of the defect layer to obtain the second composite structure; wherein the sum of the thickness of the first isolation layer and the thickness of the second isolation layer is equal to the thickness of the isolation layer, and the thickness of the second isolation layer is less than the thickness of the first isolation layer.

[0040] In a feasible implementation, the first composite film is obtained by bonding the surface of the first isolation layer in the fourth composite structure and the surface of the defect layer in the second composite structure; and the method specifically comprises the following steps:

[0041] The surface of the second isolation layer in the second composite structure and the surface of the first isolation layer in the fourth composite structure are activated respectively to bond the fourth composite structure and the second composite structure to obtain the first composite film.

[0042] In a feasible implementation, the first substrate layer is silicon or SOI;

[0043] The second substrate layer is made of one of the following materials: silicon, SOI, quartz, sapphire, or silicon carbide;

[0044] The third substrate layer is made of silicon or SOI.

[0045] In a feasible implementation, the functional film layer is made of one of the following materials: lithium niobate crystal material, potassium titanyl phosphate crystal material, or rubidium titanyl phosphate crystal material.

[0046] In a second aspect, the embodiments of the present application further provide a composite film, which is prepared by using the preparation method of the composite film according to any one of the technical solutions in the first aspect, and the composite film at least comprises a second substrate layer, a defect layer, an isolation layer, and a functional film layer which are stacked in sequence; wherein the thickness of the isolation layer is 7 μm to 25 μm.

[0047] Firstly, embodiments of this application provide a method for preparing a composite thin film. In this embodiment, a first oxide layer is prepared on the surface of a first substrate, a defect layer is prepared on the surface of a second substrate, and a functional thin film layer is prepared using a third substrate as a support. Finally, the prepared fourth composite structure and the second composite structure are bonded together to obtain a composite thin film with a defect layer and a relatively thick isolation layer. This allows for the separate preparation of the defect layer and the first oxide layer, avoiding the need to limit the temperature of the first oxide layer during preparation to reduce the influence of temperature on the defect layer lattice, which would otherwise result in a longer preparation time for the first oxide layer. Furthermore, the support of the functional thin film layer by the third substrate allows for the preparation of a functional thin film layer of the target thickness. Therefore, the configuration of this embodiment can shorten the preparation time of the composite thin film and improve production efficiency.

[0048] Secondly, embodiments of this application provide a composite thin film. In these embodiments, the composite thin film includes at least a second substrate layer, a defect layer, an isolation layer, and a functional thin film layer stacked sequentially. The thickness of the isolation layer is set to 7 μm to 25 μm. The larger thickness of the isolation layer effectively blocks signal crosstalk between the defect layer and the functional thin film layer, and the presence of a defect layer on the surface of the isolation layer further optimizes the performance of the electronic device. Therefore, the embodiments of this application provide a composite thin film that can effectively block signal crosstalk between the defect layer and the functional thin film layer and optimize the performance of the electronic device. Attached Figure Description

[0049] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and, together with their description, serve to explain this application and do not constitute an undue limitation of the invention. In the drawings:

[0050] Figure 1 This is a schematic diagram of the structure of a composite film provided in one embodiment of this application;

[0051] Figure 2 This application provides a method flow chart for preparing a composite thin film according to an embodiment. Figure One ;

[0052] Figure 3 This application provides a method flow chart for preparing a composite thin film according to an embodiment. Figure Two ;

[0053] Figure 4 yes Figure 3 The steps of a method for preparing a composite thin film Figure One ;

[0054] Figure 5is a method flow of a preparation method of a composite film provided by an embodiment of the present application Figure Three ;

[0055] Figure 6 is a method flow of a preparation method of a composite film provided by an embodiment of the present application Figure Four ;

[0056] Figure 7 is Figure 5 a step of a preparation method of a composite film in claim 1 Figure Two .

[0057] Explanation of reference signs:

[0058] 11-first composite structure; 12-second composite structure; 13-third composite structure; 14-fourth composite structure; 15-first transition structure; 16-second transition structure; 17-third transition structure; 18-fourth transition structure; 19-composite layer; 21-first composite film; 22-second composite film;

[0059] 101-first substrate layer; 102-first isolation layer; 103-functional film layer; 104-injection layer; 105-remaining quality layer; 106-second substrate layer; 107-defect layer; 108-third substrate layer; 109-isolation layer. DETAILED DESCRIPTION

[0060] In order to make the person in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person in the art without creative labor should belong to the protection scope of the present application.

