CN113359236A - Grating coupling structure based on back process and preparation method - Google Patents
Grating coupling structure based on back process and preparation method Download PDFInfo
- Publication number
- CN113359236A CN113359236A CN202110804838.6A CN202110804838A CN113359236A CN 113359236 A CN113359236 A CN 113359236A CN 202110804838 A CN202110804838 A CN 202110804838A CN 113359236 A CN113359236 A CN 113359236A
- Authority
- CN
- China
- Prior art keywords
- layer
- grating
- reflector
- mirror
- thickness
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/264—Optical coupling means with optical elements between opposed fibre ends which perform a function other than beam splitting
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/34—Optical coupling means utilising prism or grating
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Integrated Circuits (AREA)
Abstract
The invention provides a grating coupling structure based on a back process, which greatly improves the coupling efficiency of a grating and reduces the grating-optical fiber coupling loss by arranging a non-metal structure reflector layer on a waveguide diffraction grating layer. The reflector layer adopts at least one distributed Bragg reflector structure or grating reflector structure, so that the problem of metal absorption is avoided, the reflector layer is more high-temperature resistant, is more compatible with a traditional optical device without causing unnecessary loss, and the problem of process pollution of the rear section of the metal reflector is avoided; the invention also provides a preparation method of the grating coupling structure based on the back process, which adopts the standard wafer as the initial wafer, has simple single-step etching process, and can meet the optical coupling reflection requirement with larger bandwidth through single deposition etching; on the basis of not influencing the original framework, the reflection height requirements of different wave bands can be flexibly met according to design requirements, so that the method has corresponding advantages.
Description
Technical Field
The invention relates to the technical field of photonic devices, in particular to a waveguide grating coupling structure, and particularly relates to a grating coupling structure based on a back process and a corresponding preparation method.
Background
Silicon-on-insulator (SOI) based Silicon material is considered as an important direction for the development of future integrated optics because of the characteristics of CMOS process compatibility, ultra-small integration level, active and passive monolithic integration and the like. One of the major problems to be solved in the development of SOI-based integrated optics is the fiber-to-chip coupling problem. The core size of single mode fiber is typically 10.4 μm, while SOI-based single mode Si waveguides are often sub-micron wide, and the large size difference will result in large coupling losses.
One of the commonly used coupling structures is a grating coupling structure, and conventional grating designs employ a single-step etched chirped grating design where a large amount of light leaks into the substrate layer, causing an additional loss of about 3 dB. In order to improve the grating coupling directivity, the grating coupling directivity can be realized by adding a reflecting mirror. The conventional mirror is usually located in the BOX layer of the SOI wafer to increase the optical reflection efficiency of the front surface of the grating, such a design greatly reduces the coupling efficiency of the grating-optical fiber, but the architecture limits the system compatibility and the expansibility to a certain extent in the face of the requirement of different optical bands requiring different mirror heights. At present, the other coupling grating adopts a back-to-back process, but a metal reflector is commonly used, so that the problem of process pollution at the back section of the metal reflector exists.
Therefore, it is very necessary to research a grating coupling structure based on a back process and a corresponding preparation method, which can integrate reflector structures with different heights on the basis of the compatibility of the existing silicon optical SOI process and the design requirements of different optical bands without changing the original architecture, have greater compatibility and expansibility, and realize simple process, thereby further promoting the deep development and wide application of the technology.
Disclosure of Invention
In order to solve all or part of the problems in the prior art, the invention provides a grating coupling structure based on a back-facing process, which is used for improving the directivity. The invention also provides a preparation method of the grating coupling structure based on the back process, and the grating coupling structure is designed, so that the requirements of reflection heights of different wave bands can be flexibly met, and corresponding advantages are achieved.
The invention provides a grating coupling structure based on a back-facing process.
The grating coupling structure comprises a first transition layer, a waveguide diffraction grating layer, a second transition layer, a reflector layer, a third transition layer and a slide glass which are sequentially overlapped; the second transition layer covers the waveguide diffraction grating layer and is connected with the first transition layer; the reflector layer is a non-metal structural layer, and the projection covers the waveguide diffraction grating layer.
The first transition layer, the second transition layer and the third transition layer are made of SiO2(ii) a The thickness of the first transition layer is larger than that of the waveguide diffraction grating layer.
