TWI836324B - Microelectromechanical infrared sensing appartus and fabrication method thereof - Google Patents

Abstract

A MEMS infrared sensing apparatus includes a substrate and an infrared light sensing element. The infrared light sensing element is disposed above the substrate, and the infrared light sensing element includes a sensing panel and at least one supporting member. The sensing panel includes at least one infrared light absorption layer, an infrared light sensing layer, a sensing electrode and a plurality of metal elements. The sensing panel also has a plurality of openings surrounded by respective metal elements. The sensing electrode is connected with the infrared sensing layer. The metal elements are spaced apart from each other. The substrate is connected with the sensing panel through the supporting member.

Description

Microelectromechanical infrared light sensing device and manufacturing method thereof

The present invention relates to a micro-electromechanical infrared light sensing device and a manufacturing method of the micro-electromechanical infrared light sensing device.

In recent years, micro-electromechanical infrared light sensing devices have been applied to various fields. In the future, the demand for micro-electromechanical infrared light sensing devices in industrial production, environmental monitoring, home care and temperature measurement will increase significantly. Generally speaking, micro-electromechanical infrared light sensing devices mainly include an infrared light absorption layer and an infrared light sensing layer. The infrared light absorption layer absorbs infrared light radiation energy and converts the radiation energy into heat energy. The heat energy converted by absorbing infrared light causes the infrared light sensing layer or the electrode in contact with the infrared light sensing layer to heat up. This temperature change causes the resistance value of the infrared light sensing layer or the electrode to change. Due to the change in resistance value, the change in voltage value or current size can be observed, and then the temperature of the object to be measured can be inferred.

The material that can be used as the infrared light sensing layer needs to have a high temperature coefficient of resistance (TCR), so the selection of materials is limited. At present, the materials commonly used as infrared light sensing layers in the industry mainly absorb infrared light with a wavelength of 10~14 microns (μm), and cannot effectively utilize the energy of infrared light with a wavelength less than 10 μm. For example, silicon nitride, which is widely used as an infrared light sensing layer in the industry, can have an absorption rate of up to 85% for infrared light with a wavelength of 10~14 μm, but only 55% for infrared light with a wavelength less than 10 μm.

In view of the above problems, the present invention provides a micro-electromechanical infrared light sensing device having a high absorption rate in a wide infrared light band, and also provides a method for manufacturing the micro-electromechanical infrared light sensing device.

A microelectromechanical infrared light sensing device disclosed in an embodiment of the present invention includes a substrate and an infrared light sensing element disposed above the substrate. The infrared light sensing element includes a sensing plate and at least one supporting element. The sensing plate includes at least one infrared light absorbing layer, an infrared light sensing layer, a sensing electrode and a plurality of metal components. The sensing plate has a plurality of openings, each of the metal elements surrounds the openings, the sensing electrode is connected to the infrared light sensing layer, and the metal elements are spaced apart from each other. The supporting element connects the sensing plate and the base plate.

The manufacturing method of a microelectromechanical infrared light sensing device disclosed in an embodiment of the present invention includes: forming a sacrificial layer on a substrate; forming at least one supporting element in the sacrificial layer; forming a sensing plate on the sacrificial layer; A plurality of openings are formed on the plate to penetrate the metal components respectively; and the sacrificial layer is removed. The sensing plate includes at least an infrared light absorbing layer, an infrared light sensing layer, a sensing electrode and a plurality of metal components. The sensing electrode is connected to the infrared light sensing layer and the supporting component, and the metal components are spaced apart from each other.

According to the micro-electromechanical infrared light sensing device and its manufacturing method disclosed in the present invention, the sensing plate of the infrared light sensing element not only has an infrared light absorption layer but also includes a plurality of spaced metal elements and a plurality of openings surrounded by these metal elements. The metal elements help to improve the absorption rate of the sensing plate for infrared light in the wavelength range of 8 to 10 microns, especially significantly improve the absorption rate for infrared light in the wavelength range of 8 to 9 microns. In combination with the infrared light absorption layer itself having a high absorption rate for infrared light in the wavelength range of 10 to 12 microns, the infrared light sensing element can meet the demand for high absorption rate for a wide infrared light band.

The above description of the content of the present invention and the following description of the implementation methods are used to demonstrate and explain the principles of the present invention and provide a further explanation of the scope of the patent application of the present invention.

