A semiconductor photoelectric level sensor, its fabrication method and application

Abstract

This invention relates to the field of integrated circuit manufacturing, specifically disclosing a semiconductor photoelectric level sensor, its fabrication method, and its application. The sensor is a sheet-like structure comprising: a substrate including multiple photodiodes evenly distributed on a ring with a first circular axis perpendicular to the substrate as its axis of symmetry; a circular cavity located on the substrate, perpendicularly corresponding to the ring formed by the multiple photodiodes, and containing a rollable microgravity sphere; and a first signal light guide located on the circular cavity, also circular in shape and perpendicularly corresponding to the cavity, for vertically guiding actively irradiated circular signal light into the cavity. This invention utilizes the lowest point of the circular cavity where the rollable microgravity sphere can freely roll under gravity, and simultaneously guides actively irradiated circular signal light vertically into the cavity, with the multiple photodiodes accurately sensing the precise angular position of the rollable microgravity sphere.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit manufacturing, and more specifically to a semiconductor photoelectric level sensor, its fabrication method, and its application. Background Technology

[0002] Attitude control of near-ground aircraft (such as airplanes and missiles) is crucial for achieving real-time information control over their flight trajectory and stability. Specifically, the two most important parameters for defining flight attitude are: 1) pitch angle; 2) roll angle; which correspond to the pitch angle between the main axis of the aircraft and the ground plane and the angle between the left and right sides of the aircraft (wings) and the ground plane, respectively.

[0003] Since man-made aircraft, especially manned aircraft (airplanes), have taken to the skies, the real-time pitch and roll angle sensing technology and devices have become an indispensable part of aircraft equipment. People have designed and invented various electromechanical devices to sense the levelness of aircraft in the two principal directions under gravity in real time, namely pitch and roll angles.

[0004] However, with the technological and cost advantages of drones, especially micro-sized electric drones, their applications have grown rapidly in recent years. Simultaneously, miniaturization, lightweighting, and cost reduction, along with continuous improvements in flight performance (such as range and speed), represent an unchanging trend for future development. Miniaturization, lightweighting, cost reduction, low energy consumption, and high precision of airborne equipment, especially sensing devices, have become essential. Therefore, a semiconductor level sensor—a "chip" capable of achieving higher precision real-time pitch and roll level (angle) sensing with smaller size, weight, and energy consumption—is highly anticipated by micro-sized drones.

[0005] Based on this technical background, the present invention proposes a semiconductor photoelectric level sensor, its fabrication method and application. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention proposes a semiconductor photoelectric level sensor, its fabrication method, and its application. This sensor detects the lowest point of a circular cavity where a rollable microgravity ball can roll freely under gravity. Simultaneously, by vertically guiding actively irradiated annular signal light into the circular cavity, multiple photodiodes accurately sense the precise angular position of the rollable microgravity ball. This achieves miniaturization, lightweighting, cost reduction, and low energy consumption of the sensing device, enabling higher precision pitch and roll level measurements with smaller size, weight, and energy consumption.

[0007] To achieve the above objectives, a first aspect of the present invention provides a semiconductor photoelectric level sensor, comprising:

[0008] The substrate includes multiple photodiodes, which are evenly distributed on a circular ring that is symmetrical about the y-axis of the aircraft side, which is perpendicular to the substrate.

[0009] An annular cavity is located on the substrate, with the lateral y-axis of the aircraft as the axis of symmetry, and is perpendicular to the annular ring formed by the plurality of photodiodes. A rollable microgravity ball is disposed inside the annular cavity.

[0010] A signal light guide, located on the annular cavity, is circular in shape and perpendicular to the annular cavity, used to vertically guide the actively irradiated annular signal light into the annular cavity.

[0011] A second aspect of the present invention provides a method for manufacturing the above-mentioned sensor, comprising:

[0012] With the y-axis of the aircraft side perpendicular to the substrate as the axis of symmetry, a plurality of photodiodes are formed in a uniformly arranged ring shape within the substrate;

[0013] A groove in a circular cavity is formed on the top surface of the substrate. This groove is perpendicular to the circular ring formed by the arrangement of multiple photodiodes. A rollable microgravity ball is adhered to the bottom surface of the capping sheet using an adhesive. The bottom surface of the capping sheet is then bonded to the top surface of the substrate, allowing the rollable microgravity ball to be placed within the groove of the circular cavity.