[0061] It should be noted that in the following description, many specific details are set forth in order to provide a thorough understanding of the present application, however, the present application can also be implemented in other ways different from those described herein, therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0062] The composite film can meet the requirements of miniaturization, low power consumption and high performance of electronic components, therefore, the composite film becomes more and more important material in the semiconductor industry. The composite film at least includes defect layer and isolation layer which are stacked in sequence, the isolation layer with a thickness of more than 7 microns can block the signal crosstalk of the film layers on both sides of the isolation layer, and the defect layer can further optimize the performance of the electronic components.

[0063] In the related art, a composite thin film is usually prepared by a conventional layering preparation method, that is, an isolation layer is prepared on the surface of the defect layer.

[0064] However, due to the requirement of the defect layer on the process temperature, it takes a long time to prepare the isolation layer with a thickness of more than 7 μm on the surface of the defect layer.

[0065] Therefore, the embodiments of the present application provide a composite thin film and a preparation method thereof to solve the technical problem that, in the related art, it takes a long time to prepare the isolation layer with a thickness of more than 7 μm on the surface of the defect layer due to the requirement of the defect layer on the process temperature.

[0066] Figure 1 FIG. 1 is a structural schematic diagram of a composite thin film according to an embodiment of the present application.

[0067] With reference to Figure 1 The embodiments of the present application provide a composite thin film, which comprises at least a second substrate layer 106, a defect layer 107, an isolation layer 109 and a functional thin film layer 103 which are sequentially layered; wherein the thickness of the isolation layer 109 is 7 μm to 25 μm.

[0068] For example, the second substrate layer 106 can be made of one of silicon, SOI, quartz, sapphire or silicon carbide, and the thickness of the second substrate layer 106 can be set to 0.3 mm to 0.8 mm.

[0069] For example, the defect layer 107 is obtained by deposition on the surface of the second substrate layer 106, and the defect layer 107 can be a P-SI layer, wherein the thickness of the P-SI layer is 300 nm to 500 nm.

[0070] For example, the isolation layer 109 is an SIO2 layer obtained by oxidation on the surface of the first substrate layer 101, wherein the thickness of the isolation layer 109 is 7 μm to 25 μm. It should be noted that when the thickness of the isolation layer 109 is less than 7 μm, the isolation layer 109 has poor ability to block the signal crosstalk between the defect layer 107 and the functional thin film layer 103, and when the thickness of the isolation layer 109 is greater than 25 μm, not only the growth cycle of the isolation layer 109 is prolonged, the cost of the composite thin film is increased, and the thickness of the composite thin film is increased, which is not conducive to the assembly with electronic devices. Therefore, setting the thickness of the isolation layer 109 to 7 μm to 25 μm not only can effectively reduce the signal crosstalk between the defect layer 107 and the functional thin film layer 103, but also can improve the production efficiency of the composite thin film.

[0071] For example, the functional thin film layer 103 can be made of one of lithium niobate crystal material, potassium titanium oxide phosphate crystal material or rubidium titanium oxide phosphate crystal material, and the thickness of the functional thin film layer 103 can be set to 50 nm to 300 nm.

[0072] This application provides a composite thin film. In this embodiment, the composite thin film includes at least a second substrate layer 106, a defect layer 107, an isolation layer 109, and a functional thin film layer 103, which are sequentially stacked. The thickness of the isolation layer 109 is set to 7 μm to 25 μm. The relatively thick isolation layer 109 can block signal crosstalk between the defect layer 107 and the functional thin film layer 103. Furthermore, the presence of the defect layer 107 on the surface of the isolation layer 109 can further optimize the performance of the electronic device. Therefore, this application provides a composite thin film that can effectively block signal crosstalk between the defect layer 107 and the functional thin film layer 103 and optimize the performance of the electronic device.

[0073] Based on the composite thin film having a defect layer 107 and an isolation layer 109 with a thickness exceeding 7 μm, the related technology uses a lamination preparation method to directly prepare the isolation layer 109 on the surface of the defect layer 107. However, due to the process temperature requirements of the defect layer 107, the preparation of the isolation layer 109 with a thickness exceeding 7 mm on the surface of the defect layer 107 takes a long time. The present application provides a method for preparing a composite thin film to solve the above-mentioned technical problems.

[0074] Example 1:

[0075] Figure 2 This application provides a method flow chart for preparing a composite thin film according to an embodiment. Figure One ; Figure 3 This application provides a method flow chart for preparing a composite thin film according to an embodiment. Figure Two ; Figure 4 yes Figure 3 The steps of a method for preparing a composite thin film Figure One .