The detailed features and advantages of the present invention are described in detail in the following embodiments, and the contents are sufficient to enable any person skilled in the relevant art to understand the technical contents of the present invention and implement them accordingly. Moreover, according to the contents disclosed in this specification, the scope of the patent application and the drawings, any person skilled in the relevant art can easily understand the relevant purposes and advantages of the present invention. The following embodiments are to further illustrate the viewpoints of the present invention, but are not to limit the scope of the present invention by any viewpoint.

Please refer to Figures 1 and 2, wherein Figure 1 is a three-dimensional schematic diagram of a micro-electromechanical infrared light sensing device according to an embodiment of the present invention, and Figure 2 is a top view schematic diagram of the micro-electromechanical infrared light sensing device of Figure 1. In this embodiment, the micro-electromechanical infrared light sensing device 1 includes a substrate 10, an infrared light reflecting layer 20, and an infrared light sensing element 30.

The substrate 10 is, for example, but not limited to, a silicon substrate with a reading circuit. The infrared light reflective layer 20 is, for example but not limited to, a metal film, which is disposed on the substrate 10 .

The infrared light sensing element 30 is disposed above the substrate 10 , and the infrared light reflective layer 20 is interposed between the substrate 10 and the infrared light sensing element 30 . The infrared light sensing element 30 includes at least one supporting element 310 and a sensing plate 320 . The supporting element 310 is, for example but not limited to, a metal pillar, which is disposed on the substrate 10 , and the supporting element 310 is electrically connected to the reading circuit of the substrate 10 . The sensing plate 320 is suspended above the substrate 10 and the infrared light reflective layer 20 through the supporting element 310 . FIG. 1 shows that a plurality of supporting elements 310 are disposed on the substrate 10 , but the number of the supporting elements 310 is not limited to the present invention.

The sensing plate 320 has a sensing area A1 and a light absorption area A2 that do not overlap each other, and the light absorption area A2 surrounds the sensing area A1. The sensing plate 320 includes a plurality of infrared light absorbing layers, an infrared light sensing layer 323 , a sensing electrode 324 and a plurality of metal components 325 . Please refer to Figures 3 and 4 together. Figure 3 is an exploded schematic diagram of the infrared light sensing element in the MEMS infrared light sensing device of Figure 1. Figure 4 is a schematic cross-sectional view of the MEMS infrared light sensing device of Figure 1. . In this embodiment, the sensing plate 320 includes a lower infrared light absorbing layer 321 close to the infrared light reflective layer 20 and an upper infrared light absorbing layer 322 away from the infrared light reflective layer 20 .

The lower infrared light absorption layer 321 is distributed throughout the sensing area A1 and the light absorption area A2, and the lower infrared light absorption layer 321 includes a plurality of infrared light absorption sublayers. More specifically, the lower infrared light absorption layer 321 includes a first lower infrared light absorption sublayer 321a and a second lower infrared light absorption sublayer 321b between the infrared light sensing layer 323 and the first lower infrared light absorption sublayer 321a, and the first lower infrared light absorption sublayer 321a and the second lower infrared light absorption sublayer 321b may have different materials to correspond to different infrared light absorption bands. For example, the material of the first lower infrared light absorption sublayer 321a is silicon oxide, and the material of the second lower infrared light absorption sublayer 321b is silicon nitride, and the absorption wavelength ranges of the two infrared light absorption sublayers have different peaks.

The upper infrared light absorption layer 322 is distributed throughout the sensing area A1 and the light absorption area A2, and the upper infrared light absorption layer 322 includes a plurality of infrared light absorption layers. More specifically, the upper infrared light absorption layer 322 includes a first upper infrared light absorption sublayer 322a and a second upper infrared light absorption sublayer 322b between the infrared light sensing layer 323 and the first upper infrared light absorption sublayer 322a, and the first upper infrared light absorption sublayer 322a and the second upper infrared light absorption sublayer 322b may have different materials to correspond to different infrared light absorption bands. For example, the first upper infrared light absorption sublayer 322a is made of silicon oxide, and the second upper infrared light absorption sublayer 322b is made of silicon nitride, and the absorption wavelength ranges of the two infrared light absorption sublayers have different peaks.

