TWI912971B - Microelectromechanical sensing device and manufacturing method thereof - Google Patents

Abstract

A microelectromechanical sensing device includes a substrate, a plurality of support structures and a sensing structure. The plurality of support structures are disposed on the substrate. The sensing structure is supported by the supporting structures and disposed above the substrate. The sensing structure includes a first dielectric layer, an electrode layer, a sensing layer and a second dielectric layer. The first dielectric layer has a dielectric top surface, and the dielectric top surface is coplanar with a support top surface of each support structure. The electrode layer is disposed on the first dielectric layer and directly contacts the support structure. The sensing layer is disposed on the first dielectric layer and a projection of the sensing layer toward the substrate does not overlap the support structure. The second dielectric layer is disposed on the electrode layer and the sensing layer, wherein the first dielectric layer and the second dielectric layer are made of a same material.

Description

Microelectromechanical inductive measuring device and its manufacturing method

This invention relates to a microelectromechanical inductive measuring device and its manufacturing method.

Microelectromechanical sensing devices refer to microelectromechanical systems (MEMS) with sensing capabilities, operating within the micrometer scale. Typical sensing elements, such as infrared sensors used to measure temperature, often require special support structures (such as anchors) to suspend them above the substrate to reduce conductive heat dissipation and vacuum packaging to reduce convective heat dissipation.

Traditionally, anchors are designed with a large contact area and slender support feet with a large tilt angle to ensure stable deposition of the thin film on surfaces with varying elevations. The drawback of this process and structure is that the anchor occupies a large area (more than 5 micrometers by 5 micrometers), which does not meet the requirements of current device sizes (approximately 12 to 25 micrometers).

In view of the above, the present invention provides a microelectromechanical inductive measuring device and a method for manufacturing the same.

According to an embodiment of the present invention, a microelectromechanical sensing device includes a substrate, a plurality of support structures, and a sensing structure. The plurality of support structures are disposed on the substrate, and each support structure has a bottom surface and a top surface located at two opposite ends, the bottom surface of which is connected to the substrate. The sensing structure is supported by the plurality of support structures and disposed above the substrate. The sensing structure includes a first dielectric layer, an electrode layer, a sensing layer, and a second dielectric layer. The first dielectric layer has a dielectric top surface, which is coplanar with the support top surfaces of each of the plurality of support structures. The electrode layer is disposed on the first dielectric layer and directly contacts the plurality of support structures. The sensing layer is disposed on the first dielectric layer and its projection toward the substrate does not overlap with the plurality of support structures. The second dielectric layer is disposed on the electrode layer and the sensing layer, wherein the first dielectric layer and the second dielectric layer are made of the same material.

A method for manufacturing a microelectromechanical inductive measuring device according to an embodiment of the present invention includes: forming a sacrifice layer on a substrate; forming a first dielectric layer on the sacrifice layer; embedding a plurality of support structures in the sacrifice layer and the first dielectric layer, such that a support bottom surface of each of the plurality of support structures is connected to the substrate, and a support top surface of each of the plurality of support structures is coplanar with the dielectric top surface of the first dielectric layer, wherein the support bottom surface and the support top surface are respectively located at... At two opposite ends; an electrode layer and a sensing layer are formed on the first dielectric layer, wherein the electrode layer directly contacts the plurality of support structures, and the projection of the sensing layer toward the substrate does not overlap the plurality of support structures; a second dielectric layer is formed on the electrode layer and the sensing layer, wherein the second dielectric layer is made of the same material as the first dielectric layer; and openings are made in the first dielectric layer, the electrode layer and the second dielectric layer to release the sacrifice layer.

With the above structure, the microelectromechanical inductive device disclosed in this application, through the arrangement of two dielectric layers of the same material relative to the electrode layer and the sensing layer, can achieve a stress balance effect, maintaining the overall height uniformity. The manufacturing method of the microelectromechanical inductive device disclosed in this application can provide a simplified process, thereby reducing production difficulties and improving chip manufacturing yield.

The above description of the contents of this disclosure and the following description of the implementation methods are intended to demonstrate and explain the spirit and principles of this invention, and to provide a further explanation of the scope of the patent application of this invention.

The following embodiments detail the features and advantages of this invention, the content of which is sufficient to enable anyone skilled in the art to understand the technical content of this invention and implement it accordingly. Furthermore, based on the content disclosed in this specification, the scope of the patent application, and the drawings, anyone skilled in the art can easily understand the relevant objectives and advantages of this invention. The following embodiments further illustrate the viewpoints of this invention, but are not intended to limit the scope of this invention in any way.

