TW202301086A - Pseudo-piezoelectric d33 device and electronic apparatus using the same - Google Patents

Abstract

A pseudo-piezoelectric d33 device includes: a pair of integral and substantially parallel electrodes having a first sensing electrode and a second sensing electrode constituting a receiver; a moving gap being disposed between the first and second sensing electrodes and having an initial height t0, wherein the moving gap is formed after a thermal reaction between a semiconductor material and a metal material to form a semiconductor-metal compound, and the first sensing electrode includes the semiconductor-metal compound to provide an integral capacitive sensing electrode to sense a capacitance change with the second sensing electrode and generate a sensing signal; and an inter-electrode dielectric with a thickness d disposed between the first and second sensing electrodes, wherein the inter-electrode dielectric has a single-layer structure or a multi-layer structure, and has an averaged dielectric constant of [epsilon]r, wherein satisfying t0 + d/[epsilon]r ≤ 100 nm. An electronic apparatus is also disclosed.

Description

Piezoelectric d33-like device and electronic equipment using it

The present invention relates to a piezoelectric d33-like device and an electronic device using the same, and in particular to a piezoelectric d33-like structure with enhanced sensing performance, which can be integrated into a display and applied to various electronic devices , and relates to an electronic device using the above-mentioned piezoelectric d33-like structure.

Traditional vibrating transceivers (or sensors or transducers), such as sonic or ultrasonic transceivers, can be used for image measurement of medical organs, gesture detection, three-dimensional touch, fingerprint sensing, The measurement of subcutaneous biological information (microvascular information, blood flow information), etc., can use air or fluid as the medium, or it can be in contact with objects. The traditional implementation technology usually uses piezoelectric materials, such as polyvinylidene difluoride (PVDF) or lead zirconate titanate (Lead Zirconate Titanate, PZT), etc., and its operation mode is to use the d33 mode of the material, That is, the direction of the electric field applied to the material is parallel to the direction of its movement.

1A and 1B show a schematic diagram of a conventional d33 vibrating transceiver. As shown in FIGS. 1A and 1B , a conventional d33 vibrating transceiver 300 includes a piezoelectric material block 310 . The upper and lower ends of the piezoelectric material block 310 are connected to a voltage source 340 to generate an electric field to deform the piezoelectric material. When the electric field continues to change, the piezoelectric material block 310 will vibrate along the moving direction 320, and the piezoelectric material block 310 will generate When the electric field direction 330 is parallel to the moving direction 320, it is said to operate in the d33 mode. For example, in FIG. 1A, the voltage source 340 respectively applies negative voltage and positive voltage to the first sensing electrode 311 and the second sensing electrode 312, resulting in an upward electric field direction 330 and contraction of the piezoelectric material block 310; In FIG. 1B , the voltage source 340 applies a positive voltage and a negative voltage to the first sensing electrode 311 and the second sensing electrode 312 respectively, resulting in a downward electric field direction 330 and an extension of the piezoelectric material block 310 . When the alternating electric field of FIGS. 1A and 1B is applied, stretching vibration of the piezoelectric material block 310 can be caused.

In terms of manufacturing, PVDF is an engineering plastic, and it is not easy to use semiconductor processes such as lithography for exposure, development and other processing methods. Usually, the processing methods can only rely on laser processing. Therefore, it is very problematic to integrate PVDF into semiconductor process. PZT is contaminating, difficult to process, and requires the use of bulk materials to achieve the d33 mode of operation. PZT of bulk material is usually produced by sintering, and the sintering temperature is as high as 700 to 800°C, even as high as 1000°C. Therefore, the traditional d33 PZT elements are all independent elements, and it is difficult to integrate into the semiconductor manufacturing process, and it is even impossible to integrate with the integrated circuit manufacturing process to integrate the piezoelectric element into the integrated circuit. Moreover, lead is also polluting to semiconductor materials. Furthermore, PZT needs to use platinum as an electrode, making the manufacturing cost high.

Furthermore, when conventional piezoelectric materials are operated, the applied voltage is usually tens of volts to hundreds of volts. Such a high voltage is a problem during system integration, and it is also a big problem when integrating with semiconductor manufacturing processes.

TWI725826 (CN212012595U) discloses a kind of piezoelectric d33 vibrating device and a display integrated with it. Although it can achieve the effect of integrating with semiconductor manufacturing process, it has not proposed further optimized design and solution for sensing performance, structure and materials. This is the problem to be solved in this case.

Therefore, an object of the present invention is to provide a piezoelectric d33-like device with good sensing performance, which has the advantages of being easy to integrate with semiconductor manufacturing processes, easy to process, low in cost, and non-polluting, and provides a guarantee for sensing performance. Optimized design.

To achieve the above object, the present invention provides a kind of piezoelectric d33 device comprising at least: a pair of complete and substantially parallel electrodes, with first and second sensing electrodes constituting a receiver; a moving gap, located between the first and second between the two sensing electrodes and has an initial height _t0 and is produced by thermally reacting a semiconductor material and a metal material to form a semiconducting metal compound, wherein the first sensing electrode contains the semiconducting metal compound to provide a complete capacitance sensing electrode to sense the capacitance change between the second sensing electrode and generate a sensing signal; and an inter-electrode dielectric having a thickness between the first sensing electrode and the second sensing electrode d, and has a single-layer structure or a multi-layer structure, and has an average dielectric constant ε _r , where t ₀ + d/ε _r ≤ 100 nm is satisfied.

The present invention also provides an electronic device, at least including: at least one processor; and the piezoelectric d33-like device, wherein the processor is electrically connected to the piezoelectric d33-like device, and processes the sensing signal from the piezoelectric d33-like device .

The piezoelectric d33-like device in the above embodiment can be used as a biological information sensing, touch, and pressure sensing device. Using the above design criteria of d/ε _r + t ₀ ≤ 100 nm, the pressure sensing device can be Sensing performance optimization. In addition, the arrangement of the contact layer can improve the electrical contact effect.

In order to make the above content of the present invention more comprehensible, preferred embodiments are specifically cited below, together with the accompanying drawings, and described in detail as follows.

The piezoelectric d33-like device provided by the embodiment of the present invention uses a mobile capacitive structure with a vacuum or an air gap to achieve a transceiving function in which the direction of the applied electric field is the same as the vibration direction, similar to the d33 effect of traditional piezoelectric materials. The sensing performance can be optimized by selecting the dielectric constant and thickness of the inter-electrode dielectric and matching the height of the moving gap.

2A, 2B and FIG. 3 show schematic diagrams of three applications of the piezoelectric d33-like device 100 in a handheld electronic device according to a preferred embodiment of the present invention, but the present invention is not limited thereto. As shown in FIG. 2A , the piezoelectric d33-like device 100 can be integrated in a display 210 on the front of a mobile phone 200 (or an electronic device such as a notebook computer or a tablet computer) or combined under the display 210 (such as a directly or indirectly combined on the lower surface of the display 210), the piezoelectric d33-like device 100 can be electrically connected to the man-machine interface (display 210) through the processor 270 of the mobile phone 200, so that the processor 270 processes the information from the piezoelectric d33-like device 100 sensing signal. A plurality of operation blocks 220 are displayed on the display 210 for the user to click, and a front lens 230 is installed beside the display 210. Due to the manufacturing characteristics, the piezoelectric d33-like device 100 of the present invention can be integrated in or below the display of an electronic device , and can also be only a part of the area (as shown in the dotted line in Figure 2A), or cover the entire area (as shown in Figure 2B), of course, if the entire area of the display is covered, the piezoelectric d33-like device can even cover A variety of functions can be used together, and can be used as biometric sensing (such as fingerprints, finger veins, blood flow rate, heartbeat, etc.) and 3D touch and gesture detection, etc., forming an all-in-one function integration.