That is, the lower infrared light absorption layer 321 and the upper infrared light absorption layer 322 may have a stacked structure that is symmetrically arranged relative to the infrared light sensing layer 323, and the multiple infrared light absorption layers in each infrared light absorption stacked structure correspond to different infrared light absorption bands. In this embodiment, the first lower infrared light absorption sublayer 321a of the lower infrared light absorption layer 321 and the first upper infrared light absorption sublayer 322a of the upper infrared light absorption layer 322 have the same material (silicon oxide), and the second lower infrared light absorption sublayer 321b and the second upper infrared light absorption sublayer 322b have the same material (silicon nitride). This embodiment uses the material of the infrared light absorption layer as silicon oxide or silicon nitride as an example, which is not intended to limit the present invention. In other embodiments, the infrared light absorption layer may be other materials (such as silicon oxide containing nitrogen) or a composite material, and each infrared light absorption stacked structure may include more than two infrared light absorption layers.

In this embodiment, the lower infrared light absorbing layer 321 and the upper infrared light absorbing layer 322 also have the same thickness. Furthermore, the first lower infrared light absorbing sub-layer 321a and the first upper infrared light absorbing sub-layer 322a have the same thickness. thickness, and the second lower infrared light absorbing sub-layer 321b and the second upper infrared light absorbing sub-layer 322b have the same thickness.

The lower infrared light absorption layer 321 and the upper infrared light absorption layer 322 of this embodiment each have a stacked structure composed of multiple sub-layers, but the present invention is not limited thereto. In other embodiments, both infrared light absorption layers may be a single material layer, or only one of the infrared light absorption layers may have a stacked structure. In addition, the sensing plate 320 of this embodiment includes a plurality of infrared light absorption layers, but the present invention is not limited thereto. In other embodiments, the infrared light absorption layer may be formed only above the infrared light sensing layer or below the sensing electrode.

The infrared light sensing layer 323 is, for example but not limited to, amorphous silicon (a-Si) or a composite material with a high temperature coefficient of resistance, and is located between the lower infrared light absorption layer 321 and the upper infrared light absorption layer 322. In other words, the infrared light sensing layer 323 is located in the sensing area A1 and does not extend to the light absorption area A2.

The sensing electrode 324 is in thermal contact with the infrared light sensing layer 323. Specifically, the sensing electrode 324 is between the lower infrared light absorption layer 321 and the upper infrared light absorption layer 322, and the sensing electrode 324 includes an interdigitated electrode structure 324a located in the sensing area A1 and a connecting arm structure 324b located in the light absorption area A2. The interdigitated electrode structure 324a is in thermal contact with the infrared light sensing layer 323, and the interdigitated electrode structure 324a is in electrical contact with the supporting element 310 through the connecting arm structure 324b.

A plurality of metal components 325 are disposed between the lower infrared light absorption layer 321 and the upper infrared light absorption layer 322, and these metal components 325 are disposed at intervals from each other. Please also refer to FIG. 5, which is a partially enlarged schematic diagram of the micro-electromechanical infrared light sensing device of FIG. 4. These metal components 325 are all located in the light absorption area A2, and at least part of the metal components 325 are arranged periodically. The sensing electrode 324 and these metal components 325 are located in the same layer, and the metal components 325 are electrically insulated from the sensing electrode 324. The sensing plate 320 is also formed with a plurality of openings 326 at positions corresponding to the center holes 3251 of these metal components 325, so that the metal components 325 surround the corresponding openings 326. The opening 326 extends through the lower infrared light absorbing layer 321, the central hole 3251 and the upper infrared light absorbing layer 322 and passes through the sensing plate 320. The metal element 325 is, for example but not limited to, a metal ring, and a portion of the inner wall surface of the opening 326 is the inner ring surface 3252 of the metal ring that is exposed, that is, the inner ring surface 3252 of the metal ring forms a portion of the hole wall surface of the opening 326. Each metal element 325 of the present embodiment is a single square metal ring, while the metal element in other embodiments may be a metal circular ring or other polygonal ring.

The "metal element surrounding the opening" mentioned here includes the central hole of the metal element forming a part of the opening, and the edge of the central hole of the metal element being spaced from the opening. The former example is the central hole 3251 in Figures 4 and 5 serving as a part of the hole wall of the opening 326, and the latter example is the infrared light absorption layer in other embodiments filling the gap between the edge of the central hole and the opening.

