Silicon-based compound prepared based on organic modified silicate polymer bonding and preparation method thereof
By combining organically modified silicate polymer bonding layers and dielectric layers, the problems of lattice dislocation and thermal stress in the preparation process of silicon-based composite materials are solved, achieving high-temperature stability and strong bonding, thereby improving device performance and application range.
Patent Information
- Application Number
- CN202610001428.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-04
- Publication Date
- 2026-04-03
AI Technical Summary
In existing technologies, silicon-based composite materials suffer from problems such as lattice misalignment, thermal stress-induced cracking, low bonding strength, and poor high-temperature resistance during preparation, making it difficult to achieve large-scale application.
Organically modified silicate polymers were used as bonding layers to prepare silicon-based composites through organic-inorganic hybrid technology. The high melting point and stability of the organically modified silicate polymers were utilized, and the interface properties were optimized by combining the dielectric layer to achieve direct bonding.
It significantly improves the mechanical properties, electrical properties, corrosion resistance and high temperature resistance of silicon-based composites, enhances the working efficiency and stability of devices, and expands the application range.
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Figure CN121793801A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to silicon-based composites, specifically to a silicon-based composite prepared by bonding with an organically modified silicate polymer and its preparation method, belonging to the field of materials technology. Background Technology
[0002] With the development of semiconductor technology, integrated circuits are gradually approaching their performance limits, and the applicability of Moore's Law is facing challenges. To further improve device performance and reduce chip size, increasing emphasis is being placed on the performance indicators and structural design of core materials. Silicon-based composites represent a current trend in semiconductor material development. Through multilayer structure design, they maintain the various properties of functional crystalline materials while integrating the composite functions of multiple materials, further enhancing the properties and advantages of devices. The compatibility of silicon-based substrate structures with CMOS processes enables the systematic integration of multiple functional devices, reflecting a trend towards functional composite and integrated materials.
[0003] In the fabrication process of silicon-based composite materials, bonding is a core and crucial step, fundamental to achieving heterogeneous integration of functional crystals and substrate materials. Composite functional crystal materials such as silicon carbide, gallium nitride, gallium oxide, indium phosphide, sapphire, diamond, lithium tantalate, and lithium niobate, fabricated on silicon substrates, have broad application prospects and wide applicability in power devices, acousto-optic devices, surface acoustic wave (SAW) devices, sensors, and modulators. However, due to the significant difference in lattice constants between silicon wafers and these functional crystals, direct bonding without a dielectric layer results in lattice mismatches, affecting interface performance. The large difference in thermal expansion coefficients also makes the bonded pairs susceptible to thermal stress during annealing, leading to cracking and reduced yield. In dielectric bonding, polymer bonding is a commonly used method that can ignore lattice constant mismatch issues, reduce the quality requirements of the wafer surface during bonding, and improve the process yield. Currently, organic polymers (such as PMMA, BCB, PDMS, SU8, etc.) are commonly used to prepare silicon-based composites. However, these organic polymer materials are difficult to withstand high-temperature processes above 300°C and suffer from problems such as weak pressure resistance, poor solvent resistance, and low bonding strength. These issues pose significant obstacles to the subsequent processing of silicon-based composite materials and device fabrication, hindering large-scale applications. Using inorganic silicates as the bonding layer can significantly improve the high-temperature resistance and corrosion resistance of silicon-based composite materials, but it also presents problems such as high brittleness and poor conductivity, which are detrimental to device performance improvement. Summary of the Invention
[0004] To address the aforementioned shortcomings of existing technologies, the present invention aims to provide a silicon-based composite material prepared by bonding with organic modified silicate polymers and its preparation method. This solves the problems of high crystal quality requirements and high stress in silicon-based composite materials prepared by direct bonding without a dielectric layer, as well as the problems of poor high-temperature resistance, easy debonding, and easy corrosion in silicon-based composite materials prepared by bonding with commonly used organic polymers.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0006] A silicon-based composite prepared by bonding with an organically modified silicate polymer includes a substrate and a functional layer wafer, which are bonded together by a bonding layer, wherein the bonding layer is an organically modified silicate polymer layer.
