阅读说明：本技术 一种45度硅反射镜的设计制造结构以及制造方法 (Design and manufacture structure and manufacture method of 45-degree silicon reflector ) 是由 李蜀文 徐艳 李忠旭 于 2021-01-27 设计创作，主要内容包括：本发明公开了一种45度硅反射镜的设计制造结构以及制造方法,包括晶面硅片衬底,所述硅片衬底正面设置有多组腐蚀坑,所述硅片衬底的底面在靠近每两个腐蚀坑之间均设置有矩形槽,所述晶面硅片衬底在靠近腐蚀坑和矩形槽的底面均竖直设有切割道,且所述切割道的中心轴线分别与腐蚀坑和矩形槽的中心轴线相互重合。该种45度硅反射镜的设计制造结构,降低了成本,提高了器件的可靠性能,硅基材料的芯片上制作的反射镜,它具有尺寸小,产出率高,成本低、重复性好、热学性能稳定等的优点,由于是45度角,平行光入射进去,垂直入射出来,光路调整简洁,且优化的工艺成倍提高了反射镜的输出射功率,得到的图像亮度高,画质更清晰精准,色彩更逼真。(The invention discloses a design and manufacturing structure and a manufacturing method of a 45-degree silicon reflector, which comprises a crystal face silicon wafer substrate, wherein a plurality of groups of corrosion pits are arranged on the front face of the silicon wafer substrate, a rectangular groove is arranged between every two corrosion pits on the bottom face of the silicon wafer substrate, cutting channels are vertically arranged on the bottom faces of the crystal face silicon wafer substrate, the bottom faces are close to the corrosion pits and the rectangular groove, and the central axes of the cutting channels are respectively overlapped with the central axes of the corrosion pits and the rectangular groove. This kind of 45 degrees silicon reflector's manufacturing and designing structure, the cost is reduced, the reliability of device has been improved, the reflector of preparation on the chip of silicon-based material, it has the size little, the output rate is high, and is with low costs, good reproducibility, advantages such as thermal behavior stability, because be 45 degrees angles, the parallel light is incided into, the vertical incidence comes out, the light path adjustment is succinct, and the technology of optimizing has improved the output power of penetrating of reflector at double, the image brightness who obtains is high, the picture quality is more clear accurate, the color is more lifelike.)

1. A design and manufacturing method of a 45-degree silicon reflector is characterized by comprising the following operation steps:

step S1: selecting materials for corrosion, namely, adopting a (100) silicon wafer substrate, and corroding a 54.74-degree included angle between a (100) surface and a (111) surface on the front surface of the silicon wafer by using alkaline corrosive liquid such as KOH (potassium hydroxide); etching a groove structure with required depth and width on the back of the silicon wafer;

step S2: plating gold on the outer side, plating gold or other high-reflectivity metals on the smooth plane, and forming a gold reflector;

step S3: cutting and separating, namely thinning and cutting the back of the silicon wafer as required to separate an independent reflecting mirror surface;

step S4: mounting, namely, the side surface of the manufactured 54.74-degree optical reflector is attached to a carrier, and two supporting edge lines on the back surface are loaded on the same horizontal plane to form a 45-degree reflector.

2. The design and manufacturing method of a 45-degree silicon mirror according to claim 1, wherein the etching of one groove on the back side in step S1 is not limited to wet etching and dry etching.

3. The method as claimed in claim 1, wherein the high reflectivity metal in step S2 includes but is not limited to silver, gold, copper, aluminum, etc. with a thickness of 0.1-10 um.

4. The method as claimed in claim 1, wherein the material used for the overlay in step S4 is not limited to silver paste or other viscous material.

5. The method as claimed in claim 1, wherein the trench structure in step S1 has a depth and width requirement H/(2L + kerf width d) ≈ 0.08578, where H is the trench depth and 2L is the trench width.

6. The method as claimed in claim 1, wherein in step S3, the groove H/L ≈ 0.1715 on the backside is ensured during the dicing separation, wherein H is the groove depth and L is half of the groove width.

7. The design and manufacture structure of the 45-degree silicon reflector comprises a crystal face silicon wafer substrate (2) and is characterized in that a plurality of groups of corrosion pits are arranged on the front face of the silicon wafer substrate (2), rectangular grooves are formed in the bottom face of the silicon wafer substrate (2) between every two corrosion pits, cutting channels (1) are vertically arranged on the bottom face of the crystal face silicon wafer substrate (2) close to the corrosion pits and the rectangular grooves, and the central axes of the cutting channels (1) are respectively overlapped with the central axes of the corrosion pits and the rectangular grooves.