The following describes a method for manufacturing the micro-electromechanical infrared light sensing device 1. Please refer to Figures 6 to 13, which are flowcharts of manufacturing the micro-electromechanical infrared light sensing device of Figure 1. The following describes the detailed steps for manufacturing the micro-electromechanical infrared light sensing device 1, but the specific implementation of each step is not intended to limit the present invention.

As shown in FIG6 , a substrate 10 having a readout circuit is provided, and an infrared light reflecting layer 20 and a sacrificial layer 50 are sequentially formed on the substrate 10. Specifically, a metal layer (e.g., an aluminum layer with a thickness of about 300 nanometers) is deposited on the substrate 10, and is etched and patterned to form the infrared light reflecting layer 20. After the infrared light reflecting layer 20 is formed, a dielectric layer (e.g., amorphous silicon with a thickness of 1000-1500 nanometers as the sacrificial layer 50) is deposited on the substrate 10 and the infrared light reflecting layer 20. Optionally, a protective layer (e.g., SiO _x material) may be formed on the infrared light reflecting layer 20 before the dielectric layer is formed.

As shown in FIGS. 7 and 8 , the support element 310 is formed in the sacrificial layer 50. Specifically, a portion of the sacrificial layer 50 is removed by etching to form a through hole 510, and then the support element 310 is formed in the through hole 510. A conductive material (such as tungsten) may be filled in the upper surface of the sacrificial layer 50 and the through hole 510, and a portion of the conductive material located on the upper surface of the sacrificial layer 50 is removed to form the support element 310. More specifically, a chemical-mechanical planarization process (CMP) may be used to remove a portion of the conductive material and a portion of the sacrificial layer 50 to form the support element 310, thereby ensuring that the upper surface of the sacrificial layer 50 is sufficiently flat.

Then, the sensing plate 320 is formed on the sacrificial layer 50 . As shown in FIG. 9 , the lower infrared light absorbing layer 321 of the sensing plate 320 is formed on the sacrificial layer 50 . Specifically, a silicon oxide layer with a thickness of about 40 to 100 nanometers is first deposited to cover the support element 310 and the sacrificial layer 50 , wherein the silicon oxide layer and the silicon nitride layer serve as the first lower infrared light absorption layer of the lower infrared light absorption layer 321 respectively. sub-layer 321a and a second lower infrared light absorbing sub-layer 321b.

As shown in FIG10 , the sensing electrode 324 and the metal element 325 of the sensing plate 320 are formed on the lower infrared light absorption layer 321. Specifically, after the step of depositing the silicon oxide layer and the silicon nitride layer to form the lower infrared light absorption layer 321, a portion of the silicon oxide layer and the silicon nitride layer is removed by etching to expose the supporting element 310; or, before the step of depositing the silicon oxide layer and the silicon nitride layer, the supporting element 310 is covered with a mask and then the deposition process is performed, so that the supporting element 310 can be exposed after the deposition is completed. Next, a conductive layer (such as titanium nitride with a thickness of about 50-100 nanometers) is deposited on the upper surface of the lower infrared light absorption layer 321 and the supporting element 310, and then the conductive layer is patterned by etching to form the sensing electrode 324 and the metal element 325. The patterning may be performed by performing a lithography process and/or an etching process.

5 and 10 , the specifications and configuration of the metal element 325 are exemplified as follows: the outermost diameter d of each metal ring (i.e., twice the radial length from the center of the metal ring to the edge of the metal ring) is 1.3-1.5 microns, the width W of the metal ring is 0.1-0.15 microns, the thickness t of the metal ring is 50-70 nanometers, and the center distance Dint between two adjacent metal rings is three times the outermost diameter d of the metal ring.

As shown in FIG. 11 , the infrared light sensing layer 323 of the sensing plate 320 is formed on the sensing electrode 324. Specifically, a material layer with a high temperature coefficient of resistance (e.g., amorphous silicon with a thickness of about 50-100 nanometers) is deposited on the sensing electrode 324, and then the material layer is patterned by etching to form the infrared light sensing layer 323 above the interdigitated electrode structure 324a of the sensing electrode 324. The area of the material layer removed by etching can be defined as the light absorption area A2 of the sensing plate 320, and the location of the infrared light sensing layer 323 and the interdigitated electrode structure 324a can be defined as the sensing area A1. FIG10 and FIG11 show that the sensing electrode 324 is formed first and then the infrared light sensing layer 323 is formed, but the present invention is not limited thereto. In other embodiments, the infrared light sensing layer may be formed first and then the sensing electrode. In addition, the patterning may be performed by performing a lithography process and/or an etching process.