The thickness of the first transition layer is less than 10 μm, the thickness of the waveguide diffraction grating layer is less than 1 μm, and the thickness of the second transition layer is less than 10 μm;
the waveguide diffraction grating layer comprises at least one grating structure, and the grating structure meets a Bragg condition under first-order diffraction.
The reflector layer comprises at least one distributed Bragg reflector structure, and the distributed Bragg reflector structure is a periodic structure formed by alternately laminating dielectric film layers made of two materials with different refractive indexes; the physical thickness of the dielectric film layer is in direct proportion to the central wavelength of incident light and in inverse proportion to the effective refractive index of the dielectric film layer; the thickness of the distributed Bragg reflector structure is less than 2 mu m.
The reflector layer is of a grating reflector structure; the grating reflector structure comprises at least one grating structure, and the grating structure meets the Bragg condition under first-order diffraction; the thickness of the grating reflector structure is less than 1 μm.
The distance between the top of the waveguide diffraction grating layer and the bottom of the reflector layer meets the requirement that the optical path difference between reflected light and incident light reaches integral multiple of wavelength.
The invention also provides a preparation method of the grating coupling structure based on the back process, which comprises the following steps: step 1, selecting an initial waferCleaning, wherein the initial wafer is a standard wafer and comprises a substrate layer, a first transition layer and a top silicon layer; the standard wafer comprises an SOI wafer and Si3N4A wafer, a SiON wafer; step 2, etching the top silicon layer to form a waveguide diffraction grating layer, and performing SiO on the waveguide diffraction grating2Depositing and carrying out chemical mechanical polishing to obtain a second transition layer; step 3, preparing a reflector layer on the second transition layer, and performing SiO on the reflector layer2Depositing and carrying out chemical mechanical polishing; step 4, bonding the slide glass and the reflector layer; and 5, thinning the substrate layer to a first transition layer.
The thickness of the SiO2 deposit in step 2 may be preset according to different optical wave bands, where the preset thickness is a distance from the top of the waveguide diffraction grating layer to the bottom of the mirror layer, and it is required to satisfy that the optical path difference between the reflected light and the incident light reaches an integral multiple of the wavelength.
When the reflector layer in step 3 is at least one distributed bragg reflector structure, the process of preparing the reflector layer on the second transition layer includes: presetting the thickness of each dielectric film layer of the distributed Bragg reflector structure, so that the physical thickness of the dielectric film layer is in direct proportion to the central wavelength of incident light and in inverse proportion to the effective refractive index of the dielectric film layer; depositing the dielectric film layer by using chemical vapor deposition to obtain the distributed Bragg reflector structure; SiO22Depositing and filling and carrying out chemical mechanical polishing.
Further, after each distributed Bragg reflector structure is completed, the non-reflection area is etched and removed, and SiO is carried out2Depositing and filling and carrying out chemical mechanical polishing.
When the reflector layer in the step 3 is of a grating reflector structure, the process of preparing the reflector layer on the second transition layer comprises the following steps: presetting the thickness of a grating reflector structure and the etching width and period of a grating so as to meet the Bragg condition under first-order diffraction; depositing optical waveguide material, and etching the optical waveguide material to obtain grating reflector Structure (SiO)2Deposition ofFilling and carrying out chemical mechanical polishing.
The slide bonding process comprises: cleaning the surface of the slide glass, and depositing SiO2Bonding between the carrier sheet and the reflector layer is realized by molecular force, and SiO deposited between the carrier sheet and the reflector layer2The deposition layer is a third transition layer.
Compared with the prior art, the invention has the main beneficial effects that:
1. according to the grating coupling structure based on the back process, the reflector layer with the non-metal structure is arranged above the waveguide diffraction grating layer, so that the coupling efficiency of the grating and the optical fiber is greatly improved, and the coupling loss of the grating and the optical fiber is reduced. Compared with a common metal reflector layer, the distributed Bragg reflector structure and the grating reflector structure are used as the reflector layers, have no problem of metal absorption, are more high-temperature resistant, and are more compatible with a traditional optical device without causing unnecessary loss; other front-stage processes can be carried out after the reflector process, and the problem of process pollution of the rear stage of the metal reflector is solved.