As shown in FIG. 3 , the piezoelectric d33-like device 100 can also be installed under the back cover 240 or the side button area on the back of the mobile phone 200 , where the rear camera 250 is also installed on the back of the mobile phone 200 . The piezoelectric d33-like device 100 can provide biometric sensing functions, but is not limited thereto. Any physical quantity that can be sensed by static and dynamic force can be implemented by this. Of course, the device of the present invention can also be designed as an independent The capacitive microstructure of the vibration system device can be used to replace the existing piezoelectric d33 vibration element used in the market, such as using a mobile phone and a cloud system (which can be combined with artificial intelligence) to connect with the independent device of the present invention, which can be done It is a portable vibration detection system, such as medical or industrial application imaging. The present invention will be illustrated by taking fingerprint sensing applied to mobile phones as an example, so that those skilled in the art can understand the features of the present invention.

In the embodiment of the present invention, a voltage is used to drive two electrodes to generate an electric field. One of the electrodes is a thin film structure, and the other electrode is fixed on a substrate. There is a vacuum or air gap between the two electrodes. When the applied electric field is an AC When the signal is received, the film will vibrate, and if the frequency of the AC signal is the same as the mechanical resonance frequency of the film structure, the film will produce mechanical resonance, which amplifies the mechanical energy and amplitude. This is a better implementation For example, of course, the device of the present invention can also use the electrostatic attraction of the film structure or even introduce (pull-in) contact, thus changing the rigidity of the structure, and also changing the frequency of resonance. In this way, the device can be a variable frequency The transceiver, which senses the depth information of different sensed objects (features) of an object, helps to construct a complete 3D image. For example, if it is used to measure the biological information of a finger, it can even measure the finger at the same time through frequency conversion Textures and vein patterns inside fingers or blood information and other functions.

FIG. 4 and FIG. 5 are schematic configuration diagrams of piezoelectric d33-like devices according to a preferred embodiment of the present invention. As shown in FIG. 4 , the piezoelectric d33-like device 100 of this embodiment at least includes a first sensing electrode 41 , a second sensing electrode 42 and a moving gap 43 . The material of the second sensing electrode 42 is, for example, an indium tin oxide (Indium Tin Oxide, ITO) conductor, which can be integrated with an electronic device, and of course it can also be other materials, such as aluminum. In this example, the first sensing electrode 41 and the second sensing electrode 42 are a complete pair of substantially parallel capacitive sensing electrodes, which are not divided into multiple parts by any structure. The capacitance between the second sensing electrode 42 and the first sensing electrode 41 changes to generate a sensing signal. One of the sensing electrodes (eg, the first sensing electrode 41 ) of the two electrodes includes metal silicide, and forms a capacitance to be sensed with the other electrode (eg, the second sensing electrode 42 ). The first sensing electrode 41 is located on a substrate 10, the substrate 10 can be glass, polymer or semiconductor substrate on which electronic circuits can be manufactured, including semiconductor integrated circuits (especially complementary metal oxide semiconductor (Complementary Metal-Oxide Semiconductor) , CMOS)) silicon substrates used or thin-film transistors (Thin-Film Transistor, TFT) dielectric substrates used. Electronic circuits can be used to perform functions such as signal reception, transmission or processing. The second sensing electrode 42 is located above the first sensing electrode 41 along the height direction Y. The first sensing electrode 41 and the second sensing electrode 42 form a transmitter 40T or a receiver 40R, or a transceiver unit 40 including a transmitter and a receiver. The moving gap 43 is located between the first sensing electrode 41 and the second sensing electrode 42 , and the moving gap 43 has an initial height t ₀ along the height direction Y. The pressure in the moving gap 43 may be higher than, equal to or lower than one atmosphere. The receiver 40R can be used as a pure passive force or pressure sensor, and can also be used as an active vibration transmitter and receiver, so it can be called a transceiver in this case. In other examples, the receiver or transceiver can be applied to biometric information sensing, touch sensing, pressure sensing, and so on. Although only a single piezoelectric d33-like unit is shown, the architecture of this embodiment can also be applied to one-dimensional or two-dimensional piezoelectric d33-like units to form piezoelectric d33-like devices 100 meeting various requirements.

The above-mentioned piezoelectric d33-like device 100 may further include an inter-electrode dielectric 114 having a thickness d between the first sensing electrode 41 and the second sensing electrode 42 (that is, between the first sensing electrode 41 The inter-electrode dielectric 114 between the second sensing electrode 42 has a thickness d). In this embodiment, an upper surface 41T of the first sensing electrode 41 and a lower surface 114B of the inter-electrode dielectric 114 define and partially surround the moving gap 43 , and the distance between the upper surface 41T and the lower surface 114B is t ₀ . In addition, the distance between an upper surface 114T of the inter-electrode dielectric 114 (the lower surface 42B of the second sensing electrode 42 ) and the lower surface 114B is d. The material of the inter-electrode dielectric 114 will affect the performance of emission and sensing. A preferred embodiment can be a material with a dielectric constant (in the case of multi-layer materials, it can be an average value) greater than 3, or even greater than 4 or 5. . Therefore, the material of the inter-electrode dielectric 114 is selected from the group consisting of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, tantalum oxide, and titanium oxide.

The above-mentioned piezoelectric d33 device 100 may further include a protective layer 115 located on the second sensing electrode 42, which may be a single layer or a combination of multiple layers of materials, such as silicon oxide, silicon nitride, or other dielectric materials, and the above-mentioned combination of materials. The above-mentioned piezoelectric d33 device 100 may further include: an encapsulation layer 116 (such as a standard encapsulation sealing layer, encapsulation layer, molding compound), located on the protective layer 115; a coupling layer 117 (for example, in a specific application, provided on The fingerprint or touch device under the display screen is used to paste the above-mentioned components under a panel), which is located on the encapsulation layer 116; and a cover plate 118 (such as the aforementioned display panel, which can also be a single layer, such as a glass substrate Or the combination of multiple layers of different functional substrates, or the back cover of a mobile phone, or the cover of any button (at this time, the piezoelectric d33 device can be used as a button), etc. The functionality and protection of any conventional electronic device performance and aesthetics of the cover plate design), located on the coupling layer 117. The cover plate 118 may be a simple covering material layer, and may be formed of one or more of glass, plastic, ceramic, sapphire, metal or metal alloy. In some implementations, the cover plate is, for example, a cover glass or lens glass for a display. In other implementations, the cover sheet may include one or more polymers, such as one or more types of parylene. In still other implementations, the cover plate can also be a display, which can be a display based on a digital micro-shutter (Digital Micro-Shutter, DMS), a light-emitting diode (Light-Emitting Diode, LED) display, an organic light-emitting diode Body (Organic Light-Emitting Diode, OLED) display, liquid crystal display (Liquid Crystal Display, LCD), LCD display using LED as backlight, plasma display, display based on interferometric modulator (Interferometric Modulator Display, IMOD), Or another type of display suitable for use with a touch-sensitive user interface system, etc.

The example in FIG. 5 is similar to that in FIG. 4 , the difference is that the encapsulation layer may not be needed, for example, the cover plate 118 is attached to the protection layer 115 directly through the coupling layer 117 . Therefore, the coupling layer 117 is located on the protective layer 115 , and the cover plate 118 is located on the coupling layer 117 . It can be understood that the piezoelectric d33-like device of this embodiment can be properly used in combination with various structures of the above-mentioned embodiments.