As shown in FIG. 12 , the upper infrared light absorbing layer 322 of the sensing plate 320 is formed on the infrared light sensing layer 323 . Specifically, a silicon nitride layer with a thickness of about 100 to 170 nanometers is first deposited to cover the infrared light sensing layer 323 and the sensing electrode 324, and then a silicon oxide layer with a thickness of about 40 to 100 nanometers is deposited on the silicon nitride layer. layer, and then pattern the silicon oxide layer and the silicon nitride layer by etching to form the first upper infrared light absorbing sub-layer 322a and the second upper infrared light absorbing sub-layer 322b of the upper infrared light absorbing layer 322. The patterning may be performed by a photolithography process and/or an etching process.

As shown in FIG. 13 , part of the lower infrared light absorbing layer 321 , part of the upper infrared light absorbing layer 322 and part of each metal component 325 are removed to form the opening 326 and the elastic arm 327 of the sensing plate 320 . Then, the sacrificial layer 50 is removed by etching, and a gap is formed between the lower infrared light absorbing layer 321 and the infrared light reflecting layer 20 .

When infrared light is incident on the MEMS infrared light sensing device 1 from the outside, the radiation energy of the infrared light passing through the sensing plate 320 can be absorbed by the lower infrared light absorbing layer 321 and the upper infrared light absorbing layer 322, so that the infrared light sensing device 1 can detect infrared light. The temperature of the layer 323 rises, and the temperature of the sensing electrode 324 in thermal contact with the infrared light sensing layer 323 also rises. The temperature rise of the sensing electrode 324 causes its resistance value to change, so the reading circuit of the substrate 10 can obtain an electrical signal (such as a change in voltage value or a change in current value).

In this embodiment, the metal element 325 located in the light absorption area A2 and the opening 326 corresponding to the metal element 325 help to improve the absorption rate of the sensor plate 320 for the infrared light band with a wavelength of 8 to 10 microns, especially significantly improve the absorption rate for the infrared light band with a wavelength of 8 to 9 microns. FIG14 is a graph of the absorption rate of the micro-electromechanical infrared light sensing device of FIG1 for different infrared light bands. Among them, the micro-electromechanical infrared light sensing device without metal elements and openings in the sensor plate is used as a comparative example, and its absorption rate for the infrared light band with a wavelength of 8 microns is only 55%. Compared with the comparison example in which no metal elements and openings are set in the sensing plate, the sensing plate including multiple titanium nitride metal rings and openings can effectively improve the absorption rate of the infrared light band with a wavelength of 8 to 10 microns, especially the absorption rate of the infrared light band with a wavelength of 8 microns is increased by at least 25% (in FIG. 14 , the absorption rate of the infrared light band with a wavelength of 8 microns is increased from 55% to 82.5%, a full increase of 27.5%). In other embodiments of the present invention, the sensing plates of the same specifications formed by different metal materials are also proved to be able to improve the absorption rate. For example, the absorption rate of the infrared light band with a wavelength of 8 microns by the sensing plate including multiple metal rings made of gold and openings is increased from 55% to 89%, and the absorption rate of the infrared light band with a wavelength of 8 microns by the sensing plate including multiple metal rings made of copper and openings is increased from 55% to 91%.

In this embodiment, each infrared light absorption stack structure (lower infrared light absorption layer 321, upper infrared light absorption layer 322) includes multiple infrared light absorption layers for absorbing infrared light energy in different wavelength bands. The infrared light absorbing laminated structure helps to increase the absorption rate so as to increase the fill factor (Fill factor) value of the microelectromechanical infrared light sensing device 1 . In addition, the symmetrically arranged lower infrared light absorbing layer 321 and the upper infrared light absorbing layer 322 may have the same or similar material properties (such as thermal expansion coefficient or Young's coefficient), structure and size. Therefore, when manufacturing the infrared light sensing device 1 During the process, warpage or excessive thermal stress of the sensor plate 320 can be avoided, which helps to improve the manufacturing yield of the microelectromechanical infrared light sensing device 1 .