[0014] The rollable microgravity ball is adhered to the top surface of the substrate with an adhesive and aligned perpendicularly with a photodiode. A groove for the annular cavity is formed on the bottom surface of the cover sheet. The bottom surface of the cover sheet is bonded to the top surface of the substrate, so that the rollable microgravity ball is placed in the groove of the annular cavity.

[0015] Remove the adhesive and release the rollable microgravity ball to roll freely within the annular cavity;

[0016] A circular light guide is formed on the top surface of the cover plate, which is perpendicular to the circular cavity.

[0017] A third aspect of the present invention provides an application of the above-described sensor in an aircraft, comprising:

[0018] The sensor includes a first sensor and a second sensor;

[0019] The first sensor is set parallel to and fixed in a first plane formed by the longitudinal x-axis and normal z-axis of the aircraft. The sensor includes a first rollable microgravity ball disposed in its own annular cavity.

[0020] The second sensor is set parallel to and fixed in a second plane formed by the normal z-axis and the lateral y-axis of the aircraft. The sensor includes a second rollable microgravity ball disposed in its own annular cavity.

[0021] The first plane and the second plane remain perpendicular to each other;

[0022] During flight, the aircraft's pitch and roll angles are sensed by two sensors.

[0023] The technical effects of this invention include:

[0024] The semiconductor photoelectric level sensor proposed in this invention uses the lowest point of a circular cavity where a rollable microgravity ball can roll freely under gravity. Simultaneously, by vertically guiding actively irradiated circular signal light into the circular cavity, multiple photodiodes accurately sense the precise angular position of the rollable microgravity ball. This achieves miniaturization, lightweighting, low cost, and low energy consumption of the sensing device, and enables higher precision pitch and roll level measurements with smaller size, weight, and energy consumption.

[0025] The semiconductor photoelectric horizontal sensor proposed in this invention fixes two mutually perpendicular horizontal photoelectric sensors to the axial plane (a plane composed of the longitudinal axis and the normal axis) and the lateral plane (a plane composed of the lateral axis and the normal axis) of the aircraft, respectively. Then, under the action of gravity, by sensing the balance point, i.e. the angular position, of the two rollable microgravity balls in the two mutually perpendicular horizontal photoelectric sensors, the pitch angle and roll angle of the aircraft can be accurately obtained.

[0026] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0027] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0028] Figure 1 This is a schematic diagram illustrating an application of a specific embodiment of the semiconductor photoelectric level sensor proposed in this invention.

[0029] Figure 2 This is a schematic diagram of the overall structure of a specific embodiment of the semiconductor photoelectric level sensor proposed in this invention.

[0030] Figure 3 a-3g is a schematic diagram of the fabrication process in a specific embodiment of the semiconductor photoelectric level sensor proposed in this invention.

[0031] Explanation of reference numerals in the attached figures

[0032] x-axis - longitudinal axis, y-axis - lateral axis, z-axis - normal axis, X-axis - heading, Y-axis - horizontal lateral, Z-axis - gravity direction, 91 - pitch angle; 92 - roll angle, A1 - base layer, A2 - cavity layer, A3 - capping layer, A4 - signal light introduction layer, 100 - first sensor, 200 - second sensor, 111 - photodiode, 112 - semiconductor transistor, 135h / 235h - annular cavity, 135 - groove, 110 - substrate, 130 - surrounding sheet, 148 / 248 - rollable microgravity sphere, 1 40-Capping sheet, 145-Signal light guide, 150-Signal light source introducer, 160-Solid-state light source, 161-Reflective beam splitter cone, 162-Circular light guide, 163-Annular reflector, 10-Light source light, 11-Annular signal light, 129-First bonding layer, 139-Second bonding layer, 142-Third bonding layer, 143-Adhesive, 141-Passivation layer, 149-Adhesive release hole, 151-First layer adhesive bonding, 120-Interconnect layer, 128-Light radiation metal blocking sheet, Si-Silicon, SiO2-Silicon dioxide. Detailed Implementation

[0033] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0034] In this invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its normal operating state, while "inner" and "outer" refer to their position relative to the device's outline. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0035] This invention provides a semiconductor photoelectric level sensor, such as... Figure 2 As shown, it includes:

[0036] The substrate 110 includes a plurality of photodiodes 111, which are evenly distributed on a circular ring that is symmetrical about the lateral y-axis of the aircraft and perpendicular to the substrate 110.

