CN111521203B - Photon sensitive sensing chip - Google Patents

Abstract

The invention discloses a photon sensitive sensing chip, which comprises a mechanical response structure, which is used for responding to external mechanical signal changes and generating corresponding morphological changes according to the external mechanical signal changes; The morphological change of the photon correspondingly changes the physical quantity of the photon; the mechanically responsive structure and the photon-sensitive structure are interconnected; the mechanically-responsive structure and the photon-sensitive structure are fabricated on the same silicon-based material through a chip processing process. By arranging the mechanical response structure and the photon sensitive structure on the same silicon-based material, the photon physical quantity can be changed accordingly in response to the change of the external mechanical signal, so that the sensitivity to the outside world can be improved, and the sensor chip formed according to the technical solution of the present application has a simple structure. , which is convenient for applications in many fields.

Description

A photon sensitive sensor chip

technical field

The invention relates to the technical field of chips, in particular to a photon sensitive sensor chip.

Background technique

Sensors are key core components in many scientific and technological fields such as artificial intelligence, Internet of Things, intelligent driving, biomedicine, and national defense technology. High sensing sensitivity and comprehensive sensing types are two basic requirements for sensors. Although there are many kinds of sensors, chip-integrated sensors have quickly replaced traditional sensors with their advantages of small size, low cost, good performance, and low power consumption.

Today, in the chip-integrated sensor, the development of nearly mature electronic sensor chip solutions dominates. Although electronic sensor chips have been widely used in consumer electronics, industrial sensing and other fields, due to the limitations of the physical characteristics of electronics, it has encountered an insurmountable bottleneck in the realization of ultra-sensitive and comprehensive sensor chips. As a result, people's needs for higher-end sensor chips in the next-generation information technology fields such as artificial intelligence and the Internet of Things cannot be met.

For example, vibration sensors are a very important type of basic sensor. However, due to the limitation of electronic physical effects, the current vibration sensors on the market cannot be implemented by means of chip integration, which seriously affects industries such as artificial intelligence and the Internet of Things. development of.

For another example, the accuracy of the angle sensor is very important for application scenarios such as intelligent driving and inertial navigation. Although the current electronic gyroscope chip has replaced the traditional solid-state gyroscope, the accuracy of the electronic gyroscope chip still cannot meet the actual requirements. This is due to two reasons: one is that the physical effect of the gyroscope is quite weak, and even the use of expensive ultra-sensitive electronic signal amplification circuits cannot overcome the bottleneck of its physical performance; Converted into an angle signal, which inevitably leads to errors caused by static operating point drift that cannot be overcome in principle.

In order to break through the sensitivity bottleneck of electronic sensors, people have tried a variety of other technical solutions, typically optical fiber sensors and photoelectric sensors.

The optical fiber sensor uses the optical fiber refractive index to be sensitive to external signals to improve the sensitivity. For example, the accuracy of the fiber optic gyroscope may be more than ten times higher than that of the electronic sensor chip, but it requires a very long fiber length to achieve, so it is impossible to achieve miniaturization and low cost.

Although the increasing number of photoelectric sensor chips make use of the sensitivity of optical signals, they all directly convert optical signals into electrical signals through photodetectors, and the optical signals are not amplified mechanically. The chip is not sensitive to other external signals, which limits the application field of the photoelectric sensor.

SUMMARY OF THE INVENTION

In order to solve one or more of the above problems, the present application proposes a photon sensitive sensor chip.

According to one aspect of the present application, a photon-sensitive sensor chip is provided, which includes a mechanical response structure for responding to changes in external mechanical signals and generating corresponding morphological changes according to changes in external mechanical signals; The morphological change in the mechanically responsive structure correspondingly changes the physical quantity of photons; the mechanically responsive structure and the photon-sensitive structure are connected to each other; the mechanically-responsive structure and the photon-sensitive structure are fabricated on the same silicon substrate through a chip processing process on the material. The beneficial effect is that the mechanical response structure and the photon sensitive structure are arranged on the same silicon-based material, and the morphological change of the mechanical response structure and the photon physical quantity of the photon sensitive structure are connected between the two through a specific sensing mechanism. The changes of the sensors establish a necessary physical connection with each other, and the photon physical quantity can be changed correspondingly in response to the changes of the external mechanical signals, which can improve the sensitivity to the outside world. applications in many fields.

In certain embodiments, the physical link between the morphological change of the mechanically responsive structure and the photon physical quantity change of the photon-sensitive structure is through a specific sensing mechanism. The beneficial effect is that the response sensitivity to external mechanical signals is enhanced through the amplification effect of the photon-sensitive structure.

