Wafer de-bonding method and structure based on porous metal electrochemical gas production

Abstract

The invention provides a wafer de-bonding method and structure based on porous metal electrochemical gas production, and belongs to the technical field of semiconductor manufacturing, and the method comprises the steps: sequentially preparing a SiO2 insulating layer and a porous metal layer on a bonding surface of a supporting carrier plate, and pressing and contacting a precision probe at the edge of the porous metal layer; coating temporary bonding glue to form a bonding intermediate layer, and bonding the device wafer with the supporting carrier plate; according to the present invention, the porous metal layer is integrated on the bonding interface to serve as the micro-anode, the high pressure gas is controllably generated in the interface nano-gap in situ through the electrochemical reaction, and the interface separation is achieved by using the gas pressure, such that the stable separation of the wafer is achieved through the gas pressure; the whole de-bonding process can be carried out at room temperature or near room temperature, so that the thermal stress problem is fundamentally avoided.

Description

Technical Field

[0001] This invention relates to the fields of semiconductor manufacturing and microelectromechanical systems manufacturing, and particularly to a wafer bonding and debonding technology, specifically a wafer debonding method and structure based on porous metal electrochemical gas generation. Background Technology

[0002] As semiconductor devices move towards ultra-thinness and high integration, wafer thinning technology has become a key technology for advanced packaging. Ultra-thin wafers (thickness less than 100μm) are prone to warping and breakage during processing. Therefore, temporary bonding technology is needed to temporarily fix the device wafer to the support substrate, and then debond and separate them after thinning and other processes are completed.

[0003] Current mainstream debonding technologies have many drawbacks: mechanical debonding applies extremely high stress to the wafer, which can easily lead to wafer breakage in ultra-thin devices; thermal slip debonding causes high thermal stress, which can easily lead to wafer warping and changes in device performance; UV debonding requires the support substrate to be made of a material with high UV transmittance, which increases the process cost; laser debonding requires the use of special substrates, which are expensive and not suitable for opaque silicon or metal substrates; the solvents used in chemical debonding may corrode or contaminate the metal interconnect layers or dielectric layers of the device.

[0004] In the prior art, CN112382599A discloses a method for temporary bonding and debonding of semiconductor devices, which debonds through electrochemical anodic metal dissolution. However, this method achieves separation by electrolytically etching the bonded metal layer, which poses a risk of metal ion contamination, and uneven dissolution may lead to stress concentration. CN115513116A discloses a method for temporary bonding and debonding based on an electrosensitive polymer, which relies on changes in the electrochemical properties of the electrosensitive polymer to achieve debonding. However, this method requires the fabrication of a special Al-Cu bump structure and involves a complex energy harvesting system, resulting in complex processes and high costs.

[0005] Therefore, there is an urgent need to develop a debonding method that can be operated at room temperature, is non-destructive to wafers, is pollution-free, and has a simple process. Summary of the Invention

[0006] The purpose of this invention is to provide a wafer debonding method and structure based on porous metal electrochemical gas generation. It proposes for the first time to integrate a porous metal layer as a micro-anode at the bonding interface, generating high-pressure gas in situ and controllably within the nanopores of the interface through an electrochemical reaction. This gas pressure is used to achieve interface separation, a "from the inside out" separation mode. The entire debonding process can be carried out at room temperature or near room temperature, fundamentally avoiding thermal stress problems. Simultaneously, the gas pressure acts uniformly across the entire interface, avoiding localized stress concentration and greatly reducing the risk of wafer breakage, especially for ultrathin wafers. Furthermore, by precisely controlling the magnitude and duration of the applied voltage / current, the gas generation rate and total amount can be precisely controlled, thereby achieving "start-up," "pause," and "rate regulation" of the debonding process. By selecting suitable porous anode materials and electrolyte systems, it is applicable to various bonding types, including metal bonding, dielectric bonding, and polymer temporary bonding, demonstrating strong versatility.

