Pixel structure, pixel array and preparation method of pixel structure

Abstract

The invention provides a pixel structure, a pixel array and a preparation method of the pixel structure, in the pixel structure, a suspended bridge arm structure and a bridge deck structure are suspended above a reflecting layer, and the suspended bridge arm structure and the bridge deck structure are connected through a bridge deck supporting structure perpendicular to the upper surface of the reflecting layer. The bridge deck structure is an independent layer structure relative to the suspended bridge arm structure, so that the area of the bridge deck structure is larger under the condition that the area of the pixel structure is fixed, and the effective absorption area of the pixel structure is larger due to the fact that the bridge deck structure comprises the heat-sensitive material layer used for absorbing infrared radiation. And the response rate of the pixel structure is increased.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor devices, and in particular to a pixel structure, a pixel array, and a method for preparing the pixel structure. Background Art

[0002] An uncooled infrared detector is a thermal imager that does not require a cooling system. Its detector temperature is typically the same as or slightly higher than the ambient temperature. The main principle of an uncooled thermal imager is to utilize the properties of the detector material to convert infrared radiation emitted by an object into an electrical signal. Through signal processing and image reconstruction techniques, an image of the temperature distribution on the object's surface is obtained. An uncooled infrared detector consists of several pixel structures, each of which includes a pier structure, a bridge arm structure, and a bridge deck structure. The bridge deck structure absorbs infrared radiation. The larger the bridge deck structure, the higher the response rate of the pixel structure.

[0003] However, increasing the bridge deck area will increase the pixel area, thereby reducing the integration of the uncooled infrared detector. Summary of the Invention

[0004] The present invention provides a pixel structure, a pixel array and a method for preparing the pixel structure, which solves the problem that the pixel structure is difficult to have both the characteristics of a large absorption area and a high degree of integration.

[0005] According to a first aspect of the present invention, there is provided a pixel structure comprising: a substrate, wherein an integrated circuit module is disposed on the substrate; a reflective layer located on the substrate; a plurality of pad structures, located on the substrate and around the reflective layer, the pad structures being electrically connected to the integrated circuit module; a dielectric layer located on the surface of the substrate, the upper surface and side surfaces of the integrated circuit, and the side surfaces and a portion of the upper surface of the pad structure; a plurality of bridge structures, each of the bridge structures comprising a pier structure, a suspended bridge arm structure, and a bridge deck support structure perpendicular to the upper surface of the reflective layer, the pier structure being located on the upper surface of the corresponding pad structure and electrically connected to the corresponding pad structure, the suspended bridge arm structure being suspended above the reflective layer, and one end of the suspended bridge arm structure being electrically connected to the top of the pier structure; The bridge deck structure is located at least above the suspended bridge arm structure, the bridge deck support structure is located between the suspended bridge arm structure and the bridge deck structure, and the two ends of the bridge deck support structure are electrically connected to the bridge deck structure and the other end of the suspended bridge arm structure respectively, the bridge deck structure is parallel to the upper surface of the reflective layer, and the bridge deck structure includes a heat-sensitive material layer for absorbing infrared radiation.

[0006] Optionally, the side surfaces of the reflective layer are the first side, the second side, the third side and the fourth side in a clockwise direction, and several of the pad structures are divided into a first pad structure and a second pad structure, the first pad structure is located on the first side of the reflective layer, close to the fourth side relative to the second side, and the second pad structure is located on the third side of the reflective layer, close to the second side relative to the fourth side.

[0007] Optionally, several of the bridge structures are divided into a first bridge structure and a second bridge structure, the first bridge structure including a first pier structure, a first suspended bridge arm structure and a first bridge deck support structure, the first pier structure is located on the first pad structure and is electrically connected to the first pad structure, the second bridge structure includes a second pier structure, a second suspended bridge arm structure and a second bridge deck support structure, the second pier structure is located on the second pad structure and is electrically connected to the second pad structure.

[0008] Optionally, each of the bridge pier structures includes at least two sub-bridge pier structures spaced apart and arranged on the corresponding pad structure, and the distance between each of the sub-bridge pier structures and the reflective layer is the same.

[0009] Optionally, each of the sub-bridge pier structures includes, from the outside to the inside, a first sub-bridge pier protective layer, a first sub-bridge pier metal layer, a second sub-bridge pier metal layer and a second sub-bridge pier protective layer, wherein the bottom surface and part of the side wall surface of the first sub-bridge pier protective layer are in contact with the dielectric layer and the remaining side wall surface of the first sub-bridge pier protective layer is exposed, the bottom surface of the first sub-bridge pier metal layer is electrically connected to the upper surface of the first pad structure, the first sub-bridge pier protective layer is located on the side wall of the first sub-bridge pier metal layer, the first sub-bridge pier metal layer is located on the side wall of the second sub-bridge pier metal layer, and the second sub-bridge pier metal layer is located on the side wall of the second sub-bridge pier protective layer.