In certain embodiments, a specific sensing mechanism includes a change in the angle of the mechanically responsive structure resulting in a change in the photon reflection angle of the photon-sensitive structure, or a change in the lateral or longitudinal periodic displacement of the mechanically responsive structure such that the The photon diffraction angle of the photon sensitive structure is changed, or the change of the anisotropic refractive index of the mechanically responsive structure causes the photon polarization state of the photon sensitive structure to be changed. The beneficial effect is that the connection between the photon-sensitive structure and the mechanically responsive structure is established through physical laws.

In certain embodiments, chip fabrication processes include: photolithography, etching, ion implantation or doping, wafer bonding processes, sputtering or deposition processes.

In certain embodiments, the silicon-based material includes a second silicon-based material, the photon-sensitive structure is formed on one side of the mechanically responsive structure, and both the mechanically-responsive structure and the photon-sensitive structure are formed on the second silicon base material. The beneficial effect is that the mechanically responsive structure and the photon-sensitive structure are integrated on the same chip in the form of a silicon-based chip, thereby achieving high performance, miniaturization and low cost.

In certain embodiments, the mechanically responsive structure includes a rotating proof-mass and a cantilever beam structure connected to the rotating proof-mass. The beneficial effect is that the external mechanical signal is transmitted to the rotating mass through the cantilever beam structure, and the external rotation angle signal is converted into the difference between the relative angles between the rotating mass and the silicon-based material. .

In some embodiments, the photon-sensitive structure is a first reflective surface, the first reflective surface is formed on one side surface of the rotating mass, and the reflectivity of the first reflective mirror surface is ≥95%. The beneficial effect is that the relative angle difference generated by the rotating mass is converted into the angle change of the photon signal.

In some embodiments, a transmission window is further formed on the second silicon-based material, and the transmission window is used for input and output of photons. The beneficial effect is that the photon signal input from the outside is connected with the photon-sensitive structure, and the photons reflected from the photon-sensitive structure are outputted to the outside.

In some embodiments, it further includes a first silicon-based material coupled with the second silicon-based material, and the (111) crystal plane of the first silicon-based material with a crystal plane direction of (110) forms an inclination angle The inclined surface is about 54.5°, a second reflecting mirror surface is formed on the inclined surface, and the reflectivity of the second reflecting mirror surface is ≥95%. The beneficial effects are: changing the photon angle direction to facilitate the input and output of the photon signal.

In some embodiments, the first mirror surface, the second mirror surface, and the transmission window together form an input or output path for photons.

The beneficial effects of the present invention are: by arranging the mechanically responsive structure and the photon-sensitive structure on the same silicon-based material, and through a specific sensing mechanism between the two, the morphological changes of the mechanically-responsive structure and the photon-sensitive structure are combined. The change of the photon physical quantity establishes an inevitable physical relationship with each other, and the photon physical quantity is correspondingly changed in response to the change of the external mechanical signal, which can improve the sensitivity to the outside world. At the same time, the sensor chip formed according to the technical solution of the present application has a high integration degree and a simple structure. , which is convenient for applications in many fields. In addition, the silicon-based material is selected as the base material, which is rich in raw materials, which can effectively reduce the cost and facilitate the expansion of the application.

Description of drawings

FIG. 1 is a schematic block diagram of the structure of a photon sensitive sensor chip of the present invention.

FIG. 2 is a schematic diagram of the specific structure of the photon sensitive sensor chip of the present invention.

In the figure, the first silicon-based material 1; the second silicon-based material 2; the cantilever beam structure 3; the rotating mass 4; the first reflecting mirror surface 5; the second reflecting mirror surface 6; the transmission window 7; the silicon-based material 10; mechanical response Structure 20; Photon-sensitive structure 30.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

Figures 1-2 schematically show a photon-sensitive sensing chip of the present invention.

As shown in FIG. 1 , a photon-sensitive sensor chip includes a mechanical response structure 20 for responding to changes in external mechanical signals and generating corresponding morphological changes according to changes in external mechanical signals. The photon-sensitive structure 30 is used to correspondingly change the photon physical quantity according to the morphological change in the mechanically responsive structure 20 . The mechanically responsive structure 20 and the photon-sensitive structure 30 are interconnected. The mechanically responsive structure 20 and the photon-sensitive structure 30 are fabricated on the same silicon-based material through a chip processing process.

In some embodiments, the physical connection between the mechanically responsive structure 20 and the photon physical quantity change of the photon sensitive structure 30 is through a specific sensing mechanism. That is, the morphological change of the mechanically responsive structure 20 and the change of the photon physical quantity of the photon-sensitive structure 30 are mutually established through a specific sensing mechanism between the mechanically responsive structure 20 and the photon-sensitive structure 30. physical connection. Among them, the morphological changes can be angular changes, and the photon physical quantities are intensity, phase, frequency and polarization. Thus, the response sensitivity to external mechanical signals is enhanced through the amplification effect of the photon-sensitive structure.