The microelectromechanical sensing devices described in one or more embodiments herein are not limited to specific sensing applications. Appropriate material layers can be selected as sensing layers according to different sensing applications, such as temperature sensing, gas sensing, pressure sensing, and light sensing.

Please refer to Figures 1 and 2. Figure 1 is a three-dimensional structural diagram of a microelectromechanical induction device according to an embodiment of the present invention, and Figure 2 is a top view of the microelectromechanical induction device according to an embodiment of the present invention.

As shown in Figures 1 and 2, the microelectromechanical inductive device 1 includes a substrate 11, multiple support structures 12, and a sensing structure 13. The substrate 11 may be, but is not limited to, a silicon substrate containing a circuit structure (e.g., a readout circuit layer). The multiple support structures 12 may include two support pillars respectively disposed at two opposite corners of the microelectromechanical inductive device 1, and may be made of a conductive material, such as, but not limited to, a metal. The number, placement, shape, and area of the support pillars of the multiple support structures 12 can be adjusted according to the actual application to stabilize the mechanical structure of the sensing structure 13, and this invention does not impose any limitations. The sensing structure 13 can be divided into two side regions and a central region. The two side regions of the sensing structure 13 are directly connected to the support structure 12 and have elongated channels, mainly used as signal connection paths and for releasing the sacrifice layer. The central region of the sensing structure 13 is suspended above the substrate 11 and has a sensing layer, mainly used to sense changes in the environment (such as changes in temperature, gas, pressure, light, etc.) to generate sensing electrical signals. In an embodiment where the support structure 12 is implemented with a conductive material, the sensing electrical signals can be transmitted to the read circuit layer of the substrate 11 through the two side regions of the sensing structure 13 and the support structure 12. Furthermore, the comb-shaped region located in the central region shown in Figures 1 and 2 can be the region where the sensing layer is located. It should be noted that Figures 1 and 2 are merely illustrative representations of the geometry of the sensing structure 13, which can be adjusted according to actual needs.

The following description will focus on the stacking relationship between the layers of the microelectromechanical inductance device 1 along the direction (normal vector) of the substrate 11. Please refer to FIG3, which is a schematic cross-sectional view of the microelectromechanical inductance device according to an embodiment of the present invention along the section line A-A’ of FIG2.

As shown in Figure 3, each of the multiple support structures 12 of the microelectromechanical sensing device 1 is disposed on a substrate 11 and may be a solid pillar made of conductive material. Each support structure 12 has a bottom support surface 121 and a top support surface 122 located at two opposite ends, wherein the bottom support surface 121 is connected to the substrate 11. The sensing structure 13 is supported by the top support surface 122 of the support structure 12 and disposed above the substrate 11. The substrate 11 is, for example, a silicon substrate and may include a readout circuit layer 111, wherein the readout circuit layer 111 may include a readout integrated circuit (ROIC). The support structure 12 can be made of a conductive material, particularly tungsten metal, so that the support structure 12 can be directly electrically connected to the electrode layer 132 and the read circuit layer 111. The support structure 12 preferably has a small tilt angle, and more preferably is substantially perpendicular to the substrate 11, thereby having a small footprint, making it easy to control the levitation height of the sensing structure 13.

The sensing structure 13 includes a first dielectric layer 131, an electrode layer 132, a sensing layer 133, and a second dielectric layer 134. The first dielectric layer 131 has a dielectric top surface 1310, which is coplanar with the support top surface 122 of the support structure 12. The electrode layer 132 is disposed on the first dielectric layer 131 and directly contacts the support structure 12. The sensing layer 133 is disposed on the first dielectric layer 131, and its projection toward the substrate 11 does not overlap with the support structure 12. By having two dielectric layers, a first dielectric layer 131 and a second dielectric layer 134, of the same material disposed opposite to the electrode layer 132 and the sensing layer 133, the sensing structure 13 can achieve stress balance and maintain the uniformity of the overall height of the microelectromechanical sensing device 1. In particular, at the support structure 12, the first dielectric layer 131 and the second dielectric layer 134 are approximately symmetrical about the electrode layer 132, providing a better stress balance effect. It should also be noted that Figure 3 exemplarily illustrates that the electrode layer 132 is disposed on the sensing layer 133. However, in other embodiments, the sensing layer 133 may be disposed on the electrode layer 132. That is to say, this invention does not limit the stacking order of the electrode layer 132 and the sensing layer 133. The second dielectric layer 134 is disposed on the electrode layer 132 and the sensing layer 133, wherein the first dielectric layer 131 and the second dielectric layer 134 are made of the same material.