8. The design and manufacture structure of a 45-degree silicon reflector according to claim 7, wherein the angle between the etch slope of the etch pits and the crystal plane is 54.74 degrees.

9. The design and manufacturing structure of a 45-degree silicon reflector according to claim 7, wherein the whole groove width of the rectangular groove is 2L + d, where d is the width of the scribe line (1), and the groove depth H of the rectangular groove satisfies the formula H/L tan (9.74 degrees).

10. The design and manufacture structure of a 45-degree silicon reflector according to claim 7, wherein the etch pits have a reflective mirror surface on the etch slope surface, and a metal layer is sputtered/evaporated on the surface of the reflective mirror surface, and the metal layer can be Ti/AL and Ti/AU, and the reflective mirror surface is plated with a high-reflectivity metal, including but not limited to silver, gold, copper, aluminum, etc.

Technical Field

The invention relates to the technical field of manufacturing a reflector by silicon wet etching, in particular to a design and manufacturing structure and a manufacturing method of a 45-degree silicon reflector.

Background

The 45-degree reflector is widely applied to an optical system, plays a role in 90-degree conversion of a light path, and forms a 90-degree included angle between incident light and reflected light. In a silicon photonic integrated chip, the 45-degree reflector can vertically reflect light in the waveguide out of the chip, and the optical path adjustment is simpler than that of a 54.74-degree silicon reflector, and the silicon corrosion 45-degree reflector has high application value due to integration and cost requirements.

The wet etching reflector adopts a (100) crystal plane silicon wafer at present, the included angle between an etching inclined plane (111) plane and a crystal plane (100) is 54.74 degrees, the etching inclined plane (111) plane and the crystal plane (100) stop at the (111) plane, the characteristic of the (111) plane is stable and smooth, the wet etching reflector can be used as an optical reflector, but the included angle between incident light and reflected light is 109.48 degrees, and the incident angle and the reflected angle cannot be 90 degrees. Therefore, we improve this and propose a design and manufacturing structure and manufacturing method of 45-degree silicon reflector.

Disclosure of Invention

In order to solve the technical problems, the invention provides the following technical scheme:

the invention relates to a design and manufacturing method of a 45-degree silicon reflector, which comprises the following operation steps:

step S1: selecting materials for corrosion, namely, adopting a (100) silicon wafer substrate, and corroding a 54.74-degree included angle between a (100) surface and a (111) surface on the front surface of the silicon wafer by using alkaline corrosive liquid such as KOH (potassium hydroxide); etching a groove structure with required depth and width on the back of the silicon wafer;

step S2: plating gold on the outer side, plating gold or other high-reflectivity metals on the smooth plane, and forming a gold reflector;

step S3: cutting and separating, namely thinning and cutting the back of the silicon wafer as required to separate an independent reflecting mirror surface;

step S4: mounting, namely, the side surface of the manufactured 54.74-degree optical reflector is attached to a carrier, and two supporting edge lines on the back surface are loaded on the same horizontal plane to form a 45-degree reflector.

As a preferred embodiment of the present invention, the method of etching a groove on the back surface in step S1 is not limited to wet etching and dry etching.

In a preferred embodiment of the present invention, the high-reflectivity metal in step S2 includes, but is not limited to, silver, gold, copper, aluminum, etc., and has a thickness of 0.1-10 um.

As a preferred embodiment of the present invention, the material used for the facing in step S4 is not limited to a viscous material such as silver paste.

As a preferred embodiment of the present invention, the depth and width requirement of the trench structure in step S1 is H/(2L + width d of the slicing lane) ≈ 0.08578, where H is the trench depth and 2L is the trench width.

In a preferred embodiment of the present invention, in step S3, the groove H/L ≈ 0.1715 on the back surface is required to be ensured during the cutting separation, where H is the groove depth and L is a half of the groove width.

