Bulk silicon-based electro-optical modulator and preparation method thereof
By preparing the mask layer and oxidation isolation layer on the bulk silicon wafer, the problem of preparing high-speed electro-optical modulators on the bulk silicon wafer is solved, the cost of silicon optical chips is reduced, and the competitiveness in the field of optical communication is enhanced.
Patent Information
- Application Number
- CN202311864756.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-29
- Publication Date
- 2025-07-01
AI Technical Summary
There are difficulties in preparing high-speed electro-optical modulators on bulk silicon wafers, which leads to high cost of silicon optical chips and cannot effectively replace high-cost SOI wafers.
The mask layer is prepared on a bulk silicon wafer, and an oxidation is formed by forming an oxidation isolation layer to realize the preparation of an electro-optical modulator and reduce costs.
Electro-optical modulators were successfully prepared on bulk silicon wafers, reducing the cost of silicon optical chips, improving industrial competitiveness, and changing the industrial structure of the optical communication field.
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Figure CN120233490A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor technology, and particularly to a bulk silicon-based electro-optic modulator and a preparation method thereof. Background Art
[0002] With the rapid development of the information age, the demand of human society for massive data transmission has promoted the development of the optical communication field towards the direction of low cost, high integration and high bandwidth. One of the remarkable features is that silicon-based optoelectronic technology is gradually replacing the traditional compound semiconductor (III-V) technology, and silicon optical chips with higher device integration have replaced the traditional EML (Electro-absorption Modulated Laser) chips to become the core of the most advanced optical modules. The success of silicon-based optoelectronic technology largely benefits from the compatibility of its preparation process with the traditional integrated circuit process, which is conducive to large-scale mass production.
[0003] Traditional silicon optical chips are prepared on SOI (Silicon-On-Insulator) wafers (Si-SiO2-Si). Because the structure of SOI wafers provides good optical confinement, silicon optical devices can be realized on the top silicon. However, compared with the bulk silicon wafers used in the traditional integrated circuit industry, the cost of SOI wafers is an order of magnitude higher.
[0004] In order to reduce the cost of silicon optical chips, it is necessary to replace SOI wafers with bulk silicon wafers. The biggest difficulty lies in how to fabricate high-speed electro-optic modulators on bulk silicon wafers. Summary of the Invention
[0005] The present invention discloses a bulk silicon-based electro-optic modulator and a preparation method thereof, which are used to fabricate high-speed electro-optic modulators on bulk silicon wafers.
[0006] To achieve the above object, the present invention provides the following technical solutions:
[0007] In a first aspect, the present invention provides a method for preparing a bulk silicon-based electro-optic modulator, including:
[0008] Providing a bulk silicon wafer;
[0009] Preparing a first mask layer on the bulk silicon wafer;
[0010] Using the first mask layer to etch and prepare a device layer on the bulk silicon wafer, where the device layer is located between the first mask layer and the bulk silicon wafer;
[0011] Preparing a second mask layer on the bulk silicon wafer, where the second mask layer wraps the sidewalls and the first surface of the device layer, and the first surface is the surface of the device layer facing away from the bulk silicon wafer;
[0012] Etch and prepare the layer to be oxidized on the bulk silicon wafer using the second mask layer;
[0013] Oxidize the layer to be oxidized to prepare an oxidation isolation layer between the device layer and the bulk silicon wafer;
[0014] Remove the second mask layer to expose the device layer.
