CN113135547A

CN113135547A - Optical chip and method for producing the same

Info

Publication number: CN113135547A
Application number: CN202110260479.2A
Authority: CN
Inventors: 侯继东
Original assignee: Suzhou Shenshuiyu Semiconductor Co ltd
Current assignee: Suzhou Shenshuiyu Semiconductor Co ltd
Priority date: 2021-03-10
Filing date: 2021-03-10
Publication date: 2021-07-20

Abstract

The invention discloses an optical chip and a production method thereof, and the optical chip comprises: the device comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, and the pair of rotating shafts bend in the direction away from the substrate layer to form an arch. The invention has the beneficial effects that: the pair of rotating shafts are bent in the direction away from the substrate layer to form an arch, and the shape of the rotating shafts is changed to inhibit downward bending deformation of the rotating shafts caused by the received external force, so that the range of the rotating angles is enlarged.

Description

Optical chip and method for producing the same

Technical Field

The invention relates to a Micro Electro Mechanical System (MEMS) technical device, in particular to an optical chip and a production method thereof, and in particular relates to the shape change of a rotating shaft of a rotating micro-mirror chip so as to increase the range of a rotating angle.

Background

The angle of the mirror is often controlled to control the transmission direction of light, and particularly after the micro-electro-mechanical systems (MEMS) technology is developed, a semiconductor process is usually used to manufacture the micromirrors on a chip that can be driven by signals. The driving micro-mirror can adopt the modes of electromagnetic driving, heating driving, electrostatic force driving and the like. Due to the characteristics of simple assembly, low power consumption, long service life and the like, the electrostatically-driven MEMS optical chip has become the mainstream. The principle of electrostatic driving is that, by a capacitance formed between a moving electrode and a static electrode, electric charges are accumulated to generate an electrostatic force after a voltage is applied, and the electrostatic force attract each other to move the moving electrode toward the static electrode. Typically the movable electrode is attached to or part of the micromirror and is attached to the chip mounting portion by an axis. Therefore, the movable electrode and the micromirror can rotate under the action of electrostatic force, the shaft is distorted and deformed, the restoring force generated by the distortion deformation enables the micromirror to be statically balanced under a certain angle, and the movable electrode and the micromirror restore to the original positions after the voltage is withdrawn.

In this electrostatic force system, the electrostatic attraction force generated between the movable electrode and the static electrode not only generates a moment relative to the axis by the movable electrode and drives the micromirror to rotate, but also moves the movable electrode and the micromirror together toward the static electrode. A twisting deformation and a bending deformation against a downward motion occur simultaneously for the suspended movable electrode and the axis of the micromirror.

On the MEMS chip, a gap layer is located between a moving portion (composed of a moving electrode and a micromirror) and a static electrode (generally composed of a substrate or a substrate), and the deeper the gap layer is, the larger the moving range of the moving portion is. But the electrostatic force is inversely proportional to the square of the depth of the voided layer, the deeper the voided layer the greater the attenuation of the electrostatic force. Meanwhile, the deep gap layer increases the manufacturing difficulty and cost of the wafer. Typically the voided layer is in the range of a few microns to tens of microns.

For the micromirror system, it is important that the moving part rotates, not the moving part moves downward. In particular, downward movement of the moving part reduces the range of rotation. Meanwhile, when the moving part moves down over a distance of more than one third of the space layer, the restoring force of the shaft cannot balance the electrostatic force, resulting in direct adsorption of the moving part on the substrate, greatly hindering the rotation angle of the moving part. Increasing the rotation angle of the micromirror is an important task of the micromirror system, and the downward movement of the micromirror greatly reduces the angular rotation range of the micromirror. Therefore, in the electrostatic force driven micromirror system, the downward movement of the moving part must be suppressed or prevented as much as possible.