[0037] An annular cavity 135h is located on the substrate 110, with the lateral y-axis of the aircraft as the axis of symmetry, and is perpendicular to the annular ring formed by multiple photodiodes 111. A rollable microgravity ball 148 is disposed inside the annular cavity 135h.

[0038] The signal light guide 145 is located on the annular cavity 135h, and is in the shape of a ring. It is perpendicular to the annular cavity 135h and is used to guide the actively irradiated annular signal light 11 vertically into the annular cavity 135h.

[0039] In this invention, the lowest point of the annular cavity through which the rollable microgravity ball can roll freely under the action of gravity is located. At the same time, the actively irradiated annular signal light is vertically introduced into the annular cavity, and the accurate angular position of the rollable microgravity ball is accurately sensed by multiple photodiodes. This achieves miniaturization, lightweighting, low cost and low energy consumption of the sensing device, and enables higher accuracy in pitch and roll level measurement with smaller volume, weight and energy consumption.

[0040] According to the present invention, it further includes:

[0041] An interconnect layer 120 is disposed between the substrate 110 and the annular cavity 135h. Inside the layer are metal interconnects required for the readout circuit and a light radiation blocking sheet 128. The light radiation blocking sheet 128 is provided with an annular light channel. The annular light channel is used to irradiate the annular signal light 11 passing through the annular cavity 135h onto multiple photodiodes 111. The light radiation blocking sheet 128 outside the annular light channel is used to selectively block light radiation from entering the area outside the photodiodes 111.

[0042] The substrate 110 also includes a plurality of semiconductor transistors 112, each of which is electrically connected to a photodiode 111.

[0043] According to the present invention, the annular cavity 135h is surrounded laterally and centrally by a first lateral surrounding sheet 130;

[0044] The signal light guide is 145 lateral and centrally sealed by the sheet body 140.

[0045] According to the present invention, it further includes:

[0046] The signal light source introducer 150 is disposed on the signal light guide 145 and includes a solid light source 160, a reflective beam splitter cone 161, a circular light guide 162 and an annular reflector 163. The solid light source 160 emits light 10 which is split, waveguided and reflected in sequence to form an annular signal light 11 and then guided to the signal light guide 145 and projected downward.

[0047] At least one adhesive release hole 149 penetrates the outer wall of the capping sheet 140, the substrate 110, or the annular cavity 135h and communicates with the annular cavity 135h, for releasing the adhesive during the preparation process and introducing gaseous and / or volatile lubricant into the annular cavity 135h, and is sealed by the medium after the sensor preparation is completed.

[0048] According to the present invention, a rollable microgravity ball 148, having a diameter of 1 to 1000 micrometers, perturbs an annular signal light 11 introduced from above.

[0049] The disturbance includes at least one of reflection, refraction, absorption and diffraction;

[0050] The wavelength of the ring signal light 11 is 0.4 to 1.0 micrometers;

[0051] The substrate 110 is made of a semiconductor containing silicon, gallium arsenide, germanium, or an alloy thereof;

[0052] The rollable microgravity ball 148 is made of at least one of the following metals: tungsten, aluminum, titanium, gold, mercury, and silver.

[0053] The surface of the annular cavity 135h is covered with a wear-resistant passivation film, the composition of which includes silicon nitride and / or silicon carbide.

[0054] The present invention also provides a method for preparing the above-mentioned sensor, such as... Figure 3 As shown in a-3g, it includes:

[0055] With the y-axis of the aircraft side perpendicular to the substrate 110 as the axis of symmetry, a plurality of photodiodes 111 are formed in a uniformly arranged ring shape within the substrate 110;

[0056] A groove 135, forming an annular cavity 135h, is formed on the top surface of the substrate 110. The groove 135 is perpendicular to the annular ring formed by multiple photodiodes 111. A rollable microgravity ball 148 is attached to the bottom surface of the capping sheet 140 using an adhesive 143. The bottom surface of the capping sheet 140 is then bonded to the top surface of the substrate 110, allowing the rollable microgravity ball 148 to be placed inside the groove 135 of the annular cavity 135h. Alternatively...

