Formation method of semiconductor substrate structure and semiconductor substrate structure

Abstract

The invention relates to a forming method of a semiconductor substrate structure and the semiconductor substrate structure. The method comprises the following steps: providing a substrate layer; forming a first defect layer on the substrate layer, and forming a second defect layer under the substrate layer; forming an optical isolation layer on the first defect layer by adopting a vapor deposition process; the optical refractive index of the optical isolation layer is less than 1.8, and the dielectric constant is less than 6; the temperature of the vapor deposition process is lower than 200 DEG C; and forming a photoelectric function layer on the optical isolation layer to obtain the semiconductor substrate structure. According to the embodiment of the invention, the parasitic capacitance effect is suppressed by forming the first defect layer on the substrate layer, so that the microwave loss is reduced; a vapor deposition process is adopted to form an ultra-thick optical isolation layer with a low dielectric constant on the first defect layer to improve the propagation speed of microwaves, and speed matching of microwaves and light waves is achieved. According to the method, the semiconductor substrate structure can be rapidly prepared, and the electro-optical modulator prepared by using the semiconductor substrate structure can have both high bandwidth and low half-wave voltage.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic devices, and in particular relates to a method for forming a semiconductor substrate structure and a semiconductor substrate structure. Background Art

[0002] Electro-optic modulators can efficiently convert electrical signals into optical signals and load information onto optical signals through the modulation process. This function makes electro-optic modulators an indispensable core component in optoelectronic chips and communication systems. The performance of electro-optic modulators directly affects the overall rate and transmission quality of the communication system. Suitable electro-optic modulators can provide stable and reliable signal transmission for high-speed, long-distance communication systems.

[0003] Half-wave voltage and bandwidth are two important parameters that characterize the performance of electro-optic modulators. Electro-optic modulators with smaller half-wave voltage can achieve larger phase modulation at lower voltage, thus having higher modulation efficiency and lower energy consumption. Electro-optic modulators with wider bandwidth can support high-speed signal transmission, thus meeting the needs of modern communication systems for high-speed and large-capacity transmission. At the same time, wider bandwidth also means that electro-optic modulators can process more types of signals, which helps to improve the flexibility and adaptability of communication systems. Therefore, in order to improve the rate and quality of communication systems, it is necessary to reduce the half-wave voltage of the electro-optic modulator and widen its bandwidth.

[0004] In order to ensure that the electro-optic modulator has a smaller half-wave voltage, the electrode spacing usually needs to be set smaller, but this will lead to greater microwave loss, thus limiting the improvement of bandwidth. In response to this, the prior art introduces the design of T-type electrodes, but the T-type electrode will introduce a slow wave effect and cause the microwave and light wave speeds to mismatch, thereby causing the bandwidth to decrease. Therefore, a solution that can reduce the half-wave voltage of the electro-optic modulator and broaden its bandwidth is urgently needed. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a method for forming a semiconductor substrate structure and a semiconductor substrate structure.

[0006] In a first aspect, an embodiment of the present application discloses a method for forming a semiconductor substrate structure, comprising:

[0007] providing a substrate layer;

[0008] forming a first defect layer on the upper surface of the substrate layer, and forming a second defect layer on the lower surface of the substrate layer;

[0009] An optical isolation layer is formed on the upper surface of the first defect layer by a vapor deposition process; the optical refractive index of the optical isolation layer is less than 1.8, and the dielectric constant of the optical isolation layer is less than 6; the temperature of the vapor deposition process is lower than 200 degrees Celsius;

[0010] A photoelectric functional layer is formed on the upper surface of the optical isolation layer, and the second defective layer is post-processed to obtain a semiconductor substrate structure; the thickness of the remaining second defective layer is less than or equal to the thickness of the first defective layer.

[0011] In some possible embodiments,

[0012] Forming a first defect layer on the upper surface of the substrate layer includes:

[0013] A first defect layer is formed on the upper surface of the substrate layer and a second defect layer is formed on the lower surface of the substrate layer by chemical vapor deposition; the chemical vapor deposition method is low-pressure chemical vapor deposition, normal-pressure chemical vapor deposition or plasma-enhanced chemical vapor deposition; or;

[0014] An ion implantation method is used to form a first defect layer on the upper surface of the substrate layer, and a second defect layer is formed on the lower surface of the substrate layer.

[0015] In some possible embodiments,

[0016] The material of the substrate layer is single crystal silicon;

[0017] The material of the first defect layer is at least one of polycrystalline silicon, amorphous silicon or single crystal silicon implanted with ions;

[0018] The material of the second defect layer is at least one of polycrystalline silicon, amorphous silicon or single crystal silicon implanted with ions.

