Silicon optical device structure and manufacturing method thereof

Abstract

The invention discloses a silicon optical device structure and a manufacturing method thereof. The silicon optical device structure comprises a dielectric layer arranged on a substrate; the waveguide structure is arranged in the dielectric layer; the waveguide structure comprises a first waveguide, an electro-optical material pattern and a second waveguide which are sequentially stacked away from the substrate; the electro-optical material pattern and the second waveguide are sequentially formed on the first waveguide in a self-alignment mode. The groove-shaped waveguide structure capable of being subjected to photoelectric modulation can be formed by utilizing the characteristics of the electro-optical material, the groove width of the groove-shaped waveguide can be adjusted through the filling thickness of the electro-optical material, the groove-shaped waveguide structure with different intervals can be achieved, automatic alignment of the two layers of waveguides in the width direction can be achieved, and the photoelectric modulation efficiency is improved. And the dual advantages of low loss and photoelectric modulation can be realized.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor integrated circuit technology, and in particular to a silicon optical device structure and a manufacturing method thereof. Background Art

[0002] Photonic integration is a hot topic in today's scientific and technological community, and improving integration is of utmost importance. Optical waveguides are the foundation and core of photonic integration. Their main function is to confine light in a specific medium and guide light waves to propagate in a certain direction. The current mainstream optical waveguide material is SOI (Silicon-on-insulator). The refractive index difference between the Si material in the core layer of the optical waveguide and the SiO2 material in the cladding is large, and the light confinement effect is strong. Submicron optical waveguides can be prepared, greatly improving integration. As optical interconnect technology develops towards ultra-high speed and dense integration, materials such as SOI have shown an important position in photonic integration. At present, most active devices are based on SOI substrates, but due to the problem of large optical loss in SOI optical waveguide materials, it has an adverse effect on integration.

[0003] Silicon nitride is the most promising next-generation optical waveguide material. It has many advantages in optical waveguide devices:

[0004] (1) High material strength and stable structure;

[0005] (2) The bandgap is large and the transparent band is wide, and its transparent window can extend from infrared to visible light band;

[0006] (3) Compatible with standard CMOS process and low manufacturing cost;

[0007] (4) High refractive index. The refractive index difference with SiO2 is large at a wavelength of 1550nm. The waveguide size and bending radius can be very small, the integration is high, and 3D large-scale integration can be achieved.

[0008] (5) The loss is very small, 3 to 4 orders of magnitude lower than that of SOI waveguide, making it a very good waveguide material.

[0009] Therefore, the silicon nitride platform has many advantages, such as lower propagation loss, higher manufacturing flexibility, selectable refractive index, wider transparency range, adjustable operating wavelength, and high tolerance to temperature changes.

[0010] However, silicon nitride also has a centrally symmetrical structure, no intrinsic electro-optical properties, and a weak photoelectric effect. It is generally not possible to obtain optical modulation through an electric field, making it difficult to make active devices. Moreover, due to the dielectric properties of silicon nitride, optical modulation using charge diffusion cannot be applied to silicon nitride waveguide devices. Summary of the invention

[0011] The purpose of the present invention is to overcome the above-mentioned defects in the prior art and provide a silicon optical device structure and a manufacturing method thereof.

[0012] To achieve the above object, the technical solution of the present invention is as follows:

[0013] The present invention provides a silicon optical device structure, comprising:

[0014] a dielectric layer disposed on the substrate;

[0015] A waveguide structure disposed in the dielectric layer; the waveguide structure comprises a first waveguide, an electro-optical material pattern, and a second waveguide stacked in sequence away from the substrate;

[0016] The electro-optic material pattern and the second waveguide are sequentially formed on the first waveguide in a self-aligned manner.

[0017] Furthermore, a first groove is provided in the dielectric layer, and the first groove is self-alignedly formed on a first surface of the first waveguide away from the substrate, and the electro-optical material pattern and the second waveguide are sequentially filled in the first groove.

[0018] Further, the sidewalls of the first groove are self-aligned with the sides of the first waveguide, and the sides of the electro-optical material pattern and the sides of the second waveguide are connected to the sidewalls of the first groove; and / or, there is a first gap between the second waveguide and the first waveguide, and the height of the first gap perpendicular to the first surface is associated with the filling thickness of the electro-optical material pattern in the first groove.

