TW202138921A - Transducer apparatus、transducer structure and fabricating method thereof - Google Patents

Abstract

A transducer structure includes a substrate, a first electrode, an inorganic layer, a first insulator layer, second insulator portions and a second electrode. The first electrode is disposed on the substrate. The inorganic layer is on the first electrode and has a bottom membrane and holes on two sides of the bottom membrane. The first insulator layer includes a top membrane and first insulator portions. The top membrane is on the bottom membrane. The first insulator portions are on the first electrode. The first electrode, the first insulator portions and the bottom membrane collectively form a cavity. The second insulator portions are respectively on the first insulator portions and are in contact with the first insulator portions by the holes. The second insulator portions have a material different from a material of the first insulator portions. The second electrode is on the top membrane. The cavity is between the first electrode and the second electrode.

Description

Energy conversion device, energy conversion structure and manufacturing method thereof

The invention relates to an energy conversion device, an energy conversion structure and a manufacturing method thereof.

Ultrasonic imaging technology uses the principle of ultrasonic reflection to create images. For example, it transmits vibrations excited by electronic pulses into the body. After the vibrations reach the boundary of the object to be measured, they are bounced back, and then converted into electric currents. Presented for images. The ultrasonic transducer can be used in biomedical imaging, fingerprint recognition and gesture recognition. Common ultrasonic transducers include three types of technologies, such as bulk piezoelectric ceramics transducers, capacitive micromachined ultrasonic transducers (CMUT), and piezoelectric micromachined ultrasonic transducers. Acoustic wave sensor (piezoelectric micromachined ultrasonic transducer; PMUT). If the reliability of the components of the transducer is low, it may affect the transmission of ultrasonic waves.

The invention provides an energy conversion structure and an energy conversion device, and the surface of the upper oscillation part is high in flatness.

The present invention provides a manufacturing method of a transducer structure, which does not need to etch the second insulating layer, and avoids the risk of damage to the upper oscillating portion caused by over-etching the upper oscillating portion when the etching process is inaccurate.

The energy conversion structure of the present invention includes a substrate, a first electrode, an inorganic layer, a first insulating layer, a plurality of second insulating parts, and a second electrode. The first electrode is configured on the substrate. The inorganic layer is located on the first electrode, the inorganic layer has a lower oscillation part and a plurality of holes, and the holes are located on two sides of the lower oscillation part. The first insulating layer includes an upper oscillating portion and a plurality of first insulating portions, the upper oscillating portion is located on the lower oscillating portion, the multiple first insulating portions are located on the first electrode, and the first electrode, the first insulating portion and the lower oscillating portion The parts together form a cavity. The second insulating parts are respectively located on the first insulating part, the second insulating parts respectively contact the first insulating part through the holes, and the material of the second insulating part is different from the material of the first insulating part. The second electrode is located on the upper oscillating part, and the cavity is located between the first electrode and the second electrode.

The energy conversion device of the present invention includes a plurality of energy conversion structures and circuits as described above. The first electrodes of each energy conversion structure are separated from each other along at least one direction, and the first electrodes are arranged in an array. The circuit is located on one side of the energy conversion structure, wherein the first electrodes of the energy conversion structure are electrically connected to each other through the circuit, and the circuit and the first electrode are the same film layer.

The manufacturing method of the transducer structure of the present invention includes the following steps. The first electrode is formed on the substrate. A sacrificial layer is formed on the first electrode. An inorganic layer is formed on the sacrificial layer and the first electrode. The inorganic layer is patterned to form a plurality of upper holes and a lower oscillating part. The upper holes are located on two sides of the lower oscillating part, and the sacrificial layer is exposed through the upper holes. The sacrificial layer is removed to form a lower hole under the upper hole and an accommodating space under the lower oscillating part. A first insulating layer is formed on the inorganic layer, wherein the first insulating layer has a plurality of first insulating parts and an upper oscillating part, the upper oscillating part is located on the lower oscillating part, the first insulating parts are respectively filled into the lower holes, An electrode, the first insulating part and the lower oscillating part jointly form a cavity. The upper holes are respectively filled with the second insulating parts, and the upper holes are respectively filled with the second insulating parts. The second insulating parts are respectively located on the first insulating parts, and the material of the second insulating parts includes photoresist.

