CN106973351B - Micro feedback cavity sensor and manufacturing method thereof - Google Patents

Abstract

A miniature feedback cavity sensor includes: a semiconductor substrate having a sensing circuit; a bonding structure layer located on the semiconductor substrate; and a sensing element chip having a semiconductor body with a low resistance, a first end, and a second end, wherein a plurality of conductive pillars are formed in the semiconductor body, a sensing element structure is formed at the first end, and the second end is connected to the semiconductor substrate through the bonding structure layer, and a feedback cavity structure is formed between the sensing element structure, the semiconductor substrate, and the semiconductor body, and the sensing element structure is electrically connected to the sensing circuit through these conductive pillars. The sensing element structure and the feedback cavity structure jointly react to a physical signal input from the outside to generate a sensing signal output to the sensing circuit. A manufacturing method of a miniature feedback cavity sensor is also provided.

Description

Micro feedback cavity sensor and its manufacturing method

technical field

The present invention relates to a micro feedback cavity sensor and a manufacturing method thereof, and particularly relates to a micro feedback cavity sensor for acoustic waves and/or pressure and a manufacturing method thereof.

Background technique

Piezoelectric, Piezoresistive and Capacitive are the common micro-sensor technologies. Piezoelectric sensors use the characteristics of piezoelectric materials to output current or voltage after being disturbed by external forces, and convert input physical signals into electrical signals, while piezoresistive sensors use piezoresistive materials to change the resistance characteristics after being stressed. One of the most common sensing methods is capacitive, which has excellent characteristics such as easy manufacturing, high sensitivity and low power consumption, and is currently the mainstream of market development.

In particular, a sensor with a feedback cavity design, such as a micro pressure sensor and a micro microphone, such as a pressure sensor with a closed vacuum feedback cavity, produces structural deformation (piezoelectric, piezoresistive or capacitive) through the pressure difference with the outside world. physical quantity). Another example is a miniature microphone, which needs an acoustic feedback cavity to reflect the received acoustic signal. Therefore, for such a sensor with a feedback cavity design, an important sensor quality is the volume from the feedback cavity. For example, for a pressure sensor, the interior of the feedback cavity is designed to maintain a low pressure state (that is, close to high vacuum state), but there will still be some gas due to the outgassing effect of the wall of the feedback cavity after the manufacturing is completed, and the residual gas will affect the measurement due to the principle of thermal expansion and contraction. The known ideal gas equation is pV=nRT, where p is the pressure of the ideal gas, V is the volume of the ideal gas, n is the amount of gas substance, T is the thermodynamic temperature of the ideal gas, and R is the ideal gas constant. Therefore, if the volume of the feedback cavity is increased in design, which is equivalent to increasing V, a lower p can be obtained, so the thermal expansion and contraction caused by the temperature effect have a lower impact on the sensor.

Another example is miniature microphones, which are all completed using traditional packaging technology. FIG. 14 shows a schematic diagram of a package of a conventional miniature microphone. As shown in the figure, during the packaging process of the traditional miniature microphone, the microcomputer electrical sensing chip 520 and the signal processing chip 530 are firstly mounted on the packaging substrate 510 separately, and then the microcomputer electrical sensing chip 520 and the signal processing chip 520 are connected by wire bonding. The chip 530 is electrically connected, and then the cover 540 is covered to cover the microcomputer electrical sensing chip 520 and the signal processing chip 530 to form a cavity. In this packaging method, only chip-level packaging can be used, and wafer-level packaging cannot be used. When designing the package structure of the miniature microphone, the following important items must be carefully evaluated and considered. The first is the distance of the front chamber (Front Chamber), which refers to the spatial distance from the sound pressure entering the sound hole to the front of the sensor diaphragm (the traditional distance is the thickness of the substrate 510 plus the microcomputer electrical sensing chip 520, and its value is at least >300um ), too long front cavity distance will increase the sound resistance and affect the quality. Therefore, it is more appropriate that the distance of the anterior cavity should be smaller, and of course, the distance of the anterior cavity may also correspond to the volume of the anterior cavity.

Secondly, the volume of the back chamber relative to the volume of the front chamber refers to the volume of the closed space formed by the diaphragm and the inside of the package, that is, the volume of the sealed space after the sound passes through the MEMS diaphragm chip. The larger the back cavity is, the greater the sensitivity will be, because when the volume of the back cavity increases, the reaction force of the diaphragm from the air in the back cavity will be smaller, so that the sensing signal will not be distorted. Therefore, the larger the volume of the back cavity would be more appropriate. In addition, it should be noted that the space in the back cavity must be completely sealed (only remaining connected to the outside world through the diaphragm); if the back cavity is not properly sealed and communicated with the front cavity space, the frequency response curve will be in the Sensitivity reduction occurs in the low frequency range. In the known technology, a package lid is usually used to cover the MEMS chip to provide a huge back cavity. However, this packaging method is not suitable for chip integration, and the volume of the produced micro microphone is also low. It is quite bulky and cannot be mass-produced in wafer-level manufacturing.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a micro feedback cavity sensor and a manufacturing method thereof, which have the advantages of chip integration, and can be mass-produced in a wafer-level manufacturing manner, thereby reducing costs.

Another object of the present invention is to provide a micro feedback cavity sensor and a manufacturing method thereof. The micro feedback cavity sensor can be used as a microphone, and can provide a huge back cavity and a tiny front cavity to improve the sensing effect of the microphone.

Yet another object of the present invention is to provide a micro feedback cavity sensor and a manufacturing method thereof. The micro feedback cavity sensor can be used as a pressure sensor, and can provide a huge cavity volume and improve the sensing effect of the pressure sensor.

Yet another object of the present invention is to provide a micro feedback cavity sensor and a manufacturing method thereof. The micro feedback cavity sensor can provide the functions of a pressure sensor and a microphone.

To achieve the above object, the present invention adopts the following technical solutions:

The present invention provides a miniature feedback cavity sensor, comprising: a semiconductor substrate with a sensing circuit; a bonding structure layer on the semiconductor substrate; and a sensing element chip having a low-resistance semiconductor body, a A first end portion and a second end portion, a plurality of conductive pillars are formed in the semiconductor body, the first end portion is formed with at least one sensing element structure, and the second end portion is connected to the semiconductor through a bonding structure layer The substrate, at least one sensing element structure, a feedback cavity structure is formed between the semiconductor substrate and the semiconductor body, and the at least one sensing element structure is electrically connected to the sensing circuit through the conductive columns. At least one sensing element structure and the feedback cavity structure jointly respond to an externally input physical signal to generate a sensing signal and output it to the sensing circuit.

In the above-mentioned micro feedback cavity sensor, the sensing element chip may further include a first electrical I/O structure located around the feedback cavity structure, and the first electrical I/O structure has a plurality of first connection pads, It is electrically connected to the sensing circuit through the conductive pillars.

The above-mentioned micro sensor may further include: a circuit board disposed above the first electrical I/O structure and electrically connected to the first connection pads.

In the above-mentioned micro feedback cavity sensor, the first electrical I/O structure may have a conductor connection layer, and an upper surface of the conductor connection layer and an upper surface of the sensing element structure are located on the same plane.