[0019] Further, the dielectric layer includes a first dielectric layer, a second dielectric layer and a third dielectric layer stacked in sequence away from the substrate, a second groove is provided on a second surface of the first dielectric layer away from the substrate, the first waveguide is self-alignedly formed in the second groove, and a second gap is provided between the side of the first waveguide and the sidewall of the second groove, the second dielectric layer also forms a filling for the second gap, the first groove is located in the second dielectric layer, and the sidewall profile of the first groove corresponds to the boundary profile filled by the second dielectric layer along the side of the first waveguide, and the third dielectric layer also forms a cover for the first groove and the second waveguide filled therein.

[0020] Furthermore, the first dielectric layer to the third dielectric layer form a cladding of the waveguide structure.

[0021] Further, the electro-optical material includes lithium niobate or a photoconductive polymer, and / or the first waveguide and the second waveguide materials include silicon nitride.

[0022] The present invention also provides a method for manufacturing a silicon optical device structure, comprising:

[0023] providing a substrate;

[0024] forming a dielectric layer on the substrate;

[0025] A waveguide structure is formed in the dielectric layer, so that the formed waveguide structure includes a first waveguide, an electro-optical material pattern and a second waveguide which are stacked in sequence away from the substrate, and the formed electro-optical material pattern and the second waveguide are formed in sequence on the first waveguide in a self-aligned manner.

[0026] Furthermore, the forming of a dielectric layer on the substrate and the forming of a waveguide structure in the dielectric layer specifically include:

[0027] forming a first dielectric layer on the substrate;

[0028] forming a second groove on the surface of the first dielectric layer;

[0029] forming a first waveguide material layer on the surface of the first dielectric layer to cover the second groove, removing excess first waveguide material layer outside the second groove, and forming a first waveguide material layer pattern in the second groove;

[0030] forming a sacrificial layer on the surface of the first dielectric layer to cover the first waveguide material layer pattern, and forming a sacrificial layer pattern on the surface of the first waveguide material layer pattern by patterning;

[0031] Using the sacrificial layer pattern as a mask, patterning the first waveguide material layer pattern to form a first waveguide in the second groove with a second gap between the side surface and the sidewall of the second groove;

[0032] forming a second dielectric layer on the surface of the first dielectric layer to cover the second groove and the sacrificial layer pattern;

[0033] Removing redundant second dielectric layer on the sacrificial layer pattern to expose the top surface of the sacrificial layer pattern;

[0034] removing the sacrificial layer pattern to form a first groove in the second dielectric layer, the bottom surface of which is located on the first waveguide;

[0035] forming an electro-optical material pattern on the bottom surface of the first groove;

[0036] Filling the first groove on the electro-optical material pattern with a second waveguide material layer, and removing excess second waveguide material layer outside the first groove, forming a second waveguide in the first groove, thereby forming a waveguide structure including the first waveguide, the electro-optical material pattern, and the second waveguide stacked in sequence away from the substrate, and allowing the electro-optical material pattern and the second waveguide formed thereby to be sequentially self-aligned on the first waveguide;

[0037] A third dielectric layer is formed on the surface of the second dielectric layer to cover the second waveguide, so that the first dielectric layer to the third dielectric layer form a cladding of the waveguide structure.

[0038] Further, when forming the second groove, the width of the second groove is made greater than the depth of the second groove, and when forming the first waveguide in the second groove, the width of the first waveguide is adjusted by adjusting the formation width of the sacrificial layer pattern; and / or, by removing the sacrificial layer pattern, the side wall of the first groove is self-aligned with the side of the first waveguide, thereby achieving self-alignment between the electro-optical material pattern and the second waveguide and the first waveguide.

[0039] Furthermore, by depositing electro-optical material in the first groove and performing heat treatment, the electro-optical material pattern is formed to fill only the bottom surface of the first groove; and / or, by adjusting the deposition thickness of the electro-optical material, the size of the first gap between the second waveguide and the first waveguide in the formed waveguide structure is adjusted.