[0015] The above method for fabricating a bulk silicon-based electro-optic modulator can realize the fabrication of an electro-optic modulator on a bulk silicon wafer, thus solving the biggest difficulty in the transition of silicon photonic chip fabrication from an SOI wafer substrate to a bulk silicon wafer substrate. After the silicon photonic chip is fabricated on the bulk silicon wafer, the cost can be significantly reduced, thereby enhancing the industrial competitiveness of silicon photonics in the field of optical communication and changing the industrial pattern in the field of optical communication. Specifically: Deposit a mask material such as silicon nitride (SiN) on the bulk silicon wafer and pattern it to form a first mask layer, and then use the first mask layer to etch and prepare a device layer on the bulk silicon wafer, where the device layer is used to fabricate an electro-optic modulation device. Continuously deposit a mask material such as silicon nitride (SiN) on the side of the first mask layer facing away from the bulk silicon wafer and pattern it to form a second mask layer. During the process of depositing the mask material, the mask material covers both the first mask layer and the exposed surface of the bulk silicon wafer at the same time, and a second mask layer that wraps the first surface and sidewalls of the device layer is formed through patterning; Since the material of the second mask layer is the same as that of the first mask layer, after patterning, the first mask layer is also part of the second mask layer. Then use the second mask layer to etch and prepare the layer to be oxidized on the bulk silicon wafer, where the layer to be oxidized is a silicon layer. Oxidize the layer to be oxidized to form an oxidation isolation layer. It can be understood that during the oxidation process, the exposed surface of the bulk silicon wafer will also be oxidized. Finally, remove the second mask layer to expose the top silicon device layer, so as to fabricate a silicon-based electro-optic modulator on the device layer, thereby realizing the fabrication of a high-speed electro-optic modulator on the bulk silicon wafer.
[0016] In some embodiments, fabricating the second mask layer on the bulk silicon wafer includes:
[0017] Deposit a mask layer on the side of the first mask layer facing away from the bulk silicon wafer and pattern it to form the second mask layer; wherein, the orthographic projection of the mask layer on the bulk silicon wafer is larger than the orthographic projection of the first mask layer on the bulk silicon wafer.
[0018] In some embodiments, the method further includes:
[0019] Fabricate an electro-optic modulation device on the device layer;
[0020] Fabricate an isolation layer on the side of the electro-optic modulation device facing away from the bulk silicon wafer;
[0021] Fabricate a waveguide layer on the side of the isolation layer facing away from the bulk silicon wafer;
[0022] A cladding layer is prepared on the side of the waveguide layer facing away from the bulk silicon wafer;
[0023] The isolation layer and the cladding layer are etched, and a metal layer is deposited to prepare an electrode layer electrically connected to the electro-optic modulation device.
[0024] In some embodiments, the thickness of the device layer is 150 - 500 nm.
[0025] In some embodiments, the electro-optic modulation device has a ridge structure, the middle part of the ridge structure has a thickness of 150 - 500 nm, and the thickness of the edge of the ridge structure is 50 - 150 nm.
[0026] In some embodiments, the width of the second mask layer is 1 - 10 μm.
[0027] In some embodiments, the thickness of the oxidation isolation layer is 2 - 8 μm.
[0028] In some embodiments, the thickness of the waveguide layer is 150 - 450 nm;
[0029] And / or, the width of the waveguide layer is 1 - 10 μm.
[0030] In a second aspect, the present invention provides a bulk silicon-based electro-optic modulator prepared by using the method described in any one of the first aspect.