2. According to the preparation method of the grating coupling structure based on the back process, provided by the invention, when the initial wafer is the standard wafer, the consistency is good, and the uncertainty of the process is reduced; the design freedom degree can be greatly provided, reflector structures with different heights can be integrated on the basis of not changing the original framework according to the design requirements of different optical wave bands, and the compatibility and the expansibility are higher.
3. The preparation method of the grating coupling structure based on the back process can be used for preparing the back grating coupling structure, can meet the optical coupling reflection requirement of larger bandwidth through single deposition etching, has simple steps and simple process, and is also suitable for Si and Si3N4And the like. Besides the conventional structural chip, the bonding slide can also adopt an IC chip, and the photoelectric monolithic integration is realized under the framework.
Drawings
Fig. 1 is a schematic diagram of a grating coupling structure according to a first embodiment of the present invention.
Fig. 2 is a schematic diagram of a grating coupling structure in a third embodiment of the present invention.
Fig. 3 is a schematic diagram of a grating coupling structure in a third embodiment of the present invention.
Fig. 4 is a schematic diagram of a grating coupling structure in the fourth embodiment of the present invention.
Fig. 5 is a schematic flow chart of a grating coupling structure preparation method based on a back-facing process in the fifth embodiment of the present invention.
Fig. 6 is a schematic diagram of an initial wafer in step 1 in the fifth embodiment of the present invention.
Fig. 7 is a schematic diagram of the structure after step 2 in the fifth embodiment of the present invention.
Fig. 8(a) and 8(b) are schematic diagrams of two structures after step 3 in the fifth embodiment of the present invention.
Fig. 9(a) and 9(b) are schematic diagrams of two structures after step 4 in the fifth embodiment of the present invention.
Fig. 10(a) and 10(b) are schematic diagrams of two structures after step 5 in example five of the present invention.
Reference numerals: a 0-silicon substrate layer; 1-a first transition layer; 2-1-top silicon layer; 2-a waveguide diffraction grating layer; 3-a second transition layer; 4-a mirror layer; 5-a third transition layer; 6-carrying chip.
Detailed Description
The technical solutions in the specific embodiments of the present invention will be clearly and completely described below, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings. In the figures, parts of the same structure or function are denoted by the same reference numerals, and not all parts shown are denoted by the associated reference numerals in all figures for reasons of clarity of presentation.
Example one
In one embodiment of the present invention, a grating coupling structure based on a back process includes: the first transition layer, the waveguide diffraction grating layer, the second transition layer, the reflector layer, the third transition layer and the slide glass are sequentially arranged in an overlapping mode; the second transition layer covers the waveguide diffraction grating layer and is connected with the first transition layer; the reflector layer is of a non-metal structure, and the projection covers the waveguide diffraction grating layer.
As shown in fig. 1, the grating coupling structure includes, from bottom to top, a first transition layer 1, a waveguide diffraction grating layer 2, a second transition layer 3, a mirror layer 4, a third transition layer 5, and a slide 6 in sequence.
According to the grating coupling structure based on the back process, the reflector layer with the nonmetal structure is arranged on the waveguide diffraction grating layer 2, so that light is incident from the back of an initial wafer and is diffracted by the waveguide grating, most of the light is transmitted along the waveguide grating layer 2, and a small part of the light is diffracted to the vertical direction and is reflected to the waveguide grating layer 2 by the reflector layer 4 to improve the directivity, the coupling efficiency of the grating and the optical fiber is greatly improved, and the coupling loss of the grating and the optical fiber is reduced.
Example two
Example for expanding the material and thickness range of each layer in the two-pair grating coupling structure, referring to fig. 1, the material of the first transition layer 1, the second transition layer 3, and the third transition layer 5 is SiO2(ii) a The thickness of the first transition layer 1 is less than 10 μm, the thickness of the waveguide diffraction grating layer 2 is less than 1 μm, and the thickness range of the second transition layer 3 is 0-10 μm; the thickness of the first transition layer 1 is larger than that of the waveguide diffraction grating layer 2; the thickness of the second transition layer 3 depends on the height of reflection enhancement required by the design; the thickness of the third transition layer 5 is selected within a range that meets the requirements of the bonding process.
An exemplary value of the thickness of the first transition layer 1 in the present embodiment is 2 μm; an exemplary value of the thickness of the waveguide diffraction grating layer 2 is 220 nm; in other embodiments, the first transition layer 1 may also be 8 μm thick. The thickness of the waveguide diffraction grating layer is 300 nm.