How to optimize the sensing performance of the piezoelectric d33-like device will be described below with reference to FIG. 6 . FIG. 6 shows a schematic diagram of the capacitive sensing principle of FIG. 4 and FIG. 5 . As shown in Figures 4 to 6, the thickness of the inter-electrode dielectric 114 (which can be a single layer or a multilayer combination) is d, and the dielectric constant is ε _r (if it is a multilayer combination, it can be the average dielectric constant, Therefore, the average dielectric constant is uniformly used to represent single-layer or multi-layer conditions); the thickness of the moving gap 43 is t ₀ , and the dielectric constant is approximately equal to 1. On the other hand, the vacuum permittivity is ε ₀ , and the capacitance between the first sensing electrode 41 and the second sensing electrode 42 is C ₀ (the movement at this time The initial height of the gap is t ₀ , where t ₀ is defined as the average height of two parallel sensing electrodes), if the structure is deformed by an external force (such as the pressure of vibration rebound), the second sensing electrode 42 will change its The height of the moving gap between a sensing electrode 41 is t ₁ (because the structural deformation is not uniform, so t ₁ is defined as the average height under the condition of uniform deformation), where t ₁ <t ₀ , so that the distance between the two electrodes The capacitance is changed to C ₁ , and the overlapping area between the electrodes is A, because in the application, the lateral scale of A is >> 1μm (eg > 50μm), and t ₀ and d in the figure are both < 1μm, so the following calculation It can be calculated by approximating the plate capacitance formula. According to the formula of capacitance in series, the capacitance C between two electrodes, 1/C=1/C _d +1/C _a , where C _d =ε _r ε ₀ A/d, C _a =ε ₀ A/t ₀ , can be Obtain initial capacitance (undeformed) C ₀ =ε _r ε ₀ A/(d+ε _r t ₀ ), and reaction capacitance (deformed) C ₁ =ε _r ε ₀ A/(d+ε _r t ₁ ). Therefore, the capacitance change value after deformation of this structure can be obtained △C=C ₁ -C ₀ =ε _r ε ₀ A/(d+ε _r t ₁ ) -ε _r ε ₀ A/(d+ε _r t ₀ ) =(ε _r ² ε ₀ At ₀ －ε _r ² ε ₀ At ₁ )/(d+ε _r t ₁ ) (d+ε _r t ₀ ) =ε _r ² ε ₀ A (t ₀ －t ₁ )/ (d+ε _r t ₁ ) (d+ε _r t ₀ ) [Mathematical formula 1] In this capacitance sensing device, its sensing sensitivity is usually defined as the ratio of the capacitance change value to the initial capacitance value, and its It is defined as follows [Math formula 2] △C/C ₀ =ε _r (t ₀ -t ₁ )/ (d+ε _r t ₁ ) ……… [Math formula 2]

If the suspension structure of the element (including at least the second sensing electrode 42, the inter-electrode dielectric 114 and the protective layer 115, having a thickness of about micron order) is attached to a cover plate using a thick molding compound for packaging process 118, the rigidity of the structure is determined by the thickness of the entire stacked material, which is usually hundreds of microns (㎛) to several millimeters (mm). Therefore, when the entire rigid structure is deformed by an external force (including the rebounding vibration wave), the gap change (deformation amount) Δt is quite small, about the level of less than 0.1nm, that is, the upper limit of the gap change is 0.1nm, (t ₀ -t ₁ ) ≤ 0.1nm (the maximum deformation exhibited by the second sensing electrode when performing sensing is less than or equal to 0.1nm), that is, t ₀ is almost equal to t ₁ . For this reason, if a good signal-to-noise ratio (Signal to Noise Ratio, SNR) is to be obtained, further consideration must be made in the design.

In the design of the sensing circuit, it is usually required that △C/C ₀ ≥ 0.1%………[Mathematical formula 3] in order to obtain a better SNR, so how to optimize the overall mechanical structure scale is one of the key points of the present invention one.

It can be known from [Mathematical formula 2] that when d=0 in design, that is, there is no inter-electrode dielectric 114, then [Mathematical formula 3] can be written as △C/C ₀ =(t ₀ -t ₁ )/ (t ₁ ), then put in the actual number, you can get 0.1nm/t ₁ ≥ 0.1%; that is, t ₁ ≤ 100nm. Since t ₀ is almost equal to t ₁ , that is to say, t ₀ ≤ 100nm, but in application, there may be concerns about contact short circuit between the first sensing electrode 41 and the second sensing electrode 42, or arcing, breakdown, etc. etc., the inter-electrode dielectric 114 is still required. Therefore, △C/C ₀ ≈ε _r (t ₀ -t ₁ )/ (d+ε _r t ₁ ) ≥ 0.1%. Therefore, by substituting the above extremum value Δt=0.1 nm and t ₀ is approximately t ₁ , the design criterion of [Equation 4] can be obtained. d/ε _r + t ₀ ≤ 100 nm [Math 4]. In a preferred embodiment, t ₀ =50nm, d/ε _r ≤ 50nm, so that these two terms (d/ε _r ) and t ₀ can provide the same contribution to simplify the design.

Therefore, in this embodiment, the optimal structure design and dielectric material selection need to meet the following conditions: d/ε _r + t ₀ ≤ 100 nm.

In several reasonable examples, the parameters in the following [Table 1] can be derived. [Table 1] example t _{0 εr} d d/ _εr 1 50 nm 4 (silicon oxide) ≤ 200nm ≤ 50nm 2 50 nm 7 (silicon nitride) ≤ 350nm ≤ 50nm 3 75 nm 4 ≤ 100nm ≤ 25nm 4 75 nm 7 ≤ 175nm ≤ 25nm

FIG. 7 shows a schematic diagram of a piezoelectric d33-like device 100 according to a preferred embodiment of the present invention. Fig. 8 shows a partial cross-sectional view of another example of a piezoelectric d33-like device. The structures of FIGS. 4 and 5 can be applied to FIG. 7 in a manner similar to that of FIG. 8 . As shown in FIGS. 7 and 8 , the piezoelectric d33-like device 100 of this embodiment at least includes one or more transistors 30 and one or more receivers 40R. A plurality of receivers 40R are electrically connected to these transistors 30, and each transistor 30 controls each corresponding receiver 40R to receive a second vibration wave W2 generated by a first vibration wave W1 reflected by an object F to generate a sensing Signal. Each receiver 40R has a first sensing electrode 41 , a second sensing electrode 42 and a moving gap 43 between the first sensing electrode 41 and the second sensing electrode 42 and formed by semiconductor metal compound. The height of the moving gap 43 can be controlled to be quite small, such as tens of nanometers, so that the electric field generated when a driving voltage of 3.3 to 18 volts is applied to the first sensing electrode 41 and the second sensing electrode 42 is equivalent to The electric field generated by applying a driving voltage of tens to hundreds of volts to a conventional structure. Driven by the electric field, the second sensing electrode 42 vibrates up and down to generate a vibration wave, and then receives the vibration wave reflected back by the object. In this embodiment, each receiver 40R can also be used as a transmitter 40T as a transceiver unit 40 . A corresponding composition of the transceiver unit 40 and the transistors 30 is an integrated transceiver 20 . In the integrated transceiver 20, the transceiver unit 40 is adjacent to the transistor 30, and the transistor 30 controls the transceiver unit 40 to transmit the first vibration wave W1 at a first time point, and then controls the transceiver unit 40 to receive the first vibration wave W1 at a second time point. The second vibration wave W2.