[0031] In some embodiments, the bulk silicon-based electro-optic modulator is a bulk silicon-based electro-optic phase modulator;
[0032] Or, the bulk silicon-based electro-optic modulator is a bulk silicon-based electro-optic intensity modulator. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1 is a flowchart of a method for preparing a bulk silicon-based electro-optic modulator provided by an embodiment of the present invention;
[0034] Figure 2 is a flowchart of a method for preparing a bulk silicon-based electro-optic modulator provided by an embodiment of the present invention;
[0035] Figures 3 - 14 is a process flowchart for preparing a bulk silicon-based electro-optic modulator provided by an embodiment of the present invention;
[0036] Figure 15 is Figure 9 a schematic diagram of key dimensions in
[0037] Figure 16 is Figure 13 a schematic diagram of key dimensions in
[0038] Figure 17 The top view of a bulk silicon-based electro-optic phase modulator provided by an embodiment of the present invention;
[0039] Figure 18 The partial structural cross-sectional view of a bulk silicon-based electro-optic phase modulator provided by an embodiment of the present invention;
[0040] Figure 19 The top view of a bulk silicon-based electro-optic intensity modulator provided by an embodiment of the present invention;
[0041] Reference numerals: 1 - bulk silicon wafer; 2 - first mask layer; 11 - device layer; 3 - mask layer; 31 - second mask layer; 12 - layer to be oxidized; 121 - oxidation isolation layer; 13 - edge oxidation layer; 111 - electro-optic modulation device; 4 - isolation layer; 5 - waveguide layer; 6 - cladding layer; 7 - electrode layer; 100 - bulk silicon-based electro-optic phase modulator; 200 - bulk silicon-based electro-optic intensity modulator; 210 - optical waveguide; 220 - optical splitter. Detailed implementation manners
[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B may mean A or B; the "and / or" in the text is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B may mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two.
[0043] Hereinafter, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as implying or suggesting relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more than two.
[0044] In a first aspect, as Figure 1 shown, an embodiment of the present invention provides a method for manufacturing a bulk silicon-based electro-optic modulator, which specifically includes the following steps:
[0045] S101. Provide a bulk silicon wafer;
[0046] S102. Prepare a first mask layer on the bulk silicon wafer;
[0047] S103. Use the first mask layer to etch and prepare a device layer on the bulk silicon wafer, where the device layer is located between the first mask layer and the bulk silicon wafer.
[0048] S104. Prepare a second mask layer on the bulk silicon wafer, where the second mask layer wraps the sidewalls and the first surface of the device layer, and the first surface is the surface of the device layer facing away from the bulk silicon wafer.
[0049] S105. Use the second mask layer to etch and prepare a layer to be oxidized on the bulk silicon wafer.
[0050] S106. Oxidize the layer to be oxidized to prepare an oxidation isolation layer between the device layer and the bulk silicon wafer.
[0051] S107. Remove the second mask layer to expose the device layer.
[0052] The above method for preparing a bulk silicon-based electro-optic modulator can realize the preparation of an electro-optic modulator on a bulk silicon wafer, thus solving the biggest difficulty in the transition of silicon photonic chip preparation from an SOI wafer substrate to a bulk silicon wafer substrate. After the silicon photonic chip is prepared on the bulk silicon wafer, the cost can be significantly reduced, thereby improving the industrial competitiveness of silicon photonics in the field of optical communication and changing the industrial pattern in the field of optical communication. Specifically: Deposit a mask material such as silicon nitride (SiN) on the bulk silicon wafer and pattern it to form the first mask layer, and then use the first mask layer to etch and prepare a device layer on the bulk silicon wafer, where the device layer is used to prepare an electro-optic modulation device. Continue to deposit a mask material such as silicon nitride (SiN) on the side of the first mask layer facing away from the bulk silicon wafer and pattern it to form the second mask layer. During the process of depositing the mask material, the mask material simultaneously covers the exposed surfaces of the first mask layer and the bulk silicon wafer, and through patterning, a second mask layer that wraps the first surface and the sidewalls of the device layer is formed; since the material of the second mask layer is the same as that of the first mask layer, after patterning, the first mask layer is also part of the second mask layer. Then use the second mask layer to etch and prepare a layer to be oxidized on the bulk silicon wafer, where the layer to be oxidized is a silicon layer. Oxidize the layer to be oxidized to form an oxidation isolation layer. It can be understood that during the oxidation process, the exposed surface of the bulk silicon wafer will also be oxidized. Finally, remove the second mask layer to expose the top silicon device layer, so as to prepare a silicon-based electro-optic modulator on the device layer, thus realizing the preparation of a high-speed electro-optic modulator on the bulk silicon wafer.