Furthermore, the first dielectric layer 131 and the second dielectric layer 134 can both be a single material layer or a composite material layer. In an embodiment where the first dielectric layer 131 and the second dielectric layer 134 are implemented as composite material layers, the first dielectric layer 131 includes a plurality of first sublayers, and the second dielectric layer 134 includes a plurality of second sublayers, wherein the material composition of the first sublayers along the stacking direction is the same as the material composition of the second sublayers in the opposite direction along the stacking direction. The stacking direction can refer to the stacking direction of the first dielectric layer 131, the electrode layer 132, and the second dielectric layer 134. Preferably, the first dielectric layer 131 and the second dielectric layer 134 can have the same thickness to form a symmetrical structure.

The material of the sensing structure 13 can be adjusted according to the application. Taking infrared light sensing for temperature measurement as an example, the first dielectric layer 131 and the second dielectric layer 134 are each infrared light absorbing layers, which can be composed of silicon dioxide and/or silicon nitride. The electrode layer 132 can be, for example, titanium nitride (TiN). The sensing layer 133 can be a material whose resistance changes with temperature. Through the above structure, the first dielectric layer 131 and the second dielectric layer 134 of this embodiment absorb the infrared light emitted by the target and change the temperature. After the temperature of the sensing layer 133 changes, its resistance value changes accordingly. The reading circuit layer 111 then reads the change in resistance value through the support structure 12 with conductive material and the electrode layer 132 and converts the signal into the corresponding temperature change to achieve the function of temperature sensing.

Preferably, the microelectromechanical sensing device 1 does not include any dielectric layers other than the first dielectric layer 131 and the second dielectric layer 134. Additionally, the portion of each of the plurality of support structures 12 located between the substrate 11 and the first dielectric layer 131 is preferably not covered by a non-conductive material. Any of the above structural designs can simplify the manufacturing process and improve yield.

Please refer to Figure 4, which is a flowchart illustrating a method for manufacturing a microelectromechanical inductive device according to an embodiment of the present invention. As shown in Figure 4, the method for manufacturing the microelectromechanical inductive device includes: step S1: forming a sacrifice layer on a substrate; step S2: forming a first dielectric layer on the sacrifice layer; step S3: embedding a plurality of support structures in the sacrifice layer and the first dielectric layer, such that a bottom surface of each of the plurality of support structures is connected to the substrate, and the top surface of the plurality of support structures is coplanar with a top dielectric surface of the first dielectric layer, wherein the bottom surface and the top surface of the support are... The electrodes are located at opposite ends; Step S4: An electrode layer and a sensing layer are formed on the first dielectric layer, wherein the electrode layer directly contacts multiple support structures, and the projection of the sensing layer toward the substrate does not overlap with the multiple support structures; Step S5: A second dielectric layer is formed on the electrode layer and the sensing layer, wherein the second dielectric layer is made of the same material as the first dielectric layer; and Step S6: Openings are made in the first dielectric layer, the electrode layer and the second dielectric layer to release the sacrifice layer.

Please refer to Figure 5 in conjunction with Figure 4. Figure 5 is a schematic diagram of the state of the microelectromechanical inductive measuring device as shown in steps S1 and S2 of Figure 4. In step S1, a substrate 11 including a read circuit layer 111 can be prepared first, and a sacrifice layer 14 can be formed on the read circuit layer 111 of the substrate 11. The read circuit layer 111 can be formed on the substrate 11 through a standard complementary metal oxide semiconductor (CMOS) process, and a read chip 1111 can be disposed in the read circuit layer. The thickness of the aforementioned sacrificial layer 14 can be from 1.4 micrometers to 2.5 micrometers. The material of the sacrificial layer 14 can be, for example, but not limited to, amorphous silicon, and it can be formed using a deposition process. In step S2, a first dielectric layer 131 can be formed on the sacrificial layer 14 using a deposition process. In a microelectromechanical sensing device that serves as an infrared light sensing element, the first dielectric layer 131 will serve as the underlying radiation absorption layer.

Please refer to Figures 6 and 7, which are schematic diagrams illustrating the state of the microelectromechanical inductive device according to step S3 in Figure 4. Step S3 may include: forming at least one via 15 in the sacrifice layer 14 and the first dielectric layer 131; depositing a material in the at least one via 15; and performing a planarization process with the dielectric top surface 1310 of the first dielectric layer 131 as the stop surface to remove part of the material. The via 15 may be formed by an etching process, wherein the etching process stops at the top layer of the read chip 1111 of the read circuit layer 111. Through step S3, the material of the support structure 12 (especially a conductive material, such as tungsten metal) can be deposited in the through hole 15, so that the support structure 12 is electrically connected to the read chip 1111 of the read circuit layer 111 of the substrate 11. The excess material is removed by chemical planarization (CMP) process with the dielectric top surface 1310 of the first dielectric layer 131 as the stop surface, and the process stops at the dielectric top surface 1310 of the first dielectric layer 131, so that the support top surface 122 of the support structure 12 and the dielectric top surface 1310 of the first dielectric layer 131 are coplanar.