[0019] In some possible embodiments,

[0020] The thickness of the first defect layer is 0.5-10 microns;

[0021] The thickness of the second defect layer is 0.5-10 microns.

[0022] In some possible embodiments,

[0023] An optical isolation layer is formed on the upper surface of the first defect layer by a vapor deposition process, comprising:

[0024] An optical isolation layer is formed on the upper surface of the first defect layer by a chemical vapor deposition process; the deposition time of the vapor deposition process is 10-300 minutes; or;

[0025] An optical isolation layer is formed on the upper surface of the first defect layer by using a physical vapor deposition process; the deposition time of the vapor deposition process is 10-300 minutes.

[0026] In some possible embodiments,

[0027] The material of the optical isolation layer is one of amorphous silicon dioxide, polycrystalline quartz crystal material or single crystal quartz crystal material;

[0028] The thickness of the optical isolation layer is 26-200 microns.

[0029] In some possible embodiments,

[0030] A photoelectric functional layer is formed on the optical isolation layer, and the second defective layer is post-processed to obtain a semiconductor substrate structure, including:

[0031] Providing optoelectronic materials;

[0032] Ion implantation is performed on the upper surface of the photoelectric material to form an ion implantation layer; the ion implantation layer is located inside the photoelectric material;

[0033] Bonding the ion-implanted photoelectric material to the optical isolation layer to obtain a bonded body;

[0034] Annealing the bonded body to dissociate the bonded body from the inside of the ion implantation layer to obtain a substrate structure intermediate;

[0035] The substrate structure intermediate is post-processed to obtain a semiconductor substrate structure; the remaining optoelectronic material forms a optoelectronic functional layer.

[0036] In some possible embodiments,

[0037] Post-processing the substrate structure intermediate to obtain a semiconductor substrate structure, including:

[0038] removing the remaining ion implantation layer;

[0039] Planarizing the remaining optoelectronic material;

[0040] The thickness of the second defect layer is adjusted to obtain a semiconductor substrate structure; the curvature of the semiconductor substrate structure ranges from -50 microns to +50 microns.

[0041] In some possible embodiments,

[0042] The material of the photoelectric functional layer is one of lithium niobate, lithium tantalate or barium titanate;

[0043] The thickness of the photoelectric functional layer is 0.2-10 microns.

[0044] In a second aspect, an embodiment of the present application discloses a semiconductor substrate structure, including:

[0045] The second defect layer;

[0046] a substrate layer located on the second defective layer;

[0047] A first defect layer is located on the substrate layer; the thickness of the first defect layer is greater than or equal to the thickness of the second defect layer;

[0048] An optical isolation layer located on the first defect layer; the optical refractive index of the optical isolation layer is less than 1.8, and the dielectric constant of the optical isolation layer is less than 6;

[0049] The photoelectric functional layer is located on the optical isolation layer.

[0050] In a third aspect, an embodiment of the present application discloses an electro-optic modulator, comprising the above-mentioned semiconductor substrate structure.

[0051] The technical solution provided by the embodiment of the present application has the following technical effects:

[0052] The method for forming a semiconductor substrate structure in an embodiment of the present application includes: providing a substrate layer; forming a first defect layer on the upper surface of the substrate layer, and forming a second defect layer on the lower surface of the substrate layer; forming an optical isolation layer on the upper surface of the first defect layer by a vapor deposition process; the optical refractive index of the optical isolation layer is less than 1.8, and the dielectric constant of the optical isolation layer is less than 6; the temperature of the vapor deposition process is lower than 200 degrees Celsius; forming a photoelectric functional layer on the upper surface of the optical isolation layer, and post-processing the second defect layer to obtain a semiconductor substrate structure. In the embodiment of the present application, the parasitic capacitance effect is suppressed by forming a first defect layer on the substrate layer, thereby reducing microwave loss; and an ultra-thick optical isolation layer with a low dielectric constant is formed on the first defect layer by a vapor deposition process to increase the propagation speed of microwaves, thereby achieving speed matching between microwaves and light waves. This method can quickly prepare a semiconductor substrate structure, and the electro-optical modulator prepared using the semiconductor substrate structure can have both high bandwidth and low half-wave voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0054] Figure 1 It is a schematic diagram of a process of forming a semiconductor substrate structure provided by an embodiment of the present application;

[0055] Figure 2-4 and Figure 6-9 is a structural schematic diagram of a semiconductor substrate structure during formation provided by an embodiment of the present application;

