阅读说明：本技术 一种基于硅微通道阵列的光纤面板及其制备方法 (Optical fiber panel based on silicon micro-channel array and preparation method thereof ) 是由 王蓟 刘书异 王国政 杨继凯 李野 于 2021-01-14 设计创作，主要内容包括：一种基于硅微通道阵列的光纤面板及其制备方法涉及硅微细加工和光电成像技术领域,该光纤面板包括：硅微通道阵列,硅微通道阵列的孔径为1-10微米,阵列排布方式为四方排列,通道的截面为正方形或者八边形；反射层,反射层制备在硅微通道阵列内的侧表面上,材料为具有高反射率的金属或二氧化硅；填充介质,填充介质填充在反射层构成的空间内,热膨胀系数与硅接近。本发明能制备孔径小到1微米的硅微通阵列结构,提高了光纤面板的分辨率,解决了其与图像传感器匹配问题；光纤面板中纤维间是硅材料,完全解决了传统光纤面板中的光串扰问题；通道的方向都是[100]晶向,通道孔径均匀一致,不会产生传统光纤面板工艺中的畸变问题。(An optical fiber panel based on silicon micro-channel array and a preparation method thereof relate to the technical field of silicon micro-machining and photoelectric imaging, and the optical fiber panel comprises: the pore diameter of the silicon micro-channel array is 1-10 microns, the array arrangement mode is square arrangement, and the section of the channel is square or octagonal; the reflecting layer is prepared on the side surface in the silicon microchannel array and is made of metal or silicon dioxide with high reflectivity; and the filling medium is filled in the space formed by the reflecting layer, and the thermal expansion coefficient of the filling medium is close to that of silicon. The invention can prepare the silicon micro-through array structure with the aperture as small as 1 micron, improves the resolution of the optical fiber panel and solves the problem of matching with an image sensor; silicon materials are arranged among fibers in the optical fiber panel, so that the problem of optical crosstalk in the traditional optical fiber panel is completely solved; the directions of the channels are all the crystal directions of [100], the apertures of the channels are uniform and consistent, and the distortion problem in the traditional optical fiber panel process can not be caused.)

1. A fiber optic faceplate based on a silicon microchannel array, the fiber optic faceplate comprising:

the silicon microchannel array has the aperture of 1-10 microns, the array arrangement mode is square arrangement, the cross section of the channel is square or octagonal, and the lengths of two mutually perpendicular lines passing through the center of the cross section are equal;

the reflecting layer is prepared on the side surface in the silicon microchannel array and is made of metal or silicon dioxide with high reflectivity;

a filling medium filled in the space formed by the reflecting layer and having a coefficient of thermal expansion less than 100 (10) at 0-1000 deg.C^-7/K)。

2. The fiber optic faceplate based on silicon microchannel array of claim 1, wherein the silicon microchannel array has an aspect ratio of 10-500 and a diameter of 25-150 mm.

3. The fiber optic faceplate based on silicon microchannel array of claim 1, wherein the silicon material of the silicon microchannel array has a crystal orientation [100 ].

4. The fiber optic faceplate based on silicon microchannel array of claim 1, wherein the material of the reflective layer is aluminum, silver, gold, platinum.

5. The fiber optic faceplate based on silicon micro-channel array of claim 1, wherein the thickness of the reflective layer is 20-500 nm.

6. The silicon micro-tunnel array-based fiber optic faceplate of claim 1, wherein when said reflective layer is silicon dioxide, the refractive index of said filling medium is greater than that of silicon dioxide.

7. The fiber optic faceplate based on silicon micro-channel array of claim 1, wherein the material of the filling medium is optical glass.

8. The method for preparing the optical fiber panel based on the silicon micro-channel array according to any one of claims 1 to 7, wherein the method comprises the following steps:

the method comprises the following steps: photoetching, corroding, oxidizing, back thinning and channel shaping are carried out on a silicon substrate with the crystal orientation of [100] to prepare a silicon micro-channel array structure;

step two: oxidizing the silicon micro-channel array at high temperature, wherein a silicon dioxide layer is formed on the inner wall of the channel and serves as a reflecting layer, the oxidizing temperature is 900 ℃ and 1100 ℃, and the thickness of the oxidizing layer is 50-500 nanometers;

step three: placing a silicon micro-channel array with an inner wall reflecting layer into a sapphire crucible in a vacuum tube furnace, and placing solid optical glass on the silicon micro-channel array; vacuumizing and heating a vacuum tube furnace, wherein the heating temperature is higher than the softening point temperature of the solid optical glass; closing the vacuumizing mode, opening a high-purity nitrogen bottle to charge the vacuum tube furnace, and filling the molten solid optical glass into the micro-channels of the silicon micro-channel array under the action of pressure to form glass media filled in the channels; and finally, grinding and polishing the surface to finish the preparation method of the optical fiber panel based on the silicon micro-channel array.