In addition, in this embodiment, the sensing electrode 324 includes an interdigitated electrode structure 324a, and the interdigitated electrode structure 324a has the advantages of short electrode spacing and low resistance value compared to traditional electrode structures, so the interdigitated electrode structure 324a provides a higher The traditional electrode structure requires a smaller working area to have a sufficiently small noise equivalent temperature difference (NETD) to meet the thermal sensitivity requirements of the microelectromechanical infrared light sensing device 1, which is in line with the development trend of miniaturization. At the same time, due to the small working area of the interdigital electrode structure 324a, the size of the infrared light sensing layer 323 that needs to overlap with the interdigital electrode structure 324a can also be reduced, which means that the infrared light absorbing layer used to absorb infrared light energy As the working area increases, the fill factor of the microelectromechanical infrared light sensing device 1 further increases.

Furthermore, in the manufacturing method disclosed in this embodiment, since the lower infrared light absorbing layer 321 of the sensing plate 320 is formed on the sacrificial layer 50, and the upper surface of the sacrificial layer 50 is processed by a chemical mechanical planarization process, it is removed after the After the sacrificial layer 50 , the lower infrared light absorbing layer 321 has a flat surface on the side facing the infrared light reflecting layer 20 . The lower infrared light absorbing layer 321 with a flat lower surface can ensure that the gap size between the sensing plate 320 and the infrared light reflecting layer 20 remains consistent, so that the microelectromechanical infrared light sensing device 1 can achieve the best sensing performance and match The symmetrically configured infrared light absorbing stack structure design can further improve the manufacturing yield of the microelectromechanical infrared light sensing device 1 .

In the embodiments of FIGS. 1 to 5 , the area of the infrared light sensing layer 323 in the sensing plate 320 is smaller than the areas of the upper and lower infrared light absorbing layers 322 and 321 , and the opening 326 of the sensing plate 320 extends through the upper and lower infrared light absorbing layers 322 and 321 but does not extend through the infrared light sensing layer 323 , but the present invention is not limited thereto.

FIG15 is a three-dimensional schematic diagram of a micro-electromechanical infrared light sensing device according to another embodiment of the present invention. In this embodiment, the micro-electromechanical infrared light sensing device 2 includes a substrate 10, an infrared light reflecting layer 20, and an infrared light sensing element 30". The infrared light sensing element 30" includes a supporting element 310 and a sensing plate 320", and the sensing plate 320" includes at least one infrared light absorption layer 321", an infrared light sensing layer 323", a sensing electrode 324" and a metal element 325". The infrared light sensing layer 323" is disposed on the infrared light absorption layer 321" and spreads over all areas of the infrared light absorption layer 321". The sensing electrode 324" includes a plurality of branch electrodes. The opening 326" of the sensing plate 320" extends through the infrared light sensing layer 323" and the infrared light absorbing layer 321". Each metal element 325" is a single metal ring surrounding the corresponding opening 326", and the inner surface of the metal ring forms a part of the hole wall of the opening 326".

In this embodiment, these metal elements 325" and these openings 326" are spaced apart from all areas on the sensing plate 320". Furthermore, for the partial branch electrodes defined by the sensing electrodes 324" In a working area A3, the infrared light absorbing layer 321" and the infrared light sensing layer 323" of the sensing plate 320" are spread throughout the entire working area A3. After forming the infrared light absorbing layer 321", the infrared light sensing layer 323" and the metal components After 325", part of the infrared light sensing layer 323", part of the infrared light absorbing layer 321" and the metal component 325" can be removed to form an opening 326". In any working area A3, the metal elements 325" and the openings 326" are arranged periodically. In addition, as shown in FIG. 15 , the distance between the two metal elements 325 ″ in different working areas A3 may depend on the width of the branch electrode of the sensing electrode 324 ″.