[0010] Optionally, each of the suspended bridge arm structures includes at least two branch bridge arm structures, and each of the branch bridge arm structures includes a first branch bridge arm protective layer, a branch bridge arm metal layer and a second branch bridge arm protective layer stacked from bottom to top. The branch bridge arm structures in the suspended bridge arm structure in the same bridge structure correspond one-to-one to the branch bridge piers in the corresponding pier structure. One end of the first branch bridge arm protective layer is connected to the corresponding first branch bridge pier protective layer, one end of the second branch bridge arm protective layer is connected to the corresponding second branch bridge pier protective layer, one end of the branch bridge arm metal layer is electrically connected to the top surface of the corresponding first branch bridge pier metal layer, and, in the same suspended bridge arm structure, each of the first branch bridge arm protective layers is connected to each other, the other end of each of the branch bridge arm metal layers is connected to each other, and the other end of each of the second branch bridge arm protective layers is connected to each other.

[0011] Optionally, each of the bridge deck support structures includes at least two bridge deck sub-support structures, and the sub-bridge arm structures in the suspended bridge arm structure in the same bridge structure correspond one-to-one to the bridge deck sub-support structures in the corresponding bridge deck support structure. The bridge deck sub-support structures include a support protective layer and a support metal layer. The support metal layer is located on the side wall of the support metal layer and is located on the periphery of the support metal layer. The lower surface of the support metal layer is electrically connected to the corresponding sub-bridge arm metal layer, and the lower surface of the support protective layer is in contact with the second sub-bridge arm protective layer.

[0012] Optionally, the bridge deck structure includes a first bridge deck protection layer, a heat-sensitive material layer, and a second bridge deck protection layer stacked from bottom to top, the first bridge deck protection layer is located on a portion of the lower surface of the heat-sensitive material layer, the heat-sensitive material layer is electrically connected to the other end of the supporting metal layer, and the second bridge deck protection layer covers the upper surface and side wall surface of the heat-sensitive material layer.

[0013] According to a second aspect of the present invention, there is provided a pixel array comprising a plurality of the above-mentioned pixel structures distributed in an array, wherein the plurality of pixel structures are not electrically connected to each other.

[0014] According to a third aspect of the present invention, there is provided a method for preparing a pixel structure, comprising: Providing a substrate, wherein an integrated circuit module is disposed on the substrate; forming a reflective layer and a plurality of pad structures on the substrate, wherein the pad structures are located around the reflective layer and are electrically connected to the integrated circuit module; forming a dielectric layer, wherein the dielectric layer is located on the sidewall surface and the upper surface of the reflective layer and the sidewall surface and the upper surface of the pad structure; forming a plurality of bridge structures, each of the bridge structures comprising a pier structure, a suspended bridge arm structure, and a bridge deck support structure perpendicular to the upper surface of the reflective layer, the pier structure being located on the upper surface of the corresponding pad structure and electrically connected to the corresponding pad structure, the suspended bridge arm structure being suspended above the reflective layer, and one end of the suspended bridge arm structure being electrically connected to the top of the pier structure; A bridge deck structure is formed, wherein the bridge deck structure is located at least above the suspended bridge arm structure, the bridge deck support structure is located between the suspended bridge arm structure and the bridge deck structure, and the two ends of the bridge deck support structure are electrically connected to the bridge deck structure and the other end of the suspended bridge arm structure respectively, the bridge deck structure is parallel to the upper surface of the reflective layer, and the bridge deck structure includes a heat-sensitive material layer for absorbing infrared radiation.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: In a pixel structure provided by the technical solution of the present invention, several bridge structures and bridge deck structures are included. Each bridge structure includes a pier structure, a suspended bridge arm structure, and a bridge deck support structure perpendicular to the upper surface of the reflective layer. The suspended bridge arm structure is suspended above the reflective layer, and one end of the suspended bridge arm structure is electrically connected to the top of the pier structure. The bridge deck structure is at least located above the suspended bridge arm structure. The bridge deck support structure is located between the suspended bridge arm structure and the bridge deck structure, and both ends of the bridge deck support structure are electrically connected to the bridge deck structure and the other end of the suspended bridge arm structure respectively. The bridge deck structure is parallel to the upper surface of the reflective layer, and the bridge deck structure includes a thermally sensitive material layer for absorbing infrared radiation. Therefore, the suspended bridge arm structure and the bridge deck structure are both suspended above the reflective layer, and the suspended bridge arm structure and the bridge deck structure are connected by a bridge deck support structure perpendicular to the upper surface of the reflective layer, so that the bridge deck structure is an independent layer structure relative to the suspended bridge arm structure. As a result, under the condition that the area of ​​the pixel structure is certain, the area of ​​the bridge deck structure is larger. Since the bridge deck structure includes a thermally sensitive material layer for absorbing infrared radiation, the effective absorption area of ​​the pixel structure is larger, thereby increasing the response rate of the pixel structure.

[0016] Furthermore, because the bridge structure comprises at least two sub-bridge pier structures, sub-bridge arm structures corresponding one-to-one with the sub-bridge pier structures, and sub-bridge deck support structures corresponding one-to-one with the sub-bridge arm structures, the pixel structure has a high defect tolerance. Furthermore, because the suspended bridge arm structure in the bridge structure is a separate layer structure relative to the bridge deck structure, and the suspended bridge arm structure includes at least two sub-bridge arm structures, the stability and reliability of the pixel structure can be increased by appropriately increasing the size of the sub-bridge arm structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram of a single-layer pixel structure; Figure 2 It is a cross-sectional schematic diagram of a pixel structure with an umbrella structure; Figure 3-Figure 9 This is a structural diagram of the preparation process of the pixel structure provided by an embodiment of the present invention; Figure 10 This is a top view of the pixel structure provided by the embodiment of the present invention. Figure 1 ; Figure 11 This is a top view of the pixel structure provided by the embodiment of the present invention. Figure 2 . DETAILED DESCRIPTION

[0018] As described in the background art, it is difficult for a pixel structure to have both the characteristics of a large absorption area and a high degree of integration.

