Infrared detection structure

Abstract

The infrared detection structure includes a substrate, an active pixel array, a reference pixel array, a light absorbing layer, a sidewall spacer structure and a light shielding layer. The active pixel array is located on the substrate. The reference pixel array is located on the substrate and is adjacent to the active pixel array, and has a reference pixel. The reference pixel includes a substrate, a resistor element and an infrared sensing material layer. The resistor element is located on the substrate. The infrared sensing material layer is located above the resistor element. The light absorbing layer is located above the reference pixel. The sidewall spacer structure is located above the reference pixel and extends to the sidewall of the light absorbing layer. The light shielding layer is conformally formed above the light absorbing layer and the sidewall spacer structure.

Description

Technical Field

[0001] The present application relates to an infrared detection structure. Background Art

[0002] The uncooled IR focal plane array temperature sensor includes IR optical active pixels and IR optical blind reference pixels. The uncooled IR focal plane array may operate at ambient temperature and may not include active temperature stabilization. The IR optical blind reference pixels on the uncooled IR focal plane array do not absorb incident infrared radiation. The IR optical blind reference pixels are used to determine the ambient temperature of the IR focal plane array to calibrate the IR optical active pixels within the operating temperature range of the IR focal plane array. Therefore, the IR optical blind reference pixels on the uncooled IR focal plane array can correct images caused by ambient temperature drift effects. Summary of the invention

[0003] In some embodiments, the infrared detection structure includes a substrate, an active pixel array, a reference pixel array, a first light absorbing layer, a first sidewall spacer structure, and a first light shielding layer. The active pixel array is located on the substrate. The reference pixel array is located on the substrate, adjacent to the active pixel array, and has a first reference pixel. The first reference pixel includes a first substrate, a first resistor element, and a first infrared sensing material layer. The first resistor element is located on the first substrate. The first infrared sensing material layer is located above the first resistor element. The first light absorbing layer is located above the first reference pixel. The first sidewall spacer structure is located above the first reference pixel and extends to the sidewall of the first light absorbing layer. The first light shielding layer is conformally formed above the first light absorbing layer and the first sidewall spacer structure.

[0004] In some embodiments, the first light absorbing layer extends beyond two opposite edges of the first substrate.

[0005] In some embodiments, the reference pixel array further includes a second reference pixel. The second reference pixel is adjacent to the first reference pixel. The first light absorption layer extends to the second reference pixel and covers the second reference pixel.

[0006] In some embodiments, the reference pixel array further includes a second reference pixel. The second reference pixel is adjacent to the first reference pixel. The first light absorption layer does not cover the second reference pixel.

[0007] In some embodiments, the second reference pixel includes: a second substrate, a second resistor element, and a second infrared sensing material layer. The second resistor element is located on the second substrate. The second infrared sensing material layer is located above the second resistor element. The infrared detection structure further includes: a second light absorption layer, a second sidewall spacer structure, and a second light shielding layer. The second light absorption layer is located above the second reference pixel. The second sidewall spacer structure is located above the second reference pixel and extends to the sidewall of the second light absorption layer. The second light shielding layer is conformally formed above the second light absorption layer and the second sidewall spacer structure.

[0008] In some embodiments, the material of the first sidewall spacer structure is different from the material of the first light absorbing layer.

[0009] In some embodiments, the material of the first sidewall spacer structure includes silicon oxide, and the material of the first light absorbing layer includes silicon nitride.

[0010] In some embodiments, the first light shielding layer has an inverted U-shaped cross-section.

[0011] In some embodiments, the material of the first light shielding layer includes a conductive material.

[0012] In some embodiments, the first infrared sensing material layer is made of vanadium oxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to make the above and other purposes, features, advantages and embodiments of the present application more clearly understood, the attached drawings are described as follows:

[0014] Figure 1 A top view of an infrared detection structure according to some embodiments of the present application is shown.

[0015] Figure 2 A partially enlarged top view of a reference pixel array in an infrared detection structure according to some embodiments of the present application is shown.