[0056] Figure 5It is a flow chart of a method for forming a photoelectric functional layer on an optical isolation layer and post-processing a second defective layer provided in an embodiment of the present application;

[0057] Fig.10 It is a flow chart of a method for post-processing a substrate structure intermediate to obtain a semiconductor substrate structure provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0059] It should be noted that the "one embodiment" or "embodiment" referred to in the specification of the embodiment of the present application refers to a specific feature, structure or characteristic that can be included in at least one implementation of the present application. It should be understood that in the specification and claims of the embodiment of the present application and the above-mentioned drawings, the orientation or position relationship indicated by the terms "upper", "lower", "top", "bottom", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, in the description of the present embodiment, unless otherwise specified, "plurality" means two or more. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system or product including a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0060] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not indicate that the present application necessarily has the first element, component, region, layer or part.

[0061] In order to make the purpose, technical solution and advantages disclosed in the embodiments of the present application more clearly understood, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present application and are not used to limit the embodiments of the present application.

[0062] Photoelectric materials with excellent electro-optical effects, such as lithium niobate or lithium tantalate, are one of the core materials for preparing electro-optic modulators, and these photoelectric materials mostly exist in electro-optic modulators in the form of piezoelectric single crystal thin film materials on insulators.

[0063] The piezoelectric single crystal thin film material on an insulator in the prior art is a photoelectric structure composed of a substrate structure and a photoelectric functional layer located on the substrate structure, wherein the substrate structure includes a substrate layer, and the material of the photoelectric functional layer is a photoelectric material. The bandwidth of the electro-optic modulator prepared using this photoelectric structure is limited by the substrate loss of microwaves and the electrode loss of microwaves. In order to ensure that the electro-optic modulator has a smaller half-wave voltage, it is usually necessary to set a smaller electrode spacing (such as about 3-6 microns), which will cause a larger electrode loss of microwaves, thereby limiting the improvement of the bandwidth of the electro-optic modulator. In order to overcome this technical defect, the electrode structure can be set to a T-type electrode structure, but the T-type electrode structure will introduce a slow wave effect, resulting in a decrease in the propagation speed of microwaves on the photoelectric structure, making it difficult for light waves and microwaves to achieve speed matching in the photoelectric structure.

[0064] When the speeds of light waves and microwaves match, the electro-optic modulator can maintain efficient modulation performance in a wider frequency range, so speed matching helps to improve bandwidth. Conversely, when the speeds of light waves and microwaves do not match, the bandwidth of the electro-optic modulator will drop significantly. Therefore, it is necessary to improve the structure of the piezoelectric single crystal thin film material on an insulator in the prior art to increase the propagation speed of microwaves and achieve speed matching between microwaves and light waves, so that the electro-optic modulator prepared by the optoelectronic structure has both low half-wave voltage and high bandwidth.

[0065] Usually, the propagation speed of microwaves in optoelectronic structures is related to the equivalent refractive index of the optoelectronic structure. The larger the equivalent refractive index, the lower the propagation speed of microwaves. The equivalent refractive index of a material is related to the equivalent dielectric constant of the material. The larger the equivalent dielectric constant, the larger the equivalent refractive index. The equivalent refractive index of an optoelectronic structure composed of a single material is related to the dielectric constant of the single material. The equivalent refractive index of an optoelectronic structure composed of multiple stacked materials is related to the dielectric constant of each layer of material and the thickness of each layer of material. Therefore, in order to increase the propagation speed of microwaves in optoelectronic structures, it is possible to choose to reduce the equivalent dielectric constant of the optoelectronic structure. In order to reduce the equivalent dielectric constant of the optoelectronic structure, if it is not appropriate to change the optoelectronic functional layer (optoelectronic material) that has an important impact on the electro-optical modulator, it is possible to choose to change the type and thickness of materials other than the optoelectronic material.

[0066] Based on this idea, forming a thick optical isolation layer made of low dielectric constant material between the substrate layer and the optoelectronic functional layer is undoubtedly a suitable solution. When the substrate layer is made of widely used silicon material, considering that silicon dioxide is a low dielectric constant material, an ultra-thick silicon dioxide material can be formed on the silicon substrate layer as an optical isolation layer.