In the case of a shaft, the shaft is subjected to both torsional deformation and bending deformation, and it is important to prevent the shaft from being subjected to the same suction force while allowing the shaft to be subjected to the torsional deformation as much as possible. The moving electrode can be moved away from the shaft to increase the rotational torque. However, in the case of a certain gap layer, the electrode is more easily contacted with the substrate, and the rotation angle range is reduced. Better methods increase the bending modulus of elasticity of the shaft, but this also increases the torsional modulus of elasticity of the shaft. The current method is to increase the thickness of the shaft and decrease the length of the shaft, which relatively reduces the effect of bending. But the increase in thickness and the decrease in length undoubtedly increase the requirements for electrostatic driving force. To reduce the requirements for electrostatic forces (i.e., drive voltages), the shaft is made thin. However, in the practical process, the fineness of the shaft increases the difficulty of photoetching, and the finer the shaft is, the more strongly the fineness of the shaft is fluctuated, the more strongly the consistency of the driving voltage is influenced. In particular, the thinner the axis, the more easily the axis is broken, and the reliability of the device is not ensured. It is therefore important to find a way to eliminate or inhibit bowing.

Disclosure of Invention

The present invention is directed to provide an optical chip and a method for manufacturing the same, which can suppress bending deformation of a rotating shaft due to an external force by changing the shape of the rotating shaft, thereby increasing the range of a rotation angle.

In order to solve the above technical problem, the present invention provides an optical chip, including: the device comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, and the pair of rotating shafts bend in the direction away from the substrate layer to form an arch.

Based on the same inventive concept, the present invention also provides an optical chip, comprising: the device comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, the pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the pair of rotating shafts form the arch through compressive stress substances growing on the rotating shafts.

Based on the same inventive concept, the present invention also provides an optical chip, comprising: the device comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, the pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the pair of rotating shafts form the arch through the integral deformation of the chip.

Based on the same inventive concept, the present invention also provides an optical chip, comprising: the device comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, the pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the pair of rotating shafts form the arch through compressive stress substances growing on the rotating shafts and through the integral deformation of the chip.

Based on the same inventive concept, the invention also provides a production method of the optical chip, wherein the optical chip comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, and the pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the method comprises the following steps: growing a layer of polycrystalline silicon on an SOI (silicon on insulator) silicon wafer by utilizing low-pressure gas-phase chemical deposition, wherein the SOI silicon wafer comprises a substrate layer, an insulating layer and a device layer from bottom to top in sequence, and the polycrystalline silicon has compressive stress; removing a layer of polycrystalline silicon adjacent to the substrate layer; if the film is grown by Plasma Enhanced Chemical Vapor Deposition (PECVD), the backside is not treated. Removing most of polycrystalline silicon adjacent to the device layer by using photoresist as a mask through dry etching, and only reserving the polycrystalline silicon in a region corresponding to the rotating shaft; then, the photoresist is used as a mask again, and the shaft and the micromirror are etched out by a dry etching method until the insulating layer is formed; and hollowing the rotating shaft and the insulating layer below the micro mirror to suspend the rotating shaft and the micro mirror in the air.

In one embodiment, when the insulating layer is silicon dioxide, hydrofluoric acid is used to remove the insulating layer under the hinge and the micromirror, so that the hinge and the micromirror are suspended.

In one embodiment, when the insulating layer is an organic material, the hinge and the micromirror are suspended by hollowing out the insulating layer under the hinge and the micromirror by plasma of oxygen or organic solution.

In one embodiment, the hinge and the micromirror are flexibly connected, and the flexible connection is realized by connecting the hinge and the micromirror by using a beam perpendicular to the hinge.