[0019] Figure 1It is a structural diagram of a single-layer pixel structure.

[0020] Please refer to Figure 1 The single-layer pixel structure includes two contact holes 1000, two bridge arm structures 3000 corresponding to the two contact holes 1000, and a bridge deck structure 2000. The bridge deck structure 2000 is connected to the contact hole 1000 through the bridge arm structure 3000. The two contact holes 1000 and the two bridge arm structures 3000 corresponding to the two contact holes 1000 are respectively located on both sides of the bridge deck structure 2000.

[0021] However, because the bridge deck structure 2000 and the bridge arm structure 3000 are located on the same layer, the bridge deck structure 2000 is relatively small, resulting in a smaller effective absorption area for the pixel structure. This, in turn, leads to the detector comprising several single-layer pixel structures being bulky and having poor performance. Furthermore, because one side of the bridge deck structure 2000 has only one bridge arm structure 3000 and one contact hole 1000, any electrical connection anomalies between the contact hole 1000 or the bridge arm structure 3000 could cause the pixel to lose functionality. Furthermore, the thin and long bridge arm structure 3000 has a poor load-bearing capacity, resulting in low reliability.

[0022] Figure 2 It is a cross-sectional schematic diagram of a pixel structure with an umbrella structure.

[0023] Please refer to Figure 2 In order to increase the absorption area of ​​the pixel structure, an umbrella structure 4000 is added to the bridge structure 2000 in the single-layer pixel structure. However, the addition of the umbrella structure 4000 will increase the weight of the pixel structure. In addition, the low reliability problem caused by only one contact hole and a thin and long bridge arm structure on one side in the single-layer pixel structure still exists in the pixel structure with an umbrella structure.

[0024] In view of this, the present invention creatively proposes a pixel structure.

[0025] a substrate, wherein an integrated circuit module is disposed on the substrate; a reflective layer, located on the substrate; a plurality of pad structures, located on the substrate and around the reflective layer, the pad structures being electrically connected to the integrated circuit module; a dielectric layer located on the surface of the substrate, the upper surface and side surfaces of the integrated circuit, and the side surfaces and a portion of the upper surface of the pad structure; a plurality of bridge structures, each of the bridge structures comprising a pier structure, a suspended bridge arm structure, and a bridge deck support structure perpendicular to the upper surface of the reflective layer, the pier structure being located on the upper surface of the corresponding pad structure and electrically connected to the corresponding pad structure, the suspended bridge arm structure being suspended above the reflective layer, and one end of the suspended bridge arm structure being electrically connected to the top of the pier structure; The bridge deck structure is located at least above the suspended bridge arm structure, the bridge deck support structure is located between the suspended bridge arm structure and the bridge deck structure, and the two ends of the bridge deck support structure are electrically connected to the bridge deck structure and the other end of the suspended bridge arm structure respectively, the bridge deck structure is parallel to the upper surface of the reflective layer, and the bridge deck structure includes a heat-sensitive material layer for absorbing infrared radiation.

[0026] Therefore, the suspended bridge arm structure and the bridge deck structure are both suspended above the reflective layer, and the suspended bridge arm structure and the bridge deck structure are connected by a bridge deck support structure perpendicular to the upper surface of the reflective layer, so that the bridge deck structure is an independent layer structure relative to the suspended bridge arm structure. As a result, under the condition that the area of ​​the pixel structure is certain, the area of ​​the bridge deck structure is larger. Since the bridge deck structure includes a thermally sensitive material layer for absorbing infrared radiation, the effective absorption area of ​​the pixel structure is larger, thereby increasing the response rate of the pixel structure.

[0027] The following will be used in conjunction with the accompanying drawings to clearly and completely describe the embodiments of the present invention. It should be understood that the described embodiments are only some of the embodiments of the present invention, not all of the embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. The terms "first," "second," "third," etc. in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, product, or apparatus.

[0028] Figure 3-Figure 9 is a cross-sectional view of the preparation process of the pixel structure provided by an embodiment of the present invention, Figure 10 This is a top view of the pixel structure provided by the embodiment of the present invention. Figure 1 , Figure 11 This is a top view of the pixel structure provided by the embodiment of the present invention. Figure 2 .in, Figure 9 It is along Figure 10 Schematic diagram of the cross-section structure from A1 to A2, Figure 10 Only the pad structure, the first bridge pier metal layer and the second bridge arm protective layer corresponding to the bridge deck support structure are schematically shown in order to illustrate the relative positions among the pad structure, the bridge arm structure and the bridge deck support structure. Figure 11 Only the sub-pier structure, welding pad structure, second bridge deck protection layer, bridge deck sub-support structure and the second bridge arm protection layer corresponding to the bridge deck support structure are shown in the figure to show the relative positions between the pier structure, welding pad structure, bridge deck structure and bridge deck support structure.