[0040] As can be seen from the above technical scheme, the present invention forms a slot waveguide structure capable of photoelectric modulation by forming a first waveguide, an electro-optical material pattern and a second waveguide stacked in sequence in a direction away from the substrate, thereby utilizing the characteristics of the electro-optical material, and can further combine to form a silicon nitride first waveguide and a second waveguide to form a slot waveguide structure with the dual advantages of low loss and photoelectric modulation. Moreover, compared with the conventional slot waveguide perpendicular to the substrate, the slot width (first gap) of the slot waveguide of the present invention can be determined by the filling thickness of the electro-optical material, thereby realizing a slot waveguide structure with different slot widths, and is not limited by the minimum photolithography size, and is easy to realize a slot waveguide structure with a narrower slot width. At the same time, the width of the slot waveguide of the present invention can be controlled by the width of the sacrificial layer after etching, which is easy to monitor and reproduce, and can directly realize automatic alignment of the two layers of waveguides (the second waveguide and the first waveguide) in the width direction. In addition, by forming a second groove with a width greater than a depth, the aspect ratio of the first waveguide material during filling can be significantly reduced, thereby avoiding the problem of insufficient filling that may be caused by the conventional method of directly filling the waveguide material in a groove with a high aspect ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of a silicon optical device structure according to a preferred embodiment of the present invention.

[0042] Figure 2-Figure 15 The present invention is a process flow chart of a method for manufacturing a silicon optical device structure according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are 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. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the present invention belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0044] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0045] refer to Figure 1 A silicon optical device structure of the present invention includes a dielectric layer 11 disposed on a substrate 10 and a waveguide structure disposed in the dielectric layer 11 .

[0046] The waveguide structure includes a first waveguide 16, an electro-optical material pattern 17, and a second waveguide 18 stacked in sequence in a direction away from the upper surface of the substrate 10. In addition, the upper surface of the second waveguide 18 away from the substrate 10 is completely covered by the dielectric layer 11, that is, the dielectric layer 11 fully surrounds the entire waveguide structure.

[0047] The first waveguide 16 , the electro-optical material pattern 17 and the second waveguide 18 in the waveguide structure are distributed along a direction parallel to the upper surface of the substrate 10 .

[0048] In the waveguide structure, the electro-optic material pattern 17 and the second waveguide 18 are sequentially formed on the first waveguide 16 in a self-aligned manner. Further, the two side surfaces (side walls) of the electro-optic material pattern 17 are aligned with the two side surfaces (side walls) of the first waveguide 16; the two side surfaces of the second waveguide 18 are aligned with the two side surfaces of the electro-optic material pattern 17 and the two side surfaces of the first waveguide 16.

[0049] In some embodiments, a first groove 19 is provided in the dielectric layer 11. The first groove 19 is formed in a self-aligned manner on a first surface (upper surface) of the first waveguide 16 away from the substrate 10, and the electro-optical material pattern 17 and the second waveguide 18 are sequentially filled in the first groove 19. Furthermore, the upper surface of the second waveguide 18 away from the substrate 10 is flush with the top surface of the first groove 19.

[0050] The sidewalls of the first groove 19 are self-aligned with the side surfaces of the first waveguide 16 ; the side surfaces of the electro-optical material pattern 17 and the side surfaces of the second waveguide 18 are connected with the sidewalls of the first groove 19 .

[0051] There is a first gap H between the second waveguide 18 and the first waveguide 16. The size (gap height) of the first gap H away from the first surface is associated with the filling thickness of the electro-optical material pattern 17 in the first groove 19. That is, the size of the first gap H is characterized by the filling thickness of the electro-optical material pattern 17 in the first groove 19.

[0052] In some embodiments, the dielectric layer 11 includes a first dielectric layer 12, a second dielectric layer 13, and a third dielectric layer 14 which are sequentially stacked away from the substrate 10. A second groove 15 is provided on the second surface (upper surface) of the first dielectric layer 12 away from the substrate 10; the first waveguide 16 is self-alignedly formed in the second groove 15. In addition, a second gap L is provided between the side surface of the first waveguide 16 and the side wall of the second groove 15, and the second dielectric layer 13 also enters the second groove 15 to fill the second gap L.