[0057] A rollable microgravity ball 148 is adhered to the top surface of the substrate 110 via an adhesive 143 and aligned perpendicularly with a photodiode 111. A groove 135 of an annular cavity 135h is formed on the bottom surface of the cover plate 140. The bottom surface of the cover plate 140 is bonded to the top surface of the substrate 110, so that the rollable microgravity ball 148 is placed in the groove 135 of the annular cavity 135h.

[0058] Remove the adhesive 143 and release the rollable microgravity ball 148 to roll freely within the annular cavity 135h;

[0059] A circular signal light guide 145 is formed on the top surface of the capping sheet 140 and is perpendicular to the circular cavity 135h.

[0060] According to the present invention, it further includes:

[0061] An interconnect layer 120 is formed between the substrate 110 and the annular cavity 135h;

[0062] Metal interconnects and light-emitting metal blocking sheets 128 required for the readout circuit are formed within the interconnect layer 120;

[0063] A ring-shaped light channel is formed in the light radiation blocking metal sheet 128, thereby irradiating the ring signal light 11 that passes through the ring cavity 135h onto multiple photodiodes 111, and selectively blocking the area outside the photodiodes 111 from entering the light radiation.

[0064] Multiple semiconductor transistors 112 are formed on the substrate 110, and each semiconductor transistor 112 is electrically connected to a photodiode 111.

[0065] According to the present invention, it further includes:

[0066] A signal light source introducer 150 is formed on the signal light guide 145;

[0067] A solid light source 160, a reflective beam-splitting cone 161, a circular light guide 162, and an annular reflector 163 are formed in the signal light source introducer 150.

[0068] The light source 10 emitted by the solid-state light source 160 is sequentially split, waveguided, and reflected to form a ring signal light 11, which is then guided to the signal light guide 145 and projected downward.

[0069] At least one adhesive release hole 149 is formed through the outer wall of the capping sheet 140, the substrate 110, or the annular cavity 135h, so that the annular cavity 135h communicates with the outside.

[0070] After removing the adhesive 143 from the preparation process using the adhesive release hole 149, a gas phase and / or a liquid phase lubricant is introduced into the annular cavity 135h.

[0071] After the sensor is fabricated, the adhesive release hole 149 is sealed with a medium.

[0072] According to the present invention, the adhesive release hole 149 is sealed by physical or chemical vapor deposition;

[0073] Adhesive 143 is a photoresist containing an adhesive;

[0074] The method for removing the adhesive 143 during the preparation process includes: introducing a chemical reaction gas into the adhesive release hole 149 to react with the adhesive 143, and then drawing out the reaction gas through the adhesive release hole 149;

[0075] Chemical reaction gases contain ionized oxygen.

[0076] This invention also provides an application of the above-mentioned sensor in an aircraft, such as... Figure 1 As shown, it includes:

[0077] The sensor includes a first sensor 100 and a second sensor 200;

[0078] The first sensor 100 is set parallel to and fixed in a first plane formed by the longitudinal x-axis and normal z-axis of the aircraft. The sensor includes a rollable microgravity ball 148 disposed in its own annular cavity 135h.

[0079] The second sensor 200 is set parallel to and fixed in the second plane formed by the normal z-axis and the lateral y-axis of the aircraft. The sensor includes a rollable microgravity ball 248 disposed in its own annular cavity 235h.

[0080] The first plane and the second plane remain perpendicular to each other;

[0081] During flight, the aircraft's pitch angle 91 and roll angle 92 are sensed by two sensors.

[0082] In this invention, by fixing two mutually perpendicular horizontal photoelectric sensors to the axial plane (the plane formed by the longitudinal axis and the normal axis) and the lateral plane (the plane formed by the lateral axis and the normal axis) of the aircraft respectively, the pitch angle and roll angle of the aircraft can be accurately obtained by sensing the balance point, i.e., the angular position, of the two rollable microgravity balls in the two mutually perpendicular horizontal photoelectric sensors under the action of gravity.