The above piezoelectric d33-like device 100 may further include a substrate 10 and a driving and sensing circuit module 50 . The substrate 10 has a top surface 10T and a bottom surface 10B. Each integrated transceiver 20 is disposed on the upper surface 10T of the substrate 10 . It should be noted that a single integrated transceiver 20 can also achieve the functions of the present invention, and the driving and sensing circuit module 50 can be a built-in or external circuit device.

The substrate 10 may be a glass substrate, a flexible substrate (such as a polyimide (PI) substrate) or any insulating substrate, or a semiconductor substrate formed with an insulating layer, etc., of course, is not limited thereto.

Referring again to FIG. 7 , the driving and sensing circuit module 50 may be a module electrically connected to an electronic device such as the piezoelectric d33 device 100 . With the above-mentioned embodiments, the piezoelectric d33-like device can be easily integrated with the semiconductor manufacturing process, easy to process, low in cost, non-polluting, and has good emission and sensing performance. In addition, the selection of the dielectric constant and thickness of the inter-electrode dielectric and the matching of the height of the moving gap can optimize the sensing performance and achieve single-point sensing and one-dimensional sensing with high sensing performance. Or the function of two-dimensional sensing.

Fig. 8 is an embodiment of the present invention using TFT manufacturing process. As mentioned above, the device of the present invention is explained by being applied to the mobile phone system, and the most important human-machine interface of the mobile phone is the mobile phone display, so the present invention The device is manufactured using the TFT process of the mobile phone display. Therefore, it can be integrated with the OLED process of the mobile phone on a single panel, or the OLED process can be omitted and only the TFT process can be retained to complete the device. Of course, it is not limited to OLED displays, such as LCD or future μLED technology, etc., can be the applicable technology platform of the present invention, or they can be installed under the mobile phone display or the back cover or side of the mobile phone through assembly, which is one of the most important spirits of the present invention. one. A plurality of integrated transceivers 20 are arranged in an array along the X-axis direction in FIG. 8 and disposed on the substrate 10 . Each integrated transceiver 20 includes a transistor 30 (which may be one or more transistors, formed on a glass substrate) and a transceiver unit 40 . In this embodiment, the transistor 30 is described by taking a thin film transistor as an example, but the present invention is not limited thereto. The transceiver unit 40 is disposed on one side (horizontal side) of the transistor 30 . In other embodiments, the transceiver unit 40 can be stacked on the vertical side (above or below the transistor 30 , for example, two polysilicon layers or amorphous silicon layers), so that the horizontal space need not be sacrificed. The transistor 30 is disposed on the substrate 10 and has a gate 31 , a drain 32 , a source 33 and a first semiconductor layer 34 between the gate 31 , the drain 32 and the source 33 . The gate 31 is formed on the substrate 10 . Although the transistor 30 in the illustrated embodiment is disposed beside the transceiver unit 40 , in other embodiments, the transistor 30 may also be disposed below the transceiver unit.

As shown in Figure 8 and Figure 7, the transceiver unit 40 is adjacent to the transistor 30, and is directly or indirectly electrically connected to the transistor 30, the transistor 30 controls the transmission and reception (active and passive functions) of the transceiver unit 40, by controlling the first A sensing electrode 41 and a second sensing electrode 42 are energized, and a variable electric field is applied to generate the first vibration wave W1 that vibrates up and down (driving the thin film electrode) and transmits upward to the object F (which can be a living body or a non-biological body) One or more interfaces of the object F, the interface of the object F reflects the first vibration wave W1 to generate the second vibration wave W2, and the transceiver unit 40 senses the second vibration wave W2 (vibrating film electrode) or senses the second vibration wave W2 and the first vibration wave W2 A sensing signal is generated by interfering with the wave W3 of the vibration wave W1. For example, the distances between the peaks FR and the valleys FV of the object F of a finger are different, so there will be correspondingly different sensing signals. The meaning that the transceiver unit 40 is adjacent to the transistor 30 may include that the transceiver unit 40 is located on the left side, right side, upper side, lower side, upper left side, lower left side, upper right side or lower right side of the transistor 30 . In one example, the spaces covered by the integrated transceiver 20 composed of the transistor 30 and the transceiver unit 40 do not overlap with each other.

In one example, the second vibration wave W2 propagates downward, which interferes with the change of the sensing capacitance between the second sensing electrode 42 and the first sensing electrode 41 to generate a sensing signal. In another example, the second vibration wave W2 propagates downward and interferes with the first vibration wave W1 transmitted downward to generate an interference wave W3. The second sensing electrode 42 and the first sensing electrode 41 generate a sensing signal by measuring the interference wave W3 by sensing the change of capacitance. Therefore, with the design of an array piezoelectric d33 device 100, the distance information between the peaks FR and valleys FV of the finger F and the piezoelectric d33 device 100 can be measured to generate a fingerprint image (at this time, the skin is the interface ), the frequency of the first vibration wave W1 can also be adjusted at the same time or at different time periods, and the first vibration wave W1 can also be allowed to penetrate the skin, and then measure the distribution image of the blood vessels according to the different vibration waves reflected by the blood vessels (at this time the vessel wall as the interface). In one example, the interference wave W3 is generated by the constructive interference between the second vibration wave W2 and the first vibration wave W1 to obtain a larger amplitude. In another example, the interference wave W3 is generated by the destructive interference between the second vibration wave W2 and the first vibration wave W1 to obtain a smaller amplitude. In yet another example, the piezoelectric d33-like device 100 can be designed so that the second vibration wave W2 generated by the reflection of the ripple peak FR of the finger F interferes constructively with the first vibration wave W1, while the vibration wave W1 of the finger F The second vibration wave W2 generated by the reflection of the trough FV produces destructive interference with the first vibration wave W1 , so that the discrimination between the peak and the trough can be improved. Another emission sensing mode is Time Of Flight (TOF). By switching the time of emission and sensing, the time difference of sensing is used to determine the distance traveled by the vibration wave, and then a 3D image of the object F is constructed. Therefore, the reflection time of the forward wave encountering different interfaces is different, and images of different interfaces can be stacked at the same time, such as fingerprints and vein images. At the same time, the purpose of sensing different interfaces can also be achieved by emitting waves of different frequencies. In this embodiment, the frequency of the vibration wave can range from 20KHz to 200MHz, and the optimum frequency range can be from 2MHz to 40MHz. Yet another sensing mode, which can control several transceiver units at the same time, and control the phase difference of the first vibration waves of each transceiver unit, and use beam forming to concentrate energy and scan sequentially, allowing the first The energy of the first vibration wave W1 is the largest (and therefore the energy of the reflected second vibration wave W2 becomes larger), which can increase the sensing sensitivity.

For the sake of simplicity, Fig. 7 is only used to describe the basic principle and practical application of the operation of the piezoelectric d33 device of the present invention, such as the system embodiment of Fig. 3, and the device and the sensing object (such as a finger) include another A display structure, that is, the aforementioned W1/W2 system needs to be transmitted between different materials in the display to complete the function of sending and receiving. This part should be understandable to those familiar with this technology, so in this article, there will be no discussion on the display. The structure of .