Based on the above, the surface flatness of the upper oscillating part of the transducing structure and the transducing device of the present invention is high. Thereby, the frequency of the ultrasonic wave provided by the oscillating membrane formed by the upper oscillating part and the lower oscillating part has high stability. The manufacturing method of the transducer structure of the present invention can use a photomask to perform a lithography process on the second insulating layer to remove part of the second insulating layer, thereby forming the second insulating portion. Since the material of the second insulating layer is different from the material of the first insulating layer, the upper oscillation part will not be damaged when part of the second insulating layer is removed. And it does not need to etch the second insulating layer, which avoids the risk of damage to the upper oscillating part caused by over-etching the upper oscillating part when the etching process is inaccurate.

Reference will now be made in detail to the exemplary embodiments of the present invention, and examples of the exemplary embodiments are illustrated in the accompanying drawings. Whenever possible, the same component symbols are used in the drawings and descriptions to indicate the same or similar parts.

Figures 1 to 10 are schematic cross-sectional views of the manufacturing process of the transducer structure 10 according to an embodiment of the present invention. Referring to FIG. 1, first, the first electrode 102 is formed on the substrate 100. The substrate 100 may include a rigid substrate or a flexible substrate, and the material thereof is, for example, glass, plastic, or other suitable materials, or a combination of the foregoing, but is not limited thereto. In some embodiments, the material of the first electrode 102 may include metal, such as aluminum and copper. In some embodiments, the method for forming the first electrode 102 may be chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), Vacuum thermal evaporation (VTE), sputtering, or a combination thereof.

Please refer to FIG. 2, the sacrificial film material 104 is formed on the first electrode 102 in an all-round way. Next, a patterned photoresist 106 is formed on the sacrificial film material 104. In this embodiment, the sacrificial film material 104 may include metal, metal oxide or indium tin oxide (Indium Tin Oxide, ITO), where the metal is, for example, copper (Cu), titanium (Ti), aluminum (Al), Silver (Ag), iron (Fe), nickel (Ni), molybdenum (Mo), tungsten (W). The method for forming the patterned photoresist 106 is, for example, to form a photoresist material layer (not shown) on the sacrificial film material 104, and use the photomask 108 to perform a photolithography process on the photoresist material layer to form the patterned photoresist 106.

After that, using the patterned photoresist 106 as a mask, an etching process is performed on the sacrificial film material 104, and then the patterned photoresist 106 is removed to form a sacrificial layer 104A on the first electrode 102, as shown in FIG. The method of removing the patterned photoresist 106 is, for example, a photoresist stripping process. In this embodiment, the thickness t0 of the sacrificial layer 104A is 500 angstroms to 5000 angstroms.

Next, referring to FIG. 4, an inorganic layer 110 is formed on the sacrificial layer 104A and the first electrode 102. For example, the material of the inorganic layer 110 is silicon nitride (SiN _x ), for example. In this embodiment, the thickness t1 of the inorganic layer 110 is, for example, between 3000 angstroms and 9000 angstroms. In this way, the thickness t1 of the as-deposited inorganic layer 110 is small enough to prevent the substrate 100 from bending. In this embodiment, the material of the inorganic layer 110 is, for example, silicon nitride (SiN _x ).

Please refer to FIG. 5, the inorganic layer 110 is patterned to form a plurality of upper holes TH1 and a lower oscillating portion 110A. For example, two upper holes TH1 can be formed. The upper hole TH1 is located on both sides of the lower oscillating part 110A. In other words, the lower oscillation part 110A is located between the upper holes TH1. And the two ends of the sacrificial layer 104A are exposed through the upper hole TH1. The upper hole TH1 is equivalent to an etching hole for removing the sacrificial layer 104A. In this embodiment, the thickness t1 of the lower oscillating portion 110A is, for example, between 3000 angstroms and 9000 angstroms.