[0007] Furthermore, the polymer of the organic modified silicate polymer layer is prepared by polymerization reaction of precursor molecules.
[0008] Furthermore, the thickness of the bonding layer is 0.1 μm to 10 μm.
[0009] Furthermore, the functional layer wafer is made of silicon carbide, gallium nitride, gallium oxide, gallium arsenide, indium arsenide, indium phosphide, sapphire, diamond, lithium tantalate, or lithium niobate.
[0010] Furthermore, a dielectric layer is provided between the substrate and the bonding layer. The dielectric layer is pre-formed on the substrate to form a composite substrate. The surface of the composite substrate containing the dielectric layer is then bonded to the functional layer wafer through the bonding layer.
[0011] Furthermore, the dielectric layer is silicon dioxide, silicon nitride, hafnium oxide, polycrystalline silicon, titanium dioxide, aluminum oxide, or aluminum nitride.
[0012] The present invention also provides a method for preparing the above-mentioned silicon-based composite, the steps of which are as follows:
[0013] 1) Pre-treatment of substrate and functional layer wafers; the pre-treatment includes cleaning, drying and activation treatment of the bonding surfaces of both substrate and functional layer wafers;
[0014] 2) Preparation of precursor solution: Organosilane precursor molecules are divided into two categories: one category contributes the inorganic framework, mainly composed of silicates containing small organic molecules; the other category provides organic modification, mainly composed of silicates containing benzene rings, long-chain carbons, or special functional groups. One type of organosilane precursor molecule from each category is completely dissolved in an organic solvent to obtain a precursor-organic mixture. An acid or base is dissolved in deionized water to adjust the pH value to the required value to obtain a catalyst solution. The catalyst solution is then slowly added to the precursor-organic mixture, and the solution is continuously heated and stirred until a low-viscosity stable sol is formed, thus obtaining the precursor solution.
[0015] 3) The precursor solution is coated onto the bonding surface of the substrate or the bonding surface of the functional layer wafer to form a thin film with fluidity;
[0016] 4) Align the bonding surfaces of the substrate and the functional layer wafers and bond them together directly. This allows the precursor molecules in the coated precursor solution to undergo a polymerization reaction, forming a solid material that bonds the bonding surfaces of the substrate and the functional layer wafers together, thus achieving the preparation of the silicon-based composite.
[0017] Furthermore, a dielectric layer is formed on the substrate to form a composite substrate. In step 3), during coating, the precursor solution is coated on the surface of the composite substrate where the dielectric layer is located.
[0018] Further, in step 1), the activation treatment is megasonic cleaning, plasma activation, or ion beam bombardment, which is used to increase the activation energy of the bonding surface between the substrate and the functional layer and to improve the hydrophilicity of the bonding surface.
[0019] Furthermore, in step 4), when the substrate bonding surface and the functional layer wafer bonding surface are bonded together, appropriate pressure is applied; during the polymerization reaction, heating and light are used to accelerate the polymerization reaction.
[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0021] The bonding layer between the substrate and the functional layer wafer of this invention is an organically modified silicate polymer. A direct bonding process is employed, utilizing the advantages of the organically modified silicate polymer, such as its high melting point, excellent physical and mechanical properties, stable chemical properties, and tunable acousto-optical-electrical properties, to prepare a silicon-based composite material. This significantly improves the mechanical properties, electrical properties, corrosion resistance, and high-temperature resistance of device systems based on this composite material (e.g., reducing the interface resistance to below 30%, maintaining long-term stability without corrosion in strong acid and alkali environments, and improving temperature tolerance to above 500℃). This is also significant for improving key performance indicators such as device efficiency and stability, and further facilitates semiconductor integration and miniaturization of the device.