[0076] This application provides a method for preparing a composite thin film. In specific implementation, refer to... Figures 2 to 4 This includes the following steps:

[0077] S100: A first isolation layer 102 is prepared on the surface of the first substrate layer 101 to obtain a first composite structure 11.

[0078] For example, the first isolation layer 102 can be prepared on the surface of the first substrate layer 101 by thermal oxidation to obtain the first composite structure 11.

[0079] For example, refer to Figure 3For example, the first substrate layer 101 is an SI substrate, and the surface of the SI substrate is subjected to thermal oxidation to obtain SIO2, forming an SI / SIO2 structure, i.e., the first composite structure 11. In a specific implementation, the oxidation temperature of the thermal oxidation is 500 ± 50 degrees Celsius. It should be noted that if the SIO2 layer is prepared on the surface of the defect layer 107 by using a conventional layering method at a temperature of 500 ± 50 degrees Celsius, the high temperature will damage the crystal lattice of the defect layer 107.

[0080] It should be noted that the thermal oxidation is a process of forming an SIO2 oxide layer on the surface of the SI substrate by oxidation of the SI substrate and oxygen.

[0081] Of course, in a specific implementation, the first substrate layer 101 can also be an SOI in addition to the SI substrate.

[0082] S200: Preparing the defect layer 107 on the surface of the second substrate layer 106 to obtain the second composite structure 12.

[0083] For example, the second substrate layer 106 is an SI substrate, and the surface of the SI substrate is subjected to deposition to obtain a P-SI layer, thereby forming an SI / P-SI structure, i.e., the second composite structure 12.

[0084] For example, to ensure that the crystal lattice of the P-SI structure is not affected, the SI substrate needs to maintain a constant temperature required for P-SI deposition.

[0085] For example, in addition to the SI substrate, the second substrate layer 106 can also be an SOI, quartz, sapphire, or silicon carbide, which will not be described here.

[0086] S300: Preparing the composite layer 19 by using an ion implantation method.

[0087] It should be noted that the composite layer 19 includes the functional thin film layer 103, the implantation layer 104, and the remaining layer 105 which are sequentially stacked.

[0088] In a specific implementation, a thin film substrate is prepared, and the thin film substrate is formed into the functional thin film layer 103, the implantation layer 104, and the remaining layer 105 by ion implantation.

[0089] For example, the material of the thin film substrate can be one of lithium niobate crystal material, potassium titanium oxide phosphate crystal material, or rubidium titanium oxide phosphate crystal material. In the embodiment of the present application, the thin film substrate is a lithium niobate crystal, and accordingly, the functional thin film layer is a lithium niobate crystal material (LN).

[0090] For example, the ions implanted by the ion implantation method can be hydrogen ions, helium ions, nitrogen ions, oxygen ions or argon ions. The ion implantation method can have an implantation energy of 50 KeV to 1000 KeV and an implantation dose of 1×1011 ions / cm2 to 1×1014 ions / cm2. For example, when hydrogen ions are implanted, the implantation dose can be 3×1011 ions / cm2 to 8×1012 ions / cm2 and the implantation energy can be 120 KeV to 400 KeV; when helium ions are implanted, the implantation dose can be 1×1011 ions / cm2 to 1×1014 ions / cm2 and the implantation energy can be 50 KeV to 1000 KeV. For example, when hydrogen ions are implanted, the implantation dose can be 4×1011 ions / cm2 and the implantation energy can be 180 KeV; when helium ions are implanted, the implantation dose can be 4×1011 ions / cm2 and the implantation energy can be 200 KeV. Details are not described herein. 16 17 2 16 2 16 2 16 2 17 2 16 2 16 2

[0091] S400: bonding the surface of the functional thin film layer 103 in the composite layer 19 and the surface of the third substrate layer 108 to obtain a first transition structure 15.

[0092] For example, the third substrate layer 108 can be made of silicon or SOI.

[0093] S500: removing the implantation layer 104 and the residual layer 105 in the first transition structure 15 to obtain a second transition structure 16.

[0094] For example, the first transition structure 15 is subjected to an annealing treatment to break the implantation layer 104, so that the residual layer 105 is peeled off from the surface of the functional thin film layer 103 along the implantation layer 104 to obtain the second transition structure 16.

[0095] For example, referring to Figure 3 When the third substrate is made of an SI substrate, the second transition structure 16 is an SI / LN structure.