Referring to FIG. 6, the sacrificial layer 104A is removed by the upper hole TH1 to form a lower hole TH2 under the upper hole TH1 and an accommodation space SP under the lower oscillation part 110A. In this embodiment, the method for removing the sacrificial layer 104A is, for example, an etching process.

Referring to FIG. 7, a first insulating layer 112 is formed on the inorganic layer 110 and the first electrode 102. For example, the first insulating layer 112 includes an upper oscillating portion 112A and a plurality of first insulating portions 112B. For example, the first insulating layer 112 may include two first insulating portions 112B. The first insulating portion 112B is respectively filled into the lower hole TH2 through the upper hole TH1, so that the first insulating portion 112B is located on the first electrode 102, that is, the first insulating portion 112B contacts the first electrode 102, whereby the first insulating portion 112B is in contact with the first electrode 102. The electrode 102, the first insulating portion 112B, and the lower oscillating portion 110A together form a cavity CVT. The cavity CVT can be air or vacuum.

The upper oscillating part 112A is located above the lower oscillating part 110A. The thickness t2 of each first insulating portion 112B is greater than and/or equal to the height t00 of the cavity CVT (or the thickness t0 of the sacrificial layer 104A) to ensure the reliability of the subsequent manufacturing process. For example, it can be ensured that the second insulating layer 116 (see FIG. 8) to be formed on the first insulating layer 112 will not flow into the cavity CVT and affect the size of the cavity CVT. For example, , Will not reduce the size of the cavity CVT. It is known that the frequency of the ultrasonic waves that can be generated by the transducer structure 10 is inversely related to the size of the cavity CVT. In other words, the larger the size of the cavity CVT, the lower the frequency, and the smaller the size of the cavity CVT, the higher the frequency. Since the size of the cavity CVT is not affected, the reliability of the frequency of the ultrasonic waves that can be generated by the transducer structure 10 can be ensured. In this embodiment, the thickness of the first insulating layer 112 is 1000 angstroms to 5500 angstroms. For example, the thickness t2 of the first insulating portion 112B is at least 500 angstroms greater than the height t00 of the cavity CVT (or the thickness t0 of the sacrificial layer 104A), for example, the thickness t2 of each first insulating portion 112B is 1000 angstroms To 5500 angstroms, the thickness t2 of the upper oscillation portion 112A is 1000 angstroms to 5500 angstroms. In this embodiment, the material of the first insulating layer 112 is the same as the material of the inorganic layer 110. For example, the material of the first insulating layer 112 is silicon nitride (SiN _x ), for example. Thereby, the upper oscillating portion 112A of the first insulating layer 112 and the lower oscillating portion 110A of the inorganic layer 110 can jointly form the oscillating film 114 of the transducer structure 10, and the as-deposited first insulating layer 112 (for example, The thickness t2 of the upper oscillating portion 112A and the first insulating portion 112B) is small enough to avoid bending of the substrate 100, and since the thickness t2 of the first insulating layer 112 is small enough, there is no need to etch the first insulating layer 112 Therefore, the problem of uniformity of thick film etching is also avoided.

In this embodiment, the first insulating layer 112 further includes a sidewall portion 112C, and the sidewall portion 112C is located on the sidewall SS of the upper hole TH1 of the inorganic layer 110. In other words, the side wall portion 112C extends from the top surface of the first insulating portion 112B to the side wall SS of the upper hole TH1 of the inorganic layer 110 and then is connected to the upper oscillating portion 112A, so that the side wall portion 112C and each first insulating portion 112B jointly form a groove 112R . Thereby, it can be further ensured that the second insulating layer 116 (see FIG. 8) to be formed on the first insulating layer 112 will not flow into the cavity CVT and affect the size of the cavity CVT.

Referring to FIG. 8, the second insulating layer 116 is formed on the first insulating layer 112 on the entire surface. For example, the second insulating layer 116 covers the upper oscillation portion 112A of the first insulating layer 112, and the second insulating layer 116 fills the remaining space of the upper hole TH1 of the inorganic layer 110 and fills the sidewall of the first insulating layer 112 The portion 112C and each first insulating portion 112B jointly form a groove 112R. The method of forming the second insulating layer 116 is, for example, a spin coating method. For example, the material of the second insulating layer 116 includes an organic material. In this embodiment, the material of the second insulating layer 116 includes photoresist. The photoresist is a liquid material, so no vacuum equipment or low-temperature equipment is required to form the second insulating layer 116, thereby achieving process convenience. In this embodiment, the thickness of the second insulating layer 116 is 0.5 μm to 3 μm.