[0053] In some embodiments, in the above S104, preparing the second mask layer on the bulk silicon wafer specifically includes:
[0054] Deposit a mask layer on the side of the first mask layer facing away from the bulk silicon wafer and pattern it to form the second mask layer; wherein, the orthographic projection of the mask layer on the bulk silicon wafer is larger than the orthographic projection of the first mask layer on the bulk silicon wafer.
[0055] It should be noted that during the process of depositing a mask material on the side of the first mask layer away from the bulk silicon wafer to form a mask layer, the exposed surface of the bulk silicon wafer will also be deposited with the mask material. Therefore, the mask layer covers both the first mask layer and the exposed surface of the bulk silicon wafer. If the first mask layer is taken as the top and the bulk silicon wafer as the bottom, the mask layer covers the top surface of the first mask layer, the sidewalls of the first mask layer, the sidewalls of the device layer, and the exposed area on the top surface of the bulk silicon wafer. That is to say, the orthographic projection of the mask layer on the top surface of the bulk silicon wafer is larger than the orthographic projection of the first mask layer on the top surface of the bulk silicon wafer. The mask material of the mask layer can be the same as the material of the first mask layer. For example, both are SiN. The second mask layer is formed by patterning and etching the deposited mask layer and the first mask layer. In a possible implementation, the patterning process can etch the mask layer on the top of the first mask layer and the mask layer on the partially exposed area on the top surface of the bulk silicon wafer, so that the formed second mask layer wraps other surfaces except the bottom surface of the device layer to prevent the device layer from being oxidized during the oxidation process.
[0056] In some embodiments, as Figure 2 shown, the method for fabricating a bulk silicon-based electro-optic modulator provided by the embodiments of the present invention further includes the following steps:
[0057] S201. Fabricate an electro-optic modulation device on the device layer;
[0058] S202. Fabricate an isolation layer on the side of the electro-optic modulation device away from the bulk silicon wafer;
[0059] S203. Fabricate a waveguide layer on the side of the isolation layer away from the bulk silicon wafer;
[0060] S204. Fabricate a cladding layer on the side of the waveguide layer away from the bulk silicon wafer;
[0061] S205. Etch the isolation layer and the cladding layer, and deposit a metal layer to fabricate an electrode layer electrically connected to the electro-optic modulation device.
[0062] In a possible implementation manner, in the above S201, the electro-optic modulation device prepared on the device layer, i.e., the top silicon, can be a high-speed silicon-based modulation device of any structure. In the above S202, an isolation material such as silicon dioxide is deposited on the side of the electro-optic modulation device away from the bulk silicon wafer to form an isolation layer. The isolation layer can play a role in protecting the electro-optic modulation device and insulating isolation. In the above S203, a waveguide layer material such as SiN is deposited on the side of the isolation layer away from the bulk silicon wafer, and the orthographic projection of the formed waveguide layer on the bulk silicon wafer has an overlapping area with the orthographic projection of the electro-optic modulation device on the bulk silicon wafer. During the specific deposition process, only the area where the waveguide layer material needs to be deposited can be exposed, or the waveguide layer can be formed by depositing the waveguide layer material first and then patterning. In the above S204, an insulating material such as silicon dioxide is deposited on the side of the waveguide layer away from the bulk silicon wafer to form a cladding layer to wrap the waveguide layer in the silicon dioxide layer. Exemplarily, both the isolation layer and the cladding layer are made of silicon dioxide material. In the above S205, the isolation layer and the cladding layer are etched to form vias, the vias expose the electrode region of the electro-optic modulation device, metal is deposited in the vias and the metal is deposited on the top surface of the cladding layer to form an electrode layer, and the electrode layer is electrically connected to the electro-optic modulation device through the metal in the vias.