Based on the same inventive concept, the invention also provides a production method of the optical chip, wherein the optical chip comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, and the pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the method comprises the following steps: growing a layer of polycrystalline silicon on an SOI (silicon on insulator) silicon wafer by utilizing low-pressure gas-phase chemical deposition, wherein the SOI silicon wafer comprises a substrate layer, an insulating layer and a device layer from bottom to top in sequence, and the polycrystalline silicon has tensile stress; removing a layer of polycrystalline silicon adjacent to the substrate layer; removing the polysilicon in the corresponding areas of the rotating shaft and the micromirror by using photoresist as a mask and performing dry etching, and reserving most of the polysilicon adjacent to the device layer; then, the photoresist is used as a mask again, and the shaft and the micromirror are etched out by a dry etching method until the insulating layer is formed; hollowing out the insulating layer below the rotating shaft and the micro mirror to suspend the rotating shaft and the micro mirror in the air; in order to avoid the down-bending of the hinge that may occur after the hinge is released, a layer of photoresist having a compressive stress that is temporarily coated on the micromirror may be removed, and the photoresist may be removed after hollowing out the hinge and the insulating layer under the micromirror.

Based on the same inventive concept, the invention also provides a production method of the optical chip, wherein the optical chip comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, and the pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the method comprises the following steps: growing a layer of polycrystalline silicon on an SOI (silicon on insulator) silicon wafer by utilizing low-pressure gas-phase chemical deposition, wherein the SOI silicon wafer comprises a substrate layer, an insulating layer and a device layer from bottom to top in sequence, and the polycrystalline silicon has compressive stress; removing a layer of polycrystalline silicon adjacent to the device layer, and reserving a layer of polycrystalline silicon adjacent to the substrate layer; using photoresist as a mask, and etching the shaft and the micromirror by a dry etching method until the insulating layer is formed; temporarily coating a layer of photoresist with compressive stress on the micro mirror; hollowing out the insulating layer below the rotating shaft and the micro mirror to suspend the rotating shaft and the micro mirror in the air; and removing a layer of photoresist with compressive stress temporarily coated on the micromirror.

The invention has the beneficial effects that:

the pair of rotating shafts are bent in the direction away from the substrate layer to form an arch, and the shape of the rotating shafts is changed to inhibit downward bending deformation of the rotating shafts caused by the received external force, so that the range of the rotating angles is enlarged.

Drawings

FIG. 1 is a schematic view showing a first method for producing an optical chip according to the present invention.

FIG. 2 is a second schematic diagram of a first method for manufacturing an optical chip according to the present invention.

FIG. 3 is a third schematic diagram of a method for manufacturing an optical chip according to the first embodiment of the present invention.

FIG. 4 is a schematic view showing a second method for producing an optical chip according to the present invention.

FIG. 5 is a second schematic diagram of a second method for manufacturing an optical chip according to the present invention.

FIG. 6 is a schematic view showing one of the manufacturing methods of the third optical chip of the present invention.

FIG. 7 is a second schematic diagram of a third method for manufacturing an optical chip according to the present invention.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

The invention aims to solve the problem that the turning range of the electrostatically driven micromirror is reduced due to the bending deformation of the axes. Generally, the bending deformation can be weakened by reducing the width of the axis and reducing the length of the axis, but this increases the difficulty of photolithography and increases the jitter of the driving voltage index due to the uncertainty of photolithography, particularly making the axis very fragile. Alternatively, the twisting moment of the electrostatic force is increased by moving the drive portion as far away from the shaft as possible, but the drive portion limits the range of rotation. Although the rotation range can be enlarged by enlarging the sacrificial layer, the driving voltage is increased at the same time. The common method in the industry is to make the driving part into movable teeth and static teeth which are mutually nested, but the comb tooth structure has strict process requirements and difficult cost reduction, and particularly, the upper teeth and the lower teeth are mutually occluded. In the present invention, in order to avoid these problems, the method of deforming the rotating shaft is adopted, so that the shaft is slightly warped and arched, thus greatly increasing the downward bending strength of the shaft, and having no influence on the distortion. After the invention is adopted, the rotation range of the micromirror is obviously enlarged and the reliability of the device is obviously improved under the conditions of not obviously improving the driving voltage and not increasing the thickness of the sacrificial layer. It is very beneficial to manufacture optical attenuator, optical switch and laser scanning galvanometer.