Please refer to FIG. 9 to remove part of the second insulating layer 116 to form a plurality of second insulating portions 116A to fill the remaining space of the upper hole TH1 and the groove 112R, respectively. For example, two second insulating portions 116A are formed to fill the remaining space of the two upper holes TH1 and the groove 112R, respectively. The second insulating portions 116A are respectively located on the first insulating portion 112B, and the second insulating portions 116A respectively contact the first insulating portion 112B through the upper hole TH1. In this embodiment, each side wall portion 112C is located between the lower oscillating portion 110A and each second insulating portion 116A along the horizontal direction.

In this embodiment, the material of the second insulating layer 116 is different from the material of the first insulating layer 112. For example, the material of the second insulating layer 116 includes an organic material (such as photoresist). The second insulating layer 116 is subjected to a lithography process to remove part of the second insulating layer 116, thereby forming the second insulating portion 116A. Since the material of the second insulating layer 116 is different from the material of the first insulating layer 112, the first insulating layer 112 is not removed when part of the second insulating layer 116 is removed. In other words, the first insulating layer 112 will not be damaged. For example, the upper oscillating part 112A will not be damaged. It is known that the frequency and stability of the ultrasonic waves that can be generated by the transducer structure 10 are related to the characteristics of the oscillating membrane 114. For example, the frequency of the ultrasonic wave is positively correlated with the thickness of the oscillating membrane 114, and the stability of the ultrasonic wave is positively correlated with the surface flatness of the oscillating membrane 114. Since the upper oscillation portion 112A is not damaged, the surface flatness of the upper oscillation portion 112A is high, in other words, the surface roughness of the upper oscillation portion 112A is low, and the thickness t2 of the upper oscillation portion 112A is uniform. Thereby, the frequency of the ultrasonic wave provided by the oscillating membrane 114 formed by the upper oscillating portion 112A and the lower oscillating portion 110A has high stability, and the reliability of the oscillating membrane 114 is improved.

Since the upper holes TH1 of the inorganic layer 110 are respectively filled by the second insulating portion 116A, and the material of the second insulating portion 116A includes photoresist, the step of etching the second insulating layer 116 can be omitted, in other words. It is not necessary to perform precise etching process control on the second insulating layer 116, and the risk of damage to the upper oscillation portion 112A caused by over-etching the upper oscillation portion 112A caused by the inaccurate etching process is avoided, so that the transducer structure 10 The difficulty of the manufacturing process is reduced.

Referring to FIG. 10, the second electrode 120 is formed on the upper oscillating portion 112A, and the cavity CVT is located between the first electrode 102 and the second electrode 120. In some embodiments, the material of the second electrode 120 may include metal, such as aluminum and copper. In some embodiments, the method for forming the second electrode 120 may be chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), vapor deposition (VTE), sputtering (SPT) or In combination, a metal material layer (not shown) is deposited on the entire surface, and then the second electrode 120 is formed by a process of lithography and etching. At this point, the transducer structure 10 of the present invention is completed. In this embodiment, the transducer structure 10 is an example of a capacitive micromachined ultrasonic transducer (CMUT). The first electrode 102 and the second electrode 120 serve as capacitors for sensing signals, and the cavity CVT can provide a space for the second electrode 120 to vibrate. When ultrasonic waves act on the second electrode 120, the second electrode 120 will start to vibrate, causing the capacitance value between the first electrode 102 and the second electrode 120 to change. With this capacitance change, the receiving circuit ( Not shown) Obtain the signal value.

Fig. 11 is a perspective view of the transducer structure 10 of Fig. 10. For the convenience of description, FIG. 11 shows the first direction D1 and the second direction D2, where the first direction D1 and the second direction D2 intersect. In this embodiment, the first direction D1 is substantially perpendicular to the second direction D2, but the invention is not limited to this. Please refer to FIG. 11, the second electrode 120 extends along the first direction D1.