The transceiver unit 40 has a first sensing electrode 41 , a second sensing electrode 42 , a moving gap 43 and a second semiconductor layer 44 between the first sensing electrode 41 and the second sensing electrode 42 . The second semiconductor layer 44 is located between the substrate 10 and the first sensing electrode 41 . In this embodiment, the first semiconductor layer 34 and the second semiconductor layer 44 are made of the same layer of material, such as amorphous silicon, polysilicon layer or germanium (Ge) layer, which are important material layers of the transistor 30 . When thin film transistors are used, the first semiconductor layer 34 and the second semiconductor layer 44 have the same material, and even both are completed by the same manufacturing process. But the present invention is not limited thereto. For example, in FIG. polysilicon or amorphous silicon, the second semiconductor layer 44 is polysilicon or amorphous silicon, that is, the first and second semiconductor layers can be of the same layer or of different layers). A height (along the Y-axis direction of FIG. 8 ) of the moving gap 43 is less than or equal to 100 nm or even about 50 nm. Since the electric field intensity is inversely proportional to the square of the distance under the same driving voltage, and because the gap is small, even a small voltage can generate a large electric field to drive the electrodes, which is another spirit of the present invention. Therefore, the driving and sensing circuit module 50 electrically connected to each integrated transceiver 20 can provide a driving voltage of 3.3 to 18 volts to each integrated transceiver 20, instead of having to provide tens of voltages as in the prior art. Volts to hundreds of volts of driving voltage, in addition, in the actual circuit design of some occasions, in order to further improve the signal sensing effect, the driving sensing circuit module 50 can also provide a direct current plus alternating current (DC+AC) drive Voltage to the integrated transceiver 20, wherein the DC voltage is between 3.3 and 80V (volts), and can be between 5 and 50V, while the AC voltage can be between 1.5 and 35V, and can be between Between 3.3 and 25V. Therefore, the design of the system and the design of the sensing and driving integrated circuit (Integrated Circuit, IC) are relatively easy. The electrical connection can be achieved by conventional conductor connection, which will not be repeated here.

To achieve such a small movement gap in a conventional way, it is usually achieved by using a sacrificial layer. For example, a sacrificial layer and a protective layer on the sacrificial layer are formed first, and then several openings are formed on the protective layer, and the sacrificial layer is etched away through these openings. However, due to the small gap, it is difficult to remove the sacrificial layer (capillary phenomenon), or if the sacrificial layer is removed, the thin film structure will stick to the bottom electrode, so the nanoscale sacrificial layer structure is not possible. Efficient and not easy to manufacture. In addition, these openings need to be filled in the end, and the filling material is easy to fall into the opening and resist the two membranes, so that the structure cannot achieve the function of vibration. Therefore, conventional techniques cannot easily achieve this. The current trend is that the larger the area of the finger biometric sensor, the better, which can satisfy the user's blind press (any press can complete the desired function), or can press more than two fingerprints at the same time to increase security. Integrated circuit manufacturing process, the cost will remain high. If the traditional piezoelectric material block is used to integrate or apply to the thin film transistor liquid crystal display (TFT-LCD), it is very difficult to implement, the reason is as mentioned above, because the piezoelectric material block needs a very high temperature to complete the sintering . Therefore, the structure and materials of the present invention are very simple. Not only are the materials non-polluting, but the manufacturing temperature is also quite low (<400° C.), and can be integrated into any TFT manufacturing process, silicon integrated circuit manufacturing process (such as CMOS process) and the like.

In this embodiment, the first sensing electrode 41 includes a semiconductor metal compound (in this embodiment, a metal silicide layer 41A) and a metal layer 41B (not necessary, because it may become a metal silicide layer after complete reaction). 41A), to provide a complete capacitive sensing electrode to sense the capacitance change between the second sensing electrode 42 and generate a sensing signal. The metal silicide layer 41A is buried in the second semiconductor layer 44 , and the metal layer 41B is located on the metal silicide layer 41A. In one example, the metal layer 41B (materials such as nickel, titanium, tungsten, etc., especially nickel in this embodiment) and the second semiconductor layer 44 (materials such as amorphous silicon or polysilicon) undergo a thermal reaction (<400° C.) , can be partially or fully reacted to form the metal silicide layer 41A. Through the volume reduction of the metal silicide in the formation process and the selectivity of materials, for example, the preferred embodiment of the present invention uses nickel and silicon as a pair of materials, nickel and a protective layer 60 (such as silicon oxide or silicon nitride, which can be a single-layer or multi-layer material), does not react at a temperature of 400°C, so the nickel (metal layer 41B) will react toward the second semiconductor layer 44 and shrink the nickel (metal layer 41B) Therefore, the movement gap between the nickel (metal layer 41B) and the protective layer 60 begins to gradually increase from zero. Through the control of material thickness, reaction temperature and time, the nickel (metal layer 41B) can be completely reacted or partially reacted. reaction. Therefore, the moving gap 43 in this embodiment is formed after the semiconductor metal compound is formed. In other words, the moving gap 43 directly adjoins the underlying metal layer 41B, and the metal layer 41B directly adjoins the metal silicide layer 41A (since other semiconductor materials may be used, other embodiments may be semiconducting metal compounds); or, when the metal layer When 41B completely becomes a semiconducting metal compound due to complete reaction with the second semiconductor layer 44 , the mobile gap 43 directly adjoins the semiconducting metal compound thereunder. Therefore, the moving gap 43 adjoins the semiconducting metal compound through the metal layer 41B of the first sensing electrode 41 , or directly adjoins the semiconducting metal compound. The gap below the protective layer can be accurately controlled in a predetermined nanometer range. For example, the thickness of a nickel film made by semiconductor physical vapor deposition (Physical vapor deposition, PVD) can be 100nm or 50nm (can be between 300nm ~ 30nm, Even 200nm~50nm), the gap formed is the same or equivalent order of magnitude. This method can really achieve the advantages mentioned above, and only use a small operating voltage (<18V) to get a large electric field to drive Piezoelectric d33-like device.

Therefore, the piezoelectric d33-like device 100 further includes the aforementioned protective layer 60 and an insulating layer 70 (such as oxide or nitride or a stack thereof or other materials). The selection of the material of the protective layer 60 is very important, it will affect the sensing performance, in one embodiment, it can be a material with a dielectric constant greater than 3, or even greater than 5, and the material that can be used is silicon nitride or aluminum oxide, etc. High dielectric constant material. The thickness of the protective layer is less than 0.5 microns or 0.3 microns. The protection layer 60 covers the drain 32 , the source 33 , the first semiconductor layer 34 and the second semiconductor layer 44 . The moving gap 43 is surrounded by the protective layer 60 and the first sensing electrode 41 , and the second sensing electrode 42 is located on the protective layer 60 . The insulating layer 70 covers the gate 31 and the substrate 10 , and supports the first semiconductor layer 34 and the second semiconductor layer 44 . So far, those skilled in the art can understand that the device of the present invention can be completed by only adding a silicide metal process (the preferred embodiment of the metal is Ni, but not limited thereto) through the temperature and materials compatible with the TFT process. The manufacture of piezoelectric d33-like devices is not only a major advantage in integration, but also a major advantage in cost and performance. Of course, only part of the TFT process and structure are used here to illustrate, for example, other such as the latter ITO electrodes, such as OLED or LCD materials or other electronic equipment materials and structures, etc., are not the purpose of the present invention, so they are ignored here. However, any process adjustment or material change, whether it is the current technology or Future new technologies will not change or affect the spirit of the present invention.

In one example, the first sensing electrodes 41 of the transceiver units 40 are directly or indirectly electrically connected together through the second semiconductor layer 44 and the first semiconductor layer 34 to serve as an integrated common electrode. In another example, a plurality of second sensing electrodes 42 can also be electrically connected together as a common electrode.

It can be understood that although FIG. 8 belongs to a bottom-gate thin film transistor, FIG. 8 can also be changed into a top-gate thin film transistor.