[0067] Prior art mostly adopts thermal oxidation method to prepare ultra-thick silicon dioxide on silicon material, and this method generally generates silicon dioxide of the same thickness on the front and back of silicon. Due to the mismatch of thermal expansion coefficient of silicon dioxide and silicon, and the high thermal oxidation temperature (higher than 800 degrees Celsius), there is a large thermal stress between silicon dioxide and silicon. If the silicon dioxide on the back of silicon needs to be removed during subsequent chip processing, the chip will be in a stress mismatch state, thereby causing a large warpage. Therefore, it is difficult for prior art to realize the preparation process that the front of silicon has thicker silicon dioxide and the back of silicon has no silicon dioxide or only thin silicon dioxide. In addition, due to the thermal mismatch of silicon and silicon dioxide, defects will be generated at the interface of silicon and silicon dioxide in the process of preparing thicker silicon dioxide, resulting in the difficulty in realizing the preparation of silicon dioxide exceeding 10 microns of thickness.

[0068] In addition, as the thickness of the oxide increases, the speed at which oxygen diffuses into the silicon material is greatly reduced, thereby significantly reducing the speed of thermal oxidation. Existing data show that the oxidation time required to prepare 5 micron thick silicon dioxide is about 100 hours, the oxidation time required to prepare 10 micron thick silicon dioxide is about 240 hours, and the oxidation time required to prepare 15 micron thick silicon dioxide is about 400 hours. Therefore, the technology of preparing ultra-thick silicon dioxide by thermal oxidation still has the problem of low efficiency in large-scale production in actual production, making it difficult to achieve industrial application.

[0069] In addition to forming a thick optical isolation layer made of low dielectric constant material between the substrate layer and the piezoelectric functional layer, considering that the bandwidth of the electro-optical modulator prepared using the above-mentioned optoelectronic structure is also limited by the substrate loss of microwaves, it is also possible to choose to improve the optoelectronic structure from the perspective of reducing the substrate loss of microwaves to further improve the bandwidth of the electro-optical modulator.

[0070] Based on the above solution and avoiding the technical problems that may arise in the solution, the present application provides a method for forming a semiconductor substrate structure. The semiconductor substrate structure prepared by the formation method is an optoelectronic structure obtained by improving the problems existing in the above optoelectronic structure.

[0071] Figure 1 FIG. 1 is a flow chart of a method for forming a semiconductor substrate structure provided in an embodiment of the present application. Figure 1 As shown, the flow chart at least includes the following steps S101-S104:

[0072] In step S101 , a substrate layer is provided.

[0073] Figure 2 This is a schematic diagram of a semiconductor substrate structure formed in an embodiment of the present application. Figure 1 .

[0074] In the present application embodiment, Figure 2 As shown, single crystal silicon is selected to prepare the substrate layer 100, and the thickness of the substrate layer 100 is determined according to actual needs. Single crystal silicon has significant semi-conductivity and good optical properties, and can be used to manufacture optoelectronic devices. Moreover, since silicon is a common and relatively cheap material, using single crystal silicon to prepare the substrate layer 100 can reduce the preparation cost, making the electro-optic modulator more commercially competitive.

[0075] In some possible embodiments, the thickness of the substrate layer 100 is 350-800 microns.

[0076] Optionally, the thickness of the substrate layer 100 is 350 micrometers; optionally, the thickness of the substrate layer 100 is 575 micrometers; optionally, the thickness of the substrate layer 100 is 800 micrometers.

[0077] In step S102, a first defect layer is formed on the upper surface of the substrate layer, and a second defect layer is formed on the lower surface of the substrate layer.

[0078] Figure 3 This is a schematic diagram of a semiconductor substrate structure formed in an embodiment of the present application. Figure 2 .

[0079] In the embodiment of the present application, Figure 2 Based on the structure shown in FIG. 1 , a first defect layer 201 is formed on the upper surface of the substrate layer 100 by chemical vapor deposition, and a second defect layer 202 is formed on the lower surface of the substrate layer 100, so as to obtain Figure 3 The first defect layer 201 and the second defect layer 202 are formed simultaneously, and the first defect layer 201 and the second defect layer 202 have the same composition and thickness. In subsequent processes, the thickness of the second defect layer 202 can be adjusted as needed.

[0080] In some possible embodiments, the chemical vapor deposition process selected is low pressure chemical vapor deposition, atmospheric pressure chemical vapor deposition or plasma enhanced chemical vapor deposition. By adjusting the parameters and conditions of the chemical vapor deposition process, polycrystalline silicon or amorphous silicon of a desired thickness can be prepared on the surface of single crystal silicon.

[0081] In some possible implementations, an ion implantation method is used to form a first defect layer 201 on the upper surface of the substrate layer 100, and a second defect layer 202 is formed on the lower surface of the substrate layer 100. The first defect layer 201 and the second defect layer 202 are formed simultaneously, and the first defect layer 201 and the second defect layer 202 have the same composition and thickness.