[0029] Please refer to Figure 3-Figure 9 , an embodiment of the present invention provides a method for preparing a pixel structure, comprising: Please refer to Figure 3 , providing a substrate 1, wherein an integrated circuit module is provided in the substrate 1.

[0030] A reflective layer 2 and a plurality of pad structures 3 are formed on a substrate 1. The pad structures 3 are located around the reflective layer 2 and are electrically connected to the integrated circuit module. The reflective layer 2 and the plurality of pad structures 3 are both located above the integrated circuit module.

[0031] A dielectric layer 8 is formed, and the dielectric layer 8 is located on the sidewall surface and the upper surface of the reflective layer 2 and the sidewall surface and the upper surface of the pad structure 3 .

[0032] Several bridge structures are formed, each bridge structure includes a pier structure, a suspended bridge arm structure, and a bridge deck support structure perpendicular to the upper surface of the suspended bridge arm structure. The pier structure is located on the upper surface of the corresponding pad structure 3 and is electrically connected to the corresponding pad structure 3. The suspended bridge arm structure is suspended on the reflective layer 2, and one end of the suspended bridge arm structure is electrically connected to the top of the pier structure.

[0033] The method of forming the bridge structure includes: Please refer to Figure 4 , a first sacrificial layer 9 is formed on the dielectric layer 8 .

[0034] Please refer to Figure 5 A bridge pier structure is formed in the first sacrificial layer 9 , and a suspended bridge arm structure is formed on a portion of the surface of the first sacrificial layer 9 .

[0035] The method of forming the bridge pier structure and the suspended bridge arm structure includes: A plurality of first grooves 40 are formed in the first sacrificial layer 9, and a first protective material layer 410 is formed on part of the sidewalls of the first grooves 40 and on the surface of the first sacrificial layer 9. The bottom of the first groove 40 exposes part of the pad structure 3. The first protective material layer 410 on part of the sidewalls of the first groove 40 serves as a first sub-bridge pier protective layer 41.

[0036] The method for forming the first groove 40 in the first sacrificial layer 9 and forming the first protective material layer 410 on a portion of the sidewall surface of the first groove 40 and the surface of the first sacrificial layer 9 includes: etching the first sacrificial layer 9 and a portion of the dielectric layer 8 to form an initial first groove 40 in the first sacrificial layer 9, with the bottom and a portion of the sidewall surface of the initial first groove 40 exposing the dielectric layer 8; after forming the initial first groove 40, forming the first protective material layer 410 on the surface of the first sacrificial layer 9 and the bottom and sidewall surface of the initial first groove 40; etching the first protective material layer 410 and the corresponding dielectric layer 8 at the bottom of the initial first groove 40 to form the first groove 40, with the bottom of the first groove 40 exposing a portion of the pad structure 3. The side length of the first groove 40 is 0.3 microns to 1.0 microns.

[0037] A first metal material layer and a second metal material layer are sequentially formed on the first protection layer and at the bottom of the first groove 40 .

[0038] A portion of the metal material layer is removed by etching to form a second sub-bridge pier metal layer 43 above the first groove 40 .

[0039] A second protective material layer is formed on the second sub-bridge pier metal layer 43 and the first metal material layer.

[0040] The second protective material layer, the first metal material layer, and the first protective material layer 410 are etched to form a bridge arm structure and a bridge pier structure. The first protective material layer 410, the first metal material layer, and the second protective material layer located on the first sacrificial layer 9 respectively serve as the first sub-bridge arm protective layer 51, the sub-bridge arm metal layer 52, and the second sub-bridge arm protective layer 53 of the bridge arm structure. The first protective material layer 410, the first metal material layer, and the second protective material layer located above the first groove 40 respectively serve as the first sub-bridge pier protective layer 41, the first sub-bridge pier metal layer 42, and the second sub-bridge pier protective layer 44 of the bridge pier structure.

[0041] Please refer to Figure 6 After the bridge pier structure and the suspended bridge arm structure are formed, a second sacrificial layer 10 is formed on the bridge pier structure, the suspended bridge arm structure and the exposed surface of the first sacrificial layer 9 .

[0042] A bridge deck support structure is formed in the second sacrificial layer 10 and penetrates the second sacrificial layer 10 . The bridge deck support structure is relatively perpendicular to the suspended bridge arm structure.

[0043] The method of forming the bridge deck support structure includes: A plurality of initial second grooves 60 are formed in the second sacrificial layer 10, and the bottoms of the initial second grooves 60 partially expose the second branch bridge arm protection layer 53. The side length of the initial second grooves 60 is 0.3 micrometers to 1.0 micrometers.

[0044] A third protection material layer 710 is formed on the surface of the second sacrificial layer 10 , the bottoms of the pair of initial second grooves 60 , and the sidewall surfaces.

[0045] The third protection material layer 710 and the corresponding second branch bridge arm protection layer 53 at the bottom of the initial second groove 60 are removed by etching, so that a portion of the branch bridge arm metal layer 52 is exposed, forming a second groove.