[0063] To make the solution provided by the embodiments of the present invention easier to understand, the following uses a specific embodiment to detail the method for manufacturing a bulk silicon-based electro-optic modulator provided by the embodiments of the present invention. As Figures 3 - 14 shown, the process includes the following steps:
[0064] As Figure 3 shown, a bulk silicon wafer 1 is provided. The bulk silicon wafer 1 can be used as a silicon substrate, and the bulk silicon wafer 1 can be a columnar structure. Define Figure 3 the upper surface of the bulk silicon wafer 1 as the top surface and the lower surface as the bottom surface. Remove the natural oxide layer on the top surface of the bulk silicon wafer 1, deposit SiN on the top surface, and etch the SiN to obtain the designed pattern to form the first mask layer 2, as Figure 4 shown. Using the first mask layer 2 as a hard mask, etch the silicon substrate to form the device layer 11, i.e., the top silicon, as Figure 5 shown. Remove the natural oxide layer on the surface of the silicon substrate and the device layer 11, deposit SiN on the exposed areas on the top surface of the device layer 11 and the top surface of the silicon substrate to form a mask layer 3, as Figure 6 shown. It should be noted that Figure 6 the obvious boundary line between the mask layer 3 and the first mask layer 2 is only for distinguishing the two layers. In the actual process, since the materials of the mask layer 3 and the first mask layer 2 are both SiN, there may be no obvious interlayer boundary line between the two. Etch the SiN of the mask layer 3 so that the surface and side walls of the top silicon of the device layer 11 are wrapped by SiN to form the second mask layer 31, as Figure 7 shown. Using SiN as a hard mask, etch the silicon substrate to form the layer to be oxidized 12, asFigure 8 As shown. Thermal oxidation of silicon forms a silicon dioxide (SiO2) layer to isolate the top silicon from the silicon substrate, i.e., an oxidation isolation layer 121 is formed between the top silicon and the silicon substrate to limit the optical mode, such as Figure 9 As shown. During the oxidation process, a partial area on the top surface of the silicon substrate is exposed, and the exposed area is also oxidized simultaneously to form an edge oxide layer 13. The SiN hard mask, i.e., the second mask layer 31, is removed to expose the top silicon, such as Figure 10 As shown.
[0065] Ion implantation and silicon etching are performed on the device layer 11, i.e., the top silicon, to form a ridge structure. Then, silicon dioxide is deposited as the isolation layer 4 and chemical mechanical polishing (CMP) is carried out to fabricate a conventional silicon-based electro-optic modulator on the top silicon, such as Figure 11 As shown. It should be noted that the silicon-based electro-optic modulator can be a high-speed silicon-based modulator of any structure, not limited to Figure 11 the one shown in Figure 11 In there is an obvious boundary line between the isolation layer 4, the oxidation isolation layer 121, and the edge oxide layer 13, which is only for distinguishing each layer. In the actual process, since the materials are all SiO2, there may be no obvious interlayer boundary line among the three. SiN is deposited on the top surface of the isolation layer 4 and etched to obtain the designed pattern to form the waveguide layer 5, such as Figure 12 As shown. This layer of SiN is used to fabricate SiN material integrated optical devices. Silicon dioxide is deposited as the cladding layer 6, such as Figure 13 As shown. Figure 13 In there is an obvious boundary line between the cladding layer 6 and the isolation layer 4, which is only for distinguishing each layer. In the actual process, since the materials are all SiO2, there may be no obvious interlayer boundary line among the three. Silicon dioxide is etched to form vias and metal is deposited to fabricate the electrode layer 7 connecting the electro-optic modulation device 111, such as Figure 14 As shown.
[0066] In some embodiments, such as Figure 15 As shown, the thickness d1 of the device layer 11 is 150 - 500 nm. For example, d1 can be 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 360 nm, 370 nm, 380 nm, 390 nm, 400 nm, 410 nm, 420 nm, 430 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm, 490 nm, 500 nm.
