Wafer composite film and method for manufacturing the same

Abstract

The application discloses a wafer composite film and a preparation method thereof, and belongs to the technical field of semiconductor preparation. The method comprises the following steps: (1) performing hydrogen ion or hydrogen-helium mixed ion implantation on a piezoelectric wafer to obtain an implanted wafer, wherein the implanted wafer comprises a film layer, an implanted layer and a residual layer in sequence; (2) sequentially forming a defect layer and a separation layer on a supporting substrate; (3) bonding the separation layer and the film layer of the implanted wafer to obtain a bonded body; (4) heating the implanted layer by using a laser, then performing annealing heat treatment on the bonded body to realize complete peeling of the film, and obtaining the wafer composite film after polishing and cleaning, wherein the wavelength of the laser is 100-700 nm, the power is 50 mw-100 w, and the scanning speed is 10-50 mm / s. The method can effectively realize complete peeling of the composite film, the combination of the laser and the heat annealing process has high process stability, and can greatly improve the yield of the composite film and shorten the time cost of composite film processing.

Description

TECHNICAL FIELD

[0001] The application relates to a wafer composite film and a preparation method thereof, and belongs to the technical field of semiconductor preparation. BACKGROUND

[0002] Lithium niobate or lithium tantalate piezoelectric wafer has the advantages of high Curie temperature, strong spontaneous polarization, high electromechanical coupling coefficient, excellent electro-optic effect and the like, and is widely used in the fields of nonlinear optics, ferroelectricity, piezoelectricity, electro-optics and the like. In recent years, composite films on insulators have attracted attention and attention of the industry, and the structure can be simply understood as a three-layer structure, wherein the uppermost functional layer, the intermediate dielectric layer and the semiconductor support substrate. The active layer can be a piezoelectric film such as lithium niobate and lithium tantalate. At present, the methods for preparing lithium niobate or lithium tantalate piezoelectric composite films mainly include ion beam separation method and thinning and polishing method.

[0003] In the ion beam separation method for preparing the composite film, the bonding body after bonding of the support substrate and the piezoelectric wafer after ion implantation needs to be annealed, so as to retain the film layer on the substrate layer, so as to prepare the piezoelectric composite film. However, in the actual annealing process, the piezoelectric wafer and the support substrate are usually heterogeneous materials, and there is a difference in the thermal expansion coefficient, which causes the bonding body to warp during heating, and a large force is generated on the piezoelectric film, thereby causing the composite film to break, and increasing the production cost of the composite film.

[0004] In order to solve the problem, patent CN118969628A discloses a method for preparing a thin film wafer based on laser peeling of a heterogeneous substrate crystal film, which focuses laser on the injection stop layer of the lithium niobate film sheet, so that the injection layer is quickly heated to realize peeling, and the thin film wafer and the substrate material away from the injection layer are slowly heated, which simply and efficiently solves the problem of fragments caused by the overall heating of the bonded wafer. In the case that the thermal expansion coefficients of the substrate and the film are inconsistent, the film is completely peeled off. The applicant finds that in the above laser peeling process, the laser can quickly heat the focused part to realize peeling, and during the laser scanning, the top of the wafer injection layer is peeled off but the bottom has not been peeled off, which will introduce a large peeling stress, thereby reducing the yield of the composite film preparation. At the same time, the instantaneous temperature reaches 400℃-600℃ due to the rapid heating of the laser, and since the thickness of the composite film is generally less than 2μm, which is very close to the bonding layer, the bonding body will be debonded, thereby affecting the preparation of the composite film. Therefore, it is necessary to develop a new preparation method of the composite film to solve the above problems. SUMMARY

[0005] In order to solve the above problems, a wafer composite film preparation method is provided. The method first performs laser heating on the injection layer of the bonded body, so that micro bubbles are formed between the thin film layer and the residual layer but are not separated, and then the complete separation of the composite film is realized by annealing heat treatment. The combination of laser and annealing process has high process stability, can greatly improve the yield of the composite film, and shorten the time cost of the composite film processing.