[0022] The organic-modified silicate polymer of this invention achieves synergistic performance optimization through organic-inorganic hybrid technology, and has many advantages in physical, chemical, optical, electrical and dielectric properties. It can also meet the needs of more applications in terms of corrosion resistance, thermal stability, mechanical properties and biocompatibility. The silicon-based composite based on organic-modified silicate polymer bonding has shown positive application value in many high-tech fields. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the silicon-based composite material structure in Embodiment 1 of the present invention;
[0024] Figure 2 This is a schematic diagram of the silicon-based composite material structure (containing a dielectric layer) of Embodiment 2 of the present invention;
[0025] Figure 3 This is a schematic diagram of the process for preparing silicon-based composites based on organic-modified silicate polymer bonding according to the present invention;
[0026] Figure 4 This is a schematic diagram of the polymerization process of organic modified silicate molecules according to the present invention. Detailed Implementation
[0027] The present invention will now be described in further detail with reference to the accompanying drawings.
[0028] This invention provides a method and product for preparing silicon-based composites based on organically modified silicate polymer bonding. The method involves preparing a precursor solution with a special molecular structure and then using a catalyst to initiate a polymerization reaction to achieve the preparation of the bonding layer. Utilizing polymer bonding improves the bonding process's tolerance to bonding parameters such as wafer surface roughness and flatness, avoiding over-processing of functional crystals, especially ultra-hard crystals such as silicon carbide, diamond, sapphire, gallium nitride, and aluminum nitride, which are difficult to polish and have low surface activity. Compared to traditional organic polymer materials composed of long-chain molecules, organic-modified silicate polymer materials achieve three-dimensional network structures or intercalated spatial structures through organic-inorganic hybridization methods. They possess characteristics such as high temperature resistance and stable chemical and physical properties, which can increase the temperature tolerance of the back-end processes of materials and devices to over 500°C. At the same time, by selecting the types of organic molecules, the electrical and dielectric properties of the bonding layer can be further optimized, greatly expanding the application scenarios of silicon-based composite materials. They are inexpensive, reproducible, and have a high yield, providing a new solution and approach for the preparation of high-performance, low-cost, and integrable devices based on complex film structure materials.
[0029] Please see Figure 1The silicon-based composite material of the present invention includes a substrate 1 and a functional layer wafer 3, wherein the substrate 1 and the functional layer wafer 3 are bonded together by a bonding layer 2, wherein the bonding layer 2 is an organic modified silicate polymer layer.
[0030] The substrate of this invention is a silicon substrate wafer, which can promote the integration of devices based on silicon-based composite materials and is of great significance for reducing system size and realizing multi-module integration.
[0031] The thickness of the substrate is 0.1 mm to 50 mm, with a preferred thickness of 0.35 mm to 5 mm.
[0032] The organically modified silicate polymer layer of this invention can be prepared by polymerization of precursor molecules. Commonly used precursor molecules mainly consist of two types: one type contributes the inorganic framework, primarily silicates containing small organic molecules, such as tetramethoxysilane, methyltrimethoxysilane, tetraethoxysilane, and methyltrichlorosilane; the other type provides organic modification, primarily silicates containing benzene rings, long-chain carbons, or special functional groups, such as phenyltriethoxysilane, tridecafluorooctyltriethoxysilane, vinyltrimethoxysilane, (3-glycidyloxypropyl)trimethoxysilane, and (3-methacryloyloxypropyl)trimethoxysilane. Organically modified silicate polymers with high stability, high temperature resistance, and corrosion resistance can be achieved by adjusting the ratio of two types of precursor molecules, such as (3-aminopropyl)triethoxysilane, 1,4-bis(triethoxysilyl)ethylbenzene, n-octyltriethoxysilane, 1,2-bis(triethoxysilyl)ethane, bis-[3-(triethoxysilyl)propyl]-tetrasulfide, γ-methacryloyloxypropyltrimethoxysilane, and γ-glycidyl etheroxypropyltrimethoxysilane. Typically, the proportion of organic modified molecules is 5%–45%, and the solvent is usually an organic solvent, such as ethanol or isopropanol. Mixed solvents can also be used. The molar ratio of the total amount of the two types of precursor molecules to the solvent is usually 5%–20%. The catalyst is mainly an acid or base reagent such as hydrochloric acid, nitric acid, or ammonia. The catalyst solution is obtained by dissolving the acid or base in deionized water, and the effect is better when the pH value is below 5 or above 9. In the precursor solution preparation process, the catalyst solution is slowly added to the completely dissolved precursor organic mixture, and the solution is continuously stirred until it reaches a low viscosity and a stable state, thus obtaining the precursor solution. This process significantly improves the bonding quality of silicon-based polymers and enhances the corrosion resistance and high-temperature resistance of devices. However, this invention is not limited to this.