[0083] The present invention will now be described in more detail through specific embodiments. Example

[0084] This embodiment provides a semiconductor photoelectric level sensor, its fabrication method, and its application. Figure 1 'a' represents the aerial attitude of a near-Earth (Earth) aircraft and its calibrated coordinates (longitudinal x-axis, lateral y-axis, and normal z-axis) relative to the heading X-axis, horizontal lateral Y-axis, and gravity direction Z-axis fixed to the Earth. In this embodiment, only the pitch and roll attitudes of the aircraft are considered. It is assumed that the longitudinal x-axis lies in the fixed plane formed by the X-axis and Z-axis, and the angle between the x-axis and Z-axis is the pitch angle 91°; the angle between the y-axis and the Y-axis is the roll angle 92°.

[0085] Figure 1 Figure b shows two photoelectric horizontal sensors in a vertical configuration, which are perpendicular to the lateral y-axis and longitudinal x-axis of the aircraft (aircraft), respectively. By setting the balance angle of the first rollable microgravity ball 148 and the second rollable microgravity ball 248 in the first annular cavity 135h symmetrical to the y-axis and the second annular cavity 235h symmetrical to the x-axis in the dry sheet sensor, the pitch angle and roll angle 91 and 92 of the pair of mutually perpendicular and fixed on the aircraft are determined by photoelectric sensing.

[0086] Figure 2 for Figure 1 A detailed cross-sectional view of the semiconductor photoelectric level sensor along section A'-A'. This semiconductor photoelectric level sensor is sheet-like, perpendicular to the y-axis, which corresponds to the lateral axis of the aircraft. It is composed of four sheet-like layered structures: a base layer A1, a cavity layer A2, a capping layer A3, and a signal light introduction layer A4, stacked and connected vertically. The base layer A1 is the bottommost layer, namely the semiconductor substrate 110, including a series of photodiodes 111 and connected semiconductor transistors 112. These are arranged according to the angular positioning rules corresponding to each pair of photodiodes 111 and semiconductor transistors 112 on a ring symmetrical about the y-axis (as opposed to the previous layer). Corresponding to the annular cavity 135h within the layer; in addition to the interconnect layer 120 for forming the metal interconnects required for the readout circuit, the base layer A1 also contains (at the top of the base layer A1) a light radiation blocking metal sheet 128, preferably patterned PVD aluminum, to block the substrate 110 from irradiating the photodiode 111 and thus affecting the readout circuit; of course, the substrate 110 is preferably a silicon semiconductor, and the photodiode 111 is more effective in absorbing and sensing wavelengths in the visible and near-infrared range, i.e., 0.4 to 1.0 microns. Solid-state LEDs in this band are small in size, low in cost, and have good reliability, which is the preferred feature of this invention;

[0087] The cavity layer A2 above the base layer A1 is a cavity layer of annular cavity 135h, which is surrounded by a lateral surrounding sheet 130, preferably a silicon wafer. To increase the wear resistance of the bottom and sides of the cavity, the sides and bottom can be constructed with a medium that is more wear-resistant than silicon, such as silicon nitride or silicon carbide (both are materials commonly used in silicon-based CMOS back-end processes, and the bottom is ensured to have a certain degree of light transmittance (such as light radiation of 0.4 to 1.0 micrometers). Of course, the other most important component in this layer is a rollable microgravity ball 148 that can roll freely under the action of gravity in the annular cavity 135h. Preferably, the rollable microgravity ball 148 is made of a medium and / or metal with a relatively high specific gravity and preferably opaque or low light transmittance, such as tungsten, aluminum, titanium, gold, mercury, silver and Al2O3. It can be selected as a metal gold solder ball commonly used in ball grid array (BGA) chip packaging, with a diameter between 20 and 200 micrometers.

[0088] Layer A3 is a capping layer. The main body is preferably composed of a silicon-based capping sheet 140. The main component contained in the sheet is a signal light guide 145 that passes vertically through the sheet, is positioned directly above the annular cavity 135h, and is vertically aligned with the photodiode 111 on the substrate 110 of the lower layer A1. The external signal beam is guided into the annular cavity 135h and directed towards the corresponding photodiode 111 below. If the rollable microgravity ball 148 is located between the paired signal light guide 145 and the photodiode 111, the light received by the photodiode 111 is blocked or disturbed, thereby determining the angular position of the rollable microgravity ball 148 under the action of gravity.