Please refer to Figure 8 in conjunction with Figure 4. Figure 8 is a schematic diagram of the state of the microelectromechanical inductive device as illustrated in steps S4 and S5 of Figure 4. In step S4, an electrode layer 132 and a sensing layer 133 can be formed on the first dielectric layer 131 and the support structure 12, wherein the electrode layer 132 directly contacts the support structure 12, and the projection of the sensing layer 133 toward the substrate 11 does not overlap with the support structure 12. It should be noted that Figure 8 shows an example in which the sensing layer 133 is deposited on the electrode layer 132; however, in other embodiments, the sensing layer 133 may also be deposited on the first dielectric layer 131 and below the electrode layer 132. In step S5, a second dielectric layer 134 can be formed on the electrode layer 132 and the sensing layer 133, wherein the second dielectric layer 134 is made of the same material as the first dielectric layer 131. It should be noted that although the upper surface of the second dielectric layer 134 in FIG8 is presented in a flat form, this invention is not limited to this. For example, the second dielectric layer 134 can protrude upward at the position corresponding to the sensing layer 133 to have a higher height. Thus, a film layer structure covering the top surface of the support structure 12 can be formed on the support structure 12 using two first dielectric layers 131 and second dielectric layers 134 of the same material, ensuring that the structure is stable and does not deform when suspended. The electrode layer 132 is directly connected to the support structure 12, without the need for an additional metal layer.

Please refer to Figures 9 and 10, which are schematic diagrams of the state of the microelectromechanical inductive device as shown in step S6 of Figure 4. In step S6, the shape of the infrared light sensing device (microelectromechanical inductive device), including elongated channels and radiation absorption surfaces, is first defined and etched on the first dielectric layer 131, electrode layer 132, and second dielectric layer 134 to form an opening 16. Then, the sacrificial layer 14 is removed by etching, so that the sensing structure 13 of the infrared light sensing device (microelectromechanical inductive device) is suspended.

Preferably, in the manufacturing process of the above-described microelectromechanical sensing device, the formation of dielectric layers other than the first dielectric layer 131 and the second dielectric layer 134 may be omitted to maintain the film structure covering the top surface of the support, ensuring structural stability and non-deformation during suspension, and simplifying the manufacturing process. In the above process, the first dielectric layer 131 and the second dielectric layer 134 may each be an infrared light absorption layer, and the sensing layer 133 is a material whose resistance changes with temperature. The support structure 12 is a conductive material, specifically tungsten metal, and the support structure 12 is a solid pillar. The manufacturing method does not include covering the portion of the support structure 12 located between the substrate 11 and the first dielectric layer 131 with a non-conductive material.

Please refer to Figure 11, which is a schematic diagram of the structure of a microelectromechanical inductance device according to another embodiment of the present invention. As shown in Figure 11, the first dielectric layer 131 includes a plurality of first sublayers 1311, 1312 and 1313, and the second dielectric layer 134 includes a plurality of second sublayers 1341, 1342 and 1343. The material composition of the plurality of first sublayers 1311, 1312 and 1313 along the stacking direction D is the same as the material composition of the plurality of second sublayers 1341, 1342 and 1343 along the opposite direction of the stacking direction D. In other words, the first sublayer 1311 and the second sublayer 1341 are made of the same material; the first sublayer 1312 and the second sublayer 1342 are made of the same material; and the first sublayer 1313 and the second sublayer 1343 are made of the same material. Specifically, the first sublayer 1311 and the second sublayer 1341 can be made of silicon dioxide; the first sublayer 1312 and the second sublayer 1342 can be made of silicon nitride; and the first sublayer 1313 and the second sublayer 1343 can be made of silicon dioxide. Through the above-mentioned composite film layers, the absorption rate of the dielectric layer for infrared light can be improved. In this embodiment, the first sublayer 1311 and the second sublayer 1341 are made of the same material (silicon dioxide), but this embodiment is not limited to this. Furthermore, in this embodiment, the first sublayer 1311 and the second sublayer 1341 have approximately the same thickness (e.g., 40 nanometers); the first sublayer 1312 and the second sublayer 1342 have approximately the same thickness (e.g., 165 nanometers); and the first sublayer 1313 and the second sublayer 1343 have approximately the same thickness (e.g., 40 nanometers). This material and thickness symmetry structure allows for stress balance in the composite film layers, maintaining the stability of the sensing structure.