9. The preparation method according to claim 8, wherein in the channel shaping process in the first step, the etching solution is tetramethylammonium hydroxide solution, the solution concentration is 0.5-5 wt%, the etching temperature is 5-50 ℃, the wall thickness of the etched silicon microchannel is less than 1 micron, and the ratio of the channel opening area is more than 80%.

10. The method according to claim 8, wherein the second step is replaced by preparing the metal reflective layer by an atomic layer deposition method, wherein the thickness of the metal reflective layer is 20-100 nm.

Technical Field

The invention relates to the technical field of silicon micromachining and photoelectric imaging, in particular to an optical fiber panel based on a silicon micro-channel array and a preparation method thereof.

Background

The optical fiber panel (optical fiber panel for short) is formed by regularly arranging tens of millions of optical fibers, has the characteristics of high numerical aperture, small interstage coupling loss, high resolution, zero optical thickness and the like, can transmit high-definition images without distortion, and is widely applied to low-light-level image intensifiers, high-brightness high-definition displays, photoelectric coupling devices (CCD, CMOS) and other high-definition image receiving, transmitting and coupling instruments and equipment.

The resolution is an important parameter of the optical fiber panel, the resolution is mainly determined by the aperture of a single fiber, the smaller the aperture is, the higher the resolution is, and the traditional optical fiber panel drawing process is particularly difficult to prepare the small-aperture optical fiber, and the current domestic minimum aperture mentioned in the Chinese patent application No. 201120531389.4 is 4 microns. The fiber arrangement mode of the traditional optical fiber panel is a hexagonal close-packed structure, and the structure is different from the arrangement mode of pixel points of image sensors such as a CCD (charge coupled device), a CMOS (complementary metal oxide semiconductor) and the like, so that the Moire effect is easy to occur, and the application of the fiber in the field of digital imaging is influenced.

In the traditional process, the core material and the cladding material can diffuse mutually in the heat treatment processes such as drawing, fusion pressing and the like, so that optical crosstalk is caused, and the resolution is reduced. In the chinese patent application No. 201010238439.X, when a large-area optical fiber panel is prepared, the radial temperature difference may increase during the fusion-pressing process, which may cause the fiber in the central portion not to be well fused and the core sheath of the peripheral fiber to diffuse, which may seriously affect the quality of the optical fiber panel. Chinese patent application No. 201810380549.6 states that magnification distortion may also occur during the fusion process. The conventional drawing process also produces serpentine distortion, which degrades the image quality.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a silicon micro-channel array-based optical fiber panel and a preparation method thereof, and solves the problems that the aperture of the optical fiber panel is difficult to reduce, the resolution cannot be greatly improved, and the optical fiber panel is not matched with image sensors such as a CCD (charge coupled device), a CMOS (complementary metal oxide semiconductor) and the like because the fiber arrangement mode of the traditional optical fiber panel is hexagonal close-packed arrangement.

The technical scheme adopted by the invention for solving the technical problem is as follows:

a fiber optic faceplate based on a silicon micro-tunnel array, the fiber optic faceplate comprising:

the silicon microchannel array has the aperture of 1-10 microns, the array arrangement mode is square arrangement, the cross section of the channel is square or octagonal, and the lengths of two mutually perpendicular lines passing through the center of the cross section are equal;

the reflecting layer is prepared on the side surface in the silicon microchannel array and is made of metal or silicon dioxide with high reflectivity;

a filling medium filled in the space formed by the reflecting layer and having a coefficient of thermal expansion less than 100 (10) at 0-1000 deg.C^-7/K)。

Preferably, the length-diameter ratio of the silicon microchannel array is 10-500, and the diameter of the plate surface is 25-150 mm.

Preferably, the crystal orientation of the silicon material of the silicon microchannel array is [100 ].

Preferably, the material of the reflecting layer is aluminum, silver, gold or platinum.

Preferably, the thickness of the reflective layer is 20 to 500 nm.

Preferably, when the reflective layer is silicon dioxide, the refractive index of the filling medium is greater than that of silicon dioxide.

Preferably, the material of the filling medium is optical glass.