[0006] According to one aspect of the present application, a wafer composite film preparation method is provided, comprising the steps of:

[0007] (1) hydrogen ion or hydrogen-helium mixed ion injection is performed on a piezoelectric wafer to obtain an injection wafer, the injection wafer comprising a thin film layer, an injection layer and a residual layer in sequence;

[0008] (2) a defect layer and an isolation layer are formed in sequence on a support substrate;

[0009] (3) the isolation layer is bonded with the thin film layer of the injection wafer to obtain a bonded body;

[0010] (4) laser is used to heat the injection layer, and then the bonded body is subjected to annealing heat treatment, and after polishing and cleaning, a wafer composite film is obtained, the wavelength of the laser is 100-700 nm, the power is 50 mw-1w, and the scanning speed is 10-50 mm / s.

[0011] After hydrogen ion or hydrogen-helium mixed ion injection, the thin film layer, the injection layer and the residual layer are formed. The two kinds of ions can reduce the lattice damage to the thin film layer and reduce the total thickness deviation of the thin film layer, thereby improving the uniformity of the composite film. At the same time, the thickness of the injection layer is moderate. In step (4), the injection layer is heated by laser, and the core parameters such as wavelength and power of the laser are accurately controlled, so that a large number of bubbles are formed in the injection layer in a short time. Then, the bonded body is subjected to annealing heat treatment to realize the complete separation of the thin film, and the stress of the thin film layer can be reduced.

[0012] Optionally, the annealing heat treatment of step (4) is:

[0013] Primary annealing heat treatment: temperature 100-300℃, annealing time 1min-60min;

[0014] Secondary annealing heat treatment: temperature 350℃-500℃, annealing time 1-8h.

[0015] The above annealing heat treatment is divided into two steps. The primary annealing can realize the separation of the thin film, and the secondary annealing can repair the lattice damage caused by ion injection. The above secondary heat treatment can reduce the stress of the composite film and improve the quality of the composite film.

[0016] Optionally, the energy of the hydrogen ion implantation in step (1) is 50KeV-1000KeV, and the dosage is 3x10 15 ions / cm 2 . 18 ions / cm 2 .

[0017] More preferably, the implantation can be performed in 3-10 steps, the energy of each implantation is constant, and the dosage is evenly distributed according to the total required dosage. For example, if the energy required for implantation is 200KeV, and the dosage is 8x10 16 ions / cm 2 , when the implantation is performed in 10 times, the energy of each implantation is 200KeV, and the dosage is 8x10 15 ions / cm 2 . Multiple implantations can reduce the warpage of the wafer during ion implantation and improve the uniformity of the film. During ion implantation, the particle beam generated by the shower is used to spray the ion beam to reduce the surface particles of the implanted wafer.

[0018] The greater the energy of the hydrogen ion implantation, the deeper the depth of the implanted layer, and vice versa.

[0019] Optionally, when the hydrogen-helium mixed ion implantation is performed in step (1), the ratio of hydrogen ions to helium ions is 1:(2-5).

[0020] Under this setting, the total dosage of ions required for implantation can be significantly reduced, and the temperature required for annealing can be reduced.

[0021] Preferably, the energy of the hydrogen-helium mixed ion implantation is 50KeV-1000KeV, and the dosage is 3x10 15 ions / cm 2 -8x10 16 ions / cm 2 .

[0022] More preferably, the implantation can be performed in 3-10 steps, the energy of each implantation is constant, and the dosage is evenly distributed according to the total required dosage. For example, if the energy required for implantation is 200KeV, and the dosage is 8x10 15 ions / cm 2 , when the implantation is performed in 10 times, the energy of each implantation is 200KeV, and the dosage is 8x10 15 ions / cm 2 . Multiple implantations can reduce the warpage of the wafer during ion implantation and improve the uniformity of the film. During ion implantation, the particle beam generated by the shower is used to spray the ion beam to reduce the surface particles of the implanted wafer.