[0016] Figure 3 A three-dimensional diagram of reference pixels in a reference pixel array according to some embodiments of the present application is shown.

[0017] Figure 4A , Figure 4B Draw along Figure 2 Cross-sectional view of line segment A1-A1' and line segment B1-B1'.

[0018] Figure 5 Flow chart of a method for forming an infrared detection structure according to some embodiments of the present application.

[0019] Figures 6 to 13The diagram shows a method for forming an infrared detection structure at various stages according to some embodiments of the present application.

[0020] Fig.14 A partially enlarged top view of a reference pixel array in an infrared detection structure according to some embodiments of the present application is shown.

[0021] Fig.15A , Fig. 15B , Fig. 15C Draw along Fig.14 Cross-sectional view of line segment A2-A2', line segment B2-B2', and line segment C2-C2'. DETAILED DESCRIPTION

[0022] Please refer to Figure 1 . Figure 1 A top view of an infrared detection structure 100 according to some embodiments of the present application is shown. In some embodiments, the infrared detection structure 100 can be referred to as an uncooled infrared focal plane array thermometer and can be used on a thermal radiation thermometer chip structure. The infrared detection structure 100 includes a substrate 101, an active pixel array 102, and a reference pixel array 103. In some embodiments, the active pixel array 102 can also be referred to as an infrared optical active pixel array, and the reference pixel array 103 can also be referred to as an infrared optical reference pixel array or an infrared optical compensation pixel array. The active pixel array 102 is located on the substrate 101 and is coupled to a readout integrated circuit located on the substrate 101. The reference pixel array 103 is located on the substrate 101 and is adjacent to the active pixel array 102.

[0023] The materials and positions of the components in the active pixels of the active pixel array 102 are related to Figure 2 , Figure 3 , Figure 4A The materials and positional relationship of the reference pixel array 103 in the associated description are basically the same, and therefore, for the sake of clarity, reference may be made to the relevant paragraphs without further description. Since the reference pixel array 103 is coupled to the readout integrated circuit located on the substrate 101 to serve as an electrical reference point, the reference pixel array 103 includes additional elements compared to the active pixel array 102 to make it have the characteristics of not absorbing light or gathering heat. For example, the difference between the reference pixel array 103 and the active pixel array 102 is at least that the reference pixel array 103 is covered with an additional metal layer so that light cannot enter the reference pixel array 103, and thus the reference pixel array 103 can serve as an electrical reference point.

[0024] Please refer to Figures 2 to 4B . Figure 2A partial enlarged top view of a reference pixel array 103 in an infrared detection structure 100 according to some embodiments of the present application is shown. Figure 3 A three-dimensional diagram of a reference pixel 131 in a reference pixel array 103 according to some embodiments of the present application is shown, wherein in order to better understand the present application, Figure 3 The reference pixel 131 in FIG. Figure 4A The infrared sensing material layer 134 , the light absorbing layer 135 , the sidewall spacer structure 136 and the light shielding layer 137 are shown. Figure 4A , Figure 4B Draw along Figure 2 Cross-sectional view of line segment A1-A1' and line segment B1-B1'.

[0025] like Figure 2 As shown, the reference pixel array 103 has a plurality of reference pixels 131. Figure 3 as well as Figure 4A As shown, the reference pixel 131 includes a substrate 132, a resistor 133, and an infrared sensing material layer 134 (see Figure 4A ).At Figure 3 In the embodiment, the substrate 132 is located above the substrate 101 and can be a MEMS floating bridge structure. The substrate 132 is attached to the substrate 101 through relatively long and thin support arms 151 and 153 to increase the thermal insulation between the substrate 101 and the resistor 133. Therefore, if the reference pixel 131 is not covered with the light absorbing layer 135, the sidewall spacer structure 136 and the light shielding layer 137 (see FIG. Figure 4A ), the infrared radiation impinging on the resistor element 133 may heat the resistor element 133 without heating the substrate 101 located below the resistor element 133. In some embodiments, the elongated thermal paths of the support arms 151 and 153 may hinder heat transfer between the base plate 132 and the substrate 101. The support posts 155 and 157 are electrically coupled from the support arms 151 and 153 to corresponding contacts on the substrate 101.