Please refer to Figures 12a to 12e, which illustrate various embodiments of the support structure of the microelectromechanical sensing device of the present invention. In this embodiment, the metal pillars serving as the support structure are used to conduct signal communication between the lower connected read circuit layer and the upper sensing layer to read changes in resistance. Through the above-described planarization and encapsulation structure design, both the top surface (upper surface) of the metal pillar support and the radiation absorption surface (the surface above the second dielectric layer) are flat surfaces (height difference less than 2 nanometers), meeting the requirements of CMOS manufacturing processes. The process of this invention avoids structural height differences that could cause uneven film deposition or residues of photoresist, process byproducts, etc. In this case, the thin film stacking process covers the upper end of the metal pillar, which also enhances the strength of the suspension structure.

Figure 12a shows a support structure 12 with metal pillars of rectangular cross-section arranged approximately perpendicular to the elongated channel, and a surrounding sensing structure 13. Figure 12b shows a support structure 12 with metal pillars of rectangular cross-section arranged approximately parallel to the elongated channel, and a surrounding sensing structure 13. Figure 12c shows a support structure 12 with metal pillars of small area (1 micrometer by 1 micrometer) of square cross-section, particularly suitable for applications with small overall component size. Figures 12d and 12e show a support structure 12 with a plurality of metal pillars and a surrounding sensing structure 13, wherein the support structure 12 in Figure 12d includes two metal pillars at one corner, and the support structure 12 in Figure 12e includes six metal pillars at one corner. This plural metal pillar support structure 12 is particularly suitable for maintaining a relatively stable overall structure for components at specific wire bonding frequencies.

Please refer to Figures 13 and 14. Figure 13 is a cross-sectional schematic diagram of a microelectromechanical sensing device according to another embodiment of the present invention, and Figure 14 is a three-dimensional schematic diagram of a microelectromechanical sensing device according to another embodiment of the present invention. As shown in Figures 13 and 14, the microelectromechanical sensing device 1', which includes a substrate 11, a support structure 12, and a sensing structure 13, may further include a sealing cover 17 covering a sensing array SA formed by the sensing structure 13 and the support structure 12, and sealing it with the substrate 11 to form an accommodating space S. The sealing cover 17 has at least one of an inner surface facing the accommodating space S and an outer surface opposite to the inner surface, which has a plurality of columnar structures 171.

In this embodiment, the sensing structure 13 is composed of multiple sensing units 130 arranged in an array; each sensing unit 130 includes a portion of a first dielectric layer, a portion of a second dielectric layer, a portion of an electrode layer, and a portion of a sensing layer. The sensing units 130 and the support structure 12 together form a sensing array SA.

In this embodiment, the structure of the microelectromechanical sensing device 1 is basically the same as that of the microelectromechanical sensing device 1 in FIG1. The material of the package cover 17 can be an infrared-transmitting material, such as silicon. The package cover 17 can cover the sensing array SA by means of metal bonding, and form an accommodating space S between it and the substrate 11. In this example, the outer surface of the package cover 17 opposite to the inner surface has a plurality of columnar structures 171. However, in other embodiments, the inner surface of the package cover 17 may have a plurality of columnar structures, or both the inner and outer surfaces may have a plurality of columnar structures. This invention is not limited to this. Multiple columnar structures 171 may have different sizes, such as columnar structures 171a, 171b, 171c, 171d from wide to narrow, which may be arranged periodically along the radius of the sealing cap 17, but are not limited thereto.

Specifically, the packaging cover 17 encapsulates the microelectromechanical sensing device 1' using wafer-level packaging (WLP) technology, and the accommodating space S can be a vacuum space. In this way, by forming multiple columnar structures for imaging on the wafer-level packaging cover 17, this invention avoids the need to package and integrate a large additional lens assembly with the sensing device, thereby achieving a miniaturization of the overall size of the microelectromechanical sensing device 1'.

Please refer to Figure 15, which is a flowchart illustrating a method for manufacturing a microelectromechanical sensing device according to another embodiment of the present invention. As shown in Figure 15, the method for manufacturing a microelectromechanical sensing device may further include, after the aforementioned step S6: step S7: providing a packaging cover; step S8: etching a plurality of columnar structures on at least one of an inner surface and an outer surface opposite to the inner surface of the packaging cover; and step S9: covering the sensing array with the packaging cover and sealing a receiving space between the packaging cover and the common substrate.