The MEMS chip is driven by external force and rotates by the distortion of the rotating shaft, and the core of the MEMS chip is that the rotating shaft is bent upwards to form an arch shape, so that the downward bending deformation of the shaft is restrained. The spindle twisted in the MEMS chip is made of single crystal silicon, and the chip is manufactured by using an SOI wafer. In the present invention, the insulating layer in the SOI wafer may be silicon dioxide, or may be another insulating material. In the present invention, upward refers to a direction away from a substrate layer (handle layer) of the SOI.

The first production method comprises the following specific steps: firstly, growing a layer of polycrystalline silicon film on an SOI silicon wafer by LPCVD (low-pressure gas-phase chemical deposition), wherein the SOI silicon wafer comprises a substrate layer, an insulating layer and a device layer from bottom to top in sequence. Polysilicon can form both fine and coarse microstructures depending on the growth temperature. Generally bounded at around 580 c, below which the flow and pressure of the silane during growth are small and fines are formed. Above this temperature, the silane flow and pressure used can be relatively high, forming coarse particles. The polycrystalline silicon thin film of the coarse grain structure has compressive stress. The polysilicon with the fine grain structure has tensile stress after high-temperature annealing above 700 ℃. The first production method of the present invention employs the above-mentioned coarse-grained polycrystalline silicon thin film having a compressive stress. If the LPCVD process is used, it is necessary to remove the polysilicon entirely from the back side of the SOI wafer (i.e., immediately adjacent to the substrate layer) and leave only the polysilicon film on the front side (i.e., above the device layer), as shown in fig. 1. And then, using photoresist as a mask, removing most of the polycrystalline silicon film on the front surface by dry etching, and only reserving the film in the region corresponding to the rotating shaft. Then, the photoresist is used as a mask again, and the rotating shaft, the micro mirror and other parts are etched by a dry etching method until the insulating layer is formed. For a common SOI silicon wafer, the insulating layer is silicon dioxide, and the silicon dioxide under the hinge and the micromirror is removed by hydrofluoric acid to suspend the hinge and the micromirror, which is called a release process. In the case of an insulating layer made of an organic material, the insulating layer under the micromirror and the axis can be hollowed out by plasma of oxygen or an organic solvent. Under the action of the polysilicon film, the axial direction is arched, as shown in fig. 2. The rotating shaft and the micro mirror are connected through flexibility, so that the rotating shaft has a larger arching effect. The flexible connection method can use a beam perpendicular to the rotation axis to connect the rotation axis and the micromirror, as shown in fig. 3.

The second production method comprises the following specific steps: firstly, growing a layer of polycrystalline silicon on an SOI silicon wafer by LPCVD (low-pressure gas-phase chemical deposition), wherein the SOI silicon wafer comprises a substrate layer, an insulating layer and a device layer from bottom to top in sequence. Polysilicon can form both fine and coarse microstructures depending on the growth temperature. Generally bounded at around 580 c, below which the flow and pressure of the silane during growth are small and fines are formed. Above this temperature, the silane flow and pressure used can be relatively high, forming coarse particles. The polycrystalline silicon thin film of the coarse grain structure has compressive stress. The polysilicon with fine grain structure is annealed at high temperature above 700 deg.c to form tensile stress film. The second production method of the present invention is to use the above-mentioned polycrystalline silicon thin film having a fine grain structure and subject to high-temperature annealing, the thin film having a tensile stress. If the LPCVD process is used, it is necessary to remove the polysilicon entirely from the back side of the SOI wafer (i.e., near the substrate layer) and leave only the polysilicon film on the front side (i.e., next to the device layer), as shown in fig. 1. Removing the polysilicon in the corresponding areas of the rotating shaft and the micromirror by using photoresist as a mask and performing dry etching, and reserving most of the polysilicon adjacent to the device layer; then, the photoresist is used as a mask again, and the rotating shaft and the micro mirror are etched by a dry etching method until the insulating layer is formed; temporarily coating a layer of photoresist with compressive stress on the micro mirror; hollowing out the insulating layer below the rotating shaft and the micro mirror to suspend the rotating shaft and the micro mirror in the air; and removing a layer of photoresist with compressive stress temporarily coated on the micromirror.