The above-mentioned micro feedback cavity sensor may further comprise a shielding chip having a low-resistance semiconductor body, a first end and a second end, and the second end of the shielding chip is connected to the first end of the sensing element chip. One end, and an open working cavity formed by removing part of the semiconductor body that shields the chip to expose part or all of the sensing element structure, the sensing element structure senses the physical signal received through the open working cavity to generate sensing measurement signal.

In the above-mentioned micro feedback cavity sensor, the sensing element chip may further include a first electrical I/O structure located around the feedback cavity structure, and the first electrical I/O structure has a plurality of first connection pads, The shielding chip further includes a second electrical I/O structure located around the open working cavity and on the first electrical I/O structure to be electrically connected to the sensing circuit through the conductive pillars. The I/O structure has a plurality of second connection pads, which are respectively electrically connected to the first connection pads.

The micro feedback cavity sensor may further include: a circuit board disposed above the shielding chip and electrically connected to the second connection pads.

In the above-mentioned micro feedback cavity sensor, the physical signal may enter the open working cavity through the gap between the circuit board and the second connection pads.

In the above-mentioned micro feedback cavity sensor, the second electrical I/O structure may further include: a plurality of vertical conductors passing through the shielding chip and electrically connected to the second connection pads and the first connection pads.

In the above-mentioned micro feedback cavity sensor, the sensing element structure may include: a first electrode plate fixedly disposed on the semiconductor body and having a plurality of holes; and a second electrode plate movably disposed on the semiconductor body Above the first electrode plate, the first electrode plate and the second electrode plate form a sensing capacitor, and a gap is formed between the first electrode plate and the second electrode plate.

In the above-mentioned micro feedback cavity sensor, the sensing element structure may be a floating structure, which is deformed by sensing a physical signal, and the floating structure includes: a first electrode plate; a piezoelectric material layer disposed on the first electrode plate; and a second electrode plate, disposed on the piezoelectric material layer.

In the above-mentioned micro feedback cavity sensor, the semiconductor substrate may include: a first silicon substrate having a sensing circuit; a molding compound layer surrounding one or more side surfaces of the first silicon substrate; and a conductor connection layer located on the On the first silicon substrate and the molding compound layer, the sensing circuit is electrically connected to the sensing element chip.

In the above-mentioned micro feedback cavity sensor, the shielding chip may include an exposed conductor layer electrically connected to a fixed potential.

In the above-mentioned micro feedback cavity sensor, the shielding chip includes an exposed conductor layer, the integrated conductor layer is located on the semiconductor body of the shielding chip, and further penetrates the semiconductor body of the shielding chip and a part of the sensing element chip , and is electrically connected to an electrical I/O structure of the sensing element chip, so as to be electrically connected to the sensing circuit.

The above-mentioned micro feedback cavity sensor may further include a circuit board disposed above the shielding chip and electrically connected to a plurality of connection pads on the shielding chip, wherein the physical signal is passed through the circuit board and the plurality of connection pads. into the open working chamber.

The above-mentioned micro feedback cavity sensor may further include a circuit board disposed under the semiconductor substrate and electrically connected to a plurality of connection pads on the lower surface of the semiconductor substrate.

In the above-mentioned micro feedback cavity sensor, the semiconductor substrate may further have a second sensing circuit; the sensing element chip may further have at least one second sensing element structure, and a plurality of second conductive pillars are formed in the semiconductor body , a second feedback cavity structure is formed between at least one second sensing element structure, the semiconductor substrate and the semiconductor body, and at least one second sensing element structure is electrically connected to the second sensing element through the second conductive pillars test circuit. The at least one second sensing element structure and the second feedback cavity structure jointly respond to a second physical signal input from the outside to generate a second sensing signal and output it to the second sensing circuit.

The present invention also provides a method for manufacturing a micro feedback cavity sensor, comprising the following steps: providing a semiconductor substrate with a sensing circuit; forming a first bonding structure on the semiconductor substrate; providing a composite structure layer, including: a a sensing structure layer; and a semiconductor substrate on the sensing structure layer; bonding the composite structure layer with the semiconductor substrate through a first bonding structure to form a bonding structure layer; removing a part of the composite structure layer , to form: a sensor chip with a low-resistance semiconductor body, a first end portion and a second end portion, a plurality of conductive pillars are formed in the semiconductor body, and the first end portion is formed with at least a sensing element structure, the second end is connected to the semiconductor substrate through the bonding structure layer, a feedback cavity structure is formed between the bottom of at least one sensing element structure and the semiconductor substrate, at least one sensing element structure It is electrically connected to the sensing circuit through the conductive posts. At least one sensing element structure and the feedback cavity structure jointly respond to an externally input physical signal to generate a sensing signal and output it to the sensing circuit.

In the above manufacturing method, the sensor chip formed by the step of removing a part of the composite structure layer may further include a first electrical input/output structure located around the feedback cavity structure, the first electrical output The input structure has a plurality of first connection pads, which are electrically connected to the sensing circuit through the conductive pillars.

In the above-mentioned manufacturing method, the sensor chip formed by the step of removing a part of the composite structure layer may further include a shielding chip having a low-resistance semiconductor body, a first end portion and a second end portion , the second end of the shielding chip is connected to the first end of the sensing element chip, and an open working cavity formed by removing part of the semiconductor body of the shielding chip to expose part or all of the sensing element structure, the sensing element The metastructure senses the physical signal received via the open working cavity to generate the sensing signal.

In the above manufacturing method, the sensor chip formed by the step of removing a part of the composite structure layer may further include a first electrical input/output structure located around the feedback cavity structure, the first electrical output The input structure has a plurality of first connection pads, which are electrically connected to the sensing circuit through the conductive pillars, and the shielding chip further includes a second electrical input/output structure located around the open working cavity and the first electrical On the electrical I/O structure, the second electrical I/O structure has a plurality of second connection pads, which are respectively electrically connected to the first connection pads.

In the above manufacturing method, the shielding chip may include an integrated conductor layer, the integrated conductor layer is located on the semiconductor body of the shielding chip and further penetrates the semiconductor body of the shielding chip and the sensing element chip. A part is electrically connected to an electrical I/O structure of the sensing chip, so as to be electrically connected to the sensing circuit.

The beneficial effects of the present invention are: through the above embodiment, the micro feedback cavity sensor can be used as a microphone, and can also be used as a pressure sensor, or the micro feedback cavity sensor can have the functions of a microphone and a pressure sensor at the same time, so that the sensor can be used as a sensor. integrated effect. In addition, the present invention utilizes the wafer-level manufacturing technology, which can be mass-produced and reduce the cost. Furthermore, the manufacturing method of the present invention can greatly increase the volume of the working cavity (back cavity), reduce the volume of the front cavity of the microphone, and can also greatly reduce the size of the micro feedback cavity sensor.

In order to make the above-mentioned content of the present invention more obvious and easy to understand, preferred embodiments are exemplified below, and are described in detail as follows in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 shows a partial cross-sectional view of a micro feedback cavity sensor according to a first embodiment of the present invention.

2A to FIG. 4C are partial cross-sectional views showing each step of the manufacturing method of the micro feedback cavity sensor according to the first embodiment of the present invention.

FIG. 5 shows a partial cross-sectional view of a micro feedback cavity sensor according to a second embodiment of the present invention.