[0046] A third metal material layer is deposited in the second groove to form a plurality of bridge deck support structures in the plurality of second grooves, wherein the third metal material layer in the second groove serves as the supporting metal layer 61 , and the third protective material layer 710 in the second groove serves as the supporting protective layer 62 .

[0047] Please refer to Figure 7 and Figure 8 , forming a bridge deck structure, the bridge deck structure is located at least above the suspended bridge arm structure, the bridge deck support structure is located between the suspended bridge arm structure and the bridge deck structure, and the two ends of the bridge deck support structure are electrically connected to the bridge deck structure and the other end of the suspended bridge arm structure respectively, the bridge deck structure is parallel to the upper surface of the reflective layer 2, and the bridge deck structure includes a heat-sensitive material layer 72 for absorbing infrared radiation.

[0048] The method of forming the bridge deck structure includes: A heat-sensitive material layer 72 and a fourth protective material layer are sequentially deposited on the upper surface of the supporting metal layer 61 and the exposed surface of the third protective material layer 710 .

[0049] Part of the fourth protective material layer, the heat-sensitive material layer 72 and the third protective material layer 710 are removed by etching, so that the area of ​​the fourth protective material layer, the heat-sensitive material layer 72 and the third protective material layer 710 is smaller than the area of ​​the pixel structure.

[0050] A fifth protection material layer is deposited on the surface of the fourth protection material layer, the exposed surface of the second sacrificial layer 10 , and the sidewall surfaces of the fourth protection material layer, the heat-sensitive material layer 72 , and the third protection material layer 710 .

[0051] A portion of the fifth protective material layer is removed by etching, where the fifth protective material layer is at least on the sidewall surfaces of the fourth protective material layer, the heat-sensitive material layer 72 and the third protective material layer 710 , to form a bridge structure.

[0052] Please refer to Figure 9 After the bridge deck structure is formed, the first sacrificial layer 9 and the second sacrificial layer 10 are removed.

[0053] The material of the first sacrificial layer 9 and the second sacrificial layer 10 is polyimide, and the method for removing the first sacrificial layer 9 and the second sacrificial layer 10 includes: passing carbon tetrafluoride gas on the surface of the pixel structure.

[0054] Please refer to Figure 9 The present invention also provides a pixel structure, including: a substrate 1, a dielectric layer 8, a reflective layer 2, a plurality of pad structures 3, a plurality of bridge structures and a bridge deck structure.

[0055] The substrate 1 is a silicon substrate, and an integrated circuit module is provided in the substrate 1 .

[0056] The reflective layer 2 and several pad structures 3 are both located on the substrate 1. The pad structures 3 are located around the reflective layer 2 and are electrically connected to the integrated circuit module. Specifically, the reflective layer 2 is used to reflect infrared radiation emitted from the surface of the reflective layer 2 back to the surface of the bridge structure, thereby improving the absorption efficiency of the pixel structure. The reflective layer 2 can be made of aluminum, copper, or a copper-aluminum alloy.

[0057] The dielectric layer 8 is located on the surface of the substrate 1, the upper surface and side surfaces of the integrated circuit, and the side surfaces and part of the upper surface of the pad structure 3. The dielectric layer 8 includes multiple silicon oxide layers with different properties and a silicon nitride layer located on the multiple silicon oxide layers with different properties.

[0058] In this embodiment, please refer to Figure 11 The side surfaces of the reflective layer 2 are the first side, the second side, the third side and the fourth side in a clockwise direction. The plurality of pad structures 3 are divided into a first pad structure 3 and a second pad structure 3. The first pad structure 3 is located on the first side of the reflective layer 2, close to the fourth side relative to the second side, and the second pad structure 3 is located on the third side of the reflective layer 2, close to the second side relative to the fourth side.

[0059] Each bridge structure includes a pier structure, a suspended bridge arm structure, and a bridge deck support structure perpendicular to the upper surface of the reflective layer 2. The pier structure is located on the upper surface of the corresponding pad structure 3 and is electrically connected to the corresponding pad structure 3. The suspended bridge arm structure is suspended above the reflective layer 2, and one end of the suspended bridge arm structure is electrically connected to the top of the pier structure. The suspended bridge arm structure is parallel to the surface of the dielectric layer 8.

[0060] In this embodiment, several bridge structures are divided into a first bridge structure and a second bridge structure. The first bridge structure includes a first pier structure, a first suspended bridge arm structure and a first bridge deck support structure. The first pier structure is located on the first pad structure 3 and is electrically connected to the first pad structure 3. The second bridge structure includes a second pier structure, a second suspended bridge arm structure and a second bridge deck support structure. The second pier structure is located on the second pad structure 3 and is electrically connected to the second pad structure 3.

[0061] In this embodiment, the projections of the first bridge deck support structure and the second bridge deck support structure on the bridge deck structure are diagonally positioned on the surface of the bridge deck structure, so that the first bridge deck support structure and the second bridge deck support structure support the bridge deck evenly, thereby better supporting the bridge deck.

[0062] In this embodiment, each pier structure includes at least two sub-pier structures 400 spaced apart on the corresponding pad structure 3 , and the distance between each sub-pier structure 400 and the reflective layer 2 is the same.