[0007] This invention provides the following technical solution: A wafer debonding method and structure based on porous metal electrochemical gas generation includes the following steps: A SiO2 insulating layer is thermally grown on the bonding surface of the support substrate, followed by the deposition of a porous metal layer with a nanoscale pore structure, and a precision probe is pressed into the edge of the porous metal layer. A temporary bonding adhesive is coated on the surface of the porous metal layer to form a bonding intermediate layer; The device wafer and the support substrate are bonded together through the bonding intermediate layer to form a bonding pair; After completing the wafer thinning process, the porous metal layer is connected to the positive terminal of a DC power supply, a cathode is set in an electrolytic cell and an electrolyte is injected to form an electrochemical circuit. A DC voltage is applied to the electrochemical circuit to cause an electrochemical reaction on the surface of the porous metal layer to generate gas. The gas nucleates, grows and accumulates in the nanopores of the porous metal layer, generating a gas pressure sufficient to overcome the bonding energy, thereby achieving stable separation of the device wafer from the support substrate.

[0008] The key advantage of this approach lies in achieving reliable electrical connection and isolation by sequentially fabricating a SiO2 insulating layer and a porous metal layer on the bonding surface of the support substrate, and then pressing a precision probe at the edge of the porous metal layer. The SiO2 insulating layer prevents current leakage, ensuring the electrochemical reaction concentrates on the surface of the porous metal layer. The precision probe pressing method avoids potential damage caused by traditional wire bonding, thus improving process reliability. The entire debonding process is conducted at room temperature, and separation pressure is generated at the interface through electrochemical gas generation, preventing damage to the ultrathin wafer from thermal and mechanical stresses.

[0009] Preferably, the porous metal layer is made of one or more of platinum, gold, ruthenium, iridium oxide or their alloys, with a thickness of 10 nm-5 μm and a porosity of 20%-80%.

[0010] The key advantage of this approach lies in defining the material, thickness, and porosity range of the porous metal layer, thereby ensuring the catalytic activity and gas production efficiency of the electrochemical reaction. Materials such as platinum, gold, ruthenium, and iridium oxide possess excellent electrocatalytic performance, reducing the overpotential of the water oxidation reaction and increasing the gas production rate. A thickness range of 10 nm to 5 μm and a porosity range of 20% to 80% ensure sufficient mechanical strength while providing ample gas production surface area and gas diffusion channels.

[0011] Preferably, the electrolyte in the electrochemical circuit is ultrapure water or an ultra-low concentration neutral salt solution, the DC voltage is 1-10V, and the current density is 0.1-10A / cm².

[0012] The technical advantage of this solution lies in limiting the electrolyte to ultrapure water or an ultra-low concentration neutral salt solution, thus avoiding corrosion and contamination of the device by strong acids and alkalis. The DC voltage range of 1-10V and the current density range of 0.1-10A / cm² ensures the stable conduct of the electrochemical reaction, while avoiding problems such as localized overheating, electrode damage, or excessively rapid gas generation that may result from excessively high voltage or current densities.

[0013] Preferably, the electrochemical reaction is the oxidation reaction of water: 2H₂O → O₂↑ + 4H₂O + +4e - The gas produced is oxygen.

[0014] The key advantage of this approach lies in clearly defining the electrochemical reaction as the oxidation of water, producing oxygen as the gas. Oxygen has low solubility in the electrolyte, making it prone to nucleation and accumulation in the pores, which facilitates the generation of sufficient gas pressure to achieve debonding. This reaction process is clean and pollution-free, producing no harmful byproducts and meeting the requirements of green manufacturing.

[0015] Preferably, the porous metal layer is prepared by electrodeposition, sputtering or chemical vapor deposition, and its pore size is 1-100 nm.

[0016] The key advantage of this approach lies in defining the fabrication method and pore size range of the porous metal layer. Electrodeposition, sputtering, and chemical vapor deposition are all mature semiconductor processes that are easily integrated into existing production lines. The pore size range of 1-100 nm ensures sufficient gas nucleation sites while also facilitating gas accumulation and pressure transmission within the pores, thus ensuring a smooth debonding process.

[0017] Preferably, the temporary bonding adhesive is a thermoplastic adhesive or a photosensitive adhesive.

[0018] The key advantage of this approach lies in its limitation on the type of temporary bonding adhesive, including thermoplastic adhesives and photosensitive adhesives. These adhesives offer good compatibility with semiconductor processes, adjustable bond strength, and easy removal of adhesive residue after debonding, preventing contamination of the device surface. The selection of different types of bonding adhesives based on specific process requirements enhances the method's applicability.

[0019] Preferably, the porous metal layer has a gradient porous structure, with its pore size gradually changing from a large pore size near the support substrate side to a small pore size near the temporary bonding adhesive side, wherein the large pore size is 50-100nm and the small pore size is 1-10nm.