[0082] In some possible embodiments, the material of the first defect layer 201 and the second defect layer 202 is at least one of polycrystalline silicon, amorphous silicon, or single crystal silicon after ion implantation.

[0083] In some possible embodiments, in the low-pressure chemical vapor deposition process, silane or trimethylsilane is selected as the silicon source gas, and hydrogen is selected as the diluent gas, and polycrystalline silicon can be formed on the upper and lower surfaces of the substrate layer 100 through a chemical reaction between the silicon source gas and the hydrogen. In addition, in the low-pressure chemical vapor deposition process, the gas environment is easier to control, and the diffusion coefficient of the reaction gas is large, so the film formation quality of the first defect layer 201 and the second defect layer 202 is better and the film formation speed is faster.

[0084] In some possible embodiments, in the atmospheric pressure chemical vapor deposition process, silane or trimethylsilane is selected as the silicon source gas, and nitrogen is selected as the diluent gas, and amorphous silicon can be formed on the upper and lower surfaces of the substrate layer 100 through a chemical reaction between the silicon source gas and the nitrogen. In addition, amorphous silicon can also be formed on the surface of the substrate layer 100 through a plasma enhanced chemical vapor deposition process.

[0085] In some possible embodiments, the material of the first defect layer 201 and the second defect layer 202 obtained by ion implantation is ion-implanted single crystal silicon. During the ion implantation process, the depth and concentration of the ion implantation can be precisely controlled by precisely controlling parameters such as ion energy, implantation time, and implantation dose.

[0086] In some possible embodiments, the thickness of the first defect layer 201 is 0.5-10 micrometers.

[0087] Optionally, the thickness of the first defect layer 201 is 0.5 micrometers; the thickness of the first defect layer 201 is 5 micrometers; the thickness of the first defect layer 201 is 10 micrometers.

[0088] In some possible embodiments, the thickness of the second defect layer 202 is 0.5-10 microns.

[0089] Optionally, the thickness of the second defect layer 202 is 0.5 micrometers; the thickness of the second defect layer 202 is 5 micrometers; the thickness of the second defect layer 202 is 10 micrometers.

[0090] In step S103, an optical isolation layer is formed on the upper surface of the first defect layer by a vapor deposition process; the optical refractive index of the optical isolation layer is less than 1.8, and the dielectric constant of the optical isolation layer is less than 6; the temperature of the vapor deposition process is lower than 200 degrees Celsius.

[0091] Figure 4 This is a schematic diagram of a semiconductor substrate structure formed in an embodiment of the present application. Figure 3 .

[0092] In the embodiment of the present application, Figure 3 Based on the structure shown in FIG. 1 , an optical isolation layer 300 is formed on the upper surface of the first defect layer 201 by using a chemical vapor deposition process to obtain a structure as shown in FIG. Figure 4 The structure shown in FIG. 1 is shown in FIG. 1 , wherein the deposition time of the vapor deposition process is 10-300 minutes, and the temperature of the vapor deposition process is lower than 200 degrees Celsius.

[0093] In some possible embodiments, a physical vapor deposition process is used to form the optical isolation layer 300 on the upper surface of the first defect layer 201. The deposition time of the vapor deposition process is 10-300 minutes, and the temperature of the vapor deposition process is lower than 200 degrees Celsius.

[0094] In the embodiment of the present application, in order to increase the propagation speed of microwaves, a material with low optical refractive index and low dielectric constant is selected as the optical isolation layer 300. The optical refractive index of the formed optical isolation layer 300 is less than 1.8 and the dielectric constant is less than 6.

[0095] In the embodiment of the present application, the material of the optical isolation layer 300 is one of amorphous silicon dioxide, polycrystalline quartz crystal material or single crystal quartz crystal material.

[0096] In some possible embodiments, the optical isolation layer 300 has a thickness of 26-200 micrometers.

[0097] Optionally, the thickness of the optical isolation layer 300 is 26 micrometers; optionally, the thickness of the optical isolation layer 300 is 113 micrometers; optionally, the thickness of the optical isolation layer 300 is 200 micrometers.

[0098] In step S104, a photoelectric functional layer is formed on the upper surface of the optical isolation layer, and the second defect layer is post-processed to obtain a semiconductor substrate structure; the thickness of the remaining second defect layer is less than or equal to the thickness of the first defect layer.

[0099] Figure 5 1 is a flow chart of a method for forming a photoelectric functional layer on an optical isolation layer and post-processing the second defective layer provided in an embodiment of the present application. Figure 5 As shown, the flow chart at least includes the following steps S501-S505:

[0100] In step S501 , a photoelectric material is provided.