A design and manufacture structure of a 45-degree silicon reflector comprises a crystal face silicon wafer substrate, wherein multiple groups of corrosion pits are arranged on the front face of the silicon wafer substrate, a rectangular groove is formed in the bottom face of the silicon wafer substrate between every two corrosion pits, cutting channels are vertically arranged on the bottom face of the crystal face silicon wafer substrate, close to the corrosion pits and the rectangular groove, and the central axes of the cutting channels are respectively overlapped with the central axes of the corrosion pits and the rectangular groove.

As a preferable technical scheme of the invention, the included angle between the corrosion inclined plane of the corrosion pit and the crystal plane is 54.74 degrees.

As a preferable aspect of the present invention, the entire groove width of the rectangular groove is 2L + d, where d is the width of the cutting street, and the groove depth H of the rectangular groove satisfies the formula H/L ═ tan (9.74 degrees).

In a preferred embodiment of the present invention, a reflective mirror is disposed on the corrosion slope surface of the etch pit, and a metal layer is sputtered/evaporated on the surface of the reflective mirror, and the metal layer may be Ti/AL and Ti/AU, and the reflective mirror is plated with a high-reflectivity metal, and the high-reflectivity metal includes, but is not limited to, silver, gold, copper, aluminum, and other materials.

The invention has the beneficial effects that:

the technical scheme of this patent, the cost is reduced has improved the reliable performance of device, and the speculum of preparation on the chip of silicon-based material, it has the size little, and the output rate is high, with low costs, good reproducibility, durability are strong, advantages such as calorifics stable performance. Because of the angle of 45 degrees, parallel light enters, and vertical incidence comes out, and the light path adjustment is succinct, and the technology of optimizing has improved the output power of speculum doubly, and the image brightness that obtains is high, and the picture quality is more clear accurate, and the color is more lifelike, belongs to ultra-precision optical components and parts.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a side view of the chip internal structure of a 45-degree silicon mirror design and manufacturing structure of the present invention, when the wafer is completely manufactured and is not cut;

FIG. 2 is a side view of a 45-degree silicon mirror design and fabrication configuration of the present invention without rotation of the mirror;

FIG. 3 is a side view of a 45 degree silicon mirror after 9.74 degrees clockwise rotation in the direction of the dotted line for a design and manufacturing configuration of the 45 degree silicon mirror of the present invention;

FIG. 4 is a side view of a 45 degree silicon mirror design and fabrication configuration to perform the 45 degree mirror function of another embodiment of the present invention;

FIG. 5 is a top view of the basic structure of a 45-degree silicon mirror design and fabrication structure 54.74-degree mirror according to the present invention.

In the figure: 1. cutting a channel; 2. and (3) a silicon wafer substrate.

Detailed Description

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.

Example (b): the invention relates to a design and manufacturing method of a 45-degree silicon reflector, which comprises the following operation steps:

step S1: selecting materials for corrosion, namely, adopting a (100) silicon wafer substrate, and corroding a 54.74-degree included angle between a (100) surface and a (111) surface on the front surface of the silicon wafer by using alkaline corrosive liquid such as KOH (potassium hydroxide); etching a groove structure with required depth and width on the back of the silicon wafer;

step S2: plating gold on the outer side, plating gold or other high-reflectivity metals on the smooth plane, and forming a gold reflector;

step S3: cutting and separating, namely thinning and cutting the back of the silicon wafer as required to separate an independent reflecting mirror surface;

step S4: mounting, namely, the side surface of the manufactured 54.74-degree optical reflector is attached to a carrier, and two supporting edge lines on the back surface are loaded on the same horizontal plane to form a 45-degree reflector.

As a preferred embodiment of the present invention, the method of etching a groove on the back surface in step S1 is not limited to wet etching and dry etching.

In a preferred embodiment of the present invention, the high-reflectivity metal in step S2 includes, but is not limited to, silver, gold, copper, aluminum, etc., and has a thickness of 0.1-10 um.

As a preferred embodiment of the present invention, the material used for the facing in step S4 is not limited to a viscous material such as silver paste.

As a preferred embodiment of the present invention, the depth and width requirement of the trench structure in step S1 is H/(2L + width d of the slicing lane) ≈ 0.08578, where H is the trench depth and 2L is the trench width.

In a preferred embodiment of the present invention, in step S3, the groove H/L ≈ 0.1715 on the back surface is required to be ensured during the cutting separation, where H is the groove depth and L is a half of the groove width.