[0053] The first trench 19 is located in the second dielectric layer 13, and the sidewall profile of the first trench 19 corresponds to the boundary profile when the second dielectric layer 13 is filled upward along the side of the first waveguide 16. The third dielectric layer 14 also forms a complete coverage of the first trench 19 and the second waveguide 18 filled therein. Thus, the first dielectric layer 12 to the third dielectric layer 14 (i.e., the dielectric layer 11) form a cladding of the waveguide structure.

[0054] In some embodiments, the substrate 10 may be a silicon substrate 10. The material of the dielectric layer 11 (the first dielectric layer 12 to the third dielectric layer 14) may be silicon dioxide, but is not limited thereto.

[0055] In some embodiments, the electro-optic material (EO-material) of the electro-optic material pattern 17 includes lithium niobate or a photoconductive polymer. The materials of the first waveguide 16 and the second waveguide 18 include silicon nitride, but are not limited thereto.

[0056] In some embodiments, a functional layer is further provided on the dielectric layer 11 for forming active devices, etc. The functional layer may be a silicon layer or other functional material layer.

[0057] Therefore, by utilizing the properties of silicon nitride as an excellent waveguide material and the photoelectric effect of electro-optical materials, the weak photoelectric effect of silicon nitride waveguide can be improved, enabling silicon nitride optical devices to have a certain optical modulation capability.

[0058] A method for manufacturing a silicon optical device structure of the present invention is further described in detail below through specific implementations and in conjunction with the accompanying drawings.

[0059] refer to Figure 2-Figure 15 The present invention provides a method for manufacturing a silicon optical device structure, which can be used to manufacture the above-mentioned Figure 1 A silicon photonic device structure may include the following steps:

[0060] Step S1: providing a substrate 10 .

[0061] refer to Figure 2 A silicon substrate 10 may be used for fabricating the waveguide structure of the present invention thereon.

[0062] Step S2: forming a first dielectric layer 12 and a second dielectric layer 13 on the substrate 10 , and forming a waveguide structure in the first dielectric layer 12 and the second dielectric layer 13 .

[0063] like Figure 2 As shown, a first dielectric layer 12 such as silicon dioxide is formed on the upper surface of the silicon substrate 10 by using a dielectric deposition process.

[0064] like Figure 3 As shown, then, a patterning process, such as photolithography and etching process, is used to form a second groove 15 on the upper surface of the first dielectric layer 12. The second groove 15 is used as a prefabricated groove structure for manufacturing the first waveguide 16, and the second groove 15 is located at the approximate position for manufacturing the first waveguide 16, and the area (key dimension of width) of the second groove 15 is greater than or equal to the area (key dimension of width) of the first waveguide 16 to be manufactured, so that the first waveguide 16 can be manufactured in the second groove 15. At the same time, the depth of the second groove 15 should not be less than the height of the first waveguide 16 to be manufactured in the vertical direction.

[0065] like Figure 4 As shown, then, a dielectric deposition process is used to form a first waveguide material layer 161 such as silicon nitride on the upper surface of the first dielectric layer 12 to cover the second trench 15, so that the first waveguide material layer 161 is completely filled in the second trench 15 and forms a covering film of a certain thickness.

[0066] like Figure 5As shown, a planarization process, such as a chemical mechanical polishing process, is then used to remove the redundant first waveguide material layer 161 on the upper surface of the first dielectric layer 12 outside the second groove 15, thereby forming a first waveguide material layer pattern (first waveguide transition pattern) 162 in the second groove 15. Through the chemical mechanical polishing process, the depth of the second groove 15 is adapted to the thickness of the first waveguide 16 to be manufactured.

[0067] like Figure 6 As shown, after that, a dielectric deposition process is used to further form a sacrificial layer 20 on the surface of the first dielectric layer 12 to cover the first waveguide material layer pattern 162 .

[0068] like Figure 7 As shown, then, a patterning process, such as photolithography and etching process, is used to form a sacrificial layer pattern 201 on the surface of the first waveguide material layer pattern 162. The width critical dimension of the sacrificial layer pattern 201 is adapted to the width critical dimension of the first waveguide 16 to be manufactured. By adjusting the formed width of the sacrificial layer pattern 201, the width of the first waveguide 16 to be formed subsequently can be adjusted.