FIG. 12A is a three-dimensional schematic diagram of an ultrasonic probe 30 according to an embodiment of the present invention. In this embodiment, the ultrasonic probe 30 is an arc-shaped probe (convex-probe) as an example. The ultrasonic probe 30 includes a housing 200, a transducer 20, an acoustic matching layer 202, a backing material 204, an acoustic lens 206, and a cable (not shown). The backing material 204 can reduce the pulse duration and increase the axial resolution. The sonic lens 206 is used for axial focusing, and the sonic matching layer 202 is used to reduce multiple reflections caused by the difference in acoustic impedance between the skin and the ultrasonic probe 30.

Fig. 12B is a schematic top view of the transducer device 20 of Fig. 12A. FIG. 12C is a schematic top view of a transducer device 20a according to another embodiment. Figure 13 is a partial image of Figure 12B under an electron microscope. Figure 14 is a cross-sectional image of Figure 12B along the section line 14-14'. Figure 15 is an enlarged schematic view of area R in Figure 14. Please refer to Figures 12B, 13, 14 and 15 together. The transducer device 20 includes a plurality of transducer structures 10 and at least one circuit 122. The structure of the energy conversion structure 10 is as described above, and will not be repeated here. In this embodiment, the first electrode 102 is disposed on the substrate 100 in a full-surface manner. In addition, the top-view shape of each second electrode 120 is a strip shape and is arranged in an array at intervals along the second direction D2. The circuit 122 is located on one side of the energy conversion structure 10, wherein the first electrodes 102 of the energy conversion structure 10 are electrically connected to each other through the circuit 122, and the circuit 122 and the first electrode 102 are the same film layer. The energy conversion device 20 further includes a circuit 124, wherein the second electrodes 120 of the energy conversion structure 10 are electrically connected to each other through the circuit 124. In this embodiment, the line 124 and the second electrode 120 are the same film layer.

Please see FIG. 14 and FIG. 15, it can be seen that the surface of the oscillating film 114 has a high flatness, and the second insulating layer 116 (see FIG. 8) does not flow into the cavity CVT.

Next, please return to FIG. 12C. For the convenience of description, the upper oscillating portion 112A, the first insulating portion 112B, and the second insulating portion 116A are omitted in FIG. 12C. In this embodiment, the first electrodes 102a of the transducer structures 10 are at least separated from each other along the second direction D2, and the first electrodes 102a are arranged in an array along the second direction D2. In this embodiment, the top view shape of each first electrode 102a is strip-shaped. Thereby, the energy conversion device 20a can have a high light transmittance.

16 to 21 are schematic cross-sectional views of the manufacturing process of the transducer structure 10' according to another embodiment of the present invention. First, referring to FIG. 16, a first electrode 102, a sacrificial layer 104A, and an inorganic layer 110 are sequentially formed on the substrate 100, and then a second electrode 120 ′ is formed on the inorganic layer 110. The formation methods and materials of the first electrode 102, the sacrificial layer 104A, and the inorganic layer 110 are the same as the manufacturing process in FIG. 1 to FIG. 4, so they will not be repeated here. The method for forming the second electrode 120 may be chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), vapor deposition (VTE), sputtering (SPT) or a combination thereof to deposit a whole surface The metal material layer (not shown) of, and then the second electrode 120 is formed by the process of lithography and etching. For example, the material of the inorganic layer 110 is silicon nitride (SiN _x ), for example. In this embodiment, the thickness t1 ′ of the inorganic layer 110 is, for example, between 3000 angstroms and 9000 angstroms. In this way, the thickness t1 ′ of the as-deposited inorganic layer 110 is sufficiently small to avoid bending of the substrate 100. In this embodiment, the material of the inorganic layer 110 is, for example, silicon nitride (SiN _x ).