[0096] S600: bonding the surface of the functional thin film layer 103 in the second transition structure 16 and the surface of the first isolation layer 102 in the first composite structure 11 to obtain a third composite structure 13.

[0097] ​​​​​​​​​​​​​​​For example, the surface of the functional film layer 103 in the second transition structure 16 and the surface of the first isolation layer 102 in the first composite structure 11 are activated respectively to obtain the third composite structure 13.

[0098] For another example, referring to Figure 3 , the second transition structure 16 can be an LN / SI structure and the first composite structure 11 can be an SI / SiO2 structure. In a specific implementation, the LN layer in the LN / SI structure and the SiO2 layer in the SI / SiO2 structure are activated respectively to bond the LN / SI structure and the SI / SiO2 structure to obtain an SI / SiO2 / LN / SI structure, i.e., the third composite structure 13.

[0099] S700: The first substrate layer 101 in the third composite structure 13 is removed to obtain a fourth composite structure 14.

[0100] For example, the SI layer in the SI / SiO2 / LN / SI structure is removed by chemical etching to obtain an SiO2 / LN / SI structure, i.e., the fourth composite structure 14.

[0101] For example, the SI layer in the SI / SiO2 / LN / SI structure is removed by chemical etching to obtain an SiO2 / LN / SI structure, i.e., the fourth composite structure 14.

[0102] Of course, the SI layer in the SI / SiO2 / LN / SI structure can also be removed by a CMP process to obtain an SiO2 / LN / SI structure, i.e., the fourth composite structure 14.

[0103] S800: The surface of the first isolation layer 102 in the fourth composite structure 14 and the surface of the defect layer 107 in the second composite structure 12 are bonded to obtain a first composite film 21.

[0104] In a specific implementation, the surface of the first isolation layer 102 in the fourth composite structure 14 and the surface of the defect layer 107 in the second composite structure 12 are activated respectively to bond the fourth composite structure 14 and the second composite structure 12 to obtain the first composite film 21.

[0105] For example, the SiO2 layer in the SiO2 / LN / SI structure and the P-SI layer in the SI / P-SI structure are activated respectively to bond the SiO2 / LN / SI structure and the SI / P-SI structure to obtain an SI / P-SI / SiO2 / LN / SI structure, i.e., the first composite film 21.

[0106] S900: The third substrate layer 108 in the first composite film 21 is removed to obtain a second composite film 22.

[0107] In a specific implementation, the SI layer in the SI / P-SI / SiO2 / LN / SI structure is removed to obtain a SI / P-SI / SiO2 / LN structure.

[0108] It should be noted that in this embodiment, the thickness of the isolation layer 109 is the thickness of the first isolation layer 102, and the thickness of the isolation layer 109 is 7 μm to 25 μm, i.e. the thickness of the first isolation layer 102.

[0109] Embodiment Two

[0110] Figure 5 is a method flow of a preparation method of a composite film provided in an embodiment of the present application Figure Three ; Figure 6 is a method flow of a preparation method of a composite film provided in an embodiment of the present application Figure Four ; Figure 7 is Figure 5 a step of a preparation method of a composite film in Figure Two .

[0111] The present embodiment provides a preparation method of a composite film, in a specific implementation, referring to Figures 5 to 7 , comprising the following steps:

[0112] S100: preparing a first isolation layer 102 on the surface of the first substrate layer 101 to obtain a first composite structure 11.

[0113] For example, a thermal oxidation method can be used to prepare the first isolation layer 102 on the surface of the first substrate layer 101 to obtain the first composite structure 11.

[0114] For example, referring to Figure 5 , taking the SI substrate as an example, the surface of the SI substrate is thermally oxidized to obtain SiO2, forming an SI / SiO2 structure, i.e. the first composite structure 11. In a specific implementation, the oxidation temperature of thermal oxidation is 500°C±50°C. It should be noted that if the SiO2 layer is prepared on the surface of the defect layer 107 by using a conventional layering method at a temperature of 500°C±50°C, the crystal lattice of the defect layer 107 will be damaged due to the high temperature.

[0115] It should be noted that thermal oxidation is a process of oxidizing the surface of the SI substrate with oxygen to form a SiO2 oxidation layer.

[0116] Of course, in a specific implementation, in addition to using the SI substrate, the first substrate layer 101 can also use SOI.

[0117] S200: preparing a defect layer 107 on the surface of the second substrate layer 106 to obtain a second composite structure 12.