[0063] In this embodiment, each sub-bridge pier structure 400 includes, from the outside to the inside, a first sub-bridge pier protective layer 41, a first sub-bridge pier metal layer 42, a second sub-bridge pier metal layer 43, and a second sub-bridge pier protective layer 44. The bottom surface and part of the side wall surface of the first sub-bridge pier protective layer 41 are in contact with the dielectric layer 8, and the remaining side wall surface of the first sub-bridge pier protective layer 41 is exposed. The bottom surface of the first sub-bridge pier metal layer 42 is electrically connected to the upper surface of the first pad structure 3. The first sub-bridge pier protective layer 41 is located on the side wall of the first sub-bridge pier metal layer 42, the first sub-bridge pier metal layer 42 is located on the side wall of the second sub-bridge pier metal layer 43, and the second sub-bridge pier metal layer 43 is located on the side wall of the second sub-bridge pier protective layer 44.

[0064] Among them, the material of the first sub-bridge pier protective layer 41 and the second sub-bridge pier protective layer 44 is silicon nitride, the material of the first sub-bridge pier metal layer 42 is a mixed metal of titanium and titanium nitride, and the material of the second sub-bridge pier metal layer 43 is metallic aluminum. The second sub-bridge pier metal layer is used to further support the sub-bridge pier structure 400. If only the first sub-bridge pier metal layer 42 is used to support the sub-bridge pier structure 400, the sub-bridge pier structure will crack or tilt due to the tensile stress or compressive stress (controlled by the silicon nitride composition) of other structures at both ends.

[0065] In this embodiment, each suspended bridge arm structure includes at least two branch bridge arm structures, and each branch bridge arm structure includes a first branch bridge arm protective layer 51, a branch bridge arm metal layer 52, and a second branch bridge arm protective layer 53 stacked from bottom to top. The branch bridge arm structures in the suspended bridge arm structure in the same bridge structure correspond one-to-one to the branch bridge piers in the corresponding pier structure. One end of the first branch bridge arm protective layer 51 is connected to the corresponding first branch bridge pier protective layer 41, one end of the second branch bridge arm protective layer 53 is connected to the corresponding second branch bridge pier protective layer 44, and one end of the branch bridge arm metal layer 52 is electrically connected to the top surface of the corresponding first branch bridge pier metal layer 42. In addition, in the same suspended bridge arm structure, each first branch bridge arm protective layer 51 is connected to each other, the other end of each branch bridge arm metal layer 52 is connected to each other, and the other end of each second branch bridge arm protective layer 53 is connected to each other.

[0066] The material of the first branch bridge arm protective layer 51 is the same as that of the first branch bridge pier protective layer 41 , the material of the branch bridge arm metal layer 52 is the same as that of the first branch bridge pier metal layer 42 , and the material of the second branch bridge arm protective layer 53 is the same as that of the second branch bridge pier protective layer 44 .

[0067] In this embodiment, each bridge deck support structure includes at least two bridge deck sub-support structures 600, and the sub-bridge arm structures in the suspended bridge arm structure in the same bridge structure correspond one-to-one to the bridge deck sub-support structures 600 in the corresponding bridge deck support structure. The bridge deck sub-support structure 600 includes a support protective layer 62 and a support metal layer 61. The support metal layer 61 is located on the side wall of the support metal layer 61 and is located on the periphery of the support metal layer 61. The lower surface of the support metal layer 61 is electrically connected to the corresponding sub-bridge arm metal layer 52, and the lower surface of the support protective layer 62 is in contact with the second sub-bridge arm protective layer 53.

[0068] The material of the support protection layer 62 is the same as that of the second branch bridge arm protection layer 53 , and the material of the support metal layer 61 is the same as that of the branch bridge arm metal layer 52 .

[0069] As can be seen from the above, the bridge structure is composed of the pier structure, the suspended bridge arm structure, the bridge deck support structure, and the bridge deck structure in the direction from B2 to B1. Therefore, the suspended bridge arm structure and the bridge deck structure are relatively independent layer structures, so that when the area of ​​the pixel structure is constant, the area of ​​the bridge deck structure and the area of ​​the suspended bridge arm structure are larger. Furthermore, the area of ​​the bridge deck structure can be slightly smaller than the area of ​​the pixel structure, so that the absorption area of ​​the pixel structure is larger, and the area of ​​the suspended bridge arm structure can also be made as large as possible without affecting the heat dissipation. Among them, under the same heat dissipation conditions, that is, when the area of ​​the suspended bridge arm structure is the same, making the bridge arm structure shorter and thicker can increase the stability of the pixel structure. In addition, since the bridge deck structure is a relatively independent single-layer structure, the pixel structure in this embodiment has a lighter weight than the pixel structure with an umbrella structure.

[0070] Please refer to Figure 10 and Figure 11 The bridge deck structure is at least located above the suspended bridge arm structure, the bridge deck support structure is located between the suspended bridge arm structure and the bridge deck structure, and the two ends of the bridge deck support structure are electrically connected to the bridge deck structure and the other end of the suspended bridge arm structure respectively. The bridge deck structure is parallel to the upper surface of the reflective layer 2, and the bridge deck structure includes a thermal sensitive material layer 72 for absorbing infrared radiation.