[0101] In the embodiment of the present application, the optoelectronic material 400 is a material having a significant electro-optical effect, such as lithium niobate, lithium tantalate or barium titanate.

[0102] In step S502, ions are implanted into the upper surface of the photoelectric material to form an ion implantation layer; the ion implantation layer is located inside the photoelectric material.

[0103] Figure 6 This is a schematic diagram of a semiconductor substrate structure formed in an embodiment of the present application. Figure 4 .

[0104] In the embodiment of the present application, ion implantation is performed on the upper surface of the photoelectric material 400 to form an ion implantation layer 401 inside the photoelectric material 400, and the photoelectric material 400 is formed as follows: Figure 6 The position of the ion implantation layer 401 in the photoelectric material 400 can be controlled by controlling the parameters of the ion implantation, so that the thickness of the photoelectric thin film layer located above the ion implantation layer 401 can be adjusted.

[0105] In some possible embodiments, the ion species of the ion implantation include at least one of hydrogen ions and helium ions. The energy of the ion implantation is 30 to 300 keV. The dose of the ion implantation is 10 16 to 5×10 16 Pieces / square centimeter.

[0106] Optionally, the energy of the ion implantation is 30 keV; optionally, the energy of the ion implantation is 165 keV; optionally, the energy of the ion implantation is 300 keV.

[0107] Optionally, the ion implantation dose is 10 16 / cm2; the ion implantation dose is 3×10 16 / cm2; the ion implantation dose is 5×10 16 Pieces / square centimeter.

[0108] In step S503, the photoelectric material after ion implantation is bonded to the optical isolation layer to obtain a bonded body.

[0109] Figure 7 This is a schematic diagram of a semiconductor substrate structure formed in an embodiment of the present application. Figure 5 .

[0110] In the embodiment of the present application, the wafer bonding method is used. Figure 6 The photovoltaic thin film layer in the photovoltaic material 400 after ion implantation is similar to the photovoltaic thin film layer in the photovoltaic material 400 shown in FIG. Figure 4 The optical isolation layer 300 in the structure shown is bonded to obtain Figure 7 The bonded body shown.

[0111] In step S504, the bonded body is annealed to dissociate the bonded body from the inside of the ion implantation layer, thereby obtaining a substrate structure intermediate.

[0112] Figure 8 This is a schematic diagram of a semiconductor substrate structure formed in an embodiment of the present application. Figure 6 .

[0113] In the present application embodiment, Figure 7 As the annealing process proceeds, the bond body dissociates from the inside of the ion implantation layer 401, part of the ion implantation layer 401 and the photoelectric material 400 located above the ion implantation layer 401 will separate from the bond body, and the photoelectric thin film layer will be transferred to the bond body along with the remaining ion implantation layer 401, and the bond body shown in FIG. Figure 8 The substrate structure intermediate is shown.

[0114] In some possible embodiments, the annealing temperature is 200-1000 degrees Celsius, and the annealing time is 1-50 hours.

[0115] Optionally, the annealing temperature is 200 degrees Celsius; optionally, the annealing temperature is 600 degrees Celsius; optionally, the annealing temperature is 1000 degrees Celsius.

[0116] Optionally, the annealing time is 1 hour; optionally, the annealing time is 25.5 hours; optionally, the annealing time is 50 hours.

[0117] In step S505, the substrate structure intermediate is post-processed to obtain a semiconductor substrate structure; the remaining optoelectronic material forms a optoelectronic functional layer.

[0118] Fig. 9 This is a schematic diagram of a semiconductor substrate structure formed in an embodiment of the present application. Figure 7 .

[0119] Fig.10 1 is a flow chart of a method for post-processing a substrate structure intermediate to obtain a semiconductor substrate structure provided by an embodiment of the present application. Fig.10 As shown, the flow chart at least includes the following steps S1001-S1003:

[0120] In step S1001 , the remaining ion implantation layer is removed.

[0121] In step S1002 , the remaining photoelectric material is planarized.

[0122] In step S1003, the thickness of the second defective layer is adjusted to obtain a semiconductor substrate structure; the curvature of the semiconductor substrate structure ranges from -50 microns to +50 microns.

[0123] In the embodiment of the present application, the remaining ion implantation layer 401 is removed by etching or the like, and the photoelectric thin film layer is planarized and the thickness is adjusted by chemical mechanical polishing, so that the remaining photoelectric thin film layer becomes the photoelectric functional layer 402 of the required thickness. Finally, the thickness of the second defect layer 202 is adjusted to change the morphology of the semiconductor substrate structure, thereby obtaining the following Fig. 9 The semiconductor substrate structure shown has high flatness.