[0033] The thickness of the bonding layer is 0.1 μm to 10 μm, with a preferred thickness of 1 μm to 10 μm.
[0034] The functional layer wafer of the silicon-based composite material of this invention can be made of various functional crystal materials, such as silicon carbide, gallium nitride, gallium oxide, gallium arsenide, indium arsenide, indium phosphide, sapphire, diamond, lithium tantalate, lithium niobate, etc. The structure of this material can be freely designed and fabricated based on device development needs to fabricate power devices, integrated optical devices, MEMS devices, detectors, sensors, etc., but this invention is not limited to these.
[0035] The thickness of the functional layer is 0.1mm to 50mm, with a preferred thickness of 0.2mm to 1mm.
[0036] Please see Figure 2 As another embodiment of the present invention, the silicon-based composite material in Figure 1 In addition, it also includes a dielectric layer 4, which is a thin film medium for improving the electrical properties of the composite material. The dielectric layer 4 is formed on the bonding surface of the substrate 1, that is, between the substrate 1 and the bonding layer 2.
[0037] The dielectric layer 4 of this invention can be silicon dioxide, silicon nitride, hafnium oxide, polycrystalline silicon, titanium dioxide, aluminum oxide, aluminum nitride, etc. However, this invention is not limited to these. The thickness of the dielectric layer is 0.01 μm to 20 μm, preferably 0.05 μm to 5 μm.
[0038] The dielectric layer of the present invention can be prepared by magnetron sputtering, low-pressure chemical vapor deposition, metal-organic chemical vapor deposition, molecular beam evaporation, thermal oxidation, molecular beam epitaxy, atomic layer deposition, pulsed laser deposition, etc., but is not limited to these methods.
[0039] Based on device requirements, the addition of dielectric layers optimizes the interface state of materials, especially the electrical and dielectric properties of the interface, thereby reducing leakage current and improving device power loss and heat dissipation.
[0040] See also Figure 3 The method for manufacturing the silicon-based composite material of the present invention is a direct bonding process, the steps of which are as follows:
[0041] 1) Pre-treatment of substrate and functional layer wafers; The specific pre-treatment process is as follows: the silicon wafer of the substrate and the silicon carbide wafer of the functional layer are cleaned and dried by means of spin drying, nitrogen blowing, infrared drying, etc.; the bonding surfaces of the substrate wafer and the functional layer wafer are activated by means of megasonic cleaning, plasma activation, ion beam bombardment, etc. to increase the activation energy of the wafer surface and improve its hydrophilicity.
[0042] 2) Precursor solution preparation: This invention provides two examples of precursor solution preparation;
[0043] Example 1: 40 mmol of tetraethoxysilane and 80 mmol of 1,4-bis(triethoxysilyl)ethylbenzene, the precursor molecules of organosilanes, were taken in a molar ratio of 1:2 and added to 200 mL of ethanol. The mixture was fully dissolved at room temperature by ultrasonic or magnetic stirring to obtain a precursor organic mixture. Then, 0.5 mL of 0.1 M hydrochloric acid solution was added to 5.7 mL of deionized water and stirred to dilute and obtain an acidic catalyst solution with a pH of about 2. The catalyst solution was slowly added dropwise to the precursor organic mixture and heated and stirred continuously until the solution formed a low-viscosity stable sol, which is the precursor solution.