In addition to sensing fingerprints, the above-mentioned piezoelectric d33-like device 100 can also be used to sense vein images or blood flow information of the finger F, which can be achieved through time-of-fly (TOF) sensing, combined with The aforementioned implementation of fingerprint sensing in Figure 7, the present invention can combine both, using the same device to simultaneously sense fingerprints and finger veins, and even measure blood flow rate and heartbeat.

FIG. 9 shows a schematic diagram of integrating the piezoelectric d33 device of the present invention into a CMOS back-end process. That is to say, the transistors and circuits in the front-end process are manufactured first, and then the transceiver unit in the back-end is manufactured. As shown in FIG. 9 , only a part of the piezoelectric d33-like device 100 is shown, that is, only the part of the transceiver unit, and the part of the transistor is omitted. The piezoelectric d33-like device 100 of this embodiment at least includes a body 110 , a first sensing electrode 41 , a second sensing electrode 42 and a moving gap 43 .

The first sensing electrode 41 is located in the body 110 . The second sensing electrode 42 is located in the body 110 and corresponds to the first sensing electrode 41. At least one of the first sensing electrode 41 and the second sensing electrode 42 is made of a metal material (especially nickel) and a semiconductor. Compounds formed by the reaction of materials, especially silicon. The moving gap 43 is formed in the body 110 and located between the first sensing electrode 41 and the second sensing electrode 42 .

The body 110 includes a substrate 10 (equivalent to the substrate 10 in FIG. 8 ), a dielectric layer group 112 (similar to the insulating layer 70 in FIG. Dielectric layer, can also be arranged in the corresponding position of Figure 4), a semiconductor material layer 113 (equivalent to the second semiconductor layer 44 in Figure 8), an inter-electrode dielectric 114 (equivalent to the protective layer in Figure 8 60) and protective layer 115. The semiconductor material layer 113 includes the aforementioned semiconductor materials.

The dielectric layer set 112 is located on the substrate 10 . The semiconductor material layer 113 is located on the dielectric layer set 112 , and the first sensing electrode 41 is located on the semiconductor material layer 113 . The inter-electrode dielectric 114 and the first sensing electrode 41 jointly define a moving gap 43 , and the second sensing electrode 42 is located on the inter-electrode dielectric 114 . The passivation layer 115 covers the inter-electrode dielectric 114 and the second sensing electrode 42 .

The first sensing electrode 41 includes a metal silicide layer 41A and a metal layer 41B. The metal layer 41B may include the aforementioned metal material. The metal silicide layer 41A is located on the semiconductor material layer 113 . The metal layer 41B is adjacent to the moving gap 43 and is located on the metal silicide layer 41A. The metal silicide layer 41A is formed after the metal layer 41B and the semiconductor material layer 113 are thermally reacted.

In this embodiment, the first sensing electrode 41 includes a metal conductor such as nickel (Ni), titanium (Ti), tungsten (W) and the like. The second sensing electrode 42 can be the same metal conductor or low-resistance semiconductor or polymer conductor as the first sensing electrode, and the semiconductor material layer 113 is polysilicon or amorphous silicon layer, and can also be other semiconductor material layers. , such as a germanium (Ge) layer.

The dielectric layer set 112 is located on the substrate 10 . It should be noted that the dielectric layer group 112 can be a multi-layer structure, and in the composition structure of a general integrated circuit, it can be a conductor layer (such as a metal layer) formed in a back-end process, a dielectric layer between conductor layers, and a conductor layer between conductor layers. Embolism conductor (via conductor), since this technology is a known technology, so it will not be repeated here. Of course, the dielectric layer group 112 may include circuits composed of multiple dielectric layers and multiple metal connection layers, and cooperate with active circuit elements and passive circuit elements in the silicon substrate 10 to form a set of integrated circuits 112A with a specific function. Therefore, the embodiment of the present invention may further include an integrated circuit 112A located on the bottom or side of the piezoelectric d33-like device and electrically connected to the first sensing electrode 41 and the second sensing electrode 42 for signal processing.

The semiconductor material layer 113 is located on the dielectric layer set 112 . The metal silicide layer 41A is formed in the semiconductor material layer 113 . The metal layer 41B is located on the semiconductor material layer 113 and connected to and corresponding to the metal silicide layer 41A. Through photolithography, the semiconductor material layer 113, the metal layer 41B and the metal silicide layer 41A only occupy part of the area of the dielectric layer group 112, so the inter-electrode dielectric 114 can also be located in a part of the dielectric layer group 112 superior. Therefore, a moving gap 43 is formed through the sealing of the surrounding and the upper and lower sides, and the characteristics of the formation of this cavity will be described later. At the same time, it is worth noting that the metal layer 41B originally occupies the entire volume of the moving gap 43 , but part of the volume is consumed due to the formation of a compound with the underlying semiconductor material layer 113 at high temperature, thus forming the moving gap 43 .

The moving gap 43 is located between the inter-electrode dielectric 114 and the metal layer 41B, and the inter-electrode dielectric 114 may or may not be separated therebetween. The second sensing electrode 42 is located on the inter-electrode dielectric 114 and corresponds to the moving gap 43 and the metal layer 41B. The protective layer 115 is located on the second sensing electrode 42 and the inter-electrode dielectric 114 . The surface of the protective layer 115 can thus be pressed by objects. The protective layer 115 may also be a multiple-layer insulating layer structure, and conductive materials may be added thereon due to system design requirements such as electrostatic protection requirements. Therefore, the uppermost surface of the protective layer 115 can be pressed by an object to which multiple information can be input. Of course, if the second sensing electrode 42 is not affected by environmental interference, for example, it will not be exposed to corrosion, then the protective layer 115 in this embodiment may also be unnecessary. Therefore, the transceiver unit further has: a dielectric layer group 112, located between the substrate 10 and the first sensing electrode 41, the substrate 10 and the dielectric layer group 112 together form an integrated circuit 112A, electrically connected to the first sensing electrode 41 And the second sensing electrode 42 ; the inter-electrode dielectric 114 located between the moving gap 43 and the second sensing electrode 42 ; and the protection layer 115 covering the second sensing electrode 42 . It is worth noting that the protective layer 115 is not a necessary component, so it can also be omitted.

In the above embodiments, a glass substrate or a flexible substrate can be used, the cost of which is much lower than that of a semiconductor substrate, and it is easy to integrate with the manufacturing process of a mobile phone display. The piezoelectric d33-like device 100 can be used to sense biological information such as gestures, fingerprints, and finger veins, or non-biological information (industrial applications). For a fingerprint sensor, the integrated transceivers 20 are arranged in a two-dimensional array with a pitch of about 50 to 70 microns. The piezoelectric d33-like device 100 can be an independent device, or can be integrated with a display to become a part of the display.