[0020] The key advantage of this design lies in its gradient porous structure, where the pore size gradually changes from 50-100 nm near the support substrate to 1-10 nm near the temporary bonding adhesive. This gradient structure enables a gradual release of gas pressure, avoiding localized stress concentration. The large pore size region facilitates gas nucleation and initial growth, while the small pore size region promotes gas accumulation and pressure transmission, making it particularly suitable for debonding ultrathin wafers and further reducing the risk of wafer damage.

[0021] Preferably, the porous metal layer is a metal-carbon nanotube composite structure, wherein the carbon nanotubes form a three-dimensional conductive network, and the metal nanoparticles are loaded on the surface of the carbon nanotubes as catalytic sites. The size of the metal nanoparticles is 1-10 nm, and the loading amount is 5-30 wt%.

[0022] The key advantage of this approach lies in its use of a metal-carbon nanotube composite structure. The carbon nanotubes form a three-dimensional conductive network, with metal nanoparticles loaded onto the surface of the carbon nanotubes. This composite structure maintains high catalytic activity while improving the mechanical strength and conductivity of the electrode. The porous structure of the carbon nanotubes facilitates gas diffusion and accumulation, while the metal nanoparticles, with sizes ranging from 1-10 nm and loading amounts of 5-30 wt%, provide abundant catalytic sites, enhancing electrochemical gas generation efficiency. Simultaneously, it reduces the amount of precious metals required, achieving a balance between performance and cost.

[0023] Preferably, the method further includes: real-time monitoring of gas pressure using a pressure sensor located at the bonding interface, and adjusting the DC voltage based on pressure feedback to achieve closed-loop control of the debonding process; the temporary bonding adhesive is doped with pH-responsive microcapsules, which react with the H2O generated by the electrolytic reaction. + When the set concentration is reached, the bond breaks down, releasing a debonding promoter (through chemical action, such as reducing surface energy, forming a weak boundary layer, or introducing thermally decomposable groups), thus achieving chemical-mechanical synergistic debonding.

[0024] The technical advantage of this solution lies in its real-time monitoring of gas pressure via a pressure sensor, and the adjustment of DC voltage based on pressure feedback to achieve closed-loop control of the debonding process. This avoids wafer damage or debonding failure caused by over- or under-voltage. pH-responsive microcapsules are doped into the temporary bonding adhesive, allowing the H2O generated during the electrolytic reaction to react with the gas pressure. + When a set concentration is reached, the debonding promoter is released, achieving synergistic chemical-mechanical debonding. This intelligent triggering mechanism initiates chemical debonding when the gas pressure accumulates to a certain level, reducing the required gas pressure, further decreasing the debonding stress, and improving process stability and yield.

[0025] A wafer bonding structure applicable to the debonding method of claim 1, characterized in that it comprises: Device wafers; Support plate; SiO2 insulating layer and porous metal layer are sequentially prepared on the bonding surface of the support carrier plate; A temporary bonding adhesive layer located on the surface of the porous metal layer is used to temporarily bond the device wafer to the support substrate.