[0118] For example, the second substrate layer 106 can be formed by deposition on the surface of the second substrate layer 106. For example, referring to Figure 5 For example, the second substrate layer 106 can be formed by deposition on the surface of the second substrate layer 106. For example, referring to

[0119] For example, the second substrate layer 106 can be formed by deposition on the surface of the second substrate layer 106. For example, referring to

[0120] For example, the second substrate layer 106 can be formed by deposition on the surface of the second substrate layer 106. For example, referring to

[0121] S300: The composite layer 19 is prepared by ion implantation.

[0122] The composite layer 19 includes the functional thin film layer 103, the implantation layer 104, and the residual layer 105.

[0123] In a specific implementation, a thin film substrate is prepared, and the thin film substrate is formed into the functional thin film layer 103, the implantation layer 104, and the residual layer 105 by ion implantation.

[0124] For example, the thin film substrate can be made of lithium niobate crystal material, potassium titanium oxide phosphate crystal material, or rubidium titanium oxide phosphate crystal material. In the embodiment, the thin film substrate is made of lithium niobate crystal, and the functional thin film layer is made of lithium niobate crystal material (LN).

[0125] For example, the ions implanted by the ion implantation method can be hydrogen ions, helium ions, nitrogen ions, oxygen ions, or argon ions. The implantation energy of the ion implantation method is 50 KeV-1000 KeV, and the implantation dose is 1×10 16 ions / cm 17 ions / cm 2 For example, when hydrogen ions are implanted, the implantation dose can be 3×10 16 ions / cm 2 ions / cm 16 ions / cm 2 For example, when helium ions are implanted, the implantation dose can be 1×10 16 ions / cm 2 ions / cm 17 ions / cm 2 For example, when hydrogen ions are implanted, the implantation dose can be 4×10 16ions / cm 2 The injection energy can be 180 keV; when injecting helium ions, the injection dose is 4 × 10⁻⁶. 16 ions / cm 2 The injected energy was 200 keV. Further details will not be elaborated here.

[0126] S400: The surface of the functional thin film layer 103 in the composite layer 19 and the surface of the first isolation layer 102 in the first composite structure 11 are bonded to obtain the third transition structure 17.

[0127] For example, after activating the surface of the functional thin film layer 103 and the surface of the first isolation layer 102 respectively, they are bonded to bond the composite layer 19 and the first composite structure 11 to obtain the third transition structure 17.

[0128] S500: Remove the injection layer 104 and the residual mass layer 105 from the third transition structure 17 to obtain the fourth transition structure 18.

[0129] For example, annealing the third transition structure 17 breaks the injection layer 104, so that the residual layer 105 is peeled off from the surface of the functional thin film layer 103 along the injection layer 104 to obtain the fourth transition structure 18.

[0130] In practice, the third transition structure 17 is annealed. After annealing, the injection layer 104 is fractured, allowing the residual layer 105 to peel off from the third transition structure 17 along the injection layer 104, thus obtaining the fourth transition structure 18. (Refer to...) Figure 6 Taking the first substrate layer 101 as an SI substrate and the thin film substrate as a lithium niobate crystal material as an example, the fourth transition structure 18 is a SI / SiO2 / LN structure.

[0131] S600: The surface of the third substrate layer 108 and the surface of the functional thin film layer 103 in the fourth transition structure 18 are bonded to obtain the third composite structure 13.

[0132] For example, the surfaces of the third substrate layer 108 and the functional thin film layer 103 in the fourth transition structure 18 are activated to bond the third substrate layer 108 and the fourth transition structure 18, thereby obtaining the third composite structure 13. For example, refer to Figure 6 The third substrate 108 is an SI substrate, and the fourth transition structure 18 is a SI / SiO2 / LN structure. Therefore, the third composite structure 13 can be obtained as a SI / SiO2 / LN / SI structure.

[0133] It should be noted that, in addition to using a SI substrate, the third substrate 108 can also use an SOI substrate.

[0134] It should be further explained that in this step, the third substrate layer 108 surface and the functional thin film layer 103 surface are bonded, so as to support the functional thin film layer 103 and avoid the functional thin film layer 103 from being broken in subsequent operations, thereby affecting the quality of the composite film.

[0135] S700: removing the first substrate layer 101 in the third composite structure 13 to obtain a fourth composite structure 14.

[0136] For example, the first substrate layer 101 in the third composite structure 13 can be removed by a chemical etching method to obtain the fourth composite structure 14.