[0071] In this embodiment, the bridge deck structure includes a first bridge deck protection layer 71, a heat-sensitive material layer 72, and a second bridge deck protection layer 73 stacked from bottom to top. The first bridge deck protection layer 71 is located on a portion of the lower surface of the heat-sensitive material layer 72, and the heat-sensitive material layer 72 is electrically connected to the other end of the supporting metal layer 61. The second bridge deck protection layer 73 covers the upper surface and side wall surface of the heat-sensitive material layer 72.

[0072] Among them, the material of the thermosensitive material layer 72 is a thermistor, and the material of the first bridge deck protection layer 71 and the second bridge deck protection layer 73 is silicon nitride. Therefore, the first bridge deck protection layer 71 and the second bridge deck protection layer can be used to absorb infrared radiation, and the thermosensitive material layer 72 can change its own resistance according to the ambient temperature.

[0073] For details, please refer to Figure 9 、 Figure 10Because the first and second bridge deck protection layers 71 and 73 surround the entire surface of the heat-sensitive material layer 72 and absorb infrared radiation, their temperatures rise, increasing the ambient temperature of the heat-sensitive material layer 72. This, in turn, changes the resistance of the heat-sensitive material layer 72. Since the pad structure 3 is connected to the heat-sensitive material layer 72 via the first sub-bridge pier metal layer 42, the sub-bridge arm metal layer 52, and the supporting metal layer 61, and is electrically connected to the integrated circuit module, the integrated circuit module can read the resistance change of the heat-sensitive material layer 72 through the conductive path from the pad structure 3 to the first sub-bridge pier metal layer 42, the sub-bridge arm metal layer 52, and the supporting metal layer 61. This information is then amplified, converted to analog-to-digital (ADC), and processed using algorithms (such as non-uniformity correction and noise reduction) to ultimately generate a thermal image.

[0074] In addition, since a bridge structure includes at least two conductive paths formed by the first sub-bridge pier metal layer 42, the sub-bridge arm metal layer 52 and the supporting metal layer 61, when there is an error in one of the conductive paths, it will not cause the entire conductive path between the integrated circuit module and the heat-sensitive material layer 72 to fail, thereby improving the defect tolerance of the pixel structure and further improving the reliability of the pixel structure.

[0075] In summary, in a pixel structure provided in an embodiment of the present invention, since the suspended bridge arm structure and the bridge deck structure are both suspended above the reflective layer 2, and the suspended bridge arm structure and the bridge deck structure are connected by a bridge deck support structure perpendicular to the upper surface of the reflective layer 2, the bridge deck structure is an independent layer structure relative to the suspended bridge arm structure. Therefore, under the condition that the area of ​​the pixel structure is certain, the area of ​​the bridge deck structure is larger. Since the bridge deck structure includes a thermal-sensitive material layer 72 for absorbing infrared radiation, the effective absorption area of ​​the pixel structure is larger, thereby increasing the response rate of the pixel structure.

[0076] Furthermore, because the bridge structure includes at least two sub-bridge pier structures 400, sub-bridge arm structures corresponding one-to-one with the sub-bridge pier structures 400, and sub-bridge deck support structures 600 corresponding one-to-one with the sub-bridge arm structures, the pixel structure has a high defect tolerance. Furthermore, because the suspended bridge arm structure in the bridge structure is a separate layer structure relative to the bridge deck structure, and the suspended bridge arm structure includes at least two sub-bridge arm structures, the stability and reliability of the pixel structure can be increased by appropriately increasing the size of the sub-bridge arm structures.

[0077] An embodiment of the present invention further provides a pixel array, comprising a plurality of pixel structures as shown above distributed in an array, wherein the plurality of pixel structures are not electrically connected to each other.

[0078] In this embodiment, the distance between the pixel structures is 0.4 micrometers to 0.8 micrometers.

[0079] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A pixel structure, characterized in that: include: a substrate, wherein an integrated circuit module is disposed on the substrate; a reflective layer located on the substrate; a plurality of pad structures, located on the substrate and around the reflective layer, the pad structures being electrically connected to the integrated circuit module; a dielectric layer located on the substrate surface, the upper surface and side surfaces of the reflective layer, and the side surfaces and a portion of the upper surface of the pad structure; a plurality of bridge structures, each of the bridge structures comprising a pier structure, a suspended bridge arm structure, and a bridge deck support structure perpendicular to the upper surface of the reflective layer, the pier structure being located on the upper surface of the corresponding pad structure and electrically connected to the corresponding pad structure, the suspended bridge arm structure being suspended above the reflective layer, and one end of the suspended bridge arm structure being electrically connected to the top of the pier structure; The bridge deck structure is located at least above the suspended bridge arm structure, the bridge deck support structure is located between the suspended bridge arm structure and the bridge deck structure, and the two ends of the bridge deck support structure are electrically connected to the bridge deck structure and the other end of the suspended bridge arm structure respectively, the bridge deck structure is parallel to the upper surface of the reflective layer, and the bridge deck structure includes a heat-sensitive material layer for absorbing infrared radiation.

2. The pixel structure according to claim 1, wherein: The side surfaces of the reflective layer are, in a clockwise direction, the first side, the second side, the third side, and the fourth side. The plurality of pad structures are divided into a first pad structure and a second pad structure. The first pad structure is located on the first side of the reflective layer, at a position close to the fourth side relative to the second side, and the second pad structure is located on the third side of the reflective layer, at a position close to the second side relative to the fourth side.