[0069] like Figure 8 As shown, then, an anisotropic etching process is adopted and the sacrificial layer pattern 201 is used as a mask to etch and pattern the first waveguide material layer pattern 162, retaining the material of the first waveguide material layer pattern 162 below the sacrificial layer 20, and removing the material of the first waveguide material layer pattern 162 except the side surface of the sacrificial layer 20, thereby forming a first waveguide 16 in the second trench 15 with a second gap L between the side surface and the sidewall of the second trench 15. The second gap L is greater than or equal to 0.

[0070] By making the width of the second groove 15, which is the prefabricated groove of the first waveguide 16, larger than the actual width of the first waveguide 16, and making the width of the second groove 15 larger than the depth of the second groove 15, the problem of insufficient filling in the groove that may be caused by directly depositing silicon nitride film to fill the groove of the waveguide pattern with a high aspect ratio in the past can be avoided. In addition, the use of the groove filling method to form the first waveguide transition pattern can alleviate the problem of excessive stress caused by directly depositing silicon nitride on the first dielectric layer 12 and then patterning it. Moreover, after forming the silicon nitride prefabricated groove, the sacrificial layer process is used to structure the prefabricated groove into a waveguide, which further avoids the corresponding quality problems caused by filling the high aspect ratio groove required for directly forming the waveguide structure in the traditional way.

[0071] like Fig. 9As shown, then, a dielectric deposition process is used to form a second dielectric layer 13 such as silicon dioxide on the upper surface of the first dielectric layer 12 to cover the second groove 15 and the sacrificial layer pattern 201, so that the second dielectric layer 13 material is completely filled in the second groove 15, and a covering film of a certain thickness is formed on the top surface of the sacrificial layer pattern 201.

[0072] like Fig.10 As shown, then, a planarization process, such as a chemical mechanical polishing process, is used to remove the redundant second dielectric layer 13 on the sacrificial layer pattern 201 to expose the top surface of the sacrificial layer pattern 201 .

[0073] like Fig.11 As shown, then, the sacrificial layer pattern 201 is removed, thereby forming a first groove 19 with the bottom surface on the first waveguide 16 in the second dielectric layer 13. It can be seen that, through the above method, the width dimension of the formed first groove 19 can correspond to the width dimension of the first waveguide 16 below it. That is, the first groove 19 and the first waveguide 16 with equal width and self-alignment can be formed. Among them, by controlling the grinding thickness during the chemical mechanical polishing process, the depth of the formed first groove 19 can be controlled to be greater than the sum of the thicknesses of the electro-optical material pattern 17 and the second waveguide 18 to be formed.

[0074] like Fig.12 As shown, then, electro-optic material is deposited on the upper surface of the second dielectric layer 13, so that the electro-optic material fills the first groove 19 and is at a certain distance from the top surface of the first groove 19. Then, taking advantage of the fact that the electro-optic material has a low softening temperature and is easy to redistribute after heat treatment, heat treatment is performed to redistribute the electro-optic material after heat treatment, so that the electro-optic material is deposited only at the bottom of the first groove 19, and no effective film layer is formed on the sidewall of the first groove 19, that is, the formed electro-optic material pattern 17 is filled only on the bottom surface of the first groove 19. Thus, an electro-optic material pattern 17 with a certain thickness is formed on the bottom surface of the first groove 19.

[0075] By adjusting the deposition thickness of the electro-optic material, the size of the first gap H between the second waveguide 18 and the first waveguide 16 in the subsequently formed waveguide structure can be adjusted. Compared with the existing vertical slot waveguide structure, the slot width (first gap H) of the slot waveguide of the present invention can be determined by the filling thickness of the electro-optic material, so that it is not limited by the minimum photolithography size (capability), and it is easy to realize a slot waveguide structure with a narrower slot width.

[0076] like Fig.13As shown, then, a dielectric deposition process is used to form a second waveguide material layer 181 such as silicon nitride on the upper surface of the second dielectric layer 13 to cover the first groove 19, so that the second waveguide material layer 181 material completely fills the electro-optical material pattern 17 in the first groove 19, and forms a covering film of a certain thickness on the upper surface of the second dielectric layer 13.