9A to 9C show schematic diagrams of several variations of FIG. 9 . As shown in FIG. 9A , this modification is similar to FIG. 9 , except that the dielectric layer group 112 has a plurality of metal plugs 112B, such as copper plugs or tungsten plugs (of course not limited thereto), which are set Between the first sensing electrode 41 and the integrated circuit 112A, the first sensing electrode 41 is electrically connected to the integrated circuit 112A by electrically contacting the metal silicide layer 41A. The integrated circuit 112A has the aforementioned at least one transistor electrically connected to the transceiver unit, and is disposed on or in the substrate 10 . The substrate 10 is, for example, a silicon substrate used in a CMOS device, and of course it is not limited to a silicon semiconductor substrate or a CMOS device. It should be noted that the dielectric layer set 112 and the metal connection layer can also be electrically connected through other metal plugs (not shown). In addition, FIG. 9 may also have a metal plug, at this time, the metal plug is disposed between the dielectric layer group 112 and the semiconductor material layer 113 , and electrically connects the first sensing electrode 41 to the integrated circuit 112A. Therefore, in FIG. 9 and FIG. 9A , the metal plug 112B can serve as an electrical contact layer between the integrated circuit 112A and the metal silicide layer 41A or a semiconductor material layer 113 of the second sensing electrode. As shown in FIG. 9B , this embodiment is similar to FIG. 9A , except that the second sensing electrode 42 is formed. In FIG. 9B, after the inter-electrode dielectric 114 is completed, a planarization process such as chemical mechanical polishing (CMP) is performed on the inter-electrode dielectric 114, and then the prepared silicon wafer (single An insulating layer 410 is formed on the insulating layer 400, and then a polysilicon layer (42) is formed on the insulating layer 410, and the polysilicon layer (42) is bonded to the inter-electrode dielectric 114. In one example, the inter-electrode dielectric 114 is, for example, a chemically mechanically polished silicon oxide layer used as an interface layer for fusion bonding. The inter-electrode dielectric 114 forms an interface with hydrogen bond strength with another single crystal silicon wafer through low temperature fusion bonding. Of course, before forming the low-temperature joint, in order to achieve surface activation, it may also include surface plasma (Plasma) treatment, such as exposure to the plasma environment of oxygen (O ₂ ) and nitrogen (N ₂ ), and in order to make the joint surface Very good flatness, and the surface to be joined can be polished and flattened by CMP. Next, the silicon wafer 400 is thinned, and the remaining silicon wafer 400 is etched to expose the insulating layer 410, and then the insulating layer 410 is removed (or the removal 410 may not be removed) to expose the polysilicon layer (42), and the polysilicon layer ( 42) Patterning to form the second sensing electrodes 42 . Finally, the protective layer 115 shown in FIG. 9A is formed (this protective layer can also be the aforementioned insulating layer 410). It should be noted that the above-mentioned polysilicon layer (42) can also be replaced by another single crystal silicon wafer, and the process used is a known silicon on insulating layer (Silicon On Insulator, SOI) process. Let me repeat.

As shown in FIG. 9C , this embodiment is similar to FIG. 9A , except that the second sensing electrode 42 is formed. In FIG. 9C, after the inter-electrode dielectric 114 is completed, a planarization process such as CMP is performed on the inter-electrode dielectric 114, and then the prepared silicon wafer (single crystal silicon) 400 is bonded to the inter-electrode dielectric. Quality 114 (similar to the fusion junction described above). Of course, polymer bonding technology or other metal fusion bonding technology (eutectic bonding) and the like may also be used. Next, the silicon wafer 400 is thinned to form the second sensing electrodes 42 . Finally, the protective layer 115 shown in FIG. 9A is formed.

FIG. 10 shows a schematic diagram of a variant of FIG. 4 . As shown in FIG. 10 , this example integrates FIG. 4 to FIG. 9C , and the piezoelectric d33-like device 100 further includes a substrate 10 and a circuit layer 112T. The circuit layer 112T (including passive elements (optional), at least one active element (such as a transistor) and interconnection lines) is located on the substrate 10 or partially located in the substrate 10, the first sensing electrode 41 is located on the circuit layer 112T, And electrically connected to the circuit layer 112T, the circuit layer 112T controls the corresponding receiver to generate a sensing signal. The circuit layer 112T may be formed by TFT or CMOS process. In this embodiment, the moving gap 43 is generated after the semiconductor material and the metal material react thermally to form a semiconductor metal compound. The circuit layer 112T includes at least a plurality of metal plugs 112V, at least one metal wiring layer 112M, and an integrated circuit 112A. Electrically connected to integrated circuit 112A. The integrated circuit 112A includes at least transistors. The underlying metal 41C is under the semiconducting metal compound and on the circuit layer 112T.

In actual production, semiconductor material (especially silicon) can be disposed on the circuit layer 112T (the deposition temperature of the semiconductor material should be lower than 400° C. to avoid damaging the function of the underlying circuit layer 112T), and metal material can be disposed on the semiconductor material ( Especially silicon) (the deposition temperature of the metal material should be lower than 300°C to avoid the formation of semiconducting metal compounds during deposition), and then sequentially form the inter-electrode dielectric 114 (the deposition temperature should be lower than 300°C to avoid deposition During the formation of semiconducting metal compound), the second sensing electrode 42 and the protective layer 115, and then heated to higher than 300 ° C or even 350 ° C, so that the metal material and the semiconductor material react to form a semiconducting metal compound, and at the same time form the moving gap 43, wherein Both the semiconductor material and the metal material may have just finished reacting, or one or both of them remain partially.

In another example, during actual fabrication, after the metal wiring layer 112M is formed, an uppermost layer of dielectric (which may be a single or multiple layers of dielectric) can be used to cover the metal wiring layer 112M, and then the dielectric Etching to define the hole of the metal plug 112V, and then filling the hole with a metal material (such as titanium, tungsten or molybdenum), and at the same time, the metal material covers the dielectric to form the bottom metal 41C, the bottom metal 41C can be single-layer or multi-layer Metallic material structures to act as contacting metal structures. The deposition temperature of the underlying metal 41C should be lower than 400° C. to avoid damaging the function of the underlying circuit layer 112T. Next, a semiconductor material layer (the deposition temperature of the semiconductor material should be lower than 400° C. to avoid the formation of a semiconductor metal compound) and a metal material (such as nickel) are respectively formed on the underlying metal 41C to form a sandwich structure and an inter-electrode dielectric 114 ( The deposition temperature should be lower than 300°C to avoid the formation of semiconducting metal compounds during deposition), the second sensing electrode 42 and the protective layer 115, and then to higher than 300°C or even 350°C for thermal reaction to form the moving gap 43 and the first A sensing electrode 41 . For example, titanium and silicon require a very high temperature (combination reaction temperature) to form titanium silicide, and the reaction temperature of nickel and silicon is relatively low, so when nickel and silicon form nickel silicide, titanium will not interfere with nickel silicide form. Therefore, the metal plug 112V first electrically contacts the underlying metal 41C, and the underlying metal 41C electrically contacts the first sensing electrode 41 . In this way, it is more helpful to reduce the resistance value of the connection between the first sensing electrode 41 and the circuit layer 112T at the bottom.

Although the aforementioned metal plug 112V and the underlying metal 41C have the same material, in another example, the metal plug 112V and the underlying metal 41C may have different materials, and the underlying metal 41C may be composed of multiple layers of materials.

The piezoelectric d33-like device in the above embodiment can be used as a biological information sensing, touch, and pressure sensing device. Using the above design criteria of d/ε _r + t ₀ ≤ 100 nm, the pressure sensing device can be Sensing performance optimization. In addition, the arrangement of the contact layer can improve the electrical contact effect.

The specific embodiments proposed in the detailed description of the preferred embodiments are only used to facilitate the description of the technical content of the present invention, rather than restricting the present invention to the above-mentioned embodiments in a narrow sense, without departing from the spirit of the present invention and applying for patents below The circumstances of the range, the implementation of various changes, all belong to the scope of the present invention. For example, the first sensing electrode and the second sensing electrode mentioned above can be intermodulated in position, as long as one of the sensing electrodes contains a semiconducting metal compound and is formed by the thermal reaction process of the semiconducting metal compound. Just move the gap.