[0023] The greater the energy of the hydrogen-helium mixed ion implantation, the deeper the depth of the implantation layer, and vice versa. In this way, the depth of the implantation layer is moderate, which facilitates the separation of the thin film layer and the substrate, and the composite thin film is stable in performance.

[0024] The energy of the ion implantation also affects the thickness of the thin film layer. The greater the energy of the implantation, the greater the thickness of the thin film layer, and the smaller the energy of the implantation, the smaller the thickness of the thin film layer. In this way, the thickness of the thin film layer is in the range of 100 nm to 3000 nm, which meets the use requirements of the composite thin film.

[0025] Optionally, the thickness of the thin film layer is 100 nm to 3000 nm, the surface roughness of the thin film layer is less than 0.5 nm, and the warping and bending of the composite thin film are less than 20 μm.

[0026] Optionally, the material of the isolation layer is at least one of silicon dioxide, silicon oxynitride, and silicon nitride, the thickness of the isolation layer is 100 nm to 5000 nm, and the surface roughness of the isolation layer is less than 1 nm.

[0027] Optionally, the material of the defect layer is at least one of polysilicon, amorphous silicon, and polycrystalline germanium, and the thickness of the defect layer is 100 nm to 3000 nm.

[0028] Optionally, the piezoelectric wafer is one of lithium niobate, lithium tantalate, quartz, lithium tetraborate, and lanthanum gallium silicate.

[0029] The support substrate is at least one of sapphire, silicon, silicon carbide, quartz, diamond, gallium nitride, and gallium arsenide, and is preferably silicon.

[0030] Optionally, the initial thickness of the piezoelectric wafer and the support substrate is 100 μm to 1000 μm, and the diameter of the piezoelectric wafer and the support substrate is 3 inches to 12 inches.

[0031] Preferably, the thickness of the support substrate is 625 μm.

[0032] Optionally, the defect layer is formed by a deposition method, and the isolation layer is formed by a deposition method or an oxidation method. The deposition method is not limited, and can be chemical vapor deposition (CVD), physical vapor deposition (PVD), magnetron sputtering, etc.

[0033] According to another aspect of the present application, a wafer composite thin film prepared by the preparation method of any one of the above is provided.

[0034] The beneficial effects of the present application include but are not limited to:

[0035] 1. According to the wafer composite film preparation method of this application, the supporting substrate and piezoelectric wafer are not heated during the initial heating of the injection layer by laser. Afterwards, the entire bond is subjected to annealing heat treatment. This can avoid the composite film breakage caused by the difference in thermal expansion coefficients between the piezoelectric wafer and the supporting substrate during annealing separation, thereby improving the yield of piezoelectric composite films and reducing the production cost of composite films. It can also avoid the debonding of the bond due to excessively high laser temperature, thereby improving the yield of composite films.

[0036] 2. According to the wafer composite thin film preparation method of this application, controlling the wavelength, power and scanning speed of the laser to heat the injection layer can ensure that uniformly arranged microbubbles are formed on the surface of the injection layer in contact with the thin film layer and the residual layer, which lays the foundation for subsequent annealing heat treatment. In the subsequent annealing heat treatment, the annealing time can be reduced, greatly shortening the time cost, while improving the uniformity of the thin film.

[0037] 3. According to the wafer composite thin film preparation method of this application, hydrogen ions or hydrogen-helium mixed ions are used for ion implantation to obtain implanted wafers, which can significantly reduce the total ion dose required for implantation and reduce the temperature required for annealing.

[0038] 4. According to the wafer composite thin film preparation method of this application, annealing is used in the annealing heat treatment to achieve film peeling and repair lattice damage caused by ion implantation. The temperature of the first annealing is 100-300℃ to achieve film peeling, and the temperature of the second annealing is 350-500℃ to repair lattice damage caused by ion implantation. Furthermore, the above-mentioned two-stage heat treatment annealing can reduce the stress of the composite thin film and improve the quality of the composite thin film.