[0026] The beneficial effects of this invention are: 1. Extremely low risk of thermal and mechanical stress damage: The entire debonding process is carried out at room temperature or near room temperature, which fundamentally avoids the high-temperature thermal stress problems caused by traditional thermal slip debonding (200-400℃) and laser debonding. At the same time, the gas pressure is uniformly applied to the entire bonding interface, avoiding the risk of wafer breakage caused by local stress concentration in mechanical debonding. It is especially suitable for ultra-thin wafers with a thickness of less than 50μm. 2. High cleanliness and pollution-free characteristics: Ultrapure water or low-concentration neutral salt solution is used as electrolyte, avoiding the risk of corrosion of the device's metal interconnect layer by organic solvents in chemical debonding. The electrochemical reaction products are only oxygen and hydrogen ions, and no metal ion pollution or other harmful byproducts are introduced, which meets the high cleanliness requirements of semiconductor manufacturing. 3. Strong process compatibility and flexible selection of carrier materials: Compared with UV debonding and laser debonding, this invention does not have special optical property requirements for the material of the supporting carrier. It can use silicon carriers with low cost and excellent mechanical properties, as well as various materials such as glass and ceramics, which greatly reduces process costs and the complexity of material management. 4. Globally controllable and adjustable debonding process: By precisely controlling the magnitude and duration of the applied voltage / current, the gas generation rate and total amount can be precisely controlled, thus enabling the debonding process to have "start-pause-rate adjustment" controllability. This dynamic control capability provides a flexible solution for processes with different bond strength requirements. 5. Stress optimization effect of gradient porous structure: By adopting a gradient porous structure with pore size gradually changing from 50-100nm to 1-10nm, the gas pressure is gradually released. The large pore size region promotes gas nucleation and initial growth, while the small pore size region is conducive to gas accumulation and pressure transmission, effectively avoiding local stress concentration and significantly reducing the peak stress during the debonding process. 6. Performance advantages of metal-carbon nanotube composite structure: The three-dimensional network structure of carbon nanotubes not only provides excellent conductive pathways, but its inherent mechanical strength also enhances the stability of the electrode. The high dispersion of metal nanoparticles significantly increases the density of catalytic active sites, effectively improving the electrochemical gas generation efficiency under the same amount of precious metal. 7. Precision of the intelligent closed-loop control system: By monitoring the interface gas pressure in real time through a pressure sensor and dynamically adjusting the power output in combination with a PID control algorithm, a pressure control accuracy of ±5% is achieved. This closed-loop control mechanism effectively prevents wafer damage or incomplete debonding caused by pressure runaway. 8. Synergistic debonding effect of pH-responsive microcapsules: When H+ is generated by the electrolysis reaction... + When the concentration reaches the set threshold, the pH-responsive microcapsules intelligently release the debonding promoter, forming a chemical-mechanical synergistic debonding mechanism. This dual-action mode significantly reduces the required gas pressure and further reduces the debonding stress. 9. Significantly reduced process costs: No expensive special carrier plates or complex laser systems are required. Conventional DC power supplies and ordinary electrolytes are used, greatly reducing equipment investment costs. At the same time, the reusable support carrier plate design further reduces the consumable costs per process. 10. Universality applicable to multiple bonding types: By selecting appropriate porous anode materials and electrolyte systems, this method is compatible with multiple bonding types such as metal bonding, dielectric bonding, and polymer temporary bonding, and has broad application prospects in fields such as 3D integration, MEMS manufacturing, and advanced packaging. 11. Excellent compatibility with existing semiconductor processes: All fabrication processes (thermal oxidation, sputtering, electrodeposition, etc.) are mature semiconductor manufacturing technologies that are easy to integrate into existing production lines without the need for large-scale equipment modifications or process adjustments. 12. Environmental and Safety Advantages: Compared with the organic solvents used in traditional chemical debonding, the electrolyte used in this invention is environmentally friendly, non-toxic, and non-flammable, greatly improving process safety and environmental friendliness. In summary, this invention, through innovative electrochemical gas generation mechanism and structural design, successfully solves a series of technical problems existing in current debonding technologies. While ensuring the debonding effect, it achieves multiple technical advantages such as low stress, high cleanliness, low cost, and high controllability, providing a reliable debonding solution for advanced semiconductor manufacturing. Attached Figure Description

[0027] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure fabricated on the support substrate and device wafer in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure for aligning and bonding the support substrate and the device wafer in Embodiment 1 of the present invention; Figure 3 yes Figure 2 A schematic diagram of the structure of the subsequent processing technology; Figure 4 This is a schematic diagram of the structure of debonding in an electrolytic reaction; Figure 5 This is a schematic diagram of the structure after debonding is completed; Figure 6 This is a three-dimensional schematic diagram of a partially magnified structure of a porous metal layer, as shown in Embodiment 1 of the present invention. Markings in the diagram: 101. Support substrate; 102. SiO2 insulating layer; 103. Porous metal layer; 104. Temporary bonding adhesive layer; 201. Device wafer; 301. Electrolytic cell; 302. Inert metal lead; 303. DC power supply; 304. Platinum electrode. Detailed Implementation

[0028] Example 1: Preparation of basic structure like Figure 1-6 As shown, the wafer bonding structure provided by the present invention includes a support substrate 101, a SiO2 insulating layer 102, a porous metal layer 103, a temporary bonding adhesive layer 104, and a device wafer 201.