FIGS. 6A to 6D are partial cross-sectional views of each step of the manufacturing method of the micro feedback cavity sensor according to the second embodiment of the present invention.

7 shows a partial cross-sectional view of a micro feedback cavity sensor according to a third embodiment of the present invention.

8A and 8B show a partial cross-sectional view and a schematic top view of another example of the sensing element structure of the micro feedback cavity sensor according to various embodiments of the present invention.

9 shows a partial cross-sectional view of another example of a semiconductor substrate of a micro feedback cavity sensor according to various embodiments of the present invention.

10 shows a partial cross-sectional view of a micro feedback cavity sensor according to a fourth embodiment of the present invention.

FIGS. 11A to 12F are partial cross-sectional views showing various steps of a manufacturing method of a micro feedback cavity sensor according to a fourth embodiment of the present invention.

13 shows a partial cross-sectional view of a micro feedback cavity sensor according to a fifth embodiment of the present invention.

FIG. 14 shows a schematic diagram of a package of a conventional miniature microphone.

Reference numerals: CV: fixed potential; H: hole; 10: semiconductor substrate; 10': semiconductor substrate; 11: first silicon substrate; 12: sensing circuit; 13: molding compound layer; 14: conductor connection layer; 15 : side surface; 16: lower surface; 20: sensing element chip; 21: semiconductor body; 22: first end portion; 23: sensing element structure; 23A: second sensing element structure; 24: second end portion; 25: feedback cavity structure; 25A: second feedback cavity structure; 26: first electrical I/O structure; 27, 27': conductive posts; 27A, 27A': second conductive posts; 28: first connection pads ; 29, 29': conductive path; 29A, 29A': second conductive path; 30: shield chip; 31: semiconductor body; 32: first end; 34: second end; 35: open working cavity; 36 : second electrical I/O structure; 37: conductor layer; 38: second connection pad; 39: groove; 40: bonding structure layer; 41: first bonding structure; 42: second bonding structure; 50: circuit board ; 50C: opening; 60: connecting part; 71: insulating layer; 72: insulating layer; 73, 73A, 73B: insulating layer; 74: insulating layer; 80: integrated conductor layer; , 100D: micro feedback cavity sensor; 200: composite structure layer; 210: semiconductor substrate; 211: trench; 220: sensing structure layer; 231: first electrode plate; 231A: first electrode plate; 232: second electrode plate; 232A: second electrode plate; 233: upper surface; 234: piezoelectric material layer; 235, 235': gap; 236: groove; 262: conductor connection layer; 263: upper surface; 301: semiconductor substrate; 302 : insulating layer; 303: first electrode plate layer; 304: groove; 305: insulating layer; 306: groove; 307: second electrode plate layer; 308: groove; 309: insulating layer; 310: groove; 311: lower surface; 363: vertical conductor; 400: semiconductor substrate.

Detailed ways

The miniature feedback cavity sensor with the feedback cavity design of the embodiment of the present invention can be used as an acoustic wave sensor (such as a microphone), an ultrasonic sensor, or a pressure sensor, or can have functions such as a microphone and a pressure sensor at the same time. , to achieve the effect of sensor integration. Of course, it is not limited to this. Other types of sensors that can improve the quality of the sensor through the design of the feedback cavity, such as thermal-type sensors, motion-type sensors, etc., can also be applied to the present invention. structure and manufacturing process. In addition, the present invention utilizes the wafer-level manufacturing technology, which can be mass-produced and reduce the cost. Furthermore, the present invention completely abandons the traditional packaging method to manufacture the volume of the working cavity (back cavity), and completely uses the wafer-level manufacturing method to complete the volume design and manufacture of the large working cavity (back cavity) at the same time, and also completes the wafer-level manufacturing process. Circular-level packaging techniques, such as reducing the length of the front cavity of the microphone, have also greatly reduced the size of the micro feedback cavity sensor. These features are completely absent from the known technology. To this end, the following examples will illustrate the features of the present invention and extend it to all sensors that require a feedback cavity design.

FIG. 1 shows a partial cross-sectional view of a micro feedback cavity sensor 100 according to a first embodiment of the present invention. As shown in FIG. 1 , the micro feedback cavity sensor 100 of this embodiment includes a semiconductor substrate 10 , a bonding structure layer 40 and a sensor chip 20 .

The semiconductor substrate 10 has a sensing circuit 12 . For example, the semiconductor substrate 10 includes a first silicon substrate 11 and a conductor connection layer 14 . The sensing circuit 12 is formed in the first silicon substrate 11 . The conductor connection layer 14 is located on the first silicon substrate 11 and the sensing circuit 12 , and electrically connects the sensing circuit 12 to the sensing element chip 20 . The conductor connection layer 14 includes conductor connection lines and an interlayer dielectric layer (Inter-Layer Dielectric, ILD) or a metal interlayer dielectric layer (Inter-Metal Dielectric, IMD), which mainly provides the function of electrical connection, and can utilize the current semiconductor The manufacturing technology is easy to accomplish, so it is not repeated here.

The sensor chip 20 has a low-resistance semiconductor body 21 , a first end 22 (chip front) and a second end 24 (chip back). The bonding structure layer 40 is located on the semiconductor substrate 10 and includes a first bonding structure 41 and a second bonding structure 42 . The materials of the first bonding structure 41 and the second bonding structure 42 may be selected from the group consisting of aluminum, copper, germanium, gold, tin, indium, silicon, and the like. For example, the material of the first bonding structure 41 is aluminum, and the material of the second bonding structure 42 is germanium, wherein aluminum and germanium can form eutectic bonding at about 420° C., and these two materials are compatible with CMOS The manufacturing process is compatible, and it is more suitable for the design with integrated circuit integration in this embodiment. In another case, the second bonding structure 42 does not exist, the silicon material of the semiconductor body 21 itself may be the material of the second bonding structure 42, and the first bonding structure 41 may be gold (Au).

The material of the semiconductor body 21 is silicon, for example, wherein the semiconductor body 21 is designed and manufactured in several parts to include a plurality of independent conductive pillars 27 . The first end portion 22 is formed with at least one sensing element structure 23 located on the front surface of the semiconductor body 21 . The backside of the semiconductor body 21 and the second end portion 24 are connected to the semiconductor substrate 10 through the bonding structure layer 40 , and a feedback cavity is formed between at least one sensing element structure 23 , the semiconductor substrate 10 and the sidewalls of the surrounding semiconductor body 21 . Structure 25. At least one sensing element structure 23 is electrically connected to the sensing circuit 12 through the conductive pillars 27 , wherein the conductive pillars 27 are part of the entire conductive path 29 . In this embodiment, the sensing element structure 23 includes a first electrode plate 231 and a second electrode plate 232, and this arrangement is a capacitive sensing structure. The first electrode plate 231 is fixedly disposed on the semiconductor body 21 and has a plurality of holes H, so that when, for example, sound waves vibrate the second electrode plate 232, the air between the two electrode plates can reflect the vibration and pass through. The plurality of holes H enter into the feedback cavity structure 25 . The second electrode plate 232 is movably disposed above the first electrode plate 231 . The first electrode plate 231 and the second electrode plate 232 form a sensing capacitor, and a gap 235 is formed between the first electrode plate 231 and the second electrode plate 232. The design of the second electrode plate 232 varies depending on the sensor, and is used as a microphone When the diaphragm is used, it can be an elastic structure that is not completely sealed. When the micro feedback cavity sensor 100 is used as a pressure sensor, the second electrode plate 232 is a closed structure, which completely blocks the cavity of the feedback cavity structure 25 from communicating with the outside world, and is deformed by the change of fluid pressure, thereby generating capacitance Variation, the feedback cavity structure 25 is a closed cavity, especially an ultra-low pressure cavity. In the present invention, the height of the cavity in the feedback cavity structure is completely determined by the thickness of the silicon wafer and can be fabricated to more than 700 microns (um). Therefore, the present invention fully utilizes the flexibility of wafer fabrication to produce a large volume (The Z axis is determined by the thickness, and the X and Y axes are determined by the reticle design). If the traditional TSV structure is used to electrically connect the sensing element structure 23 to the sensing circuit 12, the TSV technology is limited, and the thickness of the semiconductor body 21 is about 100um-150um, which means that the volume of the cavity will be only 1/4 of the present invention ~1/10, will degrade sensor quality. The main inventive feature of the large-volume feedback cavity design here comes from the fact that it does not require TSV design at all, but uses photolithography technology to produce independent silicon conductor columns, which are air-insulated, and use the same process to complete this. Large volume feedback cavity design. Therefore, this is also a feature and advantage provided by the embodiments of the present invention.