[0124] In the embodiment of the present application, the curvature of the semiconductor substrate structure ranges from -50 microns to +50 microns. When the curvature is a negative value, it indicates that the surface of the semiconductor substrate structure is concave; when the curvature is a positive value, it indicates that the surface of the semiconductor substrate structure is convex. The curvature of the semiconductor substrate structure prepared by the formation method provided by the present application is greatly reduced, which helps to improve the modulation performance of the electro-optic modulator prepared by the semiconductor substrate structure.

[0125] In some possible embodiments, the material of the photoelectric functional layer 402 is lithium niobate, lithium tantalate or barium titanate.

[0126] In some possible embodiments, the thickness of the optoelectronic functional layer 402 is 0.2-10 micrometers.

[0127] Optionally, the thickness of the photoelectric functional layer 402 is 0.2 micrometers; optionally, the thickness of the photoelectric functional layer 402 is 5.1 micrometers; optionally, the thickness of the photoelectric functional layer 402 is 10 micrometers.

[0128] In the embodiment of the present application, parasitic capacitance effects may be generated between the substrate layer 100 and the material in contact therewith. In the electro-optic modulator, these parasitic capacitance effects will particularly significantly affect the transmission of microwave signals, resulting in an increase in microwave loss. Forming the first defect layer 201 on the substrate layer 100 can effectively suppress the parasitic capacitance effect, thereby reducing the microwave loss of the substrate layer 100. By reducing the microwave loss of the substrate layer 100, it is helpful to improve the bandwidth of the electro-optic modulator prepared by the semiconductor substrate structure.

[0129] In the embodiment of the present application, the ultra-thick optical isolation layer 300 with a low dielectric constant is formed on the first defect layer 201 to increase the propagation speed of microwaves, thereby achieving speed matching between microwaves and light waves. By achieving speed matching between microwaves and light waves, the electro-optic modulator made of the semiconductor substrate structure can have a low half-wave voltage and a high bandwidth.

[0130] In the embodiment of the present application, a first defect layer 201 is formed on the substrate layer 100, and then a vapor deposition process is used to form an ultra-thick optical isolation layer 300 with a low dielectric constant on the first defect layer 201. A semiconductor substrate structure with high flatness can be quickly prepared in a short time, and the electro-optic modulator prepared using the semiconductor substrate structure can have both high bandwidth and low half-wave voltage.

[0131] The present application also provides a semiconductor substrate structure. Fig. 9As shown, the semiconductor substrate structure includes a second defect layer 202, a substrate layer 100 located on the second defect layer 202, a first defect layer 201 located on the substrate layer 100, an optical isolation layer 300 located on the first defect layer 201, and a photoelectric functional layer 402 located on the optical isolation layer 300. The optical refractive index of the optical isolation layer 300 is less than 1.8, and the dielectric constant of the optical isolation layer 300 is less than 6.

[0132] In the embodiment of the present application, the curvature of the semiconductor substrate structure ranges from -50 microns to +50 microns.

[0133] In the embodiment of the present application, the material of the substrate layer 100 is single crystal silicon, and the thickness of the substrate layer 100 is 350-800 microns. The material of the second defect layer 202 is at least one of polycrystalline silicon, amorphous silicon or single crystal silicon after ion implantation, and the thickness of the second defect layer 202 is 0.5-10 microns. The material of the first defect layer 201 is at least one of polycrystalline silicon, amorphous silicon or single crystal silicon after ion implantation, and the thickness of the first defect layer 201 is 0.5-10 microns. The thickness of the first defect layer 201 is greater than or equal to the thickness of the second defect layer 202. The material of the optical isolation layer 300 is one of amorphous silicon dioxide, polycrystalline quartz crystal material or single crystal quartz crystal material, and the thickness of the optical isolation layer 300 is 26-200 microns. The material of the photoelectric functional layer 402 is one of lithium niobate, lithium tantalate or barium titanate, and the thickness of the photoelectric functional layer 402 is 0.2-10 microns.

[0134] In the embodiment of the present application, the semiconductor substrate structure is prepared by the above-mentioned method for forming a semiconductor substrate structure.

[0135] The embodiment of the present application also provides an electro-optic modulator. The electro-optic modulator includes the semiconductor substrate structure and a T-shaped electrode structure located on the semiconductor substrate structure. The electro-optic modulator has both high bandwidth and low half-wave voltage.