EXAMPLE III
In the third embodiment, referring to FIG. 2, the mirror layer 4 is formed by multiple layersA Distributed Bragg Reflector (DBR) structure of the dielectric film, wherein the DBR structure is a periodic structure formed by two materials with different refractive indexes in an alternative arrangement mode, and common dielectric layer materials Si and Si in the prior art are selected3N4The thickness of the dielectric film layer is reasonably designed according to the reflection wavelength and the refractive index of the dielectric film, and the effect of reflection enhancement can be achieved.
The physical thickness of each dielectric film layer of the distributed Bragg reflector structure is recorded as t and satisfies the following conditions:
wherein
Is the center wavelength of the light emitted by the light source,
for each dielectric layer effective refractive index; the total thickness of the distributed bragg reflector structure in this embodiment is less than 2 μm.
As shown in fig. 2, the first transition layer 1, the waveguide diffraction grating layer 2, the second transition layer 3, the mirror layer 4, the third transition layer 5, and the carrier 6 are arranged from bottom to top in sequence. In this embodiment, the material of the first transition layer 1, the second transition layer 3, and the third transition layer 5 is SiO2(ii) a The material of the waveguide diffraction grating layer 4 is Si or Si3N4(ii) a The reflector layer 4 is formed by a Distributed Bragg Reflector (DBR) structure, which is a Si/OX/Si dielectric film layer structure, and may be Si in other embodiments3N4/OX/ Si3N4The dielectric film layer structure of (1).
Light is emitted from the back side of the wafer
The angle incidence, the grating structure of the waveguide diffraction grating layer 2 satisfies the bragg condition under the first-order diffraction:
media in which n is the light exit face are effectiveThe refractive index of the light beam is measured,
is the effective refractive index of the grating bloch,
in order to be the period of the grating,
is the coupling angle.
The distance H between the top of the waveguide diffraction grating layer 2 and the bottom of the reflector layer 4 is required to satisfy the optical path difference between the reflected light and the incident light reaching integral multiple of the wavelength.
In this embodiment, the mirror layer 4 is formed by one dbr structure, but in other embodiments, the mirror layer 4 may include a plurality of dbr structures. For example, in the case shown in fig. 3, the first transition layer 1, the waveguide diffraction grating layer 2, the second transition layer 3, the mirror layer 4, the third transition layer 5, and the carrier sheet 6 are arranged in this order from bottom to top; the reflector layer 4 comprises two distributed Bragg reflector structures, the distances H1 and H2 from the bottoms of the distributed Bragg reflector structures in different position areas to the top of the waveguide diffraction grating can be flexibly designed according to actual requirements and different optical wave bands, and the optical path difference between reflected light and incident light can reach integral multiple of wavelength.
Example four
The main difference between the fourth embodiment and the third embodiment is that the mirror layer 4 is a grating mirror structure.
As shown in fig. 4, the first transition layer 1, the waveguide diffraction grating layer 2, the second transition layer 3, the mirror layer 4, the third transition layer 5, and the carrier 6 are arranged from bottom to top in sequence. The waveguide diffraction grating layer 2 satisfies the bragg condition at the first order diffraction:
n is the effective refractive index of the medium of the light emitting surface,
is a gratingThe effective refractive index of the bloch is,
in order to be the period of the grating,
is the coupling angle. The thickness of the grating reflector structure and the width and the period of the grating meet the Bragg condition under first-order diffraction, and the maximum light reflection efficiency is achieved.
The thickness of the waveguide diffraction grating layer 4 or the grating mirror structure in this embodiment is less than 1 μm.
In this embodiment, the distance H between the top of the waveguide diffraction grating layer 4 and the bottom of the grating mirror structure is required to satisfy the optical path difference between the reflected light and the incident light to be an integral multiple of the wavelength.
In the third and fourth embodiments, the mirror layer 4 respectively adopts the distributed bragg reflector structure or the grating reflector structure, and compared with a common metal reflector structure, the distributed bragg reflector structure and the grating reflector structure have no problem of metal absorption, are more resistant to high temperature, and are more compatible with a conventional optical device without causing unnecessary loss; other front-stage processes can be carried out after the reflector process, and the problem of process pollution of the rear stage of the metal reflector is solved. It should be noted that, in some other feasible cases, the mirror layer 4 may also adopt other reflective structures made of other non-metal dielectric materials, such as a reflective structure of a single silicon oxide film layer, and is not limited.
