Method and system for wafer-level mass transfer printing of heterogeneous films

Abstract

The invention relates to a wafer-level massive heterogeneous film transfer printing method and system, and the method can transfer different types of materials to the same substrate through a wafer-level transfer printing method, thereby achieving the in-plane integration of a plurality of functional devices, and achieving the preparation of a plurality of types of systems under the same substrate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor hetero-integration, and particularly relates to a wafer-level mass transfer of hetero-thin films and a system. BACKGROUND

[0002] Wafer in-plane multi-material integration and multi-layer material stacking have become an important development trend for high-function-density electronic device preparation. However, due to the lattice and crystal type mismatch between materials, it is difficult to realize high-quality device-level hetero-integration between different thin film materials and between thin film materials and substrate materials, and due to the difference in the thermal expansion coefficient between different materials, there is thermal stress between the thin films after hetero-epitaxy, which affects the function and reliability of the device. Therefore, a new multi-layer stress-free thin film transfer technology is provided. SUMMARY

[0003] The technical problem to be solved by the application is to provide a wafer-level mass transfer of hetero-thin films, which can transfer different types of materials to the same substrate, thereby realizing in-plane integration of multiple functional devices, and further realizing preparation of multiple systems on the same substrate.

[0004] The application provides a wafer-level mass transfer of hetero-thin films, comprising the following steps:

[0005] S1. Providing n kinds of interface detachable hetero-wafers comprising functional thin films and original substrates, wherein n≥2;

[0006] S2. Arraying and etching the functional thin films, and then releasing the stress of the hetero-wafer until the functional thin films are completely detached from the original substrates;

[0007] S3. Transferring the obtained functional thin films to temporary substrates respectively, realizing in-plane integration of multiple hetero-materials in the temporary substrate wafer or vertical stacking of multiple functional thin films on the temporary substrate wafer;

[0008] S4. Activating the lower surface of the functional thin films on the temporary substrate and the upper surface of the target substrate;

[0009] S5. Pressing the activated functional thin films and the target substrate to promote the formation of stable chemical bonds at the interface of the functional thin films and the target substrate, and finally reinforcing the interface;

[0010] S6. Separating the temporary substrate to realize in-plane integration and multi-layer stacking of the n kinds of functional thin films and the target substrate.

[0011] Preferably, the size of the hetero-wafer in step S1 is 2-8 inches, and the number of structure layers is≥2 layers.

[0012] Preferably, the hetero-wafer in step S1 further comprises a sacrificial layer.

[0013] Preferably, the functional film in step S1 comprises at least one of Ga2O3, GaN, LiNbO3, LiTaO3, Al2O3, SiC.

[0014] Preferably, the etching pattern in step S2 is circular, rectangular or irregular, the etching depth is ≥ the thickness of the functional film, and the etching pattern spacing is ≥ 10 nm.

[0015] Preferably, the activation process parameters in step S4 are: the activation gas is Ar, N2 or O2, the activation time is 1-1000 s, the power is 1 mW-100 W, and the activation environment vacuum degree is 1x10 -6 -1x10 5 Pa.

[0016] Preferably, the pressurization process parameters in step S5 are: the pressurization time is 1-1000 s, and the pressure is 1-100000 N.

[0017] Preferably, the interface reinforcement process parameters in step S5 are: the annealing temperature is 300-1000℃, and the annealing time is 1-30 h.

[0018] The application also provides a wafer-level mass transfer of a hetero thin film system, comprising a surface activation device, a transmission arm and a laser reinforcement module; the surface activation device is used to activate the lower surface of the functional film on the temporary substrate and the upper surface of the target substrate; the transmission arm is used to transfer the activated functional film and the target substrate; and the laser reinforcement module is used for interface reinforcement.

[0019] Advantages

[0020] The wafer-level transfer method of the application can transfer different types of materials to the same substrate, thereby realizing in-plane integration of multiple functional devices, and further realizing preparation of multiple systems on the same substrate, avoiding the disadvantages of large volume, high cost and significant parasitic effects caused by current die-to-wafer chip-level integration. In addition, by activating the surface of the material to be transferred and the transfer substrate material during the transfer process, in-situ hetero-interface reinforcement is realized, the stability of the material during the process is ensured, thereby meeting the urgent demand for high performance and small size of high performance radio frequency and optoelectronic module integration. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The process flowchart of the application.

[0022] Figure 2 The process flowchart of the application.

[0023] Figure 3 The transfer equipment schematic diagram of the application. DETAILED DESCRIPTION

[0024] The application is further described in conjunction with the specific embodiments. It is to be understood that these embodiments are merely used to illustrate the application and not to limit the scope of the application. Furthermore, it is to be understood that those skilled in the art can make various modifications or alterations to the application after reading the content of the application, and these equivalent forms are also within the scope of the appended claims.