F: Object/Finger FR: Ribbon FV: Wenya W1: the first vibration wave W2: second vibration wave W3: Interference wave X, Y: coordinate axis 10: Substrate 10B: lower surface 10T: upper surface 20: Integrated transceiver 30: Transistor 31: gate 32: drain 33: source 34: The first semiconductor layer 40: transceiver unit 40R: Receiver 40T: Transmitter 41: the first sensing electrode 41A: metal silicide layer 41B: metal layer 41C: Underlying metal 41D: residual semiconductor material layer 41E: Reactive compound layer 41T: upper surface 42: The second sensing electrode 42B: lower surface 43: Mobile gap 44: Second semiconductor layer 50: Drive sensing circuit module 60: protective layer 70: insulation layer 100: Piezoelectric d33-like device 110: Ontology 112: Dielectric layer group 112A: integrated circuit 112B: metal plug 112M: metal wiring layer 112T: circuit layer 112V: metal plug 113: Semiconductor material layer 114: Dielectric between electrodes 114B: lower surface 114T: upper surface 115: protective layer 116: encapsulation layer 117:Coupling layer 118: cover plate 200: mobile phone 210: Display 220: Operation block 230: front lens 240: back cover 250: rear lens 270: Processor 300:d33 vibrating transceiver 310: piezoelectric material block 311: the first sensing electrode 312: the second sensing electrode 320: Vibration direction 330: Electric field direction 340: Voltage source 400: silicon wafer 410: insulating layer

[Fig. 1A] and [Fig. 1B] show a schematic diagram of a traditional d33 vibrating transceiver. [ FIG. 2A ], [ FIG. 2B ] and [ FIG. 3 ] are schematic diagrams showing three applications of piezoelectric d33 -like devices according to preferred embodiments of the present invention. [ FIG. 4 ] and [ FIG. 5 ] show schematic diagrams of the configuration of piezoelectric d33 -like devices according to a preferred embodiment of the present invention. [Fig. 6] is a schematic diagram showing the capacitive sensing principle of [Fig. 4] and [Fig. 5]. [FIG. 7] A schematic diagram showing a piezoelectric d33-like device according to a preferred embodiment of the present invention. [ Fig. 8 ] A partial cross-sectional view showing another example of the piezoelectric d33-like device. [FIG. 9] A schematic diagram showing the integration of the piezoelectric d33 device of the present invention into a CMOS back-end process. [ FIG. 9A ] to [ FIG. 9C ] are schematic diagrams showing several modification examples of [ FIG. 9 ]. [ FIG. 10 ] A schematic diagram showing a modified example of [ FIG. 4 ].

X, Y: coordinate axis

d: thickness

t ₀ : initial height

10: Substrate

40: transceiver unit

40R: Receiver

40T: Transmitter

41: the first sensing electrode

41T: upper surface

42: The second sensing electrode

42B: lower surface

43: Mobile gap

100: Piezoelectric d33-like device

114: Dielectric between electrodes

114B: lower surface

114T: upper surface

115: protective layer

116: encapsulation layer

117:Coupling layer

118: cover plate

Claims (24)

A piezoelectric d33 device comprising at least: a pair of complete and substantially parallel electrodes having a first sensing electrode and a second sensing electrode constituting a receiver; a moving gap located at the first sensing electrode and the second sensing electrode, wherein the moving gap has an initial height _t0 and is generated by a semiconductor material and a metal material through a thermal reaction to form a semiconductor metal compound, and the first sensing electrode includes the semiconductor metal compound to provide a complete capacitive sensing electrode to sense the capacitance change between the second sensing electrode and generate a sensing signal; The second sensing electrodes have a thickness d, have a single-layer structure or a multi-layer structure, and have an average dielectric constant ε _r , where t ₀ +d/ε _r ≤ 100 nm is satisfied. The piezoelectric d33-like device as claimed in claim 1, wherein the semiconductor material is amorphous silicon or polysilicon, and the metal material is nickel deposited at a temperature lower than 300°C. The piezoelectric d33-like device as claimed in claim 1, wherein ε _r ≥ 3. The piezoelectric d33-like device as claimed in claim 1, wherein ε _r ≥ 5. The piezoelectric d33-like device as claimed in claim 1, wherein 25 nm ≤ t ₀ ≤ 75 nm. The piezoelectric d33-like device as claimed in claim 1, wherein the inter-electrode dielectric is a material deposited below 300°C. The piezoelectric d33-like device as claimed in claim 1, wherein a material of the inter-electrode dielectric is selected from the group consisting of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, tantalum oxide, and titanium oxide Group. The piezoelectric d33-like device as claimed in claim 1, wherein the first sensing electrode further comprises an underlying metal located under the semiconductor metal compound. The piezoelectric d33-like device as claimed in claim 8, wherein the underlying metal has a single-layer structure or a multi-layer structure. The piezoelectric d33-like device as claimed in claim 8, wherein a material of the underlying metal is selected from the group consisting of titanium, titanium nitride, tungsten and molybdenum. The piezoelectric d33-like device as described in Claim 1, further comprising at least: a substrate; and a circuit layer, including at least one active circuit element and at least one interconnection line, and located on the substrate or partially located in the substrate, wherein the first sensing electrode is located on the circuit layer and electrically connected to the circuit layer, and The circuit layer controls the receiver to generate the sensing signal. The piezoelectric d33-like device as claimed in claim 11, wherein the first sensing electrode further comprises an underlying metal deposited at a temperature lower than 400° C., located under the semiconductor metal compound and electrically connected to the circuit layer. The piezoelectric d33-like device as described in claim 11, wherein the circuit layer includes a plurality of metal plugs, at least one metal wiring layer, and an integrated circuit, and the metal plugs pass through the at least one metal wiring layer to the The first sensing electrode is electrically connected to the integrated circuit. The piezoelectric d33-like device as claimed in claim 13, wherein the first sensing electrode further comprises an underlying metal under the semiconductor metal compound, wherein the metal plugs and the underlying metal are made of the same material constitute. The piezoelectric d33-like device as claimed in claim 13, wherein the first sensing electrode further comprises an underlying metal under the semiconductor metal compound, wherein the metal plugs and the underlying metal are made of different materials constitute. The piezoelectric d33-like device as described in claim item 11, wherein the receiver is further used as a transmitter, and as a transceiver unit, and the transceiver unit and the circuit layer form an integrated transceiver, and the circuit layer is formed on a The first time point controls the transceiver unit to receive a second vibration wave at a second time point after the transceiver unit emits a first vibration wave. The piezoelectric d33-like device as described in claim 16 further includes a driving and sensing circuit module electrically connected to the integrated transceiver, and provides a driving voltage of a DC voltage plus an AC voltage to the integrated Transceivers to further improve signal transmission and sensing effects. The piezoelectric d33-like device as claimed in claim 17, wherein the direct current voltage is between 3.3 and 80 volts, and the alternating current voltage is between 1.5 and 35 volts. The piezoelectric d33-like device as described in Claim 1, wherein the receiver is further used as a transmitter, and as a transceiver unit, wherein the second sensing electrode vibrates at a first time point and emits a first vibration wave , and then receive a second vibration wave at a second time point. The piezoelectric d33-like device as described in claim 1, further comprising: a protective layer located on the second sensing electrode; and A coupling layer is located on the protection layer. The piezoelectric d33-like device as described in claim 1, further comprising: a protection layer located on the second sensing electrode; an encapsulation layer located on the protective layer; and A coupling layer is located on the encapsulation layer. The piezoelectric d33-like device as claimed in claim 20 or 21 further includes a cover plate located on the coupling layer. The piezoelectric d33-like device as described in Claim 22 is used as a button. An electronic device comprising at least: at least one processor; and The piezoelectric d33-like device according to any one of claims 1 to 21, wherein the processor is electrically connected to the piezoelectric d33-like device and processes the sensing signal from the piezoelectric d33-like device.

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