[0029] Preparation of SiO2 insulating layer: A SiO2 insulating layer 102 with a thickness of 100 nm-1 μm is thermally grown on the bonding surface of the support substrate 101. The SiO2 insulating layer 102 can be grown on the silicon surface by thermal oxidation at high temperature (900-1100℃) by introducing oxygen or water vapor. The function of the SiO2 insulating layer 102 is to provide electrical isolation and prevent current leakage or short circuit during the electrochemical debonding process.

[0030] Preparation of the porous metal layer: A porous metal layer 103 with a thickness of 200 nm and a porosity of 50% is deposited on the surface of the SiO2 insulating layer 102. The material of the porous metal layer 103 is selected from one or more of platinum, gold, ruthenium, iridium oxide, or their alloys, and can be prepared by electrodeposition, sputtering, or chemical vapor deposition. The pore size of the porous metal layer 103 is 1-100 nm, and it serves as the anode of the electrochemical reaction, generating gas during electrolysis.

[0031] Precision probe 302 contact: A precision probe 302 is pressed into the edge of the porous metal layer 103 for connecting to the positive terminal of the DC power supply. The precision probe 302 is made of corrosion-resistant materials such as tungsten, platinum, or rhodium. Appropriate pressure is applied by a spring loading mechanism to ensure good electrical contact with the porous metal layer 103 while avoiding damage to the porous metal layer.

[0032] Temporary bonding adhesive coating: A temporary bonding adhesive layer 104 is coated on both the surface of the porous metal layer 103 and the device wafer 201. The temporary bonding adhesive can be a thermoplastic adhesive or a photosensitive adhesive. Thermoplastic adhesives soften upon heating and are temporarily fixed by hot-press bonding; photosensitive adhesives cure under ultraviolet light irradiation; the thickness of the temporary bonding adhesive layer 104 is 1-10 μm, depending on the bonding strength requirements.

[0033] Bonding Steps: The device wafer 201 and the support substrate 101 are bonded together using a temporary bonding adhesive layer 104 to form a bond pair. The bonding method can be thermoforming or UV curing, depending on the type of temporary bonding adhesive. After bonding, the bond pair is formed, and subsequent processes such as thinning are performed.

[0034] Example 2: Debonding process Based on the basic structure fabrication of Example 1, after completing the thinning process of device wafer 201, debonding is performed.

[0035] Electrolytic cell setup: Place the bonded pair in electrolytic cell 301, and inject electrolyte into electrolytic cell 301. The electrolyte is ultrapure water or an ultra-low concentration neutral salt solution (such as 0.1 mol / L sodium sulfate aqueous solution) to avoid contamination of the device.

[0036] Electrochemical circuit connection: The precision probe 302 on the surface of the porous metal layer 103 is connected to the positive terminal of the DC power supply 304 via an inert metal lead 303. A platinum electrode 305 is placed in the electrolytic cell 301 as the cathode and connected to the negative terminal of the DC power supply 304. The output voltage of the DC power supply 304 is 1-10V, and the current density is controlled between 0.1-10A / cm².

[0037] Electrochemical reaction: After applying a DC voltage, an electrochemical reaction occurs on the surface of the porous metal layer 103. The reaction is the oxidation of water: 2H₂O → O₂↑ + 4H₂O+ +4e - The generated oxygen bubbles nucleate, grow, and accumulate in the nanopores of the porous metal layer 103.

[0038] Gas pressure separation: As gas accumulates in the pores, the pressure gradually increases. When the accumulated pressure is sufficient to overcome the bonding energy of the temporary bonding adhesive layer 104, it pushes the device wafer 201 to separate from the support substrate 101. The entire debonding process can be carried out at room temperature or near room temperature, avoiding thermal stress problems.

[0039] Example 3: Gradient Porous Metal Layer Structure This embodiment improves upon Embodiment 1 by adopting a gradient porous structure design for the porous metal layer 103. The pore size of the gradient porous metal layer gradually changes from a large pore size (50-100 nm) near the support substrate 101 to a small pore size (1-10 nm) near the temporary bonding adhesive layer 104. This gradient structure can be achieved by adjusting electrodeposition parameters or sputtering process conditions. During electrodeposition, the deposition rate and morphology can be controlled by gradually changing the deposition current density or deposition time, thereby forming a gradient porous structure. During sputtering, the density and porosity of the film can be controlled by adjusting the sputtering power, working gas pressure, or substrate bias, achieving a gradient change. The gradient porous structure enables a gradual release of gas pressure, avoiding localized stress concentration. During debonding, the gas first nucleates and grows in the large pore size region near the support substrate 101, and gradually expands towards the small pore size region near the temporary bonding adhesive layer 104 as pressure accumulates. This gradual pressure release method can effectively avoid wafer damage caused by sudden stress changes, and is particularly suitable for debonding ultra-thin wafers (thickness less than 50μm).