A design and manufacture structure of a 45-degree silicon reflector comprises a crystal face silicon wafer substrate 2, wherein multiple groups of corrosion pits are arranged on the front face of the silicon wafer substrate 2, a rectangular groove is formed in the bottom face of the silicon wafer substrate 2 and is close to each two corrosion pits, cutting channels 1 are vertically arranged on the bottom face of the crystal face silicon wafer substrate 2, which is close to the corrosion pits and the rectangular groove, and the central axes of the cutting channels 1 are respectively overlapped with the central axes of the corrosion pits and the rectangular groove.

As a preferable technical scheme of the invention, the included angle between the corrosion inclined plane of the corrosion pit and the crystal plane is 54.74 degrees.

As a preferable aspect of the present invention, the entire groove width of the rectangular groove is 2L + d, where d is the width of the scribe line 1, and the groove depth H of the rectangular groove satisfies the formula H/L ═ tan (9.74 degrees).

In a preferred embodiment of the present invention, a reflective mirror is disposed on the corrosion slope surface of the etch pit, and a metal layer is sputtered/evaporated on the surface of the reflective mirror, and the metal layer may be Ti/AL and Ti/AU, and the reflective mirror is plated with a high-reflectivity metal, and the high-reflectivity metal includes, but is not limited to, silver, gold, copper, aluminum, and other materials.

Implementation 1:

a structure with a crystal plane at 54.74 degrees was first fabricated according to conventional methods: as shown in fig. 5. Adopting a substrate 2 with a (100) crystal orientation to grow a layer of mask layer, selecting silicon dioxide or silicon nitride films with different thicknesses or double-layer films of the silicon dioxide and the silicon nitride for the mask layer according to process requirements, and designing a rectangular window for a window of the mask layer to be opened by adopting photoetching and dry etching methods: two sides are parallel to the <110> flat side, and the other two sides are perpendicular to the <110> flat side. Then, etching silicon downwards at the window opened by the mask layer by using a KOH etching solution with a certain concentration at a specific temperature, etching by using a 30% KOH aqueous solution at 80 ℃ usually in a laboratory, and finally etching to form an included angle between a (100) plane and a (111) plane, which is the actual included angle of the reflector, of 54.74 degrees, as shown in FIG. 1.

Further, the back surface of the wafer is turned over, the front surface of the wafer is dug, the front surface of the wafer is protected by a film, and a rectangular groove pit is formed on the back surface of the wafer through corrosion: here we use a trench etched by dry etching. As shown in FIG. 1, the overall slot width is 2L + d, d being the scribe line width. The groove depth H satisfies the formula H/L tan (9.74 degrees), and for example, when L is 200um, the etching depth H is 34.3 um. The cutting path d is 60um, and the size of d is related to cutting and is not related to angle. If the width is fixed at 200um, the angle is 45+/-1 degrees with a corresponding H of 34.3+/-3.5um, with a tolerance of about +/-10%. If the reflection angle is 45+/-2 degrees and the H tolerance is about +/-20 percent, finally removing the protective film on the front surface of the wafer, cleaning and then removing the silicon dioxide/silicon nitride film, but if a high-quality mirror surface is obtained, a metal layer, such as Ti/AL or Ti/AU, needs to be sputtered/evaporated on the surface of the front surface.

Further mounting the cut minimum units according to the glue surface shown in the figure 3: the left side surface and the right side surface of the mirror surface are attached to the adhesive surface according to one surface required, and the two groove edges of the bottom surface of the mirror surface are pressed downwards to be in contact with the plane, so that the excellent and stable 45-degree reflecting mirror surface is formed.

Implementation 2:

a structure having a crystal plane of 54.74 degrees was first fabricated according to a conventional method in accordance with example 1.

Further, the back surface of the wafer is turned over, the front surface of the wafer is dug, the front surface of the wafer is protected by a film, and a rectangular groove pit is formed on the back surface of the wafer through corrosion: here we mainly use the wet method to etch the trench: a rectangular window at the bottom is opened, and then an inclined groove pit is formed by wet KOH corrosion. In the process design, the included angle between the connecting line of the groove edge line on the back and the inclined plane is only ensured to be 45 degrees, as shown in fig. 4.

This patent the structure:

in the process, the angle difference is compensated by design, a required 45-degree inclined plane is obtained, and any angle smaller than 54.7 degrees can be obtained by adjusting the ratio of the back etching depth to the width.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.