When the distributed Bragg reflector structure is adopted to form the reflector layer 4, the requirement of multiband reflection can be met by processing a plurality of distributed Bragg reflector structures. When the grating reflector structure is adopted as the reflector layer 4, the reflection efficiency and the reflection bandwidth of the reflector to different optical wave bands can be adjusted by adjusting the thickness of the reflector layer 4, the etching width of the grating and the grating period Λ.
EXAMPLE five
In the fifth embodiment, an example of a method for manufacturing a grating coupling structure based on a back process is described.
As shown in fig. 5, includes: step 1, selecting and cleaning an initial wafer, wherein the initial wafer is a standard wafer and comprises a substrate layer, a first transition layer and a top silicon layer. The standard wafer of the present embodiment includes an SOI wafer, a strained silicon on insulator wafer (strained SOI wafer, such as optional Si3N4Wafer, SiON wafer, etc.), in this embodiment, as shown in fig. 6, the initial wafer is an SOI wafer, and includes, from bottom to top, a Si substrate layer 0, a first transition layer 1, and a top silicon layer 2-1. In this embodiment, the material of the first transition layer 1 is SiO2And the material of the top silicon layer 2-1 is Si. Step 2, etching the top silicon layer 2-1 to form a waveguide diffraction grating layer, and performing SiO on the waveguide diffraction grating layer2And depositing and carrying out chemical mechanical polishing to obtain a second transition layer. As shown in fig. 7, the Si substrate 0, the first transition layer 1, the waveguide grating layer 2, and the second transition layer 3 are arranged in sequence from bottom to top. Step 3, preparing a reflector layer on the second transition layer 3; SiO on the mirror layer 42Depositing and carrying out chemical mechanical polishing. As shown in fig. 8(a) and 8(b), the substrate layer 0, the first transition layer 1, the waveguide diffraction grating layer 2, the second transition layer 3, the mirror layer 4, and the third transition layer 5 are arranged in this order from bottom to top. Wherein the mirror layer 4 in FIG. 8(a) is Si or Si3N4A distributed Bragg reflector structure formed of a material; the mirror layer 4 in fig. 8(b) is a grating mirror structure. Step 4, bonding the slide glass and the reflector layer 4; as shown in fig. 9(a) and 9(b), the substrate layer 0, the first transition layer 1, the waveguide diffraction grating layer 2, the second transition layer 3, the mirror layer 4, the third transition layer 5, and the carrier sheet 6 are arranged in sequence from bottom to top. Wherein the mirror layer 4 in FIG. 9(a) is Si or Si3N4The distributed bragg reflector structure formed by the material, and the reflector layer 4 in fig. 9(b) is a grating reflector structure. And 5, thinning the substrate layer 0 to the first transition layer 1, namely removing the substrate layer 0. As shown in fig. 10(a) and 10(b), the first transition layer 1, the waveguide diffraction grating layer 2, the second transition layer 3, the mirror layer 4, the third transition layer 5, and the carrier sheet 6 are arranged in this order from bottom to top. Wherein the mirror layer 4 in FIG. 10(a) is Si or Si3N4Distributed Bragg reflection of materialsThe mirror structure, the mirror layer 4 in fig. 10(b), is a grating mirror structure. Wherein, SiO in step 22The deposited thickness can be designed according to different optical wave bands, the preset thickness is the distance from the top of the waveguide diffraction grating layer to the bottom of the reflector layer, and the requirement that the optical path difference of reflected light and incident light reaches integral multiple of the wavelength is met.
In this embodiment, the initial wafer is an SOI wafer, but in other embodiments, it may also be Si3N4The wafer, the SiON wafer and the like are not limited, the film thickness and the wafer uniformity are strictly controlled, the consistency is good, and the uncertainty of the process is reduced. By adopting the framework of the back process, the design freedom degree can be greatly provided on the basis of the compatibility of the existing silicon optical SOI process, the reflector structures with different heights can be integrated on the basis of not changing the original framework according to the design requirements of different optical wave bands, and the compatibility and the expansibility are higher.