Please refer to Figures 16 to 20 in conjunction with Figure 15. Figures 16 to 20 are schematic diagrams illustrating the manufacturing process of the microelectromechanical inductive device according to steps S6 to S9 in Figure 15. As shown in Figure 16, in step S6, after releasing the sacrifice layer, the unpackaged portion of the microelectromechanical inductive device 1' can be formed, wherein multiple sensing units 130 of the sensing structure 13 form a sensing array. The substrate 11 can be a wafer, and the substrate 11 can be disposed on a circuit board (PCB). As shown in Figure 17, in step S7, a packaging cover 17 can be provided. As shown in Figure 18, in step S8, multiple columnar structures 171 can be etched on at least one of an inner surface and an outer surface opposite to the inner surface of the packaging cover 17. As shown in Figure 19, in step S9, the top cover 17 can be placed over the sensing array, sealing the top cover 17 and the substrate 11 to form an accommodating space, wherein the inner surface faces the accommodating space. Specifically, the top cover connecting portions 172a and 172b of the top cover 17 can be joined together by metal bonding to form a connecting portion 172, thereby sealing and forming an accommodating space.

Specifically, the execution order of step S8, which etches to form multiple columnar structures, and step S9, which performs wafer-level packaging, can be reversed. For example, Figure 18 illustrates an embodiment of forming multiple columnar structures 171 on the inner surface of the package cover 17, in which case etching can be performed before packaging. In another example, if multiple columnar structures are to be formed on the outer surface of the package cover 17, packaging can be performed before etching. Alternatively, as shown in the example of Figure 20, if multiple columnar structures 171 are to be formed on both the outer and inner surfaces of the package cover 17 simultaneously, the inner surface of the package cover 17 can be etched first, then packaged, and then the outer surface of the package cover 17 can be etched.

The above-mentioned method of forming columnar structures by etching can be implemented through dry etching or wet etching, and this invention does not impose any restrictions. The following example describes the geometric parameters that need to be considered in the design of forming multiple columnar structures to meet imaging requirements, but this invention is not limited to this. Please refer to relation (1), which describes the formula for the phase difference generated on the imaging plane (sensor array) by columnar structures set at various positions on the surface of the package cover. In relation (1), ∆i is the phase difference. Let λ be the incident light wavelength, r be the distance of the columnar structure from the center point, and f be the imaging focal length of the multiple columnar structures.

Relation (1):

From equation (1), it can be concluded that columnar structures located at different positions (different r) will produce different phase differences (∆r). Furthermore, based on the different phase differences of these columnar structures at different positions, the geometric dimensions of these columnar structures at different positions can be determined. Please refer to Figure 21, which is a graph showing the relationship between the dimensions and phase angle of a columnar structure of a microelectromechanical inductance measuring device according to another embodiment of the present invention. The graph in Figure 21 is based on the relationship between the column width and phase angle of a columnar structure with a "rectangular prism" shape. In other embodiments, the relationship between the dimensions and phase angle of columnar structures with other shapes can also be obtained, and this invention is not limited to this. As shown in Figure 21, it depicts the relationship between the column width and the phase angle for three cases where the column height (H) is 9.8, 10, and 10.2 micrometers, respectively. Based on this figure and the above relationship (1), the geometric dimensions of the columnar structures at different positions can be determined, that is, the dimensions of each of the plurality of columnar structures can be determined according to the imaging focal length (f) and the position (r).

For example, the columnar structure in Figure 19 consists of four columnar structures 171a, 171b, 171c, and 171d with different column widths, arranged in a specific configuration. to The phase difference period, the one closest to the origin O, consists of two columnar structures 171a, one columnar structure 171b, two columnar structures 171c, and one columnar structure 171d; next, the phase difference period second furthest from the origin consists of one columnar structure 171a, one columnar structure 171b, one columnar structure 171c, and one columnar structure 171d; finally, the phase difference period furthest from the origin... The farthest phase difference period is composed of one columnar structure 171a, one columnar structure 171c, and one columnar structure 171d. Therefore, the farther away from the origin O, the shorter the length of a single phase difference period. In other words, within the phase difference period farther from the origin O, the columnar structures are arranged in a narrower range, and the number of columnar structures may be smaller, or the variety of column widths within the phase difference period may be smaller. Generally speaking, based on the above relationship (1), the more the columnar structure deviates from the center point (the larger r is), the more drastic the change in its size can be. In this embodiment, the origin O is the geometric center of the microelectromechanical inductive measuring device 1', but the origin can be designed in different positions according to requirements and is not limited to the geometric center.