In summary, according to the micro-electromechanical infrared light sensing device and its manufacturing method disclosed in the present invention, the sensing plate of the infrared light sensing element not only has an infrared light absorption layer but also includes a plurality of spaced metal elements and a plurality of openings surrounded by these metal elements. The metal elements help to improve the absorption rate of the sensing plate for infrared light in the wavelength range of 8 to 10 microns, especially significantly improve the absorption rate for infrared light in the wavelength range of 8 to 9 microns. In combination with the infrared light absorption layer itself having a high absorption rate for infrared light in the wavelength range of 10 to 12 microns, it can meet the requirements of the infrared light sensing element for having a high absorption rate for a wide infrared light band.

Although the embodiments of the present invention have been disclosed as described above, they are not intended to limit the present invention. Anyone familiar with the relevant arts can modify the shapes, structures, and features described in the scope of the present invention without departing from the spirit and scope of the present invention. Slight changes may be made to the spirit and spirit of the invention, so the patent protection scope of the present invention shall be determined by the patent application scope attached to this specification.

1, 2: Microelectromechanical infrared light sensing device 10:Substrate 20:Infrared light reflective layer 30, 30”: Infrared light sensing element 310:Support element 320, 320”: induction plate 321: Lower infrared light absorption layer 321a: The first lower infrared light absorbing sublayer 321b: The second lower infrared light absorbing sublayer 321”: Infrared light absorbing layer 322: Upper infrared light absorption layer 322a: First upper infrared light absorbing sublayer 322b: The second upper infrared light absorbing sublayer 323, 323”: Infrared light sensing layer 324, 324”: sensing electrode 324a: Interdigitated electrode structure 324b: Connecting arm structure 325, 325”: metal components 326, 326”: opening 327:Elastic arm 3251: Center hole 3252:Inner ring surface 50:Sacrifice layer 510:Through hole A1: Sensing area A2: Light absorption area A3:Working area d: The outermost diameter of the metal ring W: Width of metal ring t:Thickness of metal ring Dint: the center distance between two adjacent metal rings

FIG. 1 is a three-dimensional schematic diagram of a micro-electromechanical infrared light sensing device according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a top view of the micro-electromechanical infrared light sensing device of FIG. 1. FIG. 3 is a schematic diagram of an exploded view of an infrared light sensing element in the micro-electromechanical infrared light sensing device of FIG. 1. FIG. 4 is a schematic diagram of a cross-section of the micro-electromechanical infrared light sensing device of FIG. 1. FIG. 5 is a schematic diagram of a partial enlargement of the micro-electromechanical infrared light sensing device of FIG. 4. FIG. 6 to FIG. 13 are manufacturing flow charts of the micro-electromechanical infrared light sensing device of FIG. 1. FIG. 14 is a diagram of the absorption rate of the micro-electromechanical infrared light sensing device of FIG. 1 for different infrared light bands. FIG. 15 is a three-dimensional schematic diagram of a micro-electromechanical infrared light sensing device according to another embodiment of the present invention.

1: Microelectromechanical infrared light sensing device

10:Substrate

20: Infrared light reflection layer

30: Infrared light sensing element

310: Support element

320: Induction board

325:Metal components

326: Opening

Claims (20)