[0077] like Fig.14 As shown, then, a planarization process, such as a chemical mechanical polishing process, is used to remove the redundant second waveguide material layer 181 on the upper surface of the second dielectric layer 13 outside the first groove 19, and a second waveguide 18 is formed in the first groove 19. Thus, a waveguide structure including the first waveguide 16, the electro-optical material pattern 17, and the second waveguide 18 stacked in sequence away from the substrate 10 is formed (even if the formed waveguide structure includes the first waveguide 16, the electro-optical material pattern 17, and the second waveguide 18 stacked in sequence away from the substrate 10) is formed, and the electro-optical material pattern 17 and the second waveguide 18 formed thereby are sequentially self-aligned and formed on the first waveguide 16. The first waveguide 16 and the second waveguide 18 may be silicon nitride strip waveguides.

[0078] It can be seen that the width of the waveguide structure formed by the above method of the present invention is controlled by the width of the sacrificial layer 20 after etching, which is easy to monitor and reproduce. At the same time, by removing the sacrificial layer pattern 201, the side wall of the formed first groove 19 can be self-aligned with the side of the first waveguide 16, thereby achieving the self-alignment between the electro-optical material pattern 17 and the second waveguide 18 and the first waveguide 16, and directly achieving the automatic alignment between the two layers of waveguides (the second waveguide 18 and the first waveguide 16) in the width direction.

[0079] The two layers of silicon nitride waveguides (the first waveguide 16 and the second waveguide 18) and the electro-optical material therebetween together form a slot waveguide structure with low waveguide loss and capable of photoelectric modulation.

[0080] Step S3: forming a third dielectric layer 14 on the second dielectric layer 13 to form a waveguide structure cladding.

[0081] like Fig.15 As shown, finally, a dielectric deposition process is used to form a third dielectric layer 14 such as silicon dioxide on the surface of the second dielectric layer 13 to cover the second waveguide 18, thereby forming an upper cladding of the waveguide structure. Thus, the first dielectric layer 12 to the third dielectric layer 14 together form the cladding of the waveguide structure.

[0082] In summary, the present invention forms a first waveguide 16, an electro-optical material pattern 17, and a second waveguide 18 stacked in sequence in a direction away from the substrate 10, thereby utilizing the characteristics of the electro-optical material to form a slot waveguide structure capable of photoelectric modulation, and can further combine to form a silicon nitride first waveguide 16 and a second waveguide 18, forming a slot waveguide structure having the dual advantages of low loss and photoelectric modulation. Moreover, compared with the conventional slot waveguide perpendicular to the substrate direction, the slot width (first gap H) of the slot waveguide parallel to the substrate direction of the present invention can be determined by the filling thickness of the electro-optical material (electro-optical material pattern 17), thereby realizing a slot waveguide structure with different slot widths, and is not limited by the minimum photolithography size, and is easy to realize a slot waveguide structure with a narrower slot width. At the same time, the width of the slot waveguide of the present invention can be controlled by the width of the sacrificial layer 20 after etching, which is easy to monitor and reproduce, and can directly realize automatic alignment of the two layers of waveguides (the second waveguide 18 and the first waveguide 16) in the width direction. In addition, by forming the second trench 15 with a width greater than its depth, the aspect ratio of the first waveguide 16 material during filling can be significantly reduced, thereby avoiding the problem of insufficient filling that may be caused by the conventional method of directly filling the waveguide material in the high aspect ratio trench.

[0083] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. A silicon optical device structure, characterized in that: include: a dielectric layer disposed on the substrate; A waveguide structure disposed in the dielectric layer; the waveguide structure comprises a first waveguide, an electro-optical material pattern, and a second waveguide stacked in sequence away from the substrate; The electro-optic material pattern and the second waveguide are sequentially formed on the first waveguide in a self-aligned manner.

2. The silicon photonic device structure according to claim 1, characterized in that: A first groove is provided in the dielectric layer. The first groove is formed in a self-aligned manner on a first surface of the first waveguide away from the substrate. The electro-optical material pattern and the second waveguide are filled in the first groove in sequence.

3. The silicon photonic device structure according to claim 2, characterized in that: The sidewalls of the first groove are self-aligned with the sides of the first waveguide, and the sides of the electro-optical material pattern and the sides of the second waveguide are connected to the sidewalls of the first groove; and / or, there is a first gap between the second waveguide and the first waveguide, and the height of the first gap perpendicular to the first surface is associated with the filling thickness of the electro-optical material pattern in the first groove.