[0040] Example 4: Metal-carbon nanotube composite structure This embodiment improves upon Embodiment 1 by adopting a metal-carbon nanotube composite structure, modifying the porous metal layer 103. Carbon nanotubes 401 form a three-dimensional conductive network, and metal nanoparticles 402 (such as platinum or gold nanoparticles) are loaded onto the surface of the carbon nanotubes 401 as catalytic sites. The preparation method of the metal-carbon nanotube composite structure includes: firstly, preparing a carbon nanotube array or carbon nanotube film on the surface of the SiO2 insulating layer 102; then, loading metal nanoparticles onto the surface of the carbon nanotubes using methods such as electrodeposition, chemical reduction, or sputtering. The size of the metal nanoparticles is 1-10 nm, and the loading amount is 5-30 wt%.

[0041] This composite structure has the following advantages: (1) Carbon nanotubes form a three-dimensional conductive network, which improves the conductivity and mechanical strength of the electrode; (2) Metal nanoparticles are uniformly dispersed on the surface of carbon nanotubes, providing abundant catalytic sites and improving the efficiency of electrochemical gas generation; (3) The porous structure of carbon nanotubes is conducive to gas diffusion and accumulation; (4) The amount of precious metals used was reduced, achieving a balance between performance and cost.

[0042] Example 5: Closed-loop control system and intelligent triggering This embodiment adds a closed-loop control system and an intelligent triggering mechanism to the existing embodiment 2.

[0043] Closed-loop control system: A pressure sensor is installed at the bonding interface to monitor the gas pressure in real time. The pressure sensor transmits the pressure signal to the controller, which adjusts the output voltage of the DC power supply according to the preset pressure threshold and feedback signal to achieve closed-loop control of the debonding process. The pressure sensor can be a piezoresistive, capacitive, or piezoelectric miniature pressure sensor with a micrometer-level size, which can be integrated near the bonding interface. The controller can be a PLC controller or a microprocessor, with a preset pressure threshold of 0.1-10 MPa, specifically determined according to the type of temporary bonding adhesive and the bonding strength. pH-responsive microcapsules: pH-responsive microcapsules are doped into the temporary bonding adhesive layer 104. The shell material of the pH-responsive microcapsules is a pH-sensitive polymer (such as chitosan, polyacrylic acid, etc.), and the core material is a debonding accelerator (such as a weak alkaline solution, surfactant, etc.). The particle size of the pH-responsive microcapsules is 0.1-10 μm, the shell thickness is 10-100 nm, and the encapsulation rate of the debonding accelerator is 50-90%. During the debonding process, H2O generated by the electrolytic reaction... + This lowers the pH of the electrolyte. When the pH reaches a set threshold (e.g., pH=3-5), the pH-sensitive polymer shell swells, dissolves, or degrades, causing the microcapsules to rupture and release the debonding accelerator. The debonding accelerator reduces the adhesion of the bonded adhesive, achieving synergistic chemical-mechanical debonding.

[0044] This intelligent triggering mechanism has the following advantages: (1) When the gas pressure accumulates to a certain level, chemical debonding is initiated, which reduces the required gas pressure and further reduces the debonding stress; (2) By adjusting the type of pH-sensitive polymer and the shell thickness, the response pH and release rate of the microcapsules can be controlled; (3) The release of the debonding promoter is local and controllable, avoiding the overuse and pollution of chemical reagents.