A preparation method of an optical fiber panel based on a silicon micro-channel array comprises the following steps:

the method comprises the following steps: photoetching, corroding, oxidizing, back thinning and channel shaping are carried out on a silicon substrate with the crystal orientation of [100] to prepare a silicon micro-channel array structure;

step two: oxidizing the silicon micro-channel array at high temperature, wherein a silicon dioxide layer is formed on the inner wall of the channel and serves as a reflecting layer, the oxidizing temperature is 900 ℃ and 1100 ℃, and the thickness of the oxidizing layer is 50-500 nanometers;

step three: placing a silicon micro-channel array with an inner wall reflecting layer into a sapphire crucible in a vacuum tube furnace, and placing solid optical glass on the silicon micro-channel array; vacuumizing and heating a vacuum tube furnace, wherein the heating temperature is higher than the softening point temperature of the solid optical glass; closing the vacuumizing mode, opening a high-purity nitrogen bottle to charge the vacuum tube furnace, and filling the molten solid optical glass into the micro-channels of the silicon micro-channel array under the action of pressure to form glass media filled in the channels; and finally, grinding and polishing the surface to finish the preparation method of the optical fiber panel based on the silicon micro-channel array.

Preferably, in the channel shaping process in the first step, the etching solution is a tetramethylammonium hydroxide solution, the concentration of the solution is 0.5-5 wt%, the etching temperature is 5-50 ℃, the wall thickness of the etched silicon microchannel is less than 1 micron, and the ratio of the opening area of the channel is more than 80%.

Preferably, the second step is replaced by preparing the metal reflecting layer by an atomic layer deposition method, and the thickness of the metal reflecting layer is 20-100 nanometers.

Preferably, the filling vacuum degree in the third step is better than 10Pa, and the filling temperature is 500-1000 ℃.

The invention has the beneficial effects that:

1. the invention can prepare the silicon micro-through array structure with the aperture as small as 1 micron, the arrangement mode of the channels is tetragonal arrangement, the resolution ratio of the optical fiber panel is improved, and the problem of matching with an image sensor is solved;

2. the silicon material is arranged among fibers in the optical fiber panel prepared by the invention, so that the problem of optical crosstalk in the traditional optical fiber panel is completely solved;

3. the invention can ensure that all the channels of the optical fiber panel are in the silicon (100) crystal direction, the aperture of the channels is uniform and consistent, and the distortion problem in the traditional optical fiber panel process can not be generated;

4. according to the invention, the medium is filled in the channel through a vacuum hot melting filling process, the expansion coefficient of the filled medium is close to that of silicon, the air tightness can be ensured, and the light and thin optical fiber panel applicable to the ultra-high vacuum technical field can be prepared.

Drawings

FIG. 1 is a scanning electron microscope photograph of a silicon microchannel array according to the present invention with tetragonal arrangement of channels;

FIG. 2 is a cross-sectional view of a fiber optic faceplate of the silicon microchannel array of the present invention;

FIG. 3 is a schematic view of a fiber optic faceplate of the silicon microchannel array of the present invention;

fig. 4 is a schematic view of a vacuum hot melt medium filling device according to the present invention.

In the figure: 1. the device comprises a silicon microchannel array, 2, a reflecting layer, 3, a filling medium, 4, a high-purity nitrogen cylinder, 5, a valve, 6, a vacuum pump, 7, a vacuum tube furnace and 8, and a sapphire crucible.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

A fiber optic faceplate based on a silicon micro-tunnel array, the fiber optic faceplate comprising:

as shown in fig. 1, the silicon micro-channel array 1 is arranged in a square manner, i.e., the channel array is arranged in a square manner. The aperture of the silicon micro-channel array 1 is 1-10 microns, and the cross section of the channel is square; in this embodiment, the aperture of the silicon micro-channel array 1 is 5.5 and 2.5 microns, respectively, the area of the prepared silicon micro-channel array 1 is determined by the area of a silicon wafer, wherein the size and the arrangement mode of the channels are determined by a mask pattern in a photoetching process, and a square arrangement structure which is the same as a CCD or CMOS pixel point can be prepared. The silicon micro-channel array is prepared from a silicon material with a crystal direction along [100], visible light cannot penetrate through the silicon micro-channel array, and optical crosstalk is avoided. The aperture of the channel is uniform, and image distortion does not exist. The length-diameter ratio of the silicon micro-channel array 1 is 10-500, and the diameter of the plate surface is 25-150 mm.

A reflective layer 2, as shown in fig. 2, the reflective layer 2 is prepared on the side surface in the silicon microchannel array 1, and the material is metal or silicon dioxide with high reflectivity; when the reflective layer 2 is silicon dioxide, the reflective layer 2 may be prepared by a thermal oxidation process; when the reflecting layer 2 is made of metal, the reflecting layer 2 made of metal materials including aluminum, silver, gold, platinum and the like is prepared on the inner wall of the micro-channel by an atomic layer deposition technology, wherein the thickness of the reflecting layer 2 is 20-500 nanometers.