At least one sensing element structure 23 and the feedback cavity structure 25 jointly respond to an externally input physical signal to generate a sensing signal and output it to the sensing circuit 12 . Such physical signals include, but are not limited to, sound waves, gas pressure, and the like. When the sound wave is received, the second electrode plate 232 vibrates to generate a change in the sensing capacitance, so that a sensing signal can be obtained. Since the feedback cavity structure 25 can be formed by using a deep etching technique, the volume of the feedback cavity structure 25 can be made quite large, which greatly improves the sensing effect.

It should be noted that the micro feedback cavity sensor 100 with the above structure can achieve the effect of the embodiment of the present invention. Of course, the addition of the following structures is only to make the implementation of the embodiments of the present invention more complete, and does not limit the present invention to this.

In order to upload the signal of the sensing circuit 12 to the upper circuit board, the sensing element chip 20 further includes a first electrical I/O structure 26 located around the feedback cavity structure 25. The first electrical I/O structure 26 has a plurality of first connection pads 28, and the conductive pillars 27' formed by these parts of the semiconductor body 21 are electrically connected to the sensing circuit 12, wherein the conductive pillars 27' are part of the entire conductive path 29'. Therefore, the micro feedback cavity sensor 100 may further include a circuit board 50 disposed above the first electrical I/O structure 26 and electrically connected to the first connection pads 28 , for example, through a plurality of connection parts 60 . to the first connection pad 28 . In one example, the connection portion 60 may be a solder ball, and is packaged in a Ball Grid Array (Ball Grid Array, BGA for short) manner. Of course, other electrical connection methods can also be used.

In addition, since the semiconductor manufacturing process is used, the first electrode plate 231 and the second electrode plate 232 are made of polysilicon, for example, and a conductor connection layer 262 of the first electrical I/O structure 26 is also made of polysilicon. Therefore, the second electrode plate 232, the first electrode plate 231 and the conductor connection layer 262 can be completed in the same series of manufacturing processes. Therefore, an upper surface 263 of the conductor connection layer 262 and an upper surface 233 of the sensing element structure 23 are located on the same plane.

In order to provide the front cavity, the micro feedback cavity sensor 100 may further include a shielding chip 30 having a low-resistance semiconductor body 31 , a first end 32 and a second end 34 . The second end 34 is connected to the first end 22 of the sensing element chip 20 and an open working cavity 35 formed by removing part of the semiconductor body 31 shielding the chip 30 to expose part or all of the sensing element structure 23 . The sensing element structure 23 senses the physical signal received through the open working chamber 35 to generate a sensing signal.

It is worth noting that there is an insulating layer 71 on the conductor connection layer 14 , and the insulating layer 71 is disposed between the first bonding structures 41 and between the second bonding structures 42 to provide an insulating effect. In addition, part of the insulating layer 72 between the first electrode plate 231 and the second electrode plate 232 is removed (referred to as sacrificial layer etching), and part of the insulating layer 72 is reserved for supporting the first electrode plate 231 and the second electrode plate 232 , and an insulating layer 73 is also formed between the second electrode plate 232 and the semiconductor body 31 . Furthermore, an insulating layer 74 is also formed between the semiconductor body 21 and the first electrode plate 231 . Of course, for the consideration of manufacturing and electrical properties, the insulating layer may be a single layer or a composite layer material.

2A to FIG. 4C are partial cross-sectional views showing each step of the manufacturing method of the micro feedback cavity sensor according to the first embodiment of the present invention. First, as shown in FIG. 1 , a semiconductor substrate 10 having a sensing circuit 12 is provided, and a first bonding structure 41 is formed on the semiconductor substrate 10 . In addition, as shown in FIGS. 2A to 3C, a composite structure layer 200 is provided, which includes: a second bonding structure 42; a sensing structure layer 220 on the second bonding structure 42; and a semiconductor substrate 210 (FIG. 4B , the semiconductor substrate 210 is a part of the semiconductor substrate 400 ) located on the sensing structure layer 220 . In addition, as shown in FIG. 4A , the composite structure layer 200 is bonded through the first bonding structure 41 and the second bonding structure 42 to form the bonding structure layer 40 . Bonding may also be performed when the second bonding structure 42 is not present, as described above. In this case, the composite structure layer 200 is bonded to the semiconductor substrate 10 through the first bonding structure 41 to form the bonding structure layer 40 .

Then, as shown in FIGS. 4A to 4C (with reference to FIG. 1 ), a part of the composite structure layer 200 is removed to form: a sensor chip 20 , a semiconductor body 21 having a low resistance value, a first end A plurality of conductive pillars 27 are formed in the semiconductor body 21, at least one sensing element structure 23 is formed on the first end 22, and the second end 24 is connected to the In the semiconductor substrate 10 , a feedback cavity structure 25 is formed between the at least one sensing element structure 23 and the semiconductor substrate 10 , and the at least one sensing element structure 23 is electrically connected to the sensing circuit 12 through the conductive pillars 27 .

The sensor chip 20 formed by the step of removing a part of the composite structure layer 200 may further include the first electrical I/O structure 26 and the shielding chip 30 , as shown in FIG. 4C and FIG. 1 . The above-mentioned manufacturing processes can all be accomplished using wafer-level manufacturing processes to achieve mass production.