[0136] It should be noted that the above-mentioned sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above-mentioned specific embodiments of this specification are described. Other embodiments are within the scope of the attached claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0137] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0138] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware or by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0139] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for forming a semiconductor substrate structure, characterized in that: include: providing a substrate layer; forming a first defect layer on the upper surface of the substrate layer, and forming a second defect layer on the lower surface of the substrate layer; forming an optical isolation layer on the upper surface of the first defect layer by a vapor deposition process; The optical refractive index of the optical isolation layer is less than 1.8, and the dielectric constant of the optical isolation layer is less than 6; the temperature of the vapor deposition process is lower than 200 degrees Celsius; A photoelectric functional layer is formed on the upper surface of the optical isolation layer, and the second defect layer is post-processed to obtain a semiconductor substrate structure; the thickness of the remaining second defect layer is less than or equal to the thickness of the first defect layer.

2. The method for forming a semiconductor substrate structure according to claim 1, wherein: The forming of a first defect layer on the upper surface of the substrate layer comprises: The first defect layer is formed on the upper surface of the substrate layer, and the second defect layer is formed on the lower surface of the substrate layer by chemical vapor deposition; the chemical vapor deposition method is low pressure chemical vapor deposition, normal pressure chemical vapor deposition or plasma enhanced chemical vapor deposition; or; The first defect layer is formed on the upper surface of the substrate layer by using an ion implantation method, and the second defect layer is formed on the lower surface of the substrate layer.

3. The method for forming a semiconductor substrate structure according to claim 2, wherein: The material of the substrate layer is single crystal silicon; The material of the first defect layer is at least one of polycrystalline silicon, amorphous silicon or ion-implanted single crystal silicon; The material of the second defect layer is at least one of polycrystalline silicon, amorphous silicon or single crystal silicon implanted with ions.

4. The method for forming a semiconductor substrate structure according to claim 3, characterized in that: The thickness of the first defect layer is 0.5-10 microns; The thickness of the second defect layer is 0.5-10 microns.

5. The method for forming a semiconductor substrate structure according to claim 4, characterized in that: The method of forming an optical isolation layer on the upper surface of the first defect layer by using a vapor deposition process comprises: An optical isolation layer is formed on the upper surface of the first defect layer by a chemical vapor deposition process; the deposition time of the chemical vapor deposition process is 10-300 minutes; or; An optical isolation layer is formed on the upper surface of the first defect layer by a physical vapor deposition process; the deposition time of the vapor deposition process is 10-300 minutes.

6. The method for forming a semiconductor substrate structure according to claim 5, characterized in that: The material of the optical isolation layer is one of amorphous silicon dioxide, polycrystalline quartz crystal material or single crystal quartz crystal material; The thickness of the optical isolation layer is 26-200 microns.

7. The method for forming a semiconductor substrate structure according to claim 6, wherein: The step of forming a photoelectric functional layer on the optical isolation layer and post-processing the second defective layer to obtain a semiconductor substrate structure comprises: Providing optoelectronic materials; Performing ion implantation on the upper surface of the photoelectric material to form an ion implantation layer; the ion implantation layer is located inside the photoelectric material; Bonding the photoelectric material after ion implantation to the optical isolation layer to obtain a bonded body; Annealing the bonded body to dissociate the bonded body from the inside of the ion implantation layer to obtain a substrate structure intermediate; The substrate structure intermediate is post-processed to obtain the semiconductor substrate structure; the remaining optoelectronic material forms the optoelectronic functional layer.

8. The method for forming a semiconductor substrate structure according to claim 7, characterized in that: The post-processing of the substrate structure intermediate to obtain the semiconductor substrate structure comprises: removing the remaining ion implantation layer; Planarizing the remaining optoelectronic material; The thickness of the second defect layer is adjusted to obtain the semiconductor substrate structure; the curvature of the semiconductor substrate structure ranges from -50 microns to +50 microns.

9. The method for forming a semiconductor substrate structure according to claim 1, wherein: The material of the photoelectric functional layer is one of lithium niobate, lithium tantalate or barium titanate; The thickness of the photoelectric functional layer is 0.2-10 microns.

10. A semiconductor substrate structure, characterized in that: include: The second defect layer; a substrate layer located on the second defective layer; a first defective layer located on the substrate layer; The thickness of the first defect layer is greater than or equal to the thickness of the second defect layer; an optical isolation layer located on the first defect layer; The optical refractive index of the optical isolation layer is less than 1.8, and the dielectric constant of the optical isolation layer is less than 6; The photoelectric functional layer is located on the optical isolation layer.

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