[0137] For example, referring to Figure 6 , the SI in the SI / SiO2 / LN / SI structure is removed by a chemical etching method to obtain the SiO2 / LN / SI structure, i.e. the fourth composite structure 14.

[0138] S800: bonding the surface of the first isolation layer 102 in the fourth composite structure 14 and the surface of the defect layer 107 in the second composite structure 12 to obtain a first composite film 21.

[0139] In a specific implementation, the surface of the first isolation layer 102 in the fourth composite structure 14 and the surface of the defect layer 107 in the second composite structure 12 are activated respectively to bond the fourth composite structure 14 and the second composite structure 12, thereby obtaining the first composite film 21.

[0140] For example, referring to Figure 6 , the SiO2 layer in the SiO2 / LN / SI structure and the P-SI layer in the SI / P-SI structure are activated respectively to bond the SiO2 / LN / SI structure and the SI / P-SI structure, thereby obtaining the SI / P-SI / SiO2 / LN / SI structure, i.e. the first composite film 21.

[0141] S900: removing the third substrate layer 108 in the first composite film 21 to obtain a second composite film 22.

[0142] In a specific implementation, the SI layer in the SI / P-SI / SiO2 / LN / SI structure is removed to obtain the SI / P-SI / SiO2 / LN.

[0143] It should be noted that in this embodiment, the thickness of the isolation layer 109 is the thickness of the first isolation layer 102, and the thickness of the isolation layer 109 is 7 μm to 25 μm, i.e. the thickness of the first isolation layer 102 is 7 μm to 25 μm.

[0144] In some other examples, i.e. in Embodiment One and Embodiment Two, S200 can specifically be: after the surface of the second substrate layer 106 is deposited to obtain the defect layer 107, a second isolation layer 109 is prepared on the surface of the defect layer 107 to obtain the second composite structure 12.

[0145] For example, the second isolation layer can be prepared by thermal oxidation or deposition. Taking the second substrate layer 106 as SI for example, the surface of the SI layer is deposited to obtain the defect layer 107, i.e. the surface of the SI layer is deposited to obtain the P-SI layer to form the SI / P-SI structure, and then the surface of the P-SI layer is subjected to thermal oxidation or deposition to obtain the SIO2 layer, i.e. the SI / P-SI / SIO2 structure is formed, which is the second composite structure 12.

[0146] Further, S800 in Embodiment One and S800 in Embodiment Two can specifically be: the surface of the second isolation layer 109 in the second composite structure 12 and the surface of the first isolation layer 102 in the fourth composite structure 14 are respectively subjected to activation treatment to bond the fourth composite structure 14 and the second composite structure 12 to obtain the first composite film 21.

[0147] For example, the fourth composite structure 14 is the SIO2 / LN / SI structure, and the second composite structure 12 is the SI / P-SI / SIO2 structure. The SIO2 layer in the SIO2 / LN / SI structure and the SIO2 layer in the SI / P-SI / SIO2 structure are respectively subjected to activation treatment to bond the SIO2 / LN / SI structure and the SI / P-SI / SIO2 structure to obtain the SI / P-SI / SIO2 / LN / SI, which is the first composite film 21.

[0148] It should be noted that at this time, the thickness of the isolation layer 109 is the sum of the thickness of the first isolation layer 102 and the thickness of the second isolation layer 109.

[0149] For example, if the staff wants to obtain an isolation layer 109 with a thickness of 10 μm, the thickness of the first isolation layer 102 can be 4 μm, and the thickness of the second isolation layer can be 6 μm; or the thickness of the first isolation layer 102 can be 3 μm, and the thickness of the second isolation layer can be 7 μm.

[0150] The embodiment of the present application provides a preparation method of a composite film. In the embodiment of the present application, a first oxidation layer is prepared on the surface of the first substrate layer 101, a defect layer 107 is prepared on the surface of the second substrate layer 106, then the third substrate layer 108 is used as support to prepare a functional film layer 103, finally, the prepared fourth composite structure 14 and the second composite structure 12 are bonded to obtain the composite film with the defect layer 107 and the thick thickness of the isolation layer 109, so that the defect layer 107 and the first oxidation layer can be prepared separately, the temperature for preparing the first oxidation layer is limited to reduce the influence of temperature on the crystal lattice of the defect layer 107 when the first isolation layer 102 is prepared on the surface of the defect layer 107, so that the preparation time of the first oxidation layer is longer, and in addition, the third substrate layer 108 can support the functional film layer 103 to prepare the functional film layer 103 with a target thickness. Therefore, by the arrangement of the embodiment of the present application, the preparation time of the composite film can be shortened, and the production efficiency is improved.