[0045] Example 6: Comprehensive Application of Examples This embodiment comprehensively applies the technical features of the above embodiments to provide a high-performance wafer debonding method. First, a SiO2 insulating layer 102 is thermally grown on the surface of a support substrate 101. Then, a gradient porous metal layer 103 is fabricated on the SiO2 insulating layer 102, the gradient porous metal layer 103 employing a metal-carbon nanotube composite structure. A precision probe 302 is pressed against the edge of the porous metal layer 103. A temporary bonding adhesive layer 104 is coated on the surface of the gradient porous metal layer 103, the temporary bonding adhesive being doped with pH-responsive microcapsules. The device wafer 201 is then bonded to the support substrate 101. During debonding, the bonded pair is placed in an electrolytic cell 301, and an electrochemical circuit is connected via the precision probe 302. A pressure sensor monitors the gas pressure in real time, and a controller adjusts the output voltage of the DC power supply based on the pressure feedback. The gas generated by the electrolysis reaction accumulates in the pores of the gradient porous metal layer 103, while H2O is generated simultaneously. + The pH-responsive microcapsules rupture to release a debonding promoter. When the pressure reaches a set threshold, the device wafer 201 smoothly separates from the support substrate 101.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wafer debonding method based on porous metal electrochemical gas generation, characterized in that, Includes the following steps: A SiO2 insulating layer is thermally grown on the bonding surface of the support substrate, followed by the deposition of a porous metal layer with a nanoscale pore structure, and a precision probe is pressed into the edge of the porous metal layer. A temporary bonding adhesive is coated on the surface of the porous metal layer to form a bonding intermediate layer; The device wafer and the support substrate are bonded together through the bonding intermediate layer to form a bonding pair; After completing the wafer thinning process, the porous metal layer is connected to the positive terminal of a DC power supply, a cathode is set in an electrolytic cell and an electrolyte is injected to form an electrochemical circuit. A DC voltage is applied to the electrochemical circuit to cause an electrochemical reaction on the surface of the porous metal layer to generate gas. The gas nucleates, grows and accumulates in the nanopores of the porous metal layer, generating a gas pressure sufficient to overcome the bonding energy, thereby achieving stable separation of the device wafer from the support substrate.

2. The wafer debonding method based on porous metal electrochemical gas generation according to claim 1, characterized in that, The porous metal layer is made of one or more of platinum, gold, ruthenium, iridium oxide or their alloys, with a thickness of 10 nm-5 μm and a porosity of 20%-80%.

3. The wafer debonding method based on porous metal electrochemical gas generation according to claim 1, characterized in that, The electrolyte in the electrochemical circuit is ultrapure water or an ultra-low concentration neutral salt solution, the DC voltage is 1-10V, and the current density is 0.1-10A / cm².

4. The wafer debonding method based on porous metal electrochemical gas generation according to claim 1, characterized in that, The electrochemical reaction is the oxidation of water: 2H₂O → O₂↑ + 4H₂O + +4e - The gas produced is oxygen.

5. The wafer debonding method based on porous metal electrochemical gas generation according to claim 1, characterized in that, The porous metal layer is prepared by electrodeposition, sputtering or chemical vapor deposition, and its pore size is 1-100 nm.

6. The wafer debonding method based on porous metal electrochemical gas generation according to claim 1, characterized in that, The temporary bonding adhesive is a thermoplastic adhesive or a photosensitive adhesive.

7. The wafer debonding method based on porous metal electrochemical gas generation according to claim 1, characterized in that, The porous metal layer has a gradient porous structure, with its pore size gradually changing from a large pore size near the support substrate to a small pore size near the temporary bonding adhesive. The large pore size is 50-100 nm, and the small pore size is 1-10 nm.

8. The wafer debonding method based on porous metal electrochemical gas generation according to claim 1, characterized in that, The porous metal layer is a metal-carbon nanotube composite structure, wherein the carbon nanotubes form a three-dimensional conductive network, and the metal nanoparticles are loaded on the surface of the carbon nanotubes as catalytic sites. The size of the metal nanoparticles is 1-10 nm, and the loading amount is 5-30 wt%.

9. The wafer debonding method based on porous metal electrochemical gas generation according to claim 1, characterized in that, The method further includes: real-time monitoring of gas pressure using a pressure sensor located at the bonding interface, and adjusting the DC voltage based on pressure feedback to achieve closed-loop control of the debonding process; the temporary bonding adhesive is doped with pH-responsive microcapsules, which react with the H2O generated by the electrolytic reaction. + When the set concentration is reached, the bond breaks down, releasing the debonding promoter and achieving chemomechanical debonding.

10. A wafer bonding structure suitable for the debonding method of claim 1, characterized in that, include: Device wafers; Support plate; SiO2 insulating layer and porous metal layer are sequentially prepared on the bonding surface of the support carrier plate; A temporary bonding adhesive layer located on the surface of the porous metal layer is used to temporarily bond the device wafer to the support substrate.

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