[0039] 5. According to the wafer composite thin film preparation method of this application, the ratio, energy, and dosage of hydrogen-helium mixed ions can achieve a suitable depth of implantation layer, thereby facilitating the peeling of the thin film layer and the residual layer, resulting in a composite thin film with complete peeling and more stable performance. Attached Figure Description

[0040] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0041] Figure 1 This is a schematic diagram of the process for preparing composite films according to embodiments of this application.

[0042] Figure 2 This is a schematic diagram of the structural process for preparing composite films according to embodiments of this application.

[0043] Figure 3A schematic diagram of a laser heating injection layer scanning method for preparing a composite thin film according to an embodiment of the present application.

[0044] Parts and reference numeral list:

[0045] 110 - piezoelectric wafer, 1101 - thin film layer, 1102 - injection layer, 1103 - residual layer, 120 - support substrate, 1301 - defect layer, 1302 - isolation layer, 140 - bonded body, 1401 - injection layer with bubbles. DETAILED DESCRIPTION

[0046] The present application will be described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0047] Unless otherwise specified, the raw materials in the examples and comparative examples of the present application are purchased through commercial channels.

[0048] Unless otherwise specified, the methods used in the examples and comparative examples of the present application are conventional methods in the prior art.

[0049] EXAMPLES

[0050] REFERENCE Figure 1 The present embodiment relates to a method for preparing a wafer composite thin film, comprising the steps of:

[0051] (1) hydrogen ions or hydrogen-helium mixed ions are injected into a piezoelectric wafer 110 to obtain an injection wafer, the injection wafer comprises a thin film layer 1101, an injection layer 1102 and a residual layer 1103 in sequence;

[0052] (2) a defect layer 1301 and an isolation layer 1302 are formed in sequence on a support substrate 120;

[0053] (3) the isolation layer 1302 is bonded with the thin film layer 1101 of the injection wafer to obtain a bonded body 140;

[0054] (4) the injection layer 1102 is heated by laser, and then the bonded body 140 is subjected to annealing heat treatment, after removing the residual layer 1103, polishing and cleaning, a wafer composite thin film is obtained, the wavelength of the laser is 100-700 nm, the power is 50 mw-1 w, and the scanning speed is 10-50 mm / s.

[0055] Specifically, the application does not particularly limit the bonding method, and any bonding method in the prior art can be used, for example, surface activation is used to bond the thin film layer 1101 of the piezoelectric wafer 110, the bonding surface of the isolation layer 1302 of the support composite substrate is also activated, and then the two activated surfaces are bonded to obtain the bonding body 140. The application also does not limit the surface activation method, for example, plasma activation or chemical solution activation can be used.

[0056] As an embodiment, the thin film layer 1101 and the isolation layer 1302 are activated by plasma activation before bonding, and the parameters of the plasma activation are as follows: the vacuum degree of the plasma activation chamber is not more than 1×10 -2 Pa, the flow rate of the oxygen plasma gas used is 100-500sccm, the flow rate of the nitrogen plasma gas is 100-500sccm, the power of the plasma emitter is 10-500W, and the process time is 15-90s.

[0057] Specifically, the application does not particularly limit the direction and number of times of laser scanning when the laser heats the injection layer 1102, and the application gives a schematic diagram of the scanning direction, for example, Figure 2 (a) scanning perpendicular to the positioning flat edge, Figure 2 (b) scanning at an angle to the positioning flat edge, Figure 2 (c) scanning twice at an angle to the positioning flat edge, and Figure 2 (d) scanning twice perpendicular and parallel to the positioning flat edge. Figure 2

[0058] Specifically, the application does not particularly limit the polishing method, and any polishing method in the prior art can be used, for example, chemical mechanical polishing is used for polishing. The application also does not limit the cleaning method, for example, the standard semiconductor RCA cleaning method can be used for cleaning.

