A high quality factor substrate material, preparation method and application

Abstract

The present invention discloses a substrate material with high quality factor, a preparation method and application, including a substrate material substrate, the upper surface of the substrate material substrate is treated with heavy ions to form a polysilicon layer; an aluminum nitride layer, the lower surface of the aluminum nitride layer is treated with heavy ions to form a polycrystalline AlN layer after mixing, ball milling, pressing, pre-sintering, cold pressing sintering and high-temperature sintering, and the upper surface of the polysilicon layer is bonded with the polycrystalline AlN layer to form a bonding agent layer. The substrate material can avoid the signal cutoff or leakage of the composite part of the two materials during the signal transmission process to maintain high-quality signal transmission; at the same time, the two different materials realize signal transmission of different signal bands, filter out redundant signals, significantly improve the signal transmission quality of the device, and improve the quality factor of the substrate material. The preparation method simplifies the process, reduces power consumption, and reduces the environmental pollution caused by the use of chemical reagents in other processes.

Description

Technical Field

[0001] The present invention relates to the field of electronic materials and communication technology, and in particular to a substrate material with a high quality factor, a preparation method and an application thereof. Background Art

[0002] With the development of thin film and micro-nano manufacturing technology, electronic devices are rapidly developing in the direction of miniaturization, high-density reuse, high frequency and low power consumption. Highly integrated RF filter chips are important core components of current 5G communication mobile phones and have a huge market size. Surface acoustic wave devices (SAW) have the advantages of small size, low cost, high quality factor (Q), strong power handling capacity, high frequency and compatibility with IC technology, and are expected to play a broad application prospect in future wireless communication systems.

[0003] The quality factor in the surface acoustic wave filter (SAW) is an important indicator to measure the performance of the filter, and the important component that affects the performance of the filter is the substrate material. However, in the substrate material, due to the imbalance of the mutual matching of the substrate materials, especially the large lattice mismatch and thermal mismatch with the AlN film, the quality of the prepared crystal is poor, which has an adverse effect on the subsequent prepared devices. Summary of the invention

[0004] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide a composite material of a silicon / silicon oxide substrate material substrate and an aluminum nitride substrate layer, and a preparation method and application thereof. Through the mutual cooperation of the two materials, the signal cutoff or leakage of the composite part of the two materials can be avoided during the signal transmission process to maintain high-quality signal transmission, thereby solving the technical feasibility problem of sound wave transmission quality loss. At the same time, two different materials realize signal transmission in different signal bands, filter out redundant signals, significantly improve the signal transmission quality of the device, and improve the quality factor of the substrate material. The preparation method simplifies the process, reduces power consumption, and at the same time reduces the environmental pollution caused by the use of chemical reagents in other processes, and has important social value.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The bonding layer on the top of the substrate can significantly increase the resistance and improve the quality factor. Further combination with aluminum nitride can improve the quality factor of the entire electronic device. By processing the substrate and bonding layer, and then compounding materials with different cut-off frequencies and propagation coefficients, the quality factor of the material can be significantly improved by using the parameters of different materials to improve the overall body.

[0007] The present invention provides a substrate material with a high quality factor, comprising a substrate material substrate, wherein the upper surface of the substrate material substrate is treated with heavy ions to form a polysilicon layer; an aluminum nitride layer, wherein the lower surface of the aluminum nitride layer is treated with heavy ions to form a polycrystalline AlN layer, and the upper surface of the polysilicon layer is bonded to the polycrystalline AlN layer.

[0008] Furthermore, the substrate material substrate is silicon or silicon oxide.

[0009] Furthermore, the thickness of the substrate material substrate is less than 100 microns.

[0010] Furthermore, the heavy ions used to process the substrate material substrate are argon ions, and the heavy ions used to process the aluminum nitride layer are Fe7.

[0011] Furthermore, the polysilicon layer is a polysilicon layer without impurities introduced therein, and the thickness of the polysilicon layer is 1 micron to 10 microns.

[0012] Furthermore, the aluminum nitride layer is composed of high-purity AlN with a purity of 99.9%.

[0013] Furthermore, the method for preparing the high-purity AlN aluminum nitride layer comprises the steps of mixing, ball milling, pressing, pre-sintering, cold pressing sintering and high-temperature sintering.

[0014] Furthermore, the aluminum nitride layer has a thickness of 1 micron to 10 microns.

[0015] Another object of the present invention is to provide a method for preparing a substrate material with a high quality factor, comprising the following steps:

[0016] S1: preparing a substrate material substrate, and injecting heavy ions to generate an electrode and a polysilicon layer on the upper surface of the substrate material substrate;

[0017] S2: After the implantation process in step S1, annealing the substrate material substrate;

[0018] S3: After the aluminum nitride powder is pressed and formed, it is sintered in an atmosphere of 1600-1700° C. to prepare an aluminum nitride layer, and heavy ions are injected to generate a polycrystalline AlN layer on the upper surface of the substrate material substrate;

[0019] S4: The prepared silicon substrate and the aluminum nitride layer are bonded to form a bonding agent layer to achieve material compounding.

[0020] Furthermore, the annealing treatment conditions are 250°C-300°C and the holding time is 0.5-3h.

[0021] Furthermore, the formation of the aluminum nitride layer is mainly achieved by bonding with a bonding adhesive, and the bonding adhesive is composed of a long-chain organic polymer composed of carbon and hydrogen.