Next, referring to FIG. 17, the inorganic layer 110 is patterned to form a plurality of upper holes TH1 and a lower oscillation part 110A. For example, two upper holes TH1 can be formed. The upper hole TH1 is located on both sides of the lower oscillating portion 110A, in other words, the lower oscillating portion 110A is located between the upper holes TH1. And the sacrificial layer 104A is exposed through the upper hole TH1. The upper hole TH1 is equivalent to an etching hole for removing the sacrificial layer 104A.

Referring to FIG. 18, the sacrificial layer 104A is removed by the upper hole TH1 to form a plurality of lower holes TH2 located below the upper hole TH1 and an accommodation space SP located below the lower oscillating portion 110A. For example, two lower holes TH2 respectively located below the two upper holes TH1 can be formed. The method of removing the sacrificial layer 104A is, for example, an etching process.

Referring to FIG. 19, a first insulating layer 112 is formed on the inorganic layer 110 and the second electrode 120. The first insulating layer 112 includes an upper oscillating portion 112A and a plurality of first insulating portions 112B. For example, the first insulating layer 112 includes two first insulating portions 112B. The first insulating portion 112B respectively fills the lower hole TH2 under the upper hole TH1 through the upper hole TH1, so that the first insulating portion 112B is located on the first electrode 102, that is, the first insulating portion 112B contacts the first electrode 102, Thereby, the first electrode 102, the first insulating portion 112B, and the lower oscillating portion 110A jointly form a cavity CVT. In this embodiment, the upper oscillating portion 112A is located on the lower oscillating portion 110A and the second electrode 120'. In other words, the second electrode 120' is located between the upper oscillating portion 112A and the lower oscillating portion 110A. In this embodiment, the thickness t2' of the upper oscillating portion 112A is between 1000 angstroms and 5500 angstroms. Thereby, the upper oscillating portion 112A of the first insulating layer 112 and the lower oscillating portion 110A of the inorganic layer 110 can jointly form the oscillating film 114' of the transducer structure 10', and the as-deposited first insulating layer 112 (For example, the upper oscillating portion 112A and the first insulating portion 112B) have a thickness t2' that is small enough to avoid bending of the substrate 100. Moreover, since the thickness t2' of the first insulating layer 112 is sufficiently small and there is no need to perform an etching process on the first insulating layer 112, the problem of uniformity of thick film etching is also avoided.

In this embodiment, the first insulating layer 112 further includes a sidewall portion 112C, which is located at the sidewall SS of the upper hole TH1 of the inorganic layer 110. In other words, the sidewall portion 112C extends from the top surface of the first insulating portion 112B to the inorganic layer. The sidewall SS of the upper hole TH1 of the 110.

Referring to FIG. 20, the second insulating layer 116 is formed on the first insulating layer 112 on the entire surface. For example, the second insulating layer 116 covers the upper oscillation portion 112A of the first insulating layer 112, and the second insulating layer 116 fills the remaining space of the upper hole TH1 of the inorganic layer 110 and fills the sidewall of the first insulating layer 112 The portion 112C and each first insulating portion 112B jointly form a groove 112R. The method of forming the second insulating layer 116 is, for example, a spin coating method. For example, the material of the second insulating layer 116 includes an organic material. In this embodiment, the material of the second insulating layer 116 includes photoresist. The photoresist is a liquid material, so no vacuum equipment or low-temperature equipment is required to form the second insulating layer 116, thereby achieving process convenience.

Referring to FIG. 21, part of the second insulating layer 116 is removed to form a plurality of second insulating portions 116A to fill the remaining space of the upper hole TH1 and the groove 112R, respectively. For example, two second insulating portions 116A are formed to fill the remaining space of the two upper holes TH1 and the groove 112R, respectively. The second insulating portions 116A are respectively located on the first insulating portion 112B, and the second insulating portions 116A respectively contact the first insulating portion 112B through the upper hole TH1. In this embodiment, each side wall portion 112C is located between the lower oscillating portion 110A and each second insulating portion 116A along the horizontal direction.