[0151] It is easy to understand that, on the basis of the several embodiments provided in the present application, the embodiments of the present application can be combined, split, recombined and the like to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.

[0152] The above specific embodiments further specifically explain the purposes, technical solutions and beneficial effects of the embodiments of the present application, and it should be understood that the above is only the specific embodiment of the present application, and is not used to limit the protection scope of the embodiments of the present application, and any modification, equivalent replacement, improvement and the like made on the basis of the technical solutions of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A method for preparing a composite thin film, characterized in that, Includes the following steps: A first isolation layer (102) is prepared on the surface of the first substrate layer (101) to obtain a first composite structure (11); A defect layer (107) is prepared on the surface of the second substrate layer (106) to obtain the second composite structure (12); In the first composite structure (11), a functional thin film layer (103) and a third substrate layer (108) are sequentially prepared on the surface of the first isolation layer (102) to obtain the third composite structure (13); The first substrate layer (101) in the third composite structure (13) is removed to obtain the fourth composite structure (14); The surface of the first isolation layer (102) in the fourth composite structure (14) and the surface of the defect layer (107) in the second composite structure (12) are bonded together to obtain the first composite film (21); The third substrate layer (108) in the first composite film (21) is removed to obtain the second composite film (22).

2. The method for preparing a composite thin film according to claim 1, characterized in that, The process involves sequentially fabricating a functional thin film layer (103) and a third substrate layer (108) on the surface of the first isolation layer (102) in the first composite structure (11) to obtain the third composite structure (13); specifically including the following steps: After the functional thin film layer (103) is prepared on the surface of the third substrate layer (108), the surface of the functional thin film layer (103) is bonded to the surface of the first isolation layer (102) in the first composite structure (11) to obtain the third composite structure (13); or, after the functional thin film layer (103) is prepared on the surface of the first isolation layer (102) in the first composite structure (11), the surface of the third substrate layer (108) is bonded to the surface of the functional thin film layer (103) to obtain the third composite structure (13).

3. The method for preparing a composite thin film according to claim 2, characterized in that, After fabricating a functional thin film layer (103) on the surface of the third substrate layer (108), the surface of the functional thin film layer (103) is bonded to the surface of the first isolation layer (102) in the first composite structure (11) to obtain the third composite structure (13); or, after fabricating the functional thin film layer (103) on the surface of the first isolation layer (102) in the first composite structure (11), the surface of the third substrate layer (108) is bonded to the surface of the functional thin film layer (103) to obtain the third composite structure (13); specifically including the following steps: After the functional thin film layer (103) is prepared on the surface of the third substrate layer (108) by ion implantation, the surface of the functional thin film layer (103) is bonded to the surface of the first isolation layer (102) in the first composite structure (11) to obtain the third composite structure (13); or, after the functional thin film layer (103) is prepared on the surface of the first isolation layer (102) in the first composite structure (11) by ion implantation, the surface of the third substrate layer (108) is bonded to the surface of the functional thin film layer (103) to obtain the third composite structure (13).

4. The method for preparing a composite thin film according to claim 3, characterized in that, After the functional thin film layer (103) is prepared on the surface of the third substrate layer (108) by ion implantation, the surface of the functional thin film layer (103) is bonded to the surface of the first isolation layer (102) in the first composite structure (11) to obtain the third composite structure (13); specifically including the following steps: The composite layer (19) is prepared by ion implantation; wherein the composite layer (19) comprises a functional thin film layer (103), an implantation layer (104), and a residual layer (105) stacked sequentially. The surface of the functional thin film layer (103) in the composite layer (19) and the surface of the third substrate layer (108) are bonded together to obtain the first transition structure (15); The second transition structure (16) is obtained by removing the injection layer (104) and the residual mass layer (105) from the first transition structure (15); The surface of the functional thin film layer (103) in the second transition structure (16) is bonded to the surface of the first isolation layer (102) in the first composite structure (11) to obtain the third composite structure (13).

5. The method for preparing a composite thin film according to claim 4, characterized in that, The process of removing the injection layer (104) and the residual mass layer (105) from the first transition structure (15) to obtain the second transition structure (16) specifically includes the following steps: Annealing the first transition structure (15) breaks the injection layer (104), so that the residual layer (105) is peeled off from the surface of the functional thin film layer (103) along the injection layer (104) to obtain the second transition structure (16).