EXAMPLE six
In a sixth embodiment, when the mirror layer is at least one dbr structure, specific steps for preparing the mirror layer on the second transition layer are as follows:
step 301, presetting the thickness of each dielectric film layer of the distributed Bragg reflector structure, so that the physical thickness of the dielectric film layer is in direct proportion to the central wavelength of incident light and in inverse proportion to the effective refractive index of the dielectric film layer; depositing a multilayer dielectric film layer by using chemical vapor deposition to obtain a distributed Bragg reflector structure;
step 302, etching and removing the non-reflector region,
Depositing and filling and carrying out chemical mechanical polishing.
Step 303, if a plurality of distributed bragg reflector structures with different heights need to be designed, repeating the step 301.
EXAMPLE seven
In the seventh embodiment, when the mirror layer is a grating mirror structure, the specific steps for preparing the mirror layer on the second transition layer are as follows:
step 304, calculating the thickness of a grating reflector layer and the etching width and period of the grating according to the reflection efficiency and the reflection bandwidth of the optical waveband, so that the grating reflector layer meets the Bragg condition under first-order diffraction;
step 305. use Si or Si3N4Deposition of isooptical waveguide materials, on Si or Si3N4Etching is carried out,
Depositing and filling and carrying out chemical mechanical polishing.
The embodiment can understand that the preparation method of the grating coupling structure based on the back process can be used for preparing the back grating coupling structure, can meet the optical coupling reflection requirement of larger bandwidth through single deposition etching, has simple steps and simple process, and can flexibly meet the reflection height requirements of different wave bands according to design requirements on the basis of not influencing the original framework; and is also suitable for various material platforms such as Si, SiN and the like. Besides the conventional structural chip, the bonding carrier chip can also be an IC chip in other embodiments, and the photoelectric monolithic integration is realized under the framework.
The operations of the embodiments are depicted in the following embodiments in a particular order, which is provided for better understanding of the details of the embodiments and to provide a thorough understanding of the present invention, but the order is not necessarily one-to-one correspondence with the methods of the present invention, and is not intended to limit the scope of the present invention. It is to be noted that the flow charts and block diagrams in the figures illustrate the operational procedures which may be implemented by the methods according to the embodiments of the present invention. It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the alternative, depending upon the functionality involved.
For clarity of description, the use of certain conventional and specific terms and phrases is intended to be illustrative and not restrictive, but rather to limit the scope of the invention to the particular letter and translation thereof.
The present invention has been described in detail, and the structure and operation principle of the present invention are explained by applying specific embodiments, and the above description of the embodiments is only used to help understanding the method and core idea of the present invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
Claims (13)
1. A grating coupling structure based on a back process is characterized by comprising a first transition layer, a waveguide diffraction grating layer, a second transition layer, a reflector layer, a third transition layer and a slide glass which are sequentially overlapped;
the second transition layer covers the waveguide diffraction grating layer and is connected with the first transition layer;
the reflector layer is a non-metal structural layer, and the projection covers the waveguide diffraction grating layer.
2. The grating coupling structure based on the back-facing process as claimed in claim 1, wherein the material of the first transition layer, the second transition layer and the third transition layer is SiO2(ii) a The thickness of the first transition layer is larger than that of the waveguide diffraction grating layer.
3. The grating coupling structure based on the back-facing process as claimed in claim 2, wherein the thickness of the first transition layer is less than 10 μm, the thickness of the waveguide diffraction grating layer is less than 1 μm, and the thickness of the second transition layer is less than 10 μm.
4. The grating coupling structure based on the back-facing process as claimed in claim 1, wherein the waveguide diffraction grating layer comprises at least one grating structure, and the grating structure satisfies a bragg condition in first-order diffraction.
5. The grating coupling structure based on the back-facing process as claimed in claim 1, wherein the mirror layer comprises at least 1 distributed bragg mirror structure, and the distributed bragg mirror structure is a periodic structure formed by alternately laminating dielectric film layers made of two materials with different refractive indexes; the physical thickness of the dielectric film layer is in direct proportion to the central wavelength of incident light and in inverse proportion to the effective refractive index of the dielectric film layer; the thickness of the distributed Bragg reflector structure is less than 2 mu m.