With the above structure, the microelectromechanical sensing device disclosed in this application, through the arrangement of two dielectric layers of the same material relative to the electrode layer and the sensing layer, can achieve a stress balance effect, maintaining the overall height uniformity. The manufacturing method of the microelectromechanical sensing device disclosed in this application can provide a simplified process, thereby reducing production difficulties and improving chip manufacturing yield. In addition, the support structure made of metal material and not covered by additional dielectric material can be used, in addition to its support function, to conduct signals between the electrode layer and the read chip in the substrate. The dielectric layer formed of composite material can also improve infrared light absorption. The manufacturing method of the microelectromechanical sensing device disclosed in this application reduces production difficulties and improves chip manufacturing yield by using a planarization design process that sets the top surface of the support structure and the top surface of the dielectric layer to be coplanar. The microelectromechanical sensing device and its manufacturing method disclosed in this application can be packaged using wafer-level packaging technology, and multiple columnar structures are etched on the surface of the package cover to modulate the wavefront phase of the incident light and image it onto the sensing array formed by the sensing structure, without the need for additional optical lenses. This avoids the need to integrate a large lens assembly with the sensing device, achieving a miniaturization of the overall optical image sensor.

Although the present invention has been disclosed above with reference to the foregoing embodiments, it is not intended to limit the invention. Any modifications and refinements made without departing from the spirit and scope of the present invention are within the scope of patent protection of the present invention. For the scope of protection defined by the present invention, please refer to the attached patent application.

1,1’: Microelectromechanical sensing device 11: Substrate 111: Readout circuit layer 1111: Readout chip 12: Support structure 121: Support bottom surface 122: Support top surface 13: Sensing structure 130: Sensing unit 131: First dielectric layer 1310: Dielectric top surface 1311,1312,1313: First sublayer 132: Electrode layer 133: Sensing layer 134: Second dielectric layer 1341,1342,1343: Second sublayer 14: Sacrifice layer 15: Through-hole 16: Opening 17: Package cover 171, 171a, 171b, 171c, 171d: Columnar structure; 172: Connector; 172a, 172b: Top cover connector; SA: Sensing array; A-A’: Cut-off line; D: Direction; O: Origin; PCB: Circuit board; S1-S6, S7-S9: Steps

Figure 1 is a perspective view of a microelectromechanical inductive device according to an embodiment of the present invention. Figure 2 is a top view of the microelectromechanical inductive device according to an embodiment of the present invention. Figure 3 is a cross-sectional view of the microelectromechanical inductive device according to an embodiment of the present invention along section line A-A' in Figure 2. Figure 4 is a flowchart of the manufacturing method of the microelectromechanical inductive device according to an embodiment of the present invention. Figure 5 is a state diagram of the microelectromechanical inductive device according to steps S1 and S2 in Figure 4. Figures 6 and 7 are state diagrams of the microelectromechanical inductive device according to step S3 in Figure 4. Figure 8 is a state diagram of the microelectromechanical inductive device according to steps S4 and S5 in Figure 4. Figures 9 and 10 are schematic diagrams illustrating the state of the microelectromechanical inductive measuring device according to step S6 in Figure 4. Figure 11 is a structural schematic diagram illustrating the microelectromechanical inductive measuring device according to another embodiment of the present invention. Figures 12a to 12e show various embodiments of the support structure of the microelectromechanical inductive measuring device of the present invention. Figure 13 is a cross-sectional schematic diagram illustrating the microelectromechanical inductive measuring device according to another embodiment of the present invention. Figure 14 is a three-dimensional schematic diagram illustrating the microelectromechanical inductive measuring device according to another embodiment of the present invention. Figure 15 is a flowchart illustrating the manufacturing method of the microelectromechanical inductive measuring device according to another embodiment of the present invention. Figures 16 to 20 are schematic diagrams illustrating the state during the manufacturing process of the microelectromechanical inductive measuring device according to steps S6 to S9 in Figure 15. Figure 21 is a graph showing the relationship between the dimensions of the columnar structure of the microelectromechanical inductance device and the phase angle, according to another embodiment of the present invention.

11:Substrate

111: Reading Circuit Layers

12: Support Structure

121: Support base

122: Supporting the top surface

13: Sensing Structure

131: First dielectric layer

1310: Dielectric top surface

132: Electrode layer

133: Sensing Layer

134: Second dielectric layer

Claims (18)