[0089] Layer A4 is a signal light introduction layer, consisting of a signal light source introducer 150, an LED solid-state light source 160 located laterally at the y-axis center, a reflective beam-splitting cone 161, a circular light guide 162, and an annular reflector 163. The solid-state light source 160 emits light 10, which, after beam splitting, waveguide, and reflection, forms an annular signal light 11, which is then guided to the signal light guide 145 and projected downwards. It is worth noting that in a simple signal light guide structure, the signal light guide 145 is a continuous ring structure placed on an annular cavity 135h. Therefore, the entire annular cavity 135h receives signal light or active illumination light from above (top surface). Specifically, the location where the rolling microgravity ball 148 achieves gravitational balance is the location where the photodiode 111 can sense disturbances (such as weakened) light signals.

[0090] Figure 3 The main process of fabricating a~3g silicon-based photoelectric horizontal sensor;

[0091] Figure 3a shows the basic shape of the base layer A1, which can be completed using a more common MOS back-end (MOSBEOL) process;

[0092] Figure 3 b shows the configuration of the cavity layer A2 placed on the base layer A1, which can be obtained sequentially through SiO2-SiO2 bonding (forming the first bonding layer 129), silicon wafer thinning, and deep etching;

[0093] Figure 3 c forms an anti-wear passivation film (Si3N4) on the bottom and sidewalls of the annular cavity for 135h, and exposes SiO2 on the surface by chemical mechanical polishing (CMP) so as to form OX-OX bonds with the capping layer A3;

[0094] Figure 3 d shows the preparatory state before the capping layer A3 and the cavity layer A2 are bonded with SiO2-SiO2 (bonded through the second bonding layer 139 and the third bonding layer 142) to form an annular cavity 135h. The most critical feature is that the adhesive 143 is a photoresist with adhesive properties (surface and object). It is formed into a circle by photolithography patterning so that a pre-made rollable microgravity ball 148 can be adhered to the center of the circle (adhesive) and temporarily fixed by a die-attach machine. Before the rollable microgravity ball 148 is adhered, the following process is completed: a wear-resistant and etch-resistant silicon termination layer (forming signal light guide 145) Si3N4 is first formed on the bottom surface of the capping sheet 140 by chemical vapor deposition (CVD), and then a sheet-like SiO2 is formed.

[0095] Figure 3 e is the general Figure 3 The assembly shown in d, which is a capping layer A3 with a rollable microgravity ball 148 bonded to a base layer A1 and a cavity layer A2, is an assembly with an OX-OX (SiO2-SiO2) bonding structure. At this time, the annular cavity 135h is closed for the first time.

[0096] Figure 3The diagram illustrates three important process steps and the formation of key components. After OX-OX bonding, the top of the capping layer A3 is first thinned, then the silicon wafer is etched above the annular cavity 135h, terminating at the Si3N4 passivation layer 141. Subsequently, the signal light guide 145 is filled with SiO2 (a transparent waveguide material) via chemical vapor deposition (CVD). The second step involves deep etching through the capping wafer and the Si3N4 passivation layer 141 to form at least one adhesive release hole 149 communicating with the annular cavity 135h. The third step involves introducing gaseous and / or liquid reactants that can react with and remove the adhesive 143 through the adhesive release hole 149 communicating with the annular cavity 135h. Once the adhesive 143 is removed, a micro-roller can be used. The gravity ball 148 is thus detached from its adhesion to the top surface of the cavity and can roll freely under the influence of gravity. It is important to note that the photoresist commonly used in the industry can be supplemented with an appropriate amount of high adhesion additive hexamethylsilylamine, and the photoresist can be "burned" away by ionized oxygen. Afterwards, in order to reduce the rolling resistance of the rollable microgravity ball 148, a gas phase or / and liquid phase lubricant can be introduced through the adhesive release hole 149. The final step is to seal the adhesive release hole 149, which can be done by applying adhesive to the solids ratio, or by physical or chemical vapor deposition, especially the SiO2 chemical vapor deposition method in the back end of CMOS. Moreover, the "misalignment" on the layout can avoid the cavity of the annular cavity 135h, and at the same time, SiO2 is deposited by CVD / PVD to seal the release hole.