A specific sensing mechanism includes that the angle change of the mechanically responsive structure 20 changes the photon reflection angle of the photon sensitive structure 30 , that is, the photon reflection angle of the photon sensitive structure 30 is changed by rotating the mirror structure. Or the change of the lateral or longitudinal periodic displacement of the mechanical response structure 20 causes the photon diffraction angle of the photon sensitive structure 30 to change, that is, the photon diffraction angle of the photon sensitive structure 30 caused by the change of the grating constant of the reflection or transmission grating structure. changes happened. Or the change of the anisotropic refractive index of the mechanically responsive structure 20 causes the photon polarization state of the photon sensitive structure 30 to change, that is, the photon sensitive structure 30 changes the photon polarization state in the way of the phase change of the dual-arm interferometer structure.

In certain embodiments, chip fabrication processes include: photolithography, etching, ion implantation or doping, wafer bonding processes, sputtering or deposition processes.

In some embodiments, the silicon-based material includes a second silicon-based material 2, the photon-sensitive structure 30 is formed on one side of the mechanically responsive structure 20, and both the mechanically-responsive structure 20 and the photon-sensitive structure 30 are formed on the second silicon-based material 2 . Thus, the mechanically responsive structure and the photon-sensitive structure are integrated on the same chip in the form of a silicon-based chip, thereby achieving high performance, miniaturization, and low cost.

In some embodiments, the mechanically responsive structure includes a rotating proof mass 4 and a cantilever beam structure 3 connected to the rotating proof mass 4 . Therefore, the external mechanical signal is transmitted to the rotating mass through the cantilever beam structure, and the external rotation angle signal is converted into the difference between the relative angles between the rotating mass and the silicon-based material.

In some embodiments, the photon sensitive structure 30 is a first reflecting mirror surface 5 formed on one side of the rotating mass 4 , and the reflectivity of the first reflecting mirror surface 5 is ≥95%. Thereby, the relative angular difference produced by the rotating proof mass is converted into an angular change of the photon signal.

In some embodiments, a transmission window 7 is also formed on the second silicon-based material 2, and the transmission window 7 is used for input and output of photons. Thus, the photon signal input from the outside is connected with the photon-sensitive structure, and the photons reflected from the photon-sensitive structure are outputted to the outside.

In some embodiments, a first silicon-based material 1 coupled to the second silicon-based material 2 is further included, and the crystal plane of the first silicon-based material 1 is formed on a (111) crystal direction with a crystal plane direction of (110). An inclined surface with an inclination angle of about 54.5°, a second reflecting mirror surface 6 is formed on the inclined surface, and the reflectivity of the second reflecting mirror surface 6 is greater than or equal to 95%. Thus, the angular direction of the photon is changed to facilitate the input and output of the photon signal.

In some embodiments, the first reflecting mirror surface 5, the second reflecting mirror surface 6 and the transmission window 7 together form an input or output path for photons.

For example, the photonic sensor chip shown in Figure 2, the specific way to realize its structure is as follows:

The first silicon-based material 1, marked as W1 in FIG. 2, forms a tilt angle of about 54.5° on the (111) crystal direction with the crystal plane direction (110) through photolithography and anisotropic wet etching processes. The inclined surface is then formed into a second reflective mirror surface 6 with a thickness of about 0.8 microns through a sputtering or deposition process, and the reflectivity of the second reflective mirror surface 6 is above 95%.

The second silicon-based material 2, marked as W2 in FIG. 2, is formed on the second silicon-based material 2 through a deep dry etching process to form a rotating mass 4 structure and an elongated cantilever beam structure 3 in the middle, wherein the rotating mass The size of the cantilever beam is 100 microns x 100 microns x 300 microns, the size of the cantilever beam is 50 microns x 5 microns x 5 microns, and then a first mirror surface 5 is formed on one side of the rotating mass 4 by sputtering or deposition process. , the reflectivity of the first reflecting mirror surface 5 is above 95%.

Next, the two pieces of the first silicon-based material 1 and the second silicon-based material 2 , ie, silicon-based wafers (W1 and W2), are aligned and bonded together through a wafer bonding process to form an integral chip.

Finally, a 10-micron transmission window 7 is formed by deep dry etching on the second silicon-based material 2 above, and a micro-convex lens is placed on this transmission window 7. The placement of the convex lens can be done by artificial patching. process or with another glass wafer made of a convex lens array wafer bonded to each other.