[0059] As an embodiment, the annealing heat treatment of step (4) is as follows:

[0060] First annealing heat treatment: the temperature is 100-300℃, and the annealing time is 1min-60min;

[0061] Second annealing heat treatment: the temperature is 350-500℃, and the annealing time is 1-8h.

[0062] As an embodiment, the energy of the hydrogen ion implantation in step (1) is 50KeV-1000KeV, and the dose is 3×10 15 ions / cm​2 ~2x10 18 ions / cm 2 .

[0063] As an embodiment, the ratio of hydrogen ions and helium ions is 1: (2-5) when step (1) is performed by hydrogen-helium mixed ion implantation.

[0064] As an embodiment, the energy of hydrogen-helium mixed ion implantation is 50KeV-1000KeV, and the dose is 3x10 15 ions / cm 2 ~8x10 16 ions / cm 2 .

[0065] As an embodiment, the thickness of the thin film layer 1101 is 100nm-3000nm, and the surface roughness of the thin film layer 1101 is less than 0.5nm.

[0066] As an embodiment, the material of the isolation layer 1302 is at least one of silicon dioxide, silicon oxynitride, and silicon nitride, the thickness of the isolation layer 1302 is 100nm-5000nm, and the surface roughness of the isolation layer 1302 is less than 1nm.

[0067] As an embodiment, the material of the defect layer 1301 is at least one of polysilicon, amorphous silicon, and polycrystalline germanium, and the thickness of the defect layer 1301 is 100nm-3000nm.

[0068] As an embodiment, the piezoelectric wafer 110 is one of lithium niobate, lithium tantalate, quartz, lithium tetraborate, and lanthanum gallium silicate.

[0069] The support substrate 120 is at least one of sapphire, silicon, silicon carbide, quartz, diamond, gallium nitride, and gallium arsenide.

[0070] As an embodiment, the initial thickness of the piezoelectric wafer 110 and the support substrate 120 is 100μm-1000μm, and the diameter of the piezoelectric wafer 110 and the support substrate 120 is 3in-12in.

[0071] According to the preparation method described above, the following composite thin film is prepared as follows:

[0072] Composite film 1#:

[0073] (1) Provide 3-inch, 100μm lithium tantalate wafers and silicon carbide wafers, and perform semiconductor-grade RCA cleaning on the two wafers to obtain wafers with clean surfaces. Perform hydrogen ion implantation on the lithium tantalate wafers, and the implantation dose is 5x10 16 ions / cm 2, the injection energy is 180KeV, and a three-layer structure injection wafer with a film layer, an injection layer and a residual layer is formed;

[0074] (2) Polysilicon is deposited on the cleaned silicon carbide wafer by using the LPCVD process to form a defect layer, the deposition temperature is controlled at 610℃, the deposition thickness is 100nm, then a silicon dioxide layer is deposited on the polysilicon by using the PECVD method to form an isolation layer, the deposition thickness is 100nm, then chemical mechanical polishing is performed to obtain a smooth surface, and finally RCA cleaning is performed to obtain a clean surface;

[0075] (3) The thin film layer of the injection wafer and the isolation layer of the silicon carbide wafer with a clean surface are subjected to plasma surface activation treatment, the parameters of the plasma activation are that the vacuum degree of the plasma activation chamber is not more than 1×10 -2 Pa, the oxygen plasma gas flow rate used is 100sccm, the nitrogen plasma gas flow rate is 500sccm, the plasma emitter power is 10W, the process time is 90s, and the activated wafer is bonded together at room temperature to form a bonded body;