Specifically, as shown in FIG. 2A , a semiconductor substrate 301 is provided, and a patterned insulating layer 302 is formed on the semiconductor substrate 301 . Then, as shown in FIG. 2B , a patterned first electrode plate layer 303 having a plurality of grooves 304 is formed on the semiconductor substrate 301 and the insulating layer 302 . Next, as shown in FIG. 2C , a patterned insulating layer 305 is formed on the first electrode plate layer 303 and the grooves 304 . The insulating layer 305 has a plurality of grooves 306 to expose part of the first electrode plate layer 303 . Then, as shown in FIG. 2D , a patterned second electrode plate layer 307 is formed on the insulating layer 305 and the first electrode plate layer 303 to fill the groove 306 . Next, as shown in FIG. 2E , a plurality of first connection pads 28 are formed on the second electrode plate layer 307 . Then, as shown in FIG. 2F, a part of the second electrode plate layer 307 is removed to form a plurality of grooves 308, and an insulating layer 309 is formed in the second electrode plate layer 307 and the grooves 308, and the insulating layer A plurality of grooves 310 are formed on the 309 to expose the first connection pad 28. It is worth noting that the above-mentioned manufacturing process may further include using chemical mechanical polishing (Chemical-Mechanical Polishing, CMP) to grind the uneven surface into a flat surface, In order to facilitate thickness control, and the above-mentioned insulating layer, or even the electrode plate layer, may not be a single material, but may include a composite layer material, for example, the insulating layer can be silicon oxide, silicon nitride, aluminum oxide, silicon carbide (SiC), Diamond like carbon film (Diamond like carbon), etc. is a single layer or a combined layer, and the electrode plate layer is polysilicon in this embodiment, of course, it can also be a composite structure combined with the above insulating layer materials, such as insulating layer/polysilicon/ Insulation.

Then, as shown in FIG. 3A , a semiconductor substrate 400 is attached to the insulating layer 309 , in this embodiment, the two are formed by a low temperature fusion bonding method to form an interface with hydrogen bond strength. Of course, before forming the low-temperature bonding, water cleaning and, for example, low-concentration hydrofluoric acid may be included to remove the oxide layer (HF dip) on the surface of the semiconductor substrate 400. In order to achieve surface activation, surface plasma treatment may be included, such as It is exposed to the plasma environment of oxygen (O ₂ ) and nitrogen (N ₂ ), and in order to make the joint surface have a good flatness, chemical mechanical polishing (CMP) can be used to polish the surface to be joined and Flatten. Next, as shown in FIG. 3B , a patterned second bonding structure 42 is formed on the lower surface 311 of the semiconductor substrate 301 . Then, as shown in FIG. 3C , etching is performed using the second bonding structure 42 as a mask to remove part of the semiconductor substrate 301 to form the composite structure layer 200 having the sensing structure layer 220 . Another specific manufacturing method is that in the corresponding step of FIG. 3C , part of the insulating layer 72 between the first electrode plate 231 and the second electrode plate 232 can be directly removed (commonly referred to as sacrificial layer etching, please refer to FIG. 1 ). ) to complete the capacitive sensing element structure.

Next, as shown in FIG. 4A , the composite structure layer 200 is bonded through the first bonding structure 41 and the second bonding structure 42 to form the bonding structure layer 40 including the first bonding structure 41 and the second bonding structure 42 . Then, as shown in FIG. 4B , a part of the semiconductor substrate 400 is removed to thin the semiconductor substrate to form the semiconductor substrate 210 , in order to shorten the front cavity distance. In this embodiment, the front cavity distance is less than 100um, of course not limited to this. Then, a portion of the semiconductor substrate 210 is removed to form the semiconductor body 31 , and a portion of the insulating layer 305 is removed to form the gap 235 .

The above-described fabrication process involves capacitive sensing technology. When piezoelectric or piezoresistive sensing techniques are used, for example, the insulating layer 305 is replaced by a layer of piezoelectric material, and the first and second electrode plates are formed as contact electrodes for the layer of piezoelectric material. Those with general knowledge can easily deduce it, so I won't repeat it here.

FIG. 5 shows a partial cross-sectional view of the micro feedback cavity sensor 100 ′ according to the second embodiment of the present invention. As shown in FIG. 5 , this embodiment is similar to the first embodiment, except that the shielding chip 30 further includes a second electrical I/O structure 36 located around the open working cavity 35 and the first electrical I/O structure 26, the second electrical I/O structure 36 has a plurality of second connection pads 38, which are respectively electrically connected to the first connection pads 28, and the second electrical I/O structure 36 also includes a plurality of vertical conductors 363, penetrating the shielding The chip 30 is electrically connected to the second connection pads 38 and the first connection pads 28 . In addition, the shielding chip 30 includes an exposed conductor layer 37 that is electrically connected to a fixed potential CV, such as a ground potential or other potentials, so that the semiconductor body 31 is in a non-floating state to prevent noise from interfering with the sensing results. Notably, the connection portion 60 may also be used to connect the exposed conductor layer 37 to a fixed potential of the circuit board 50 .

In addition, the circuit board 50 is disposed above the shielding chip 30 and is electrically connected to the second connection pads 38 . In this way, physical signals enter the open working cavity 35 through the gaps between the circuit board 50 and the second connection pads 38 .

FIGS. 6A to 6D are partial cross-sectional views of each step of the manufacturing method of the micro feedback cavity sensor according to the second embodiment of the present invention. The preceding process of the manufacturing method of the present embodiment is similar to FIG. 2A to FIG. 4B , and similar parts are not repeated here.

First, as shown in FIG. 6A , a plurality of trenches 211 are formed on the semiconductor substrate 210 . Then, as shown in FIG. 6B, vertical conductors 363 are formed in the trenches 211, and in this embodiment, the vertical conductors may be tungsten (W), copper (Cu), or the like. Next, as shown in FIG. 6C , a plurality of second connection pads 38 and a plurality of exposed conductor layers 37 are formed on the semiconductor substrate 210 and the vertical conductors 363 . Next, as shown in FIG. 6D , part of the semiconductor substrate 210 is removed to form the sensor chip 20 . Therefore, as shown in FIG. 6D and FIG. 5 , the sensor chip 20 further includes a first electrical I/O structure 26 located around the feedback cavity structure 25 , and the first electrical I/O structure 26 has a plurality of first electrical I/O structures 26 . A connecting pad 28 is electrically connected to the sensing circuit 12 through the conductive pillars 27 ′ formed by the partial semiconductor bodies 21 , and the shielding chip 30 further includes a second electrical I/O structure 36 located in the open working cavity 35 Around and on the first electrical I/O structure 26 , the second electrical I/O structure 36 has a plurality of second connection pads 38 , which are electrically connected to the first connection pads 28 , respectively.

7 shows a partial cross-sectional view of a micro feedback cavity sensor 100 ″ according to a third embodiment of the present invention. As shown in FIG. 7 , this embodiment is similar to the second embodiment, except that two micro feedback cavity sensors are integrated in the Therefore, the semiconductor substrate 10 further has a second sensing circuit 12A, the sensing element chip 20 further has at least one second sensing element structure 23A, and a plurality of second conductive pillars 27A and 27A' are formed in the semiconductor body 21 , a second feedback cavity structure 25A is formed between at least one second sensing element structure 23A, the semiconductor substrate 10 and the semiconductor body 21. It should be noted that the first electrode plate of the second sensing element structure 23A can also be There are holes H, not closed, so that the insulating layer (such as an oxide layer, as a sacrificial layer) between the first electrode plate 231A and the second electrode plate 232A can be removed. In addition, at least one second sensing The meta structure 23A is electrically connected to the second sensing circuit 12A through the second conductive pillars 27A, wherein the second conductive pillars 27A are part of the entire second conductive path 29A. Furthermore, the first connection pads 28 pass through these second conductive pillars 27A. The second conductive column 27A' formed by part of the semiconductor body 21 is electrically connected to the sensing circuit 12, wherein the conductive column 27A' is a part of the entire second conductive path 29'. Through this structure, at least one second sensing element The structure 23A and the second feedback cavity structure 25A jointly respond to a second physical signal input from the outside to generate a second sensing signal and output it to the second sensing circuit 12A.