[0025] Embodiment 1

[0026] As shown in Figure 1 and Figure 2 , as a specific embodiment, the embodiment provides a wafer-level massive transfer of a heterogeneous thin film method, comprising the following steps:

[0027] S1, providing four kinds of interface detachable heterogeneous wafers including functional thin films, sacrificial layers and original substrates; the functional thin films include Ga2O3, GaN, LiNbO3 and LiTaO3; the size of the heterogeneous wafer is 4 inches;

[0028] S2, arraying and etching the above-mentioned functional thin films, the etching pattern is a square, the thickness of the functional layer is 200 nm, the etching depth is 300 nm, the thickness of the intermediate sacrificial layer is 1 μm, and the etching pattern interval is 10 nm; then, stress release is performed on the heterogeneous wafer until the functional thin film is completely detached from the original substrate;

[0029] S3, transferring the obtained functional thin films to temporary substrates respectively, realizing the integration of multiple heterogeneous materials inside the temporary substrate wafer;

[0030] S4, activating the lower surface of the functional thin film on the temporary substrate and the upper surface of the target substrate, the activation gas is O2, the activation time is 100 s, the power is 10 W, and the activation environment vacuum degree is 1×10 -5 Pa;

[0031] S5, pressurizing the activated functional thin film and the target substrate, the pressurizing time is 60 s, the pressure is 10 N, promoting the formation of stable chemical bonds between the interface of the functional thin film and the target substrate, and finally performing interface reinforcement, the annealing temperature is 1000℃, and the annealing time is 5 h; S6, separating the temporary substrate, realizing the in-plane integration of the four kinds of functional thin films and the target substrate.

[0032] Embodiment 2

[0033] As shown in Figure 3As shown, the embodiment provides a wafer-level massive transfer printing heterogeneous film system, which comprises a surface activation device 1, a transmission arm 2 and a laser reinforcement module 3; the surface activation device 1 is used for activating the lower surface of the functional film on the temporary substrate and the upper surface of the target substrate; the transmission arm 2 is used for transferring the activated functional film and the target substrate; and the laser reinforcement module 3 is used for interface reinforcement.

Claims

1. A wafer-level mass transfer method for heterogeneous thin films, comprising the following steps: S1. Providing n types of heterogeneous wafers with detachable interfaces including functional films and original substrates, wherein: n≥2； S2, performing array etching on the functional film, and then performing stress release on the heterogeneous wafer until the functional film is completely separated from the original substrate; S3, transferring the obtained functional films onto a temporary substrate respectively, to achieve integration of multiple heterogeneous materials inside the temporary substrate wafer or vertical stacking of multiple functional films on the temporary substrate wafer; S4, activating the lower surface of the functional film on the temporary substrate and the upper surface of the target substrate; S5, pressurizing the activated functional film and the target substrate to promote the formation of a stable chemical bond at the interface between the functional film and the target substrate, and finally performing interface reinforcement; S6. Separate the temporary substrate to achieve in-plane integration and multi-layer stacking of n functional thin films with the target substrate.

2. The wafer-level mass transfer method for heterogeneous thin films according to claim 1, characterized in that: The size of the heterogeneous wafer in step S1 is 2-8 inches, and the number of structural layers is ≥2.

3. The wafer-level mass transfer method for heterogeneous thin films according to claim 1, characterized in that: The heterogeneous wafer in step S1 further includes a sacrificial layer.

4. The wafer-level mass transfer method for heterogeneous thin films according to claim 1, characterized in that: The functional film in step S1 includes at least one of Ga2O3, GaN, LiNbO3, LiTaO3, Al2O3, and SiC.

5. The wafer-level mass transfer method for heterogeneous thin films according to claim 1, characterized in that: The etching pattern in step S2 is circular, rectangular or irregular, the etching depth is greater than or equal to the thickness of the functional film, and the etching pattern spacing is greater than or equal to 10 nm.

6. The wafer-level mass transfer method for heterogeneous thin films according to claim 1, characterized in that: The activation process parameters in step S4 are: activation gas is Ar, N2 or O2, activation time is 1-1000s, power is 1mW-100W, activation environment vacuum is 1×10 -6 -1×10 5 Pa.

7. The wafer-level mass transfer method for heterogeneous thin films according to claim 1, characterized in that: The process parameters of the pressurization in step S5 are: pressurization time is 1-1000s, and pressure is 1-100000N.

8. The wafer-level mass transfer method for heterogeneous thin films according to claim 1, characterized in that: The process parameters for the interface reinforcement in step S5 are: annealing temperature of 300-1000° C., and annealing time of 1-30 h.

9. A wafer-level mass transfer heterogeneous thin film system, characterized by: The invention comprises a surface activation device (1), a transfer arm (2) and a laser reinforcement module (3); the surface activation device (1) is used to activate the lower surface of the functional film on the temporary substrate and the upper surface of the target substrate; the transfer arm (2) is used to transfer the activated functional film and the target substrate; The laser reinforcement module (3) is used for interface reinforcement.

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