[0076] (4) The injection layer of the bonded body is scanned by using a laser with a wavelength of 100nm, the power of the laser is 1w, the scanning is performed in a manner perpendicular to the positioning flat edge, the scanning speed is 10mm / s, then the bonded body is subjected to annealing heat treatment until the film layer and the residual layer are separated, the annealing heat treatment is specifically as follows: first annealing heat treatment: the temperature is 100℃, and the annealing time is 2h; second annealing heat treatment: the temperature is 350℃, and the annealing time is 8h; the lithium tantalate composite thin film is obtained by removing the residual layer, the lithium tantalate composite thin film is fixed on a porous ceramic chuck of a polishing device, then chemical mechanical polishing treatment is performed, and finally semiconductor-grade RCA cleaning is performed to obtain the composite thin film 1#.

[0077] Composite film 2#

[0078] (1) A 4-inch, 1000μm lithium niobate wafer and a silicon wafer are provided, and the two wafers are subjected to semiconductor-grade RCA cleaning to obtain wafers with clean surfaces, the lithium niobate wafer is subjected to hydrogen ion injection, the injection dose is 2×10 16 ions / cm 2 , the injection energy is 250KeV, and a three-layer structure injection wafer with a film layer, an injection layer and a residual layer is formed;

[0079] (2) After cleaning, polycrystalline silicon is deposited on the silicon carbide wafer by using the LPCVD process to form a defect layer, the deposition temperature is controlled at 580℃, the deposition thickness is 500nm, then the silicon dioxide layer is prepared on the polycrystalline silicon by using the oxidation method to form the isolation layer 1302 with a thickness of 5000nm, then the chemical mechanical polishing is performed to obtain a smooth surface, and finally the RCA cleaning is performed to obtain a clean surface;

[0080] (3) The thin film layer 1101 of the injection wafer and the isolation layer 1302 of the silicon wafer with clean surfaces are subjected to the plasma surface activation treatment, the plasma activation parameters are that the vacuum degree of the plasma activation chamber is not more than 1×10 -2 Pa, the oxygen plasma gas flow rate used is 500sccm, the nitrogen plasma gas flow rate is 100sccm, the plasma emitter power is 500W, the process time is 15s, and the activated wafer is bonded together at room temperature to form a bonded body.

[0081] (4) The injection layer of the bonded body is scanned by using the laser with a wavelength of 700nm, the power of the laser is 50mw, the scanning is performed in a manner that the positioning flat edge is at an angle of 30 degrees, the scanning speed is 50mm / s, then the bonded body is subjected to the annealing heat treatment until the thin film layer and the residual layer are separated, the annealing heat treatment is specifically as follows: the first annealing heat treatment: the temperature is 300℃, the annealing time is 1min; the second annealing heat treatment: the temperature is 500℃, the annealing time is 1h; the lithium niobate composite thin film is obtained by removing the residual layer, the lithium niobate composite thin film is fixed on the porous ceramic suction disc of the polishing equipment, then the chemical mechanical polishing treatment is performed, and finally the semiconductor-grade RCA cleaning is performed to obtain the composite thin film 2#.

[0082] Composite film 3#:

[0083] (1) The lithium tantalate wafer and the silicon wafer with a diameter of 6 inches and a thickness of 100μm are provided, and the two wafers are subjected to the semiconductor-grade RCA cleaning to obtain the wafers with clean surfaces, the lithium niobate wafer is subjected to the hydrogen ion injection, the injection dose is 6×10 16 ions / cm 2 , the injection energy is 100KeV, and a three-layer structure injection wafer with a thin film layer, an injection layer and a residual layer is formed;

[0084] (2) After cleaning, polycrystalline silicon is deposited on the silicon carbide wafer by using the LPCVD process to form a defect layer 1301, the deposition temperature is controlled at 600℃, the deposition thickness is 3000nm, then the silicon dioxide layer is deposited on the polycrystalline silicon by using the PECVD to form the isolation layer 1302 with a thickness of 800nm, then the chemical mechanical polishing is performed to obtain a smooth surface, and finally the RCA cleaning is performed to obtain a clean surface;

[0085] (3) The thin film layer and the isolation layer of the silicon wafer with a clean surface are subjected to ion plasma surface activation treatment, and the plasma activation parameters are that the vacuum degree of the plasma activation chamber is not more than 1x10 -2 Pa, the oxygen plasma gas flow rate used is 300 sccm, the nitrogen plasma gas flow rate is 350 sccm, the plasma emitter power is 300 W, the process time is 65 s, and the activated wafers are bonded together at room temperature to form a bonded body.