A microelectromechanical inductive sensing device includes: a substrate; a plurality of support structures disposed on the substrate, each of the support structures having a bottom surface and a top surface located at opposite ends, the bottom surface being connected to the substrate; and a sensing structure supported by the support structures and disposed above the substrate, the sensing structure including: a first dielectric layer having a dielectric top surface, the dielectric top surface being coplanar with the top surface of each of the support structures; an electrode layer disposed on the first dielectric layer and directly contacting the support structures; and a sensing layer disposed on the first dielectric layer, the projection of which toward the substrate does not overlap with the support structures; and A second dielectric layer is disposed on the electrode layer and the sensing layer, wherein the first dielectric layer and the second dielectric layer are made of the same material, and the supporting structures are made of conductive material and electrically connected to the electrode layer. The microelectromechanical inductive measuring device as claimed in claim 1, wherein the first dielectric layer comprises a plurality of first sublayers, the second dielectric layer comprises a plurality of second sublayers, and the material composition of the first sublayers along a stacking direction is the same as the material composition of the second sublayers in the opposite direction of the stacking direction. The microelectromechanical inductive measuring device as described in claim 1 does not include dielectric layers other than the first dielectric layer and the second dielectric layer. The microelectromechanical sensing device as described in claim 1, wherein the first dielectric layer and the second dielectric layer are each infrared light absorbing layers, and the sensing layer is made of a material whose resistance changes with temperature. The microelectromechanical inductive device as claimed in claim 1, wherein each of the support structures is a solid column, and the portion of each of the support structures located between the substrate and the first dielectric layer is not covered by a non-conductive material. The microelectromechanical sensing device as claimed in claim 1, wherein the sensing structure and the supporting structures form a sensing array, and the microelectromechanical sensing device further includes: a sealing cover covering the sensing array and sealing it with the substrate to form an accommodating space, wherein at least one of an inner surface of the sealing cover facing the accommodating space and an outer surface opposite to the inner surface has a plurality of columnar structures. The microelectromechanical inductive measuring device as described in claim 6, wherein the accommodating space is a vacuum space. The microelectromechanical inductive measuring device as claimed in claim 6, wherein the columnar structures have a focal length, each of the columnar structures has a position, and the size of each of the columnar structures is determined according to the focal length and the position. The microelectromechanical inductive device as described in claim 6, wherein the inner and outer surfaces of the package cover have the columnar structures. A method for manufacturing a microelectromechanical inductive measuring device includes: forming a sacrifice layer on a substrate; forming a first dielectric layer on the sacrifice layer; embedding a plurality of support structures in the sacrifice layer and the first dielectric layer, such that a bottom surface of each of the support structures is connected to the substrate, and a top surface of each of the support structures is coplanar with a top dielectric surface of the first dielectric layer, wherein the bottom surface and the top surface of the support are located at opposite ends, and wherein the support structures are made of a conductive material; An electrode layer and a sensing layer are formed on the first dielectric layer, wherein the electrode layer directly contacts the support structures, and the projection of the sensing layer toward the substrate does not overlap the support structures; a second dielectric layer is formed on the electrode layer and the sensing layer, wherein the second dielectric layer is made of the same material as the first dielectric layer; and vias are made in the first dielectric layer, the electrode layer, and the second dielectric layer to release the sacrifice layer. The method of manufacturing a microelectromechanical inductive measuring device as described in claim 10, wherein the support structures are embedded in the sacrifice layer such that the bottom surface of each of the support structures is connected to the substrate, and the top surface of each of the support structures located opposite to the bottom surface of the support structures is coplanar with the top dielectric surface of the first dielectric layer, comprises: forming at least one through-hole in the sacrifice layer and the first dielectric layer; depositing a material in the at least one through-hole; and performing a planarization process with the top dielectric surface of the first dielectric layer as a stop surface to remove a portion of the material. The method of manufacturing a microelectromechanical inductive sensing device as described in claim 10, wherein forming the first dielectric layer on the sacrifice layer includes forming a plurality of first sublayers on the sacrifice layer along a stacking direction, forming the second dielectric layer on the electrode layer and the sensing layer includes forming a plurality of second sublayers on the electrode layer and the sensing layer along the stacking direction, and the material composition of the first sublayers along the stacking direction is the same as the material composition of the second sublayers in the opposite direction along the stacking direction. The method of manufacturing the microelectromechanical inductive measuring device as described in claim 10 does not include forming dielectric layers other than the first dielectric layer and the second dielectric layer. The method for manufacturing a microelectromechanical sensing device as described in claim 10, wherein the first dielectric layer and the second dielectric layer are each an infrared light absorbing layer, and the sensing layer is a material whose resistance changes with temperature. The method of manufacturing a microelectromechanical inductive device as described in claim 10, wherein each of the support structures is a solid column, and the manufacturing method does not include covering the portion of each of the support structures located between the substrate and the first dielectric layer with a non-conductive material. The method of manufacturing the microelectromechanical inductive sensing device as described in claim 10 further includes: providing a packaging cover; etching a plurality of columnar structures on at least one of an inner surface and an outer surface opposite to the inner surface of the packaging cover; and covering the packaging cover over a sensing array, thereby sealing a receiving space between the packaging cover and the substrate, wherein the inner surface faces the receiving space. A method of manufacturing a microelectromechanical inductive measuring device as described in claim 16, wherein a focal length is provided, each of the columnar structures has a position, and the size of each of the columnar structures is determined according to the focal length and the position. The method of manufacturing a microelectromechanical inductive measuring device as described in claim 16, wherein the accommodating space is a vacuum space.