In this embodiment, the material of the second insulating layer 116 is different from the material of the first insulating portion 112B. For example, the material of the second insulating layer 116 includes an organic material (such as photoresist). The second insulating layer 116 is subjected to a lithography process to remove part of the second insulating layer 116, thereby forming the second insulating portion 116A. Since the material of the second insulating layer 116 is different from the material of the first insulating layer 112, the first insulating layer 112 is not removed when part of the second insulating layer 116 is removed. In other words, the first insulating layer 112 will not be damaged. For example, the upper oscillating part 112A will not be damaged. It is known that the frequency and stability of the ultrasonic waves that can be generated by the transducer structure 10 are related to the characteristics of the oscillating membrane 114'. For example, the frequency of the ultrasonic wave is positively correlated with the thickness of the oscillating membrane 114', and the stability of the ultrasonic wave is positively correlated with the surface flatness of the oscillating membrane 114'. Since the upper oscillation portion 112A is not damaged, the surface flatness of the upper oscillation portion 112A is high, in other words, the surface roughness of the upper oscillation portion 112A is low, and the thickness t2' of the upper oscillation portion 112A is uniform. As a result, the frequency of the ultrasonic wave provided by the oscillating membrane 114 ′ formed by the upper oscillating portion 112A and the lower oscillating portion 110A has high stability.

Since the upper holes TH1 of the inorganic layer 110 are respectively filled by the second insulating portion 116A, and the material of the second insulating portion 116A includes photoresist, the step of etching the second insulating layer 116 can be omitted, in other words. It is not necessary to perform precise etching process control on the second insulating layer 116, and the risk of damage to the upper oscillation portion 112A caused by over-etching the upper oscillation portion 112A caused by the inaccurate etching process is avoided, so that the transducer structure 10 'The difficulty of the process is reduced.

To sum up, since the material of the second insulating layer is different from the material of the first insulating part, for example, the material of the second insulating layer includes organic materials (such as photoresist). The lithography process removes part of the second insulating layer, thereby forming the second insulating portion. Since the material of the second insulating layer is different from the material of the first insulating portion, the first insulating layer is not removed when part of the second insulating layer is removed. In other words, the first insulating layer will not be damaged. For example, it will not damage the upper oscillation part. It is known that the frequency and stability of ultrasonic waves that can be generated by the transducer structure are related to the characteristics of the oscillating membrane. For example, the frequency of the ultrasonic wave is positively correlated with the thickness of the oscillating membrane, and the stability of the ultrasonic wave is positively correlated with the surface flatness of the oscillating membrane. Since the upper oscillation part is not damaged, the surface flatness of the upper oscillation part is high, in other words, the surface roughness of the upper oscillation part is low, and the thickness of the upper oscillation part is uniform. Thereby, the frequency of the ultrasonic wave provided by the oscillating membrane formed by the upper oscillating part and the lower oscillating part has high stability, and the reliability of the oscillating membrane is improved.

10, 10': Transduction structure 14-14': Sectional line 20, 20a: Transducer 30: Ultrasonic probe 100: substrate 102, 102a: first electrode 104: Sacrificial membrane material 104A: Sacrificial layer 106: Patterned photoresist 108: Mask 110: Inorganic layer 112: first insulating layer 112A: Upper oscillation part 112B: The first insulating part 112C: Side wall 112R: Groove 114, 114': oscillating membrane 116: second insulating layer 116A: The second insulating part 118: Mask 120, 120': two electrodes 122: Line 124: Line 200: shell 202: Sonic matching layer 204: Backing material 206: Sonic lens CVT: Cavity D1: First direction D2: second direction R: area SP: housing space SS: side wall t0, t1, t2: thickness t00: height t1', t2': thickness TH1: Upper hole TH2: Lower hole

Read the following detailed description and match the corresponding diagrams to understand many aspects of this disclosure. It should be noted that many of the features in the drawing are not drawn in actual proportions according to the standard practice in the industry. In fact, the size of the feature can be increased or decreased arbitrarily to facilitate the clarity of the discussion. Figures 1 to 10 are schematic cross-sectional views of a manufacturing process of a transducer structure according to an embodiment of the present invention. Figure 11 is a perspective view of the transducer structure of Figure 10. FIG. 12A is a three-dimensional schematic diagram of an ultrasonic probe according to an embodiment of the present invention. Fig. 12B is a schematic top view of the transducer device of Fig. 12A. Figure 12C is a schematic top view of a transducer device according to another embodiment. Figure 13 is a partial image of Figure 12B under an electron microscope. Figure 14 is a cross-sectional image of Figure 12B along the section line 14-14'. Fig. 15 is an enlarged schematic diagram of area R in Fig. 14. 16 to 21 are schematic cross-sectional views of a manufacturing process of a transducer structure according to another embodiment of the present invention.