[0086] (4) The injection layer of the bonded body is scanned by a laser with a wavelength of 400 nm, the power of the laser is 1 w, the scanning is performed twice in parallel and perpendicular to the positioning flat edge, the scanning speed is 20 mm / s, and then the bonded body is subjected to annealing heat treatment until the thin film layer and the residual layer are separated, and the annealing heat treatment is specifically as follows: first annealing heat treatment: the temperature is 200℃, and the annealing time is 1 h; second annealing heat treatment: the temperature is 450℃, and the annealing time is 5 h; the lithium niobate composite thin film is obtained by removing the residual layer, the lithium niobate composite thin film is fixed on a porous ceramic suction disc of a polishing device, and then chemical mechanical polishing treatment is performed, and finally semiconductor grade RCA cleaning is performed to obtain the composite thin film 3#.

[0087] Composite film 4#:

[0088] The difference between the composite thin film and the composite thin film 3# is that in step (1), hydrogen-helium mixed ion implantation is adopted, the ratio of hydrogen ions to helium ions is 1:5, the implantation dose is 8x10 16 ions / cm 2 , the implantation energy is 50KeV, and the rest is the same as the composite thin film 3#.

[0089] Composite film 5#:

[0090] The difference between the composite thin film and the composite thin film 3# is that in step (1), hydrogen-helium mixed ion implantation is adopted, the ratio of hydrogen ions to helium ions is 1:2, the implantation dose is 3x10 15 ions / cm 2 , the implantation energy is 1000KeV, and the rest is the same as the composite thin film 3#.

[0091] Composite film 6#:

[0092] The difference between the composite thin film and the composite thin film 5# is that the ratio of hydrogen ions to helium ions is 1:1, and the rest is the same as the composite thin film 5#.

[0093] Composite film 7#:

[0094] The difference between the composite film and the composite film 5# is that the hydrogen-helium mixed ion injection dose is 10 x 10 16 ions / cm 2 , the injection energy is 50KeV, and the rest is the same as the composite film 5#.

[0095] Composite film 8#:

[0096] The difference between the composite film and the composite film 3# is that the annealing heat treatment is as follows: the first annealing heat treatment is at a temperature of 450℃ for 5h; the second annealing heat treatment is at a temperature of 200℃ for 1h, and the rest is the same as the composite film 3#.

[0097] Composite film 9#:

[0098] The difference between the composite film and the composite film 3# is that only one annealing heat treatment is performed: annealing at 300℃ for 6h, and the rest is the same as the composite film 3#.

[0099] Composite film 10#:

[0100] The difference between the composite film and the composite film 3# is that in step (1), the hydrogen ion injection is divided into 10 times, each injection energy is 100KeV, and the injection dose is 6 x 10 15 ions / cm 2 , and the rest is the same as the composite film 3#.

[0101] Composite film 11#:

[0102] The difference between the composite film and the composite film 5# is that in step (1), the hydrogen-helium mixed ion injection is divided into 3 times, each injection energy is 1000KeV, and the injection dose is 1 x 10 15 ions / cm 2 , and the rest is the same as the composite film 5#.

[0103] Comparative composite film D1#:

[0104] The difference between the comparative composite film and the composite film 3# is that in step (1), helium ion injection is used, the injection dose is 5 x 10 16 ions / cm 2 , and the injection energy is 200KeV.