[0097] Figure 3 g shows the state diagram of bonding the pre-fabricated signal light introduction layer A4 to the main chip. The optical component, signal light introduction layer A4, can be made using micromechanical / optical processing. The bonding with the main chip can be achieved using die-to-wafer bonding (through the first layer bonding 151 bonding) equipment and process, as long as a certain degree of alignment is ensured.

[0098] The semiconductor photoelectric level sensor proposed in the embodiments of the present invention uses the lowest point of a circular cavity in which a rollable microgravity ball can roll freely under the action of gravity. At the same time, by vertically guiding the actively irradiated circular signal light into the circular cavity, multiple photodiodes accurately sense the precise angular position of the rollable microgravity ball. This achieves miniaturization, lightweighting, low cost, and low energy consumption of the sensing device, and enables higher precision pitch and roll level measurement with smaller size, weight, and energy consumption.

[0099] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A semiconductor photoelectric level sensor, characterized in that, The sensor is a sheet-like body, comprising: The substrate (110) includes a plurality of photodiodes (111), which are evenly distributed on a circular ring that is symmetrical about the y-axis of the aircraft side, which is perpendicular to the substrate (110). An annular cavity (135h) is located on the substrate (110), with the lateral y-axis of the aircraft as the axis of symmetry, and is perpendicular to the annular circle formed by the plurality of photoelectric sensing diodes (111). A first rollable microgravity ball (148) is disposed inside the annular cavity (135h). The signal light guide (145) is located on the annular cavity (135h), is in the shape of a ring, and is perpendicular to the annular cavity (135h), and is used to guide the actively irradiated annular signal light (11) vertically into the annular cavity (135h).

2. The sensor according to claim 1, characterized in that, Also includes: An interconnect layer (120) is disposed between the substrate (110) and the annular cavity (135h). The internal structure contains metal interconnects required for the readout circuit and a light radiation blocking sheet (128). The light radiation blocking sheet (128) is provided with an annular light channel. The annular light channel is used to irradiate the annular signal light (11) passing through the annular cavity (135h) onto the plurality of photodiodes (111). The light radiation blocking sheet (128) outside the annular light channel is used to selectively block light radiation from entering the area outside the photodiodes (111). The substrate (110) also includes a plurality of semiconductor transistors (112), each of the semiconductor transistors (112) being electrically connected to one of the photodiodes (111).

3. The sensor according to claim 2, characterized in that, The annular cavity (135h) is surrounded laterally and centrally by a first lateral surrounding sheet (130); The signal light guide (145) is surrounded by a cover plate (140) on its sides and center.

4. The sensor according to claim 3, characterized in that, Also includes: A signal light source introducer (150) is disposed on the signal light guide (145) and includes a solid light source (160), a reflective beam splitter cone (161), a circular light guide (162), and an annular reflector (163). The solid light source (160) emits light source light (10), which is sequentially split, waveguided, and reflected to form the annular signal light (11) and then guided to the signal light guide (145) and projected downward. At least one adhesive release hole (149) penetrates the outer wall of the capping sheet (140) or the substrate (110) or the annular cavity (135h) and communicates with the annular cavity (135h), for releasing the adhesive (143) during the preparation process and introducing gaseous and / or liquid lubricant into the annular cavity (135h), and is sealed by the medium after the sensor is prepared.

5. The sensor according to claim 4, characterized in that, The first rollable microgravity ball (148) perturbs the annular signal light (11) introduced from above, and has a diameter of 1 to 1000 micrometers; The disturbance includes at least one of reflection, refraction, absorption, and diffraction; The wavelength of the ring signal light (11) is 0.4 to 1.0 micrometers; The substrate (110) is made of a semiconductor containing silicon, gallium arsenide, germanium or an alloy thereof; The first rollable microgravity ball (148) is made of at least one of tungsten, aluminum, titanium, gold, mercury and silver. The surface of the annular cavity (135h) is covered with a wear-resistant passivation film, the composition of which includes silicon nitride and / or silicon carbide.