Filling mediumA filler 3, wherein the filler 3 is filled in the space formed by the reflecting layer 2, and the coefficient of thermal expansion of the filler 3 is less than 100 (10) at 0-1000 deg.C^-7K) is added. When the material of the reflecting layer 2 is silicon dioxide, the refractive index of the filling medium 3 is greater than that of the silicon dioxide; when the reflecting layer is made of metal, the refractive index of the filling medium 3 does not need to be considered, the thermal expansion coefficient of the filling medium 3 is close to that of silicon, the air tightness can be ensured, and the light and thin optical fiber panel suitable for the application in the technical field of ultrahigh vacuum can be prepared. In the embodiment, the filling medium 3 is made of optical glass, and the models are H-LaF4GT, H-BaK7GT and H-KLGT.

Two examples of the preparation are given below:

example 1:

a preparation method of an optical fiber panel based on a silicon micro-channel array comprises the following steps:

the method comprises the following steps: carrying out photoetching, corrosion, oxidation, back thinning and channel shaping on a silicon substrate with the crystal orientation of [100] to prepare a silicon micro-channel array structure 1; and (3) corroding the micro-channels by adopting a shaping process of the silicon micro-channel array 1 to obtain square channels arranged in a square manner, enlarging the size of the channels and reducing the wall thickness. The etching solution used in the silicon substrate shaping process for preparing the silicon microchannel array 1 is a tetramethylammonium hydroxide solution, the concentration of the etching solution is 1 wt%, and the temperature of the etching solution is 40 ℃. The silicon substrate surface diameter of the silicon micro-channel array 1 is 25mm, the thickness is 350 microns, the micro-channel period is 6 microns, and the side length of the square-hole channel is 5.5 microns.

Step two: placing the silicon microchannel array 1 in high temperature for oxidation for 2 hours, wherein a silicon dioxide layer is formed on the inner wall of the channel and is used as a reflecting layer 2, the oxidation temperature is 1100 ℃, and the thickness of the oxidation layer is 50 nanometers;

step three: placing a silicon micro-channel array 1 with a silicon dioxide reflecting layer 2 on the inner wall into a sapphire crucible 8 in a vacuum tube furnace 7, and placing H-LaF4GT optical glass on the silicon micro-channel array 1; vacuumizing and heating the vacuum tube furnace 7, wherein the heating temperature is higher than the softening point temperature of the solid optical glass, the temperature is 750 ℃, the temperature is kept for 10 minutes, and the vacuum degree is better than 10 Pa; : closing the vacuum pump 6, opening the valve 5, inflating the vacuum tube furnace 7 by high-purity nitrogen 4, naturally cooling the vacuum tube furnace 7, and filling the molten H-LaF4GT optical glass into the micro-channel of the silicon micro-channel array 1 with the inner wall reflection layer under the pressure action to form a glass medium filled in the channel; and finally, grinding and polishing the surface to finish the preparation method of the optical fiber panel based on the silicon micro-channel array.

Example 2

A preparation method of an optical fiber panel based on a silicon micro-channel array comprises the following steps:

the method comprises the following steps: carrying out photoetching, corrosion, oxidation, back thinning and channel shaping on a silicon substrate with the crystal orientation of [100] to prepare a silicon micro-channel array structure 1; and (3) corroding the micro-channels by adopting a shaping process of the silicon micro-channel array 1 to obtain square channels arranged in a square manner, enlarging the size of the channels and reducing the wall thickness. The etching solution used in the silicon substrate shaping process for preparing the silicon microchannel array 1 is a tetramethylammonium hydroxide solution, the concentration of the etching solution is 1 wt%, and the temperature of the etching solution is 40 ℃. The silicon substrate surface diameter of the silicon micro-channel array 1 is 100mm, the thickness is 300 microns, the micro-channel period is 3 microns, and the side length of the square-hole channel is 2.5 microns.

Step two: depositing the silicon micro-channel array 1 by an atomic layer, and preparing a silver film on the inner wall of the channel to be used as a reflecting layer 2, wherein the thickness of the silver film is 500 nanometers;

step three: placing a silicon micro-channel array 1 with a silver film on the inner wall into a sapphire crucible 8 in a vacuum tube furnace 7, and placing H-BaK7GT optical glass on the silicon micro-channel array 1; vacuumizing and heating the vacuum tube furnace 7, wherein the heating temperature is higher than the softening point temperature of the solid optical glass; maintaining at 780 ℃ for 10 minutes, and ensuring that the vacuum degree is better than 1 Pa;

step four: closing the vacuum pump 6, opening the valve 5, charging the vacuum tube furnace 7 with high-purity nitrogen 4, naturally cooling the vacuum tube furnace 7, and filling the molten H-BaK7GT optical glass into the micro-channels of the silicon micro-channel array 1 with the inner wall reflecting layer under the pressure action to form glass media filled in the channels; and finally, grinding and polishing the surface to finish the preparation method of the optical fiber panel based on the silicon micro-channel array.