[0067] In some embodiments, such asFigure 16 As shown, the electro-optic modulation device 111 has a ridge structure. The thickness d2 in the middle of the ridge structure is 150 - 500 nm. For example, d2 can be 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 360 nm, 370 nm, 380 nm, 390 nm, 400 nm, 410 nm, 420 nm, 430 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm, 490 nm, 500 nm. The thickness d3 at the edge of the ridge structure is 50 - 150 nm. For example, d3 can be 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm.
[0068] In some embodiments, as Figure 15 shown, the width w1 of the second mask layer 31 is 1 - 10 μm. For example, w1 can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm.
[0069] In some embodiments, as Figure 15 shown, the thickness of the oxidation isolation layer 121d4 is 2 - 8 μm. For example, d4 can be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm.
[0070] In some embodiments, as Figure 16 shown, the thickness d5 of the waveguide layer 5 is 150 - 450 nm. For example, d5 can be 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 360 nm, 370 nm, 380 nm, 390 nm, 400 nm, 410 nm, 420 nm, 430 nm, 440 nm, 450 nm.
[0071] And / or, the width w2 of the waveguide layer 5 is 1 - 10 μm. For example, w2 can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm.
[0072] In a second aspect, an embodiment of the present invention further provides a bulk silicon-based electro-optic modulator, which is prepared by any one of the methods in the embodiments of the first aspect.
[0073] Embodiments of the present invention can realize the preparation of a high-speed electro-optic modulator on a bulk silicon wafer 1, thus solving the biggest difficulty in the transition of silicon photonics chip preparation from an SOI wafer substrate to a bulk silicon wafer 1 substrate.
[0074] After the silicon photonics chip is prepared on the bulk silicon wafer 1, the cost can be significantly reduced, thereby improving the industrial competitiveness of silicon photonics in the field of optical communication and changing the industrial pattern in the field of optical communication. In addition, the lower-cost silicon photonics chip will also greatly reduce the cost of high-speed optical modules and further reduce the hardware cost of key facilities in the information age such as data centers, thus being more conducive to the development and progress of China's information industry.
[0075] In some embodiments, the bulk silicon-based electro-optic modulator is a bulk silicon-based electro-optic phase modulator 100;
[0076] Alternatively, the bulk silicon-based electro-optic modulator is a bulk silicon-based electro-optic intensity modulator 200.
[0077] In a possible implementation manner, as Figure 17 and Figure 18 shown, an embodiment of the present invention further provides a bulk silicon-based electro-optic phase modulator 100, which is prepared by any one of the methods in the embodiments of the first aspect. Referring to Figure 18 , the light rays are represented by dashed lines. The light is coupled into the electro-optic modulation device 111 (i.e., the Si modulator) from the waveguide layer 5 (SiN), and after electro-optic modulation, it is coupled back into the waveguide layer 5 (SiN). The electrode layer 7 supplies power to the electro-optic modulation device 111. Figure 17 The region surrounded by the solid line in the waveguide layer 5 (SiN) is shown, the region surrounded by the dashed line represents the Si fully etched region in the electro-optic modulation device 111, and the region surrounded by the dotted line represents the Si deeply etched region in the silicon substrate.