8A and 8B show a partial cross-sectional view and a schematic top view of another example of the sensing element structure of the micro feedback cavity sensor according to various embodiments of the present invention. As shown in FIG. 8A and FIG. 8B , the sensing element structure 23 ′ is a floating structure for sensing a physical signal and deformed. The floating structure includes a first electrode plate 231 , a piezoelectric material layer 234 and a second electrode plate 231 . Electrode plate 232 . The first electrode plate 231 is disposed on the semiconductor body 21 . The piezoelectric material layer 234 is disposed on the first electrode plate 231 . The second electrode plate 232 is disposed on the piezoelectric material layer 234, and the piezoelectric material layer 234 is deformed to generate a sensing signal. Grooves 236 are formed on the second electrode plate 232 to provide deformation capability.

FIG. 9 shows a partial cross-sectional view of another example of the semiconductor substrate 10 ′ of the micro feedback cavity sensor according to various embodiments of the present invention. As shown in FIG. 9 , the semiconductor substrate 10 ′ includes a first silicon substrate 11 , a molding compound layer 13 and a conductor connection layer 14 . The first silicon substrate 11 has a sensing circuit 12 . The molding compound layer 13 surrounds one or more side surfaces 15 of the first silicon substrate 11 . The conductor connection layer 14 is located on the first silicon substrate 11 and the molding compound layer 13 , and electrically connects the sensing circuit 12 to the sensing element chip 20 . The advantage of this embodiment is that the volume of the semiconductor substrate 10 ′ is small, but the cavity volume of the feedback cavity structure 25 can be enlarged by means of fan-out.

FIG. 10 shows a partial cross-sectional view of a micro feedback cavity sensor 100C according to a fourth embodiment of the present invention. As shown in FIG. 10 , this embodiment is similar to the first embodiment, except that the shielding chip 30 includes an integrated conductor layer 80 , the integrated conductor layer is located on the semiconductor body 31 and further penetrates the semiconductor body 31 and the sensing A part of the meta-chip 20 is electrically connected to an electrical I/O structure 26 of the sensing meta-chip 20 so as to be electrically connected to the sensing circuit 12 . That is, the exposed conductor layer 37 and the conductor connection layer 262 are integrally connected together to form the integrated conductor layer 80, which may be formed of the same or different conductor materials. Therefore, the conductor connection layer 262 and the exposed conductor layer 37 can be regarded as a part of the integrated conductor layer 80 , so that the integrated conductor layer 80 is not only exposed on the semiconductor body 31 , but also further penetrates through the semiconductor body 31 , the insulating layer 73B, 73A, 73, 72 are directly connected to the conductor connection layer 262, and further connected to the conductive pillars 27' of the first electrical I/O structure 26. The exposed conductor layer 37 also forms part of the boundary of the open working cavity 35, and also has the effect of shielding noise interference. The micro feedback cavity sensor 100C further includes a circuit board 50 disposed above the shielding chip 30 and electrically connected to a plurality of connection pads 28 on the shielding chip 30 , wherein physical signals pass through the circuit board 50 and the connection pads 28 . The gap between the open working cavity 35 and the opening 50C of the circuit board 50 corresponding to the open working cavity 35 can also be entered. The micro feedback cavity sensor 100C may further include a circuit board 50 disposed above the shielding chip 30 and electrically connected to a plurality of connection pads 28 on the shielding chip 30 , wherein physical signals are connected to the connection pads 28 through the circuit board 50 . The gap between them enters the open working chamber 35 .

FIGS. 11A to 12F are partial cross-sectional views showing various steps of a manufacturing method of a micro feedback cavity sensor according to a fourth embodiment of the present invention. The manufacturing method of this embodiment is similar to that of the first embodiment, so the materials and characteristics used in the similar manufacturing process can be applied to all the embodiments.

As shown in FIG. 11A , a semiconductor substrate 301 with a low resistance value (eg, <0.01 ohm-cm) is provided, which is called a first dummy wafer, and a patterned insulating layer 302 ( The first insulating layer), such as thermal oxide (thermal oxide), of course, can also be combined with another etch stop layer, such as nitride, etc., in which a mask is used as the etch stop layer, and the first mask is used Photolithography is performed to remove the first insulating layer.

As shown in FIG. 11B , a patterned first electrode plate layer 303 having a plurality of grooves 304 is formed on the semiconductor substrate 301 and the insulating layer 302 . For example, using the first LPCVD (Low Pressure Chemical Vapor Deposition) to form N-type polysilicon with low resistance (eg <0.01 ohm-cm), it is best to use impurity doping during the manufacturing process to improve its conductivity as a thin film material. At the same time, annealing may be further performed above 1000 degrees Celsius to stabilize the stress, wherein a second mask is used for photolithography to remove a portion of the first polysilicon (303).

As shown in FIG. 11C , a patterned insulating layer 305 is formed on the first electrode plate layer 303 and the grooves 304 . The insulating layer 305 has a plurality of grooves 306 to expose part of the first electrode plate layer 303 . The insulating layer 305 is the second insulating layer, and the material can be oxide, as a sacrificial layer, the thickness is less than 2 microns, and chemical mechanical polishing (CMP) may be required to planarize the surface of the oxide layer. Then, a third mask is used for photolithography to remove part of the oxide layer, and a mask can be added for the use of ripples or dimples to provide anti-stiction purposes. . FIGS. 11A to 11C may be the same as FIGS. 2A to 2C .

As shown in FIG. 11D , a patterned second electrode plate layer 307 is formed on the insulating layer 305 and the first electrode plate layer 303 to fill the groove 306 . That is, using the second pass LPCVD to form N-type low-resistance (eg <0.01 ohm-cm) polysilicon, as a back-plate, the manufacturing parameters can be similar to the first electrode plate layer, including above 1000 degrees Celsius An annealing is performed to stabilize the stress, wherein photolithography is performed using a fourth mask to remove a portion of the second polysilicon (307).

As shown in FIG. 11E, an insulating layer 73, called a third insulating layer, is formed on the second electrode plate layer 307 and the exposed insulating layer 305, and its material is oxide. As another sacrificial layer, CMP may be required to remove the The surface of the oxide layer is flattened. Next, an insulating layer 73A, called the fourth insulating layer, is formed on the insulating layer 73, and the material may be nitride, or aluminum oxide, silicon carbide, diamond-like carbon film, etc., as an etching stopper layer. Then, an insulating layer 73B, called the fifth insulating layer, is formed on the insulating layer 73A, and its material may be an oxide for fusion bonding, and CMP may be required to planarize the surface of the oxide layer. In addition, the above-mentioned insulating layer, or even the electrode plate layer, may not be a single material, but may include a composite layer material, for example, the insulating layer may be silicon oxide, silicon nitride, aluminum oxide, silicon carbide (SiC), carbon diamond-like film ( Diamond like carbon) and other single layer or combined layer, and the electrode plate layer is polysilicon in this embodiment, of course, it can also be a composite structure combined with the above insulating layer materials, such as insulating layer/polysilicon/insulating layer.