Domestic deposit information (please note in the order of deposit institution, date and number) without Foreign hosting information (please note in the order of hosting country, institution, date, and number) without

10: Transduction structure

100: substrate

102: first electrode

110: Inorganic layer

110A: Lower oscillation part

112: first insulating layer

112A: Upper oscillation part

112B: The first insulating part

112C: Side wall

112R: Groove

114: oscillating membrane

116A: The second insulating part

120: second electrode

CVT: Cavity

SS: side wall

t00, t1, t2: thickness

TH1: Upper hole

TH2: Lower hole

Claims (10)

A kind of energy conversion structure, including: A substrate; A first electrode disposed on the substrate; An inorganic layer located on the first electrode, wherein the inorganic layer has a lower oscillation part and a plurality of holes, and the holes are located on two sides of the lower oscillation part; A first insulating layer includes an upper oscillating portion and a plurality of first insulating portions, wherein the upper oscillating portion is located on the lower oscillating portion, the first insulating portions are located on the first electrode, and the first electrode , The first insulating parts and the lower oscillating part jointly form a cavity; A plurality of second insulating parts are respectively located on the first insulating parts, wherein the second insulating parts contact the first insulating parts through the holes, and the material of the second insulating parts and the first insulating parts The material of an insulating part is different; and A second electrode is located on the upper oscillating part, and the cavity is located between the first electrode and the second electrode. The transducer structure according to claim 1, wherein the second insulating parts comprise organic materials. The transducer structure according to claim 1, wherein the thickness of the inorganic layer is 3000 angstroms to 9000 angstroms. The transducer structure according to claim 1, wherein the first insulating layer further includes a sidewall portion located on the sidewall of the hole of the inorganic layer, so that the sidewall portion and each of the first insulating portions are formed together A groove. An energy conversion device, including: A plurality of transducer structures according to any one of claims 1 to 4, wherein the first electrodes of each transducer structure are separated from each other in at least one direction, and each of the first electrodes is arranged in an array; and A circuit is located on one side of the transducer structures, wherein the first electrodes of the transducer structures are electrically connected to each other through the circuit, and the circuit and the first electrodes are the same film layer. A manufacturing method of an energy conversion structure includes: Forming a first electrode on a substrate; Forming a sacrificial layer on the first electrode; Forming an inorganic layer on the sacrificial layer and the first electrode; Patterning the inorganic layer to form a plurality of upper holes and a lower oscillation portion, the upper holes are located on two sides of the lower oscillation portion, and the sacrificial layer is exposed through the upper holes; Removing the sacrificial layer to form a plurality of lower holes respectively located below the upper holes and an accommodating space located below the lower oscillation part; A first insulating layer is formed on the inorganic layer, wherein the first insulating layer has a plurality of first insulating parts and an upper oscillating part, the upper oscillating part is located on the lower oscillating part, and the first insulating parts are respectively Filling the lower holes, the first electrode, the first insulating parts and the lower oscillating part jointly form a cavity; and The upper holes are filled with the second insulating parts, and the second insulating parts are respectively located on the first insulating parts, and the material of the second insulating parts includes photoresist. The method according to claim 6, wherein filling the upper holes with the second insulating portions respectively includes: Forming a second insulating layer on the first insulating layer on the entire surface; and A part of the second insulating layer is removed to form the second insulating parts, and the first insulating layer is not removed when part of the second insulating layer is removed. The method according to claim 7, wherein the material of the second insulating layer and the material of the first insulating layer are different. The method according to claim 6, wherein the method for forming the second insulating layer is a spin coating method. The method according to claim 6, wherein the thickness of the first insulating layer is 1000 angstroms to 5500 angstroms.

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