[0105] Comparative composite film D2#:

[0106] The difference between the comparative composite film and the composite film 3# is that in step (4), the bonding body is not scanned by laser, but directly subjected to annealing heat treatment.

[0107] Comparative composite film D3#:

[0108] The difference between the comparative composite film and the composite film 3# is that only the injection layer of the bonding body is scanned by laser in step (4), the power of the laser is 2w, two scans are performed in parallel and perpendicular to the positioning flat edge, the scanning speed is 20mm / s, and no annealing heat treatment operation is performed.

[0109] Test example

[0110] The film layer thickness of each composite film prepared in the examples was tested, and the test results are shown in Table 1, and the total thickness deviation, yield, warpage and bending of the composite film were tested, and the test results are shown in Table 1.

[0111] Table 1

[0112]

[0113]

[0114] The above is only an embodiment of the present application, and the protection scope of the present application is not limited by these specific embodiments, but is determined by the claims of the present application. The present application can have various changes and variations for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the technical idea and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for manufacturing a wafer composite film, characterized by, The method comprises the steps of: (1) implanting hydrogen ions or hydrogen-helium mixed ions into a piezoelectric wafer to obtain an implanted wafer, the implanted wafer comprising a thin film layer, an implanted layer and a residual layer in sequence; (2) forming a defect layer and an isolation layer on a supporting substrate in sequence; (3) bonding the isolation layer and the thin film layer of the implanted wafer to obtain a bonded body; (4) heating the implanted layer by using a laser, then performing annealing heat treatment on the bonded body to remove the residual layer, and then polishing and cleaning the bonded body from which the residual layer is removed to obtain a wafer composite thin film, wherein the wavelength of the laser is 100-700 nm, the power is 50 mw-1 w, and the scanning speed is 10-50 mm / s.

2. The production method according to claim 1, characterized by, The annealing heat treatment in step (4) is specifically: first annealing heat treatment: temperature is 100-300℃, annealing time is 1 min-60 min; second annealing heat treatment: temperature is 350-500℃, annealing time is 1-8 h.

3. The preparation method according to claim 1, characterized in that, The energy for hydrogen ion implantation in step (1) is 50 KeV to 1000 KeV, and the dose is 3 x 1014 ions / cm2 to 2 x 1015 ions / cm2. 15 2 18 2 .​​​ 4. The method of claim 1, wherein, When hydrogen-helium mixed ions are implanted in step (1), the ratio of hydrogen ions to helium ions is 1:(2-5).

5. The preparation method according to claim 4, characterized in that, The energy of the hydrogen-helium mixed ion implantation is 50KeV-1000KeV, and the dosage is 3x10 15 ions / cm 2 ~8x10 16 ions / cm 2 .

6. The method of claim 1, wherein, The thickness of the thin film layer is 100 nm-3000 nm, and the surface roughness is less than 0.5 nm, and the warping degree and bending degree of the composite thin film are both less than 20 μm.

7. The preparation method according to claim 1, characterized in that, The material of the isolation layer is at least one of silicon dioxide, silicon oxynitride and silicon nitride, the thickness of the isolation layer is 100 nm-5000 nm, and the surface roughness of the isolation layer is less than 1 nm.

8. The method of claim 1, wherein, The material of the defect layer is at least one of polysilicon, amorphous silicon and polycrystalline germanium, and the thickness of the defect layer is 100 nm-3000 nm.

9. The method of claim 1, wherein, The piezoelectric wafer is one of lithium niobate, lithium tantalate, quartz, lithium tetraborate and lanthanum gallium silicate; The supporting substrate is at least one of sapphire, silicon, silicon carbide, quartz, diamond, gallium nitride and gallium arsenide.

10. The method of claim 1, wherein, The initial thickness of the piezoelectric wafer and the supporting substrate is 100 μm-1000 μm, and the diameter of the piezoelectric wafer and the supporting substrate is 3 inches-12 inches.

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