The photoresist with compressive stress can also be replaced by a metal film with compressive stress, and finally the metal film on the micromirror remains to be used as a reflecting layer of the micromirror.

It can be understood that in the release process, after the hinge and the micromirror are released, the other regions deform the entire chip and bend upward due to the tensile stress on the upper surface, so that the suspended components are pressed inward. Since the hinge is very thin compared to the micromirror, most of the deformation occurs on the hinge and the micromirror is not substantially deformed. In this case, the rotation shaft may be bent either upward or downward. To avoid the downward bending, the micromirror can be temporarily coated with a photoresist before releasing, as shown in fig. 4. And controlling the thickness and baking temperature of the photoresist and the corresponding time sequence to enable the photoresist to have compressive stress. The photoresist maintains the overhang in the dome shape during release, as shown in figure 5. After release is complete, the temporary layer is removed. The rotating shaft still keeps the upward arch shape under the action of the polysilicon stress of other areas of the surface.

The third production method comprises the following specific steps: firstly, growing a layer of polycrystalline silicon on an SOI silicon wafer by LPCVD (low-pressure gas-phase chemical deposition), wherein the SOI silicon wafer comprises a substrate layer, an insulating layer and a device layer from bottom to top in sequence. Polysilicon can form both fine and coarse microstructures depending on the growth temperature. Generally bounded at around 580 c, below which the flow and pressure of the silane during growth are small and fines are formed. Above this temperature, the silane flow and pressure used can be relatively high, forming coarse particles. The polycrystalline silicon thin film of the coarse grain structure has compressive stress. The third production method of the present invention employs the above-mentioned coarse-grained polycrystalline silicon thin film having a compressive stress. Removing a layer of polysilicon adjacent to the device layer, as shown in fig. 6, and retaining a layer of polysilicon adjacent to the substrate layer; using photoresist as a mask, and etching the shaft and the micromirror by a dry etching method until the insulating layer is formed; temporarily coating a layer of photoresist with compressive stress on the micro mirror; hollowing out the insulating layer below the rotating shaft and the micro mirror to suspend the rotating shaft and the micro mirror in the air; and removing a layer of photoresist with compressive stress temporarily coated on the micromirror.

It will be appreciated that after the etching and release process described above, the die deforms due to the backside compressive stress polysilicon, causing the suspended members to be stressed inwardly. Since the hinge is very thin compared to the micromirror, most of the deformation occurs on the hinge and the micromirror is not substantially deformed. In this case, the rotation shaft may be bent either upward or downward. In order to avoid the downward bending, a layer of photoresist can be temporarily coated on the micromirror before releasing, and the thickness and baking temperature of the photoresist and the corresponding time sequence are controlled to make the photoresist have compressive stress. The photoresist maintains the overhang in the dome shape during the release process. After release is complete, the temporary layer is removed. Under the back pressure stress, the spindle still maintains the crowning shape, as in fig. 7.

It will be appreciated that the first and second, and first and third, methods above may be implemented simultaneously to increase the upward bending effect of the shaft.

While the hinge is arched upward, the micromirror and other movable parts that may be present are lifted to some extent. This also increases the distance between the micromirror and the substrate layer to some extent, contributing to an increased rotation angle. It is also noted that if there is a flexible connection between the hinge and the micromirror, the connection maintains a certain stiffness without allowing the movable part to sag under the action of electrostatic or magnetic force. Meanwhile, it should be noted that the temporary photoresist mentioned in methods 2 and 3 can also be used by evaporating or sputtering one or more layers of metal and making the metal layer have compressive stress, but after the release is completed, the metal layer can be used as a reflective layer without being removed. The hinge can also be deformed upward by making the micromirror surface convex.