[0044] Example 2: 80 mmol and 40 mmol of organosilane precursor molecules methyltrichlorosilane and phenyltriethoxysilane were respectively taken in a molar ratio of 2:1 and added to a mixed solvent of 100 mL ethanol and 50 mL isopropanol. The mixture was fully dissolved at room temperature by ultrasonic or magnetic stirring to obtain a precursor organic mixture. Then, 0.5 mL of 0.1 M hydrochloric acid solution was added to 6.5 mL of deionized water and stirred to dilute and obtain an acidic catalyst solution with a pH of about 2.5. The catalyst solution was slowly added dropwise to the precursor organic mixture and heated and stirred continuously until the solution formed a low-viscosity stable sol, which is the precursor solution.
[0045] 3) The precursor solution is coated onto the bonding surface of the substrate or the bonding surface of the functional layer wafer by spin coating, blade coating or other methods to form a thin film with fluidity, thus forming a bond;
[0046] 4) Align the bonding surfaces of the bonded material and the functional wafer by manual, mechanical, or infrared alignment, or align the bonding surfaces of the silicon substrate and the bonded material together, and directly bond them together, or bond the two wafers together with appropriate pressure assistance; through long-term static placement, heating, and light irradiation, the precursor molecules in the coated precursor solution undergo a polymerization reaction to prepare a phenyl-bridged silsesquioxane polymer layer. Its silicon-oxygen inorganic framework and spatial network structure composed of benzene as an organic chain achieve high temperature resistance above 500℃, and have certain mechanical properties and acid and alkali corrosion resistance advantages. As a bonding layer, it can tightly bond the substrate and the functional layer wafer, realizing the effective preparation of silicon-based composite materials.
[0047] Figure 4 The polymerization process of organic modified silicate molecules of the present invention is shown.
[0048] like Figure 4As shown, in the preparation of silicon-based composites, suitable precursor molecules are dissolved in an organic solvent to prepare a solution of a certain concentration. By adding reagents such as acids and bases, the alkoxy groups on the precursors are converted into highly reactive silanol groups. A non-solid layer with a certain degree of viscosity is then attached to the surface of a silicon substrate or functional crystal through spin coating or blade coating to form a bond. In direct bonding with the functional wafer or silicon substrate, the difference in lattice constant between the silicon substrate and the functional wafer material can be ignored. By increasing the tolerance to wafer surface roughness and flatness, it is easier to achieve the integration of customizable composite materials. At this time, due to the reduction of solvent, the precursor molecules undergo a certain degree of dehydration condensation and de-alcoholization condensation reactions, forming a gel state with a certain degree of fluidity and viscosity. At this time, the bonding strength is low and cannot support subsequent processes such as thinning, polishing, etching, and photolithography. Therefore, certain curing methods are needed, such as placing the composite material under light of a specific wavelength, heating it in an oven or hot table, or letting it stand in air or a specific atmosphere for a period of time, so that the precursor molecules can undergo a full polymerization reaction to form an organic modified silicate polymer with a network or intercalation structure. This further improves the stability of the bonding layer, enhances the bonding strength between the bonding layer and the substrate wafer and functional crystal, optimizes interface engineering, and achieves the preparation of high-quality silicon-based composites.
[0049] If the composite material includes a dielectric layer, it can be prepared by magnetron sputtering, low-pressure chemical vapor deposition, metal-organic chemical vapor deposition, molecular beam evaporation, thermo-oxidation, molecular beam epitaxy, atomic layer deposition, pulsed laser deposition, etc. The dielectric layer is used as the bonding interface of the silicon-based substrate material, and the silicon-based composite material is prepared by direct bonding with the bonding surface of the functional crystal through organic modified silicate polymer.
[0050] The present invention discloses a method for preparing silicon-based composites based on organic-modified silicate polymer bonding. This method employs direct bonding technology, leveraging the advantages of silicates, such as high melting point, excellent physical and mechanical properties, chemical stability, and affinity for silicon substrates. By controlling the electrical, acoustic, and optical properties of silicates through organic compounds, the mechanical, electrical, corrosion-resistant, and high-temperature-resistant properties of the bonding layer are significantly improved. The preparation of silicon-based composite materials through organosilicon polymer bonding can greatly expand the application range and prospects of functional composite crystal materials, providing significant support for current three-dimensional integration and the miniaturization of system structures.