6. A method for manufacturing a sensor according to any one of claims 1-5, characterized in that, include: With the y-axis of the aircraft side perpendicular to the substrate (110) as the axis of axial symmetry, a plurality of photodiodes (111) are formed in a uniformly arranged ring shape within the substrate (110); A groove (135) forming an annular cavity (135h) is formed on the top surface of the substrate (110). The groove (135) is perpendicular to the annular ring formed by the arrangement of multiple photodiodes (111). A first rollable microgravity ball (148) is attached to the bottom surface of the capping sheet (140) using an adhesive (143). The bottom surface of the capping sheet (140) is then bonded to the top surface of the substrate (110), so that the first rollable microgravity ball (148) is placed inside the groove (135) of the annular cavity (135h). Alternatively, The first rollable microgravity ball (148) is adhered to the top surface of the substrate (110) by an adhesive (143) and perpendicularly aligned with a photodiode (111). A groove (135) of the annular cavity (135h) is formed on the bottom surface of the cover plate (140). The bottom surface of the cover plate (140) is bonded to the top surface of the substrate (110) so that the first rollable microgravity ball (148) is placed in the groove (135) of the annular cavity (135h). Remove the adhesive (143) and release the first rollable microgravity ball (148) to roll freely within the annular cavity (135h); A signal light guide (145) is formed on the top surface of the cover plate (140) in a circular shape and perpendicular to the circular cavity (135h).

7. The preparation method according to claim 6, characterized in that, Also includes: An interconnect layer (120) is formed between the substrate (110) and the annular cavity (135h); Metal interconnects and light-emitting metal blocking sheets (128) required for the readout circuit are formed within the interconnect layer (120); An annular light channel is formed in the light radiation blocking metal sheet (128), thereby irradiating the annular signal light (11) passing through the annular cavity (135h) onto the plurality of photodiodes (111), and selectively blocking the area outside the photodiodes (111) from entering the light radiation. A plurality of semiconductor transistors (112) are formed on the substrate (110), such that each semiconductor transistor (112) is electrically connected to one of the photodiodes (111).

8. The preparation method according to claim 6, characterized in that, Also includes: A signal light source introducer (150) is formed on the signal light guide (145); A solid-state light source (160), a reflective beam-splitting cone (161), a circular light guide (162), and an annular reflector (163) are formed in the signal light source introducer (150); The light emitted by the solid-state light source (160) is split, waveguided, and reflected in sequence to form the ring signal light (11), which is then guided to the signal light guide (145) and projected downwards. At least one adhesive release hole (149) is formed through the outer wall of the capping sheet (140), the substrate (110), or the annular cavity (135h) to communicate with the outside. After removing the adhesive (143) from the preparation process using the adhesive release hole (149), a gaseous and / or liquid lubricant is introduced into the annular cavity (135h); After the sensor is fabricated, the adhesive release hole (149) is sealed with a medium.

9. The preparation method according to claim 8, characterized in that, The adhesive release pore (149) is sealed by physical or chemical vapor deposition; The adhesive (143) is a photoresist containing an adhesive; The method for removing the adhesive (143) during the preparation process includes: introducing a chemical reaction gas into the adhesive release hole (149) to react chemically with the adhesive (143), and then drawing out the reaction gas through the adhesive release hole (149); The chemical reaction gas contains ionized oxygen.

10. The application of the sensor according to any one of claims 1-5 in an aircraft, characterized in that, include: The sensor includes a first sensor (100) and a second sensor (200). The first sensor (100) is arranged in parallel and fixed in a first plane formed by the longitudinal x-axis and normal z-axis of the aircraft. The sensor includes a first rollable microgravity ball (148) disposed in its own annular cavity (135h). The second sensor (200) is arranged in parallel and fixed in a second plane formed by the normal z-axis and the lateral y-axis of the aircraft. The sensor includes a second rollable microgravity ball (248) disposed in its own annular cavity (235h). The first plane and the second plane remain perpendicular to each other; During the flight of the aircraft, the pitch angle (91) and roll angle (92) of the aircraft are sensed by two sensors.

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