As shown in FIG. 11F , the semiconductor body 31 (also referred to as the second dummy wafer, and the specifications can be the same as the first dummy wafer) are welded to the insulating layer 73B. temperature fusion bonding) to form an interface with hydrogen bonding strength. Of course, before forming the low-temperature bonding, water cleaning and, for example, low-concentration hydrofluoric acid may be included to remove the oxide layer (HF dip) on the surface of the semiconductor substrate 400. In order to achieve surface activation, surface plasma treatment may be included, such as It is exposed to the plasma environment of oxygen (O ₂ ) and nitrogen (N ₂ ), and in order to make the joint surface have a good flatness, chemical mechanical polishing (CMP) can be used to polish the surface to be joined and Flatten. In addition, high temperature annealing can be used to increase the bonding strength to above 700 degrees. For the purpose of thinning, the second dummy wafer can be thinned after welding, for example, the part drawn by the imaginary line is ground off.

As shown in FIG. 11G , a trench 39 is formed, which penetrates the semiconductor body 31 and the insulating layers 73B, 73A and 73 to expose the polysilicon belonging to the same layer as the second electrode plate layer 37 . Photolithography can be performed using a fifth mask (eg, using oxide as a hard mask), using a silicon deep etch technique to etch oxide/nitride/oxide in a self-aligned manner.

As shown in FIG. 11H , an exposed conductor layer 37 is formed in the trench 39 and on the semiconductor body 31 , which may be called the third polysilicon, but of course the invention is not limited to this, and other conductor materials may also be covered with metal materials. The polysilicon deposition technique may be used, and the conditions for the first and second polysilicon deposition may be the same or different.

As shown in FIG. 12A , the second bonding structure 42 is formed on the back surface of the semiconductor substrate 301 . For example, the semiconductor substrate 301 may be thinned to about 400 microns first, and then the second bonding structure 42 may be formed on the backside of the semiconductor substrate 301 . The materials of the first bonding structure 41 and the second bonding structure 42 may be selected from the group consisting of aluminum, copper, germanium, gold, tin, indium, silicon, and the like. For example, the material of the first bonding structure 41 is aluminum, and the material of the second bonding structure 42 is germanium, wherein aluminum and germanium can form eutectic bonding at about 420° C., and these two materials are compatible with CMOS The manufacturing process is compatible, and it is more suitable for the design with integrated circuit integration in this embodiment. In another case, the second bonding structure 42 does not exist, the silicon material of the semiconductor body 21 itself may be the material of the second bonding structure 42, and the first bonding structure 41 may be gold (Au). A metal layer such as germanium (Ge) is deposited on the backside of the semiconductor substrate 301 , and then the Ge layer is patterned by photolithography using a sixth mask.

As shown in FIG. 12B, a seventh mask (the oxide deposition layer can also be used as a hard mask) is used to deeply etch the silicon up to, for example, 400 microns to form a plurality of trenches.

As shown in FIG. 12C , parts of the insulating layers 302 and 305 (sacrificial layers) are removed to expose the first electrode plate 231 and form gaps 235 and 235 ′. In operation, buffered oxide etchant (BOE) or vapor hydrofluoric acid (Vapor HF) can be used.

As shown in FIG. 12D , the structure of FIG. 12C is bonded to the semiconductor substrate 10 on which the first bonding structure 41 and the sensing circuit 12 have been formed, which are eutectic bonded with the second bonding structure 42 to form Feedback cavity structure 25 . The semiconductor substrate 10 is, for example, part of a microphone wafer. Then, a plurality of first connection pads 28 are formed on the exposed conductor layer 37 . A metal layer can be formed on the exposed conductor layer 37 first, and then an eighth mask can be used for photolithography, or a mask can be added for a solder mask.

As shown in FIG. 12E, an open working cavity 35 is formed, which penetrates the exposed conductor layer 37, the semiconductor body 31 and the insulating layers 73B, 73A and 73, and is integrated with the gap 235' of FIG. 12C. During fabrication, the ninth mask can be used for photolithography (the oxide can be used as a hard mask), a deep etch of silicon is performed, and oxide/nitride is etched in a self-aligned manner.

As shown in FIG. 12F , the wafer-level product can be cut and soldered, and the solder balls are used as the connection parts 60 to solder the first connection pads 28 to the circuit board 50 , as shown in FIG. 10 .

FIG. 13 shows a partial cross-sectional view of the micro feedback cavity sensor 100D according to the fifth embodiment of the present invention. As shown in FIG. 13 , this embodiment is similar to the fourth embodiment, except that the first connection pads 28 are disposed on the lower surface 16 of the semiconductor substrate 10 , and the connection pads 18 and the conductor plugs 17 formed in the semiconductor substrate 10 are electrically connected to each other. Connected to the sensing circuit 12 . Therefore, the circuit board 50 is disposed under the semiconductor substrate 10 and is electrically connected to the plurality of first connection pads 28 on the lower surface 16 of the semiconductor substrate 10 . This is also a feasible solution. It should be noted that the manufacturing methods of the fourth and fifth embodiments are more compatible with the semiconductor manufacturing process and are more suitable for mass production.

Through the above embodiments, the micro feedback cavity sensor can be used as a sound wave sensor (such as a microphone), an ultrasonic sensor, or a pressure sensor, or it can have functions such as a microphone and a pressure sensor at the same time, so as to achieve the effect of sensor integration . Of course, it is not limited to this. Other types of sensors that can improve the quality of the sensor through the design of the feedback cavity, such as thermal-type sensors, motion-type sensors, etc., can also be applied to the present invention. structure and manufacturing process. In addition, the present invention utilizes the wafer-level manufacturing technology, which can be mass-produced and reduce the cost. Furthermore, the manufacturing method of the present invention can greatly increase the volume of the working cavity (back cavity), reduce the volume of the front cavity of the microphone, and can also greatly reduce the size of the micro feedback cavity sensor.

The specific embodiments proposed in the detailed description of the preferred embodiments are only for the convenience of illustrating the technical content of the present invention, rather than limiting the present invention to the above-mentioned embodiments in a narrow sense. Various changes and implementations made under different circumstances all belong to the scope of the present invention.

Claims (20)