6. The method for preparing a composite thin film according to claim 3, characterized in that, After fabricating a functional thin film layer (103) on the surface of the first isolation layer (102) in the first composite structure (11) using ion implantation, the surface of the third substrate layer (108) and the surface of the functional thin film layer (103) are bonded together to obtain the third composite structure (13); specifically including the following steps: The composite layer (19) is prepared by ion implantation; wherein the composite layer (19) comprises a functional thin film layer (103), an implantation layer (104), and a residual layer (105) stacked sequentially. The surface of the functional thin film layer (103) in the composite layer (19) and the surface of the first isolation layer (102) in the first composite structure (11) are bonded to obtain the third transition structure (17); The fourth transition structure (18) is obtained by removing the injection layer (104) and the residual mass layer (105) from the third transition structure (17); The surface of the third substrate layer (108) and the surface of the functional thin film layer (103) in the fourth transition structure (18) are bonded together to obtain the third composite structure (13).

7. The method for preparing a composite thin film according to claim 6, characterized in that, The fourth transition structure (18) is obtained by removing the injection layer (104) and the residual mass layer (105) from the third transition structure (17); specifically, the following steps are included: Annealing the third transition structure (17) breaks the injection layer (104), so that the residual layer (105) is peeled off from the surface of the functional thin film layer (103) along the injection layer (104) to obtain the fourth transition structure (18).

8. A method for preparing a composite thin film according to any one of claims 1-7, characterized in that, The third substrate layer (108) in the first composite film (21) is removed to obtain the second composite film (22); specifically including the following steps: The third substrate layer (108) is removed by CMP process or chemical etching method.

9. A method for preparing a composite thin film according to any one of claims 1-7, characterized in that, An isolation layer (109) is formed between the defect layer (107) and the functional thin film layer (103), the isolation layer (109) including at least the first isolation layer (102).

10. The method for preparing a composite thin film according to claim 9, characterized in that, The thickness of the isolation layer (109) is 7μm to 25μm.

11. The method for preparing a composite thin film according to claim 9, characterized in that, The thickness of the first isolation layer (102) is equal to the thickness of the isolation layer (109).

12. The method for preparing a composite thin film according to claim 9, characterized in that, The surface of the first isolation layer (102) in the fourth composite structure (14) and the surface of the defect layer (107) in the second composite structure (12) are bonded together to obtain a first composite film (21); specifically including the following steps: The surface of the first isolation layer (102) in the fourth composite structure (14) and the surface of the defect layer (107) in the second composite structure (12) are activated respectively to bond the fourth composite structure (14) and the second composite structure (12) to obtain the first composite film (21).

13. The method for preparing a composite thin film according to claim 9, characterized in that, A defect layer (107) is prepared on the surface of the second substrate layer (106) to obtain a second composite structure (12); specifically including the following steps: After depositing the defect layer (107) on the surface of the second substrate layer (106), a second isolation layer is prepared on the surface of the defect layer (107) to obtain the second composite structure (12); wherein the sum of the thickness of the first isolation layer (102) and the thickness of the second isolation layer is equal to the thickness of the isolation layer (109), and the thickness of the second isolation layer is less than the thickness of the first isolation layer (102).

14. The method for preparing a composite thin film according to claim 13, characterized in that, The surface of the first isolation layer (102) in the fourth composite structure (14) and the surface of the defect layer (107) in the second composite structure (12) are bonded together to obtain a first composite film (21); specifically including the following steps: The surface of the second isolation layer in the second composite structure (12) and the surface of the first isolation layer (102) in the fourth composite structure (14) are activated respectively to bond the fourth composite structure (14) and the second composite structure (12) to obtain the first composite film (21).

15. A method for preparing a composite thin film according to any one of claims 1-7, characterized in that, The first substrate layer (101) is made of silicon or SOI; The second substrate (106) is made of one of the following materials: silicon, SOI, quartz, sapphire, or silicon carbide; The third substrate layer (108) is made of silicon or SOI.

16. A method for preparing a composite thin film according to any one of claims 1-7, characterized in that, The functional thin film layer (103) is made of one of the following materials: lithium niobate crystal material, potassium titanium oxyphosphate crystal material, or rubidium titanium oxyphosphate crystal material.

17. A composite film, characterized in that, The composite thin film is prepared by any one of claims 1-16, wherein the composite thin film comprises at least a second substrate layer (106), a defect layer (107), an isolation layer (109), and a functional thin film layer (103) stacked sequentially; wherein the thickness of the isolation layer (109) is 7 μm to 25 μm.

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