6. The grating coupling structure based on the back-facing process as claimed in claim 1, wherein the mirror layer is a grating mirror structure; the grating reflector structure comprises at least one grating structure, and the grating structure meets the Bragg condition under first-order diffraction; the thickness of the grating reflector structure is less than 1 μm.
7. The grating coupling structure based on the back-facing process as claimed in claim 1, wherein the distance from the top of the waveguide diffraction grating layer to the bottom of the mirror layer is such that the optical path difference between the reflected light and the incident light reaches an integral multiple of the wavelength.
8. A method for preparing a grating coupling structure according to any one of claims 1 to 7, comprising:
step 1, selecting an initial wafer and cleaning, wherein the initial wafer is a standard wafer and comprises a substrate layer, a first transition layer and a top silicon layer; the standard wafer comprises an SOI wafer and Si3N4A wafer, a SiON wafer;
step 2, etching the top silicon layer to form a waveguide diffraction grating layer, and performing SiO on the waveguide diffraction grating2Depositing and carrying out chemical mechanical polishing to obtain a second transition layer;
step 3, in the second transition layerPreparing a reflector layer on which SiO is carried out2Depositing and carrying out chemical mechanical polishing;
step 4, bonding the slide glass and the reflector layer;
and 5, thinning the substrate layer to a first transition layer.
9. The method for preparing a grating coupling structure based on a back-facing process as claimed in claim 8, wherein the SiO in step 22The deposited thickness is preset according to different optical wave bands, the preset thickness is the distance from the top of the waveguide diffraction grating layer to the bottom of the reflector layer, and the requirement that the optical path difference between reflected light and incident light reaches integral multiple of the wavelength is met.
10. The method according to claim 8, wherein when the mirror layer in step 3 is at least one distributed bragg mirror structure, the step of preparing the mirror layer on the second transition layer includes: presetting the thickness of each dielectric film layer of the distributed Bragg reflector structure, so that the physical thickness of the dielectric film layer is in direct proportion to the central wavelength of incident light and in inverse proportion to the effective refractive index of the dielectric film layer; depositing the dielectric film layer by using chemical vapor deposition to obtain the distributed Bragg reflector structure; SiO22Depositing and filling and carrying out chemical mechanical polishing.
11. The method of claim 10, wherein after each DBR structure is completed, the non-reflective region is etched and removed, and SiO is removed2Depositing and filling and carrying out chemical mechanical polishing.
12. The method as claimed in claim 8, wherein when the mirror layer in step 3 is a grating mirror structure, the second step is carried out in the first stepThe process for preparing the reflector layer on the second transition layer comprises the following steps: presetting the thickness of a grating reflector structure and the etching width and period of a grating so as to meet the Bragg condition under first-order diffraction; depositing optical waveguide material, and etching the optical waveguide material to obtain grating reflector Structure (SiO)2Depositing and filling and carrying out chemical mechanical polishing.
13. The method for preparing a grating coupling structure based on a back-facing process as claimed in claim 8, wherein the bonding process of the carrier comprises: cleaning the surface of the slide glass, and depositing SiO2Bonding of the carrier sheet and the mirror layer is realized by molecular force, and SiO between the carrier sheet and the mirror layer2The deposition layer is a third transition layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110804838.6A CN113359236A (en) | 2021-07-16 | 2021-07-16 | Grating coupling structure based on back process and preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110804838.6A CN113359236A (en) | 2021-07-16 | 2021-07-16 | Grating coupling structure based on back process and preparation method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113359236A true CN113359236A (en) | 2021-09-07 |
Family
ID=77539813