[0078] In a possible implementation manner, as Figure 19 shown, an embodiment of the present invention further provides a bulk silicon-based electro-optic intensity modulator 200, which is prepared by any one of the methods in the embodiments of the first aspect. As Figure 19 shown and referring to Figure 17 , the bulk silicon-based electro-optic intensity modulator 200 includes optical waveguides 210, splitters 220, and an electro-optic phase modulation component. Among them, there are two optical waveguides 210, which are respectively used as the input end and the output end of the bulk silicon-based electro-optic intensity modulator 200. There are also two splitters 220, and the two splitters 220 can be but are not limited to 50 / 50 splitters. As Figure 19As shown, the two optical splitters 220 are 50 / 50 optical splitters, and the 50 / 50 optical splitter can be any device that realizes 50 / 50 splitting, such as: 50 / 50 directional coupler, 1x2 multimode interferometer (MMI), etc. The optical splitter 220 on the side close to the output end is arranged in reverse and can be used as a combiner. The electro-optic phase modulation component includes two bulk silicon-based electro-optic phase modulators 100 as shown in Figure 17 , which are respectively connected to the two outlets of the optical splitter 220 or the two inlets of the combiner. The bulk silicon-based electro-optic intensity modulator 200 can enable light to enter from the optical waveguide 210, be split into two paths by the optical splitter 220, the two paths of light respectively enter the waveguide layer 5 of the corresponding bulk silicon-based electro-optic phase modulator 100, the light is coupled into the electro-optic modulation device 111 from the waveguide layer 5, after electro-optic modulation, it is coupled back into the waveguide layer 5, and then the two paths of light are combined into one path by the combiner and emitted from the bulk silicon-based electro-optic intensity modulator 200 through the optical waveguide 210 on the other side.
[0079] Obviously, those skilled in the art can make various changes and modifications to the embodiments of 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 equivalent technologies, the present invention also intends to include these changes and modifications.
Claims
1. A method for fabricating a bulk silicon-based electro-optic modulator, characterized in that, Including: Providing a bulk silicon wafer; Preparing a first mask layer on the bulk silicon wafer; Etching and preparing a device layer on the bulk silicon wafer by using the first mask layer, where the device layer is located between the first mask layer and the bulk silicon wafer; Preparing a second mask layer on the bulk silicon wafer, where the second mask layer wraps the sidewalls and a first surface of the device layer, and the first surface is the surface of the device layer facing away from the bulk silicon wafer; Etching and preparing a layer to be oxidized on the bulk silicon wafer by using the second mask layer; Oxidizing the layer to be oxidized to prepare an oxidation isolation layer between the device layer and the bulk silicon wafer; Removing the second mask layer to expose the device layer.
2. The method according to claim 1, wherein Preparing a second mask layer on the bulk silicon wafer includes: Depositing a mask layer on the side of the first mask layer facing away from the bulk silicon wafer and patterning to form the second mask layer; wherein, the orthographic projection of the mask layer on the bulk silicon wafer is larger than the orthographic projection of the first mask layer on the bulk silicon wafer.
3. The method according to claim 1, characterized in that, The method further includes: Preparing an electro-optic modulation device on the device layer; Preparing an isolation layer on the side of the electro-optic modulation device facing away from the bulk silicon wafer; Preparing a waveguide layer on the side of the isolation layer facing away from the bulk silicon wafer; Preparing a cladding layer on the side of the waveguide layer facing away from the bulk silicon wafer; Etching the isolation layer and the cladding layer, and depositing a metal layer to prepare an electrode layer electrically connected to the electro-optic modulation device.
4. The method according to claim 1, characterized in that, The thickness of the device layer is 150 - 500 nm.
5. The method according to claim 3, wherein The electro-optic modulation device is a ridge structure, the middle thickness of the ridge structure is 150 - 500 nm, and the thickness of the edge of the ridge structure is 50 - 150 nm.
6. The method according to claim 1, wherein The width of the second mask layer is 1 - 10 μm.
7. The method according to claim 1, wherein The thickness of the oxidation isolation layer is 2 - 8 μm.
8. The method according to claim 3, wherein The thickness of the waveguide layer is 150 - 450 nm; And / or, the width of the waveguide layer is 1 - 10 μm.
9. A bulk silicon-based electro-optic modulator, characterized in that, Prepared by using the method according to any one of claims 1 - 8.
10. The bulk-silicon-based electro-optic modulator according to claim 9, characterized in that, The bulk silicon-based electro-optic modulator is a bulk silicon-based electro-optic phase modulator; Or, the bulk silicon-based electro-optic modulator is a bulk silicon-based electro-optic intensity modulator.