The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.

Claims

1. An optical chip, comprising: the device comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, and the pair of rotating shafts bend in the direction away from the substrate layer to form an arch.

2. An optical chip, comprising: the device comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, the pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the pair of rotating shafts form the arch through compressive stress substances growing on the rotating shafts.

3. An optical chip, comprising: the device comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, the pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the pair of rotating shafts form the arch through the integral deformation of the chip.

4. An optical chip, comprising: the device comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, the pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the pair of rotating shafts form the arch through compressive stress substances growing on the rotating shafts and through the integral deformation of the chip.

5. A method for producing an optical chip, wherein the optical chip comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, and a pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the method is characterized by comprising the following steps of: growing a layer of polycrystalline silicon on an SOI (silicon on insulator) silicon wafer by utilizing low-pressure gas-phase chemical deposition, wherein the SOI silicon wafer comprises a substrate layer, an insulating layer and a device layer from bottom to top in sequence, and the polycrystalline silicon has compressive stress; removing a layer of polycrystalline silicon adjacent to the substrate layer; removing most of polycrystalline silicon adjacent to the device layer by using photoresist as a mask through dry etching, and only reserving the polycrystalline silicon in a region corresponding to the rotating shaft; and etching a shaft and a micro mirror, and hollowing out the insulating layer below the rotating shaft and the micro mirror to suspend the rotating shaft and the micro mirror in the air.

6. The method for manufacturing an optical chip as claimed in claim 5, wherein when the insulating layer is silicon dioxide, the insulating layer under the hinge and the micromirror is removed with hydrofluoric acid to suspend the hinge and the micromirror.

7. The method for producing an optical chip as claimed in claim 5, wherein when the insulating layer is an organic material, the insulating layer under the spindle and the micromirror is hollowed by a plasma of oxygen or an organic solution to suspend the spindle and the micromirror.

8. The method of claim 5, wherein the hinge and the micromirror are connected by a flexible connection, the flexible connection using a beam perpendicular to the hinge to connect the hinge and the micromirror.

9. A method for producing an optical chip, wherein the optical chip comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, and a pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the method is characterized by comprising the following steps of: growing a layer of polycrystalline silicon on an SOI (silicon on insulator) silicon wafer by utilizing low-pressure gas-phase chemical deposition, wherein the SOI silicon wafer comprises a substrate layer, an insulating layer and a device layer from bottom to top in sequence, and the polycrystalline silicon has tensile stress; removing a layer of polycrystalline silicon adjacent to the substrate layer; removing the polysilicon in the corresponding areas of the rotating shaft and the micromirror, and reserving most of the polysilicon adjacent to the device layer; then etching out the axis and the micromirror; and hollowing the rotating shaft and the insulating layer below the micro mirror to suspend the rotating shaft and the micro mirror in the air.

10. A method for producing an optical chip, wherein the optical chip comprises a substrate layer, a pair of rotating shafts and a micro mirror; the micromirror is anchored on the substrate layer through a pair of the rotating shafts, and the pair of the rotating shafts are distributed on two sides of the micromirror; under the action of an external electric field or magnetic field, the micro-mirror rotates, and a pair of rotating shafts bend in the direction away from the substrate layer to form an arch, and the method is characterized by comprising the following steps of: growing a layer of polycrystalline silicon on an SOI (silicon on insulator) silicon wafer by utilizing low-pressure gas-phase chemical deposition, wherein the SOI silicon wafer comprises a substrate layer, an insulating layer and a device layer from bottom to top in sequence, and the polycrystalline silicon has compressive stress; removing a layer of polycrystalline silicon adjacent to the device layer, and reserving a layer of polycrystalline silicon adjacent to the substrate layer; etching out the shaft and the micro mirror; and hollowing the rotating shaft and the insulating layer below the micro mirror to suspend the rotating shaft and the micro mirror in the air.