4. The silicon photonic device structure according to claim 2, characterized in that: The dielectric layer includes a first dielectric layer, a second dielectric layer and a third dielectric layer stacked in sequence away from the substrate. A second groove is provided on a second surface of the first dielectric layer away from the substrate. The first waveguide is self-alignedly formed in the second groove, and a second gap is provided between a side surface of the first waveguide and a side wall of the second groove. The second dielectric layer also fills the second gap. The first groove is located in the second dielectric layer, and a side wall profile of the first groove corresponds to a boundary profile filled by the second dielectric layer along a side surface of the first waveguide. The third dielectric layer also covers the first groove and the second waveguide filled therein.

5. The silicon photonic device structure according to claim 4, characterized in that: The first to third dielectric layers form a cladding of the waveguide structure.

6. The silicon photonic device structure according to claim 1, characterized in that: The electro-optic material comprises lithium niobate or a photoconductive polymer, and / or the first waveguide and the second waveguide material comprises silicon nitride.

7. A method for manufacturing a silicon optical device structure, characterized in that: include: providing a substrate; forming a dielectric layer on the substrate; A waveguide structure is formed in the dielectric layer, so that the formed waveguide structure includes a first waveguide, an electro-optical material pattern and a second waveguide which are stacked in sequence away from the substrate, and the formed electro-optical material pattern and the second waveguide are formed in sequence on the first waveguide in a self-aligned manner.

8. The method for manufacturing a silicon optical device structure according to claim 7, characterized in that: The forming of a dielectric layer on the substrate and forming a waveguide structure in the dielectric layer specifically includes: forming a first dielectric layer on the substrate; forming a second groove on the surface of the first dielectric layer; forming a first waveguide material layer on the surface of the first dielectric layer to cover the second groove, removing excess first waveguide material layer outside the second groove, and forming a first waveguide material layer pattern in the second groove; forming a sacrificial layer on the surface of the first dielectric layer to cover the first waveguide material layer pattern, and forming a sacrificial layer pattern on the surface of the first waveguide material layer pattern by patterning; Using the sacrificial layer pattern as a mask, patterning the first waveguide material layer pattern to form a first waveguide in the second groove with a second gap between the side surface and the sidewall of the second groove; forming a second dielectric layer on the surface of the first dielectric layer to cover the second groove and the sacrificial layer pattern; Removing redundant second dielectric layer on the sacrificial layer pattern to expose the top surface of the sacrificial layer pattern; removing the sacrificial layer pattern to form a first groove in the second dielectric layer, the bottom surface of which is located on the first waveguide; forming an electro-optical material pattern on the bottom surface of the first groove; Filling the first groove on the electro-optical material pattern with a second waveguide material layer, and removing excess second waveguide material layer outside the first groove, forming a second waveguide in the first groove, thereby forming a waveguide structure including the first waveguide, the electro-optical material pattern, and the second waveguide stacked in sequence away from the substrate, and allowing the electro-optical material pattern and the second waveguide formed thereby to be sequentially self-aligned on the first waveguide; A third dielectric layer is formed on the surface of the second dielectric layer to cover the second waveguide, so that the first dielectric layer to the third dielectric layer form a cladding of the waveguide structure.

9. The method for manufacturing a silicon optical device structure according to claim 8, characterized in that: When forming the second groove, the width of the second groove is made greater than the depth of the second groove, and when forming the first waveguide in the second groove, the width of the first waveguide is adjusted by adjusting the formation width of the sacrificial layer pattern; And / or, by removing the sacrificial layer pattern, the sidewall of the formed first groove is self-aligned with the side surface of the first waveguide, thereby achieving self-alignment between the electro-optical material pattern and the second waveguide and the first waveguide.

10. The method for manufacturing a silicon optical device structure according to claim 8, characterized in that: By depositing electro-optical material in the first groove and performing heat treatment, the electro-optical material pattern is formed to fill only the bottom surface of the first groove; and / or, by adjusting the deposition thickness of the electro-optical material, the size of the first gap between the second waveguide and the first waveguide in the formed waveguide structure is adjusted.

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