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110804838.6A Pending CN113359236A (en) | 2021-07-16 | 2021-07-16 | Grating coupling structure based on back process and preparation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113359236A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113866879A (en) * | 2021-10-18 | 2021-12-31 | 联合微电子中心有限责任公司 | Bragg grating-based reflector, manufacturing method thereof and photoelectric device |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101915965A (en) * | 2010-08-23 | 2010-12-15 | 清华大学 | Grating coupler and package structure thereof |
| CN106873076A (en) * | 2017-02-16 | 2017-06-20 | 中山大学 | A kind of grating coupler and preparation method thereof |
| CN111175896A (en) * | 2020-02-21 | 2020-05-19 | 电子科技大学 | High-efficiency grating coupler with large bandwidth |
| CN111355127A (en) * | 2020-03-10 | 2020-06-30 | 中国科学院半导体研究所 | Silicon-based vertical coupling laser based on inclined grating and preparation method thereof |
| CN111933739A (en) * | 2020-07-10 | 2020-11-13 | 中国电子科技集团公司第十三研究所 | Back incidence silicon photoelectric detector based on one-dimensional grating and preparation method |
| CN112630901A (en) * | 2020-12-24 | 2021-04-09 | 华进半导体封装先导技术研发中心有限公司 | Back incidence grating coupling structure of silicon optical chip and manufacturing method thereof |
-
2021
- 2021-07-16 CN CN202110804838.6A patent/CN113359236A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101915965A (en) * | 2010-08-23 | 2010-12-15 | 清华大学 | Grating coupler and package structure thereof |
| CN106873076A (en) * | 2017-02-16 | 2017-06-20 | 中山大学 | A kind of grating coupler and preparation method thereof |
| CN111175896A (en) * | 2020-02-21 | 2020-05-19 | 电子科技大学 | High-efficiency grating coupler with large bandwidth |
| CN111355127A (en) * | 2020-03-10 | 2020-06-30 | 中国科学院半导体研究所 | Silicon-based vertical coupling laser based on inclined grating and preparation method thereof |
| CN111933739A (en) * | 2020-07-10 | 2020-11-13 | 中国电子科技集团公司第十三研究所 | Back incidence silicon photoelectric detector based on one-dimensional grating and preparation method |
| CN112630901A (en) * | 2020-12-24 | 2021-04-09 | 华进半导体封装先导技术研发中心有限公司 | Back incidence grating coupling structure of silicon optical chip and manufacturing method thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113866879A (en) * | 2021-10-18 | 2021-12-31 | 联合微电子中心有限责任公司 | Bragg grating-based reflector, manufacturing method thereof and photoelectric device |
| CN113866879B (en) * | 2021-10-18 | 2024-04-30 | 联合微电子中心有限责任公司 | Bragg grating-based reflector, manufacturing method thereof and photoelectric device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7376308B2 (en) | Optical off-chip interconnects in multichannel planar waveguide devices | |
| US9482816B2 (en) | Radiation coupler | |
| US7190524B2 (en) | Process for fabrication of high reflectors by reversal of layer sequence and application thereof | |
| EP2703858B1 (en) | High-efficient CMOS-compatible grating couplers with backside metal mirror | |
| US6111674A (en) | Multiple reflection multiplexer and demultiplexer | |
| US7352932B1 (en) | Guided-mode resonance filter and fabrication method of same | |
| CN110824612B (en) | Three-dimensional optical connection structure of multilayer silicon photon | |
| US20230054228A1 (en) | Mode multiplexer/demultiplexer using metamaterials for optical fiber communications | |
| CN115210619A (en) | Wavelength multiplexer/demultiplexer using metamaterials for optical fiber communication | |
| CN103645540A (en) | Etched diffraction grating-type wavelength division multiplexing/demultiplexing device | |
| CN216485897U (en) | Waveguide array and integrated optical phased array chip | |
| CN113359236A (en) | Grating coupling structure based on back process and preparation method | |
| US8023782B2 (en) | Method and apparatus for demultiplexing optical signals in a passive optical network | |
| US20230088292A1 (en) | Mode multiplexer/demultiplexer using metamaterials for optical communication system, and optical communication | |
| US6847491B1 (en) | Hybrid microlens array | |
| KR20010022120A (en) | Method of fabricating an optical component and optical component made thereby | |
| US6104847A (en) | Optical device having an optical waveguide structure | |
| CN106443880B (en) | Demultiplexer with blazed waveguide side wall grating and sub-wavelength grating structures | |
| CN114924350B (en) | On-chip wavelength beam splitter based on folding superlens combination | |
| TWI531824B (en) | Light receiving device | |
| US20220283366A1 (en) | Optical Circuit | |
| EP1338906A1 (en) | Integrated waveguide frequency router | |
| CN118011558A (en) | Apodization E-shaped grating coupler of bilinear etching factor | |
| CN114265147A (en) | Optical communication waveband broadband high-efficiency horizontal end face coupler and manufacturing method thereof | |
| CN117908189A (en) | Efficient asymmetric directional coupler applied to 2.5-dimensional heterogeneous integrated optical waveguide |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210907 |