A micro-electromechanical infrared light sensing device comprises a substrate and an infrared light sensing element disposed on the substrate, and the infrared light sensing element comprises: A sensing plate comprising at least one infrared light absorption layer, an infrared light sensing layer, a sensing electrode and a plurality of metal elements, the sensing plate having a plurality of openings, the metal elements respectively surrounding the openings, the sensing electrode connected to the infrared light sensing layer, and the metal elements spaced apart from each other; and at least one supporting element connecting the sensing plate and the substrate. The microelectromechanical infrared light sensing device as claimed in claim 1, wherein the number of the at least one infrared light absorbing layer is two, and the infrared light sensing layer and the metal components are located between the two infrared light absorbing layers. . The microelectromechanical infrared light sensing device of claim 2, wherein the openings extend through the infrared light sensing layer and the two infrared light absorbing layers and are arranged at equal intervals from each other in a periodic arrangement, and the metal components They are arranged at equal intervals from each other and arranged periodically. A micro-electromechanical infrared sensing device as described in claim 1, wherein each of the metal elements is a metal ring, and the inner ring surface of the metal ring forms a partial hole wall surface of the opening. A micro-electromechanical infrared light sensing device as described in claim 1, wherein the sensing plate of the infrared light sensing element has a sensing area and a light absorption area which do not overlap each other, the at least one infrared light absorption layer spreads throughout the sensing area and the light absorption area, the infrared light sensing layer is located in the sensing area and does not extend to the light absorption area, and the metal elements and the openings are all located in the light absorption area. As described in claim 5, the micro-electromechanical infrared light sensing device, wherein the openings are arranged at equal intervals and are periodically arranged in the light absorption region, and the metal elements are arranged at equal intervals and are periodically arranged in the light absorption region. A micro-electromechanical infrared light sensing device as described in claim 5, wherein the number of the at least one infrared light absorbing layer is two, the infrared light sensing layer and the metal elements are located between the two infrared light absorbing layers, and the openings extend through the two infrared light absorbing layers but do not extend through the infrared light sensing layer. The micro-electromechanical infrared light sensing device as described in claim 1, wherein the sensing electrode defines a working area of the sensing plate, the at least one infrared light absorbing layer and the infrared light sensing layer are spread throughout the entire working area, and the metal elements and the openings are spaced apart in the working area. The microelectromechanical infrared light sensing device as claimed in claim 8, wherein the metal components and the openings are periodically arranged in the working area. The microelectromechanical infrared light sensing device as claimed in claim 1, wherein the sensing electrode and the metal components are located on the same layer, the sensing electrode is in thermal contact with the infrared light sensing layer, and the sensing electrode is in thermal contact with the infrared light sensing layer. Some metal components are electrically insulated. The microelectromechanical infrared light sensing device as claimed in claim 2, wherein the two infrared light absorbing layers have the same thickness. The micro-electromechanical infrared light sensing device as described in claim 2, wherein at least one of the two infrared light absorption layers comprises a plurality of infrared light absorption sub-layers, and the materials corresponding to the infrared light absorption sub-layers are different from each other. The microelectromechanical infrared light sensing device according to claim 2, wherein the sensing electrode is between the two infrared light absorbing layers, and the sensing electrode includes an interdigitated electrode structure. A method of manufacturing a microelectromechanical infrared light sensing device, including: A sacrificial layer is formed on a substrate; at least one supporting element is formed in the sacrificial layer; a sensing plate is formed on the sacrificial layer, wherein the sensing plate includes at least one infrared light absorbing layer, one infrared light sensing layer, and one Sensing electrodes and a plurality of metal components, the sensing electrodes are connected to the infrared light sensing layer and the at least one supporting component, and the metal components are spaced apart from each other; a plurality of openings are formed on the sensing plate, wherein the Opening holes penetrate the metal components respectively; and removing the sacrificial layer. The manufacturing method of a microelectromechanical infrared light sensing device as claimed in claim 14, wherein forming the openings in the sensing plate includes: Parts of the infrared light sensing layer, parts of the at least one infrared light absorbing layer and parts of each of the metal components are removed to form the openings. The manufacturing method of a microelectromechanical infrared light sensing device as claimed in claim 14, wherein forming the openings in the sensing plate includes: Parts of the at least one infrared light absorbing layer and parts of each of the metal components are removed to form the openings, and none of the openings extend through the infrared light sensing layer. The manufacturing method of the micro-electromechanical infrared light sensing device as described in claim 14, wherein forming the at least one supporting element in the sacrificial layer comprises: forming a plurality of through holes in the sacrificial layer; filling the through holes with conductive material; and removing a portion of the conductive material to form the at least one supporting element. A method for manufacturing a micro-electromechanical infrared sensing device as described in claim 17, wherein a portion of the conductive material is removed by a chemical mechanical planarization process. The manufacturing method of the micro-electromechanical infrared light sensing device as described in claim 14, wherein the forming of the sensing plate on the sacrificial layer comprises: forming a lower infrared light absorption layer of the at least one infrared light absorption layer on the sacrificial layer; removing a portion of the lower infrared light absorption layer to expose the at least one supporting element; depositing a conductive layer on the upper surface of the lower infrared light absorption layer and the at least one supporting element; and patterning the conductive layer to form the sensing electrode and the metal elements; and forming the infrared light sensing layer on the sensing electrode. As claimed in claim 19, the method for manufacturing a microelectromechanical infrared light sensing device, forming the sensing plate on the sacrificial layer further includes: An upper infrared light absorption layer is formed on the infrared light sensing layer and the lower infrared light absorption layer.

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