1. a miniature feedback cavity sensor, is characterized in that, it comprises: a semiconductor substrate with a sensing circuit; a bonding structure layer on the semiconductor substrate; and A sensor chip has a low-resistance semiconductor body, a first end portion and a second end portion, a plurality of conductive pillars are formed in the semiconductor body, and the first end portion is formed with a plurality of conductive pillars located in the semiconductor body At least one sensing element structure on the front side, the backside of the semiconductor body and the second end are connected to the semiconductor substrate through the bonding structure layer, and the at least one sensing element structure, the semiconductor substrate and the semiconductor body are formed between A feedback cavity structure, the at least one sensing element structure is electrically connected to the sensing circuit through the plurality of conductive posts, wherein: The at least one sensing element structure and the feedback cavity structure jointly respond to an externally input physical signal to generate a sensing signal and output it to the sensing circuit. 2 . The micro feedback cavity sensor according to claim 1 , wherein the sensing element chip further comprises a first electrical I/O structure, located around the feedback cavity structure, the first electrical The I/O structure has a plurality of first connection pads, and is electrically connected to the sensing circuit through the plurality of conductive pillars. 3 . The micro feedback cavity sensor according to claim 2 , wherein the first electrical I/O structure has a conductor connection layer, and an upper surface of the conductor connection layer is connected to a surface of the sensing element structure. 4 . The upper surfaces lie on the same plane. 4 . The micro feedback cavity sensor according to claim 1 , further comprising a shielding chip having a low-resistance semiconductor body, a first end portion and a second end portion, the shielding chip having a The second end is connected to the first end of the sensing element chip, and a part of the semiconductor body of the shielding chip is removed to expose part or all of the sensing element structure. A working cavity is opened, and the sensing element structure senses the physical signal received through the open working cavity to generate the sensing signal. 5 . The micro feedback cavity sensor according to claim 4 , wherein the sensing element chip further comprises a first electrical input/output structure, located around the feedback cavity structure, and the first electrical input and output structure is located around the feedback cavity structure. The electrical I/O structure has a plurality of first connection pads, which are electrically connected to the sensing circuit through the plurality of conductive pillars, and the shielding chip further includes a second electrical I/O structure located in the open operation Around the cavity and on the first electrical I/O structure, the second electrical I/O structure has a plurality of second connection pads, which are respectively electrically connected to the plurality of first connection pads. 6. The micro feedback cavity sensor according to claim 5, further comprising: a circuit board disposed above the shielding chip and electrically connected to the plurality of second connection pads, wherein the physical signal passes between the circuit board and the plurality of second connection pads The void enters the open working chamber. 7. The micro feedback cavity sensor according to claim 5, wherein the second electrical I/O structure further comprises: A plurality of vertical conductors pass through the shielding chip and are electrically connected to the plurality of second connection pads and the plurality of first connection pads. 8. The micro feedback cavity sensor according to claim 1, wherein the sensing element structure comprises: a first electrode plate fixedly disposed on the semiconductor body and having a plurality of holes; and A second electrode plate is movably disposed above the first electrode plate, the first electrode plate and the second electrode plate form a sensing capacitor, the first electrode plate and the second electrode plate are connected A gap is formed between. 9 . The micro feedback cavity sensor according to claim 1 , wherein the sensing element structure is a suspension structure, which is deformed by sensing the physical signal, and the suspension structure comprises: 10 . a first electrode plate; a piezoelectric material layer disposed on the first electrode plate; and A second electrode plate is arranged on the piezoelectric material layer. 10. The micro feedback cavity sensor of claim 1, wherein the semiconductor substrate comprises: a first silicon substrate having the sensing circuit; a layer of molding compound surrounding one or more sides of the first silicon substrate; and A conductor connection layer is located on the first silicon substrate and the molding compound layer, and electrically connects the sensing circuit to the sensing element chip. 11 . The micro feedback cavity sensor according to claim 4 , wherein the shielding chip comprises an exposed conductor layer, which is electrically connected to a fixed potential. 12 . 12 . The micro feedback cavity sensor of claim 4 , wherein the shielding chip comprises an integrated conductor layer, and the integrated conductor layer is located on the semiconductor body of the shielding chip and further penetrates the semiconductor body. 13 . The semiconductor body of the chip and a part of the sensing element chip are shielded, and are electrically connected to an electrical I/O structure of the sensing element chip, so as to be electrically connected to the sensing circuit. 13. The micro feedback cavity sensor of claim 12, further comprising: a circuit board disposed above the shielding chip and electrically connected to a plurality of connection pads on the shielding chip, wherein the physical signal enters through the gap between the circuit board and the plurality of connection pads the open working chamber. 14. The micro feedback cavity sensor of claim 12, further comprising: A circuit board is disposed under the semiconductor substrate and is electrically connected to a plurality of connection pads on the lower surface of the semiconductor substrate. 15. The micro feedback cavity sensor according to claim 1, wherein: The semiconductor substrate further has a second sensing circuit; The sensing element chip further has at least one second sensing element structure, a plurality of second conductive pillars are formed in the semiconductor body, the at least one second sensing element structure, the semiconductor substrate and the semiconductor body A second feedback cavity structure is formed therebetween, and the at least one second sensing element structure is electrically connected to the second sensing circuit through the plurality of second conductive columns, wherein: The at least one second sensing element structure and the second feedback cavity structure jointly respond to a second physical signal input from the outside to generate a second sensing signal and output it to the second sensing circuit. 16. A method for manufacturing a miniature feedback cavity sensor, characterized in that it comprises the following steps: providing a semiconductor substrate with a sensing circuit; forming a first bonding structure on the semiconductor substrate; A composite structure layer is provided, including: a sensing structure layer; and a semiconductor substrate on the sensing structure layer; bonding the composite structure layer with the semiconductor substrate through the first bonding structure to form a bonding structure layer; A portion of this composite structural layer is removed to form: A sensor chip has a low-resistance semiconductor body, a first end portion and a second end portion, a plurality of conductive pillars are formed in the semiconductor body, and the first end portion is formed with a plurality of conductive pillars located in the semiconductor body At least one sensing element structure on the front side, the backside of the semiconductor body and the second end are connected to the semiconductor substrate through the bonding structure layer, and a feedback is formed between the bottom of the at least one sensing element structure and the semiconductor substrate A cavity structure, the at least one sensing element structure is electrically connected to the sensing circuit through the plurality of conductive posts, wherein: The at least one sensing element structure and the feedback cavity structure jointly respond to an externally input physical signal to generate a sensing signal and output it to the sensing circuit. 17 . The method for manufacturing a micro feedback cavity sensor according to claim 16 , wherein the sensor chip formed by the step of removing a part of the composite structure layer further comprises a first electrical I/O structure, 18 . Located around the feedback cavity structure, the first electrical I/O structure has a plurality of first connection pads, and is electrically connected to the sensing circuit through the plurality of conductive posts. 18 . The method for manufacturing a micro feedback cavity sensor as claimed in claim 16 , wherein the sensor chip formed in the step of removing a part of the composite structure layer further comprises a shielding chip with a low resistance value. 19 . a semiconductor body, a first end and a second end, the second end of the shielding chip is connected to the first end of the sensing element chip, and part of the shielding chip is removed The semiconductor body has an open working cavity formed by exposing part or all of the sensing element structure, and the sensing element structure senses the physical signal received through the open working cavity to generate the sensing Signal. 19 . The method for manufacturing a micro feedback cavity sensor according to claim 18 , wherein the sensor chip formed by the step of removing a part of the composite structure layer further comprises a first electrical I/O structure, 20 . Located around the feedback cavity structure, the first electrical I/O structure has a plurality of first connection pads, which are electrically connected to the sensing circuit through the plurality of conductive pillars, and the shielding chip is It also includes a second electrical I/O structure, located around the open working cavity and on the first electrical I/O structure, the second electrical I/O structure has a plurality of second connection pads, which are respectively electrically connected to the plurality of first connection pads. 20 . The method of manufacturing a micro feedback cavity sensor as claimed in claim 18 , wherein the shielding chip comprises an integrated conductor layer, the integrated conductor layer is located on the semiconductor body of the shielding chip, and further 20 . The semiconductor body of the shielding chip and a part of the sensing element chip are electrically connected to an electrical I/O structure of the sensing element chip, so as to be electrically connected to the sensing circuit.