[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described with reference to preferred embodiments, those skilled in the art should understand that various changes in form and detail can be made. All obvious changes derived from the technical solutions of the present invention are still within the scope of protection of the present invention.
Claims
1. A silicon-based composite prepared by bonding an organically modified silicate polymer, comprising a substrate and a functional layer wafer, wherein the substrate and the functional layer wafer are bonded together by a bonding layer, characterized in that: The bonding layer is an organically modified silicate polymer layer.
2. The silicon-based composite according to claim 1, characterized in that: The organic modified silicate polymer layer is prepared by polymerizing precursor molecules through a polymerization reaction.
3. The silicon-based composite according to claim 1, characterized in that: The thickness of the bonding layer is 0.1 μm to 10 μm.
4. A silicon-based composite according to claim 1, characterized in that: The substrate is a silicon substrate; the functional layer wafer is made of silicon carbide, gallium nitride, gallium oxide, gallium arsenide, indium arsenide, indium phosphide, sapphire, diamond, lithium tantalate, or lithium niobate.
5. A silicon-based composite according to claim 1, characterized in that: A dielectric layer is provided between the substrate and the bonding layer. The dielectric layer is pre-formed on the substrate to form a composite substrate. The surface of the composite substrate containing the dielectric layer is then bonded to the functional layer wafer through the bonding layer.
6. A silicon-based composite according to claim 5, characterized in that: The dielectric layer is made of silicon dioxide, silicon nitride, hafnium oxide, polycrystalline silicon, titanium dioxide, aluminum oxide, or aluminum nitride.
7. The method for preparing the silicon-based composite according to claim 1, characterized in that, The steps are as follows: 1) Pre-treatment of substrate and functional layer wafers; the pre-treatment includes cleaning, drying and activation treatment of the bonding surfaces of both substrate and functional layer wafers; 2) Preparation of precursor solution: Organosilane precursor molecules are divided into two categories: one category contributes the inorganic framework, mainly composed of silicates containing small organic molecules; the other category provides organic modification, mainly composed of silicates containing benzene rings, long-chain carbons, or special functional groups. One type of organosilane precursor molecule from each category is completely dissolved in an organic solvent to obtain a precursor-organic mixture. An acid or base is dissolved in deionized water to adjust the pH value to the required value to obtain a catalyst solution. The catalyst solution is then slowly added to the precursor-organic mixture, and the solution is continuously heated and stirred until a low-viscosity stable sol is formed, thus obtaining the precursor solution. 3) The precursor solution is coated onto the bonding surface of the substrate or the bonding surface of the functional layer wafer to form a thin film with fluidity; 4) Align the bonding surfaces of the substrate and the functional layer wafers and bond them together directly. This allows the precursor molecules in the coated precursor solution to undergo a polymerization reaction, forming a solid material that bonds the bonding surfaces of the substrate and the functional layer wafers together, thus achieving the preparation of the silicon-based composite.
8. The method for preparing the silicon-based composite according to claim 7, characterized in that, A dielectric layer is formed on the substrate to form a composite substrate. In step 3), the precursor solution is coated on the surface of the dielectric layer of the composite substrate.
9. The method for preparing the silicon-based composite according to claim 7, characterized in that, In step 1), the activation treatment is megasonic cleaning, plasma activation, or ion beam bombardment, which is used to increase the activation energy of the bonding surface between the substrate and the functional layer and to improve the hydrophilicity of the bonding surface.
10. The method for preparing the silicon-based composite according to claim 7, characterized in that, Step 4) When the substrate bonding surface and the functional layer wafer bonding surface are bonded together, apply appropriate pressure; during the polymerization reaction, heat and light are used to accelerate the polymerization reaction.