The working principle of the photonic sensor chip is as follows: when the external device fixed with the first silicon-based material 1 of the photonic sensor chip rotates, the first silicon-based material 1 will immediately rotate accordingly. The mass 4 has rotational inertia under the support of the cantilever beam structure 3, so that a relative rotation angle is formed between the rotating mass 4 and the first silicon-based material 1. Since the first reflecting mirror surface 5 on the side of the rotating mass 4 and the rotating mass The block 4 is fixedly connected, so the first reflecting mirror surface 5 on the side of the rotating mass 4 will also generate a relative rotation angle, and the resulting relative rotation angle will pass through the fixed inclined second reflecting mirror surface 6 on the first silicon-based material 1 again. After reflection, it is transformed into a very sensitive spatial position change between the input photon and the output photon on the other side of the convex lens. This sensitive spatial position change can easily pass through the back-end, general-purpose displacement-sensitive photodetector (Position Sensing Detector, PSD) detected. According to the change of the photocurrent detected by the displacement sensitive photodetector (PSD), the relatively small angle change between the first silicon-based material 1 and the rotating mass 4 can be accurately inverted, thereby realizing a sensitive small angle sensor chip.

Through the photon angle sensor chip, the accuracy of the deflection angle of 0.2 degrees can be achieved when the light intensity changes by 20dB. Since the accuracy of the photodetector can reach 0.1dB, the entire chip can realize the measurement of the change angle of one thousandth of a degree. . Its angular sensitivity is much higher than current electronic gyroscope chips, and even rivals the precision of bulky and expensive fiber-optic gyroscope devices.

The beneficial effect of the present invention is: by setting the mechanically responsive structure and the photon-sensitive structure 30 on the same silicon-based material, and through a specific sensing mechanism between the two, the morphological change of the mechanically-responsive structure 20 and the photon-sensitive structure are connected The change of the photon physical quantity of the structure 30 establishes a necessary physical relationship with each other, and by correspondingly changing the photon physical quantity in response to the change of the external mechanical signal, the sensitivity to the outside world can be improved, and the sensor chip formed according to the technical solution of the present application has a simple structure, It is convenient for application in many fields.

The foregoing are merely some of the embodiments of the present invention. For those of ordinary skill in the art, without departing from the inventive concept of the present invention, several modifications and improvements can be made, which all belong to the protection scope of the present invention.

Claims (3)

1. a photon sensitive sensor chip, is characterized in that, comprises The mechanical response structure (20) is used to respond to changes of external mechanical signals and to generate corresponding morphological changes according to changes of external mechanical signals; a photon-sensitive structure (30) for correspondingly changing the photon physical quantity according to the morphological change in the mechanically responsive structure (20); A physical connection is made between the morphological change of the mechanically responsive structure (20) and the photon physical quantity change of the photon-sensitive structure (30) through a specific sensing mechanism; The mechanically responsive structure (20) and the photon-sensitive structure (30) are fabricated on the same silicon-based material (10) through a chip processing process, the silicon-based material includes a second silicon-based material (2), and the A photon-sensitive structure (30) is formed on one side of the mechanically responsive structure (20), and both the mechanically-responsive structure (20) and the photon-sensitive structure (30) are formed on the second silicon-based material (2); The mechanically responsive structure (20) comprises a rotating mass (4) and a cantilever beam structure (3) connected with the rotating mass (4); The photon sensitive structure (30) includes a first reflecting mirror surface (5), the first reflecting mirror surface (5) is formed on one side of the rotating mass (4), and the first reflecting mirror surface (5) is Reflectivity≥95%; A transmission window (7) is also formed on the second silicon-based material (2), and the transmission window (7) is used for input and output of photons; Also includes a first silicon-based material (1) connected to the second silicon-based material (2), the first silicon-based material (1) having a crystal plane direction of (110) forming a (111) crystal direction an inclined surface with an inclination angle of ^54.5 °, a second reflecting mirror surface (6) is formed on the inclined surface, and the reflectivity of the second reflecting mirror surface (6) is ≥95%; The specific sensing mechanism includes that the angle change of the mechanically responsive structure (20) causes the photon reflection angle of the photon-sensitive structure (30) to change, or the lateral or vertical period of the mechanically responsive structure (20) The change of the displacement makes the photon diffraction angle of the photon sensitive structure (30) change, or the change of the anisotropic refractive index of the mechanically responsive structure (20) makes the photon polarization state of the photon sensitive structure (30) changes happened. 2. The photon sensitive sensor chip according to claim 1, wherein the chip processing technology comprises: photolithography, etching, ion implantation or doping, wafer bonding technology, sputtering or deposition craft. 3. The photon sensitive sensor chip according to claim 1, wherein the first reflecting mirror surface (5), the second reflecting mirror surface (6) and the transmission window (7) together form an input or output path for photons .

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