[0022] The third object of the present invention is to provide a substrate material with a high quality factor for use in the field of acoustic wave filters.

[0023] The beneficial effects of the present invention are:

[0024] 1. The substrate material can prevent the signal from being cut off or leaking in the composite part of the two materials during signal transmission, so as to maintain high-quality signal transmission and solve the technical feasibility problem of sound wave transmission quality loss;

[0025] 2. The substrate material realizes signal transmission in different signal bands, filters out redundant signals, significantly improves the signal transmission quality of the device, and improves the quality factor of the substrate material;

[0026] 3. The preparation method of the substrate material simplifies the process, reduces power consumption, and reduces environmental pollution caused by the use of chemical reagents in other processes, and has important social value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic structural diagram of a substrate material with a high quality factor provided by an embodiment of the present invention;

[0029] Description of reference numerals:

[0030] 1. Aluminum nitride layer; 2. Polycrystalline AlN layer; 3. Bonding agent layer; 4. Polycrystalline silicon layer; 5. Substrate material substrate. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0032] like Figure 1 As shown, a substrate material with a high quality factor, this embodiment provides a method for preparing an aluminum nitride substrate of an acoustic wave filter to improve the quality factor, which specifically includes the following steps:

[0033] The crystal sheet with a specific resistance of P>4KΩ is used as the substrate material substrate 5, the thickness of the carrier is 100um, and the size of the carrier is 5×5m 2 Argon ions with an energy of 50 keV and a reaction time of 5 min are implanted into the substrate, and a 10 um polysilicon layer 4 is produced on the top of the substrate by diffusion. After the implantation process, the silicon substrate is annealed at 300° C. for 3 h.

[0034] Aluminum nitride is mainly made of high-purity AlN powder, which is pressed and sintered at 1700℃ for 4 hours. The high-purity aluminum nitride ceramic is then cut and polished into 5×5m 2 , substrate with thickness of 10um.

[0035] Using heavy ion Fe7, the energy of Fe7 is 85MeV, the radiation reaction time is 20min, and a polycrystalline AlN layer 2 with a depth of 0.35um is formed by radiation.

[0036] Polyacrylate is added between the prepared silicon substrate and the aluminum nitride layer 1, and then bonding is achieved at 200°C for 60 minutes to form a bonding agent layer 3, thereby achieving the preparation of high-quality substrate materials. Example 2

[0037] The silicon oxide substrate is used as the substrate material substrate 5, the thickness of the carrier is 50um, and the size of the carrier is 10×10m 2 . Using heavy argon ions, the argon ion energy is 50keV, and the reaction time is 5min. The argon ions are implanted into the substrate, and a 10um polysilicon layer 4 is produced on the top of the substrate through diffusion. After the implantation process, the silicon oxide substrate is annealed at 300°C for 3h.

[0038] Aluminum nitride is mainly made of high-purity AlN powder, which is pressed and sintered at 1700℃ for 4 hours. The high-purity aluminum nitride ceramic is then cut and polished into 5×5m 2 , substrate with thickness of 5um.

[0039] Using heavy ion Fe7, the energy of Fe7 is 85MeV, the radiation reaction time is 100min, and a polycrystalline AlN layer 2 with a depth of 0.5um is formed by radiation.

[0040] Polyacrylate is added between the prepared silicon oxide substrate and the aluminum nitride layer 1, and then bonding is achieved at 200°C for 60 minutes to form a bonding agent layer 3, thereby achieving the preparation of high-quality substrate materials.

[0041] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A substrate material with a high quality factor, characterized in that: include A substrate material substrate, wherein the upper surface of the substrate material substrate is treated with heavy ions to form a polysilicon layer; An aluminum nitride layer, wherein the lower surface of the aluminum nitride layer is treated with heavy ions to form a polycrystalline AlN layer, and the upper surface of the polycrystalline silicon layer is bonded to the polycrystalline AlN layer; The substrate material preparation method comprises the following steps: S1: preparing a substrate material substrate, and injecting heavy ions to produce a polysilicon layer on the upper surface of the substrate material substrate; S2: After the implantation process in step S1, annealing the substrate material substrate; S3: After the aluminum nitride powder is pressed and formed, it is sintered in an atmosphere of 1600° C. to 1700° C. for 4 hours to prepare an aluminum nitride layer; S4: bonding the prepared silicon substrate and the aluminum nitride layer to achieve material compounding; The heavy ions used to treat the substrate material substrate are argon ions, and the heavy ions used to treat the aluminum nitride layer are Fe7; In step S4, the bonding is achieved by bonding glue, wherein the bonding glue is composed of a long-chain organic polymer composed of carbon and hydrogen; The substrate material substrate is silicon or silicon oxide; The annealing treatment conditions are 250° C.-300° C. and the holding time is 0.5-3 h.

2. A substrate material with a high quality factor as claimed in claim 1, characterized in that: The thickness of the substrate material is less than 100um.

3. A substrate material with a high quality factor as claimed in claim 1, characterized in that: The thickness of the polysilicon layer is 1 micron to 10 microns.

4. A substrate material with a high quality factor as claimed in claim 1, characterized in that: The aluminum nitride layer is made of high-purity AlN with a purity of 99.9%. The thickness of the aluminum nitride layer is 1 micron to 10 microns.

5. Application of a substrate material with a high quality factor as claimed in any one of claims 1 to 4 in the field of acoustic wave filters.

Images