3. The pixel structure according to claim 2, wherein: Several of the bridge structures are divided into a first bridge structure and a second bridge structure, the first bridge structure includes a first pier structure, a first suspended bridge arm structure and a first bridge deck support structure, the first pier structure is located on the first pad structure and is electrically connected to the first pad structure, the second bridge structure includes a second pier structure, a second suspended bridge arm structure and a second bridge deck support structure, the second pier structure is located on the second pad structure and is electrically connected to the second pad structure.

4. The pixel structure according to claim 1, wherein: Each of the bridge pier structures includes at least two sub-bridge pier structures spaced apart on the corresponding pad structure, and the distance between each of the sub-bridge pier structures and the reflective layer is the same.

5. The pixel structure according to claim 4, characterized in that: Each of the sub-bridge pier structures includes, from the outside to the inside, a first sub-bridge pier protective layer, a first sub-bridge pier metal layer, a second sub-bridge pier metal layer, and a second sub-bridge pier protective layer. The bottom surface and part of the side wall surface of the first sub-bridge pier protective layer are in contact with the dielectric layer, and the remaining side wall surface of the first sub-bridge pier protective layer is exposed. The bottom surface of the first sub-bridge pier metal layer is electrically connected to the upper surface of the first pad structure. The first sub-bridge pier protective layer is located on the side wall of the first sub-bridge pier metal layer, the first sub-bridge pier metal layer is located on the side wall of the second sub-bridge pier metal layer, and the second sub-bridge pier metal layer is located on the side wall of the second sub-bridge pier protective layer.

6. The pixel structure according to claim 5, characterized in that: Each of the suspended bridge arm structures includes at least two branch bridge arm structures, and each of the branch bridge arm structures includes a first branch bridge arm protective layer, a branch bridge arm metal layer, and a second branch bridge arm protective layer stacked from bottom to top. The branch bridge arm structures in the suspended bridge arm structure in the same bridge structure correspond one-to-one to the branch bridge piers in the corresponding pier structure. One end of the first branch bridge arm protective layer is connected to the corresponding first branch bridge pier protective layer, one end of the second branch bridge arm protective layer is connected to the corresponding second branch bridge pier protective layer, one end of the branch bridge arm metal layer is electrically connected to the top surface of the corresponding first branch bridge pier metal layer, and, in the same suspended bridge arm structure, each of the first branch bridge arm protective layers is connected to each other, the other end of each of the branch bridge arm metal layers is connected to each other, and the other end of each of the second branch bridge arm protective layers is connected to each other.

7. The pixel structure according to claim 6, characterized in that: Each of the bridge deck support structures includes at least two bridge deck sub-support structures, and the sub-bridge arm structures in the suspended bridge arm structure in the same bridge structure correspond one-to-one to the bridge deck sub-support structures in the corresponding bridge deck support structure. The bridge deck sub-support structures include a support protective layer and a support metal layer. The support metal layer is located on the side wall of the support metal layer and is located on the periphery of the support metal layer. The lower surface of the support metal layer is electrically connected to the corresponding sub-bridge arm metal layer, and the lower surface of the support protective layer is in contact with the second sub-bridge arm protective layer.

8. The pixel structure according to claim 7, characterized in that: The bridge deck structure includes a first bridge deck protection layer, a heat-sensitive material layer, and a second bridge deck protection layer stacked from bottom to top. The first bridge deck protection layer is located on a portion of the lower surface of the heat-sensitive material layer, and the heat-sensitive material layer is electrically connected to the other end of the supporting metal layer. The second bridge deck protection layer covers the upper surface and side wall surface of the heat-sensitive material layer.

9. A pixel array, characterized in that: The method comprises a plurality of pixel structures as claimed in any one of claims 1 to 8 distributed in an array, wherein the plurality of pixel structures are not electrically connected to each other.

10. A method for preparing a pixel structure, characterized in that: include: Providing a substrate, wherein an integrated circuit module is disposed on the substrate; forming a reflective layer and a plurality of pad structures on the substrate, wherein the pad structures are located around the reflective layer and are electrically connected to the integrated circuit module; forming a dielectric layer, wherein the dielectric layer is located on the sidewall surface and the upper surface of the reflective layer and the sidewall surface and the upper surface of the pad structure; forming a plurality of bridge structures, each of the bridge structures comprising a pier structure, a suspended bridge arm structure, and a bridge deck support structure perpendicular to the upper surface of the reflective layer, the pier structure being located on the upper surface of the corresponding pad structure and electrically connected to the corresponding pad structure, the suspended bridge arm structure being suspended above the reflective layer, and one end of the suspended bridge arm structure being electrically connected to the top of the pier structure; A bridge deck structure is formed, wherein the bridge deck structure is located at least above the suspended bridge arm structure, the bridge deck support structure is located between the suspended bridge arm structure and the bridge deck structure, and the two ends of the bridge deck support structure are electrically connected to the bridge deck structure and the other end of the suspended bridge arm structure respectively, the bridge deck structure is parallel to the upper surface of the reflective layer, and the bridge deck structure includes a heat-sensitive material layer for absorbing infrared radiation.

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