[0026] In some embodiments, the substrate 132 is formed by silicon micromachining technology, and the thickness of the substrate 132 can be thinner so that its thermal mass can be lower. Therefore, the substrate 132 can change temperature relatively quickly to produce an acceptable response time for real-time thermal imaging. The substrate 132 cooperates with the infrared sensing material layer 134 located thereon so that the active pixels in the active pixel array 102 can have the characteristics of light absorption and heat collection. In some embodiments, the material of the support arm 151 and the support arm 153 can include silicon nitride or other suitable materials. In some embodiments, the material of the support column 155 and the support column 157 can include tungsten, aluminum, copper, titanium or other suitable materials.

[0027] At Figure 4AIn the embodiment, the resistor element 133 is located on the substrate 132. The resistor element 133 is connected as follows: Figure 3 The support arms 151, 153, 155, and 157 are coupled to a readout integrated circuit on the substrate 101. The readout integrated circuit is used to process the signal from each reference pixel 131. The resistor element 133 can be regarded as an infrared sensing pixel, and the aforementioned pixel (also referred to as a reference pixel) and the active circuit (also referred to as an active pixel) are electrically connected through the readout integrated circuit on the substrate 101.

[0028] At Figure 4A In the embodiment, the infrared sensing material layer 134 is located above the resistor element 133. The resistor element 133 is coupled to the infrared sensing material layer 134. As the temperature of the infrared sensing material layer 134 changes, the resistance of the infrared sensing material layer 134 also changes accordingly. Figure 3 ) can determine the amount of thermal energy that reference pixel 131 has received through the corresponding resistance change of reference pixel 131.

[0029] like Figure 4A As shown, the infrared detection structure 100 further includes a light absorbing layer 135, a sidewall spacer structure 136 and a light shielding layer 137. Figure 4A In the embodiment, the light absorbing layer 135 is located above the infrared sensing material layer 134 and covers the infrared sensing material layer 134 to absorb the light irradiated to the reference pixel 131. The light absorbing layer 135 extends beyond the two opposite edges 132e of the substrate 132 of the reference pixel 131 (see Figure 2 ). The light absorbing layer 135 has a horizontal portion 135h and a protruding portion 135t. In some embodiments, the width W of the protruding portion 135t may be substantially equal to or close to the thickness T1 of the protruding portion 135t, so that the light shielding layer 137 formed on the light absorbing layer 135 later may be bent at multiple angles. In some embodiments, the width W of the protruding portion 135t may be greater than the thickness T1 of the protruding portion 135t. In some embodiments, the width W of the protruding portion 135t may be less than or equal to twice the thickness T1 of the protruding portion 135t. In some embodiments, the thickness T1 of the protruding portion 135t may be greater than the thickness T2 of the horizontal portion 135h. In some embodiments, the thickness T2 of the horizontal portion 135h of the light absorbing layer 135 may be less than the thickness T3 of the infrared sensing material layer 134. In some embodiments, the protruding portion 135t of the light absorbing layer 135 may also be referred to as a long strip protruding light absorbing structure. The long side 135e (see Figure 2 ) extends beyond two opposite edges 132e of the substrate 132 of the reference pixel 131. In some embodiments, the light absorbing layer 135 may be a multi-layer structure.

[0030] At Figure 4A , the sidewall spacer structure 136 is located above the infrared sensing material layer 134 and extends to the sidewall of the light absorbing layer 135. The sidewall spacer structure 136 can prevent light leakage from the side of the reference pixel 131, thereby preventing the signal drift of the infrared detection structure 100, thereby improving the sensitivity of the infrared detection structure 100. The sidewall spacer structure 136 can also be used to assist the light shielding layer 137 to be formed on the light absorbing layer 135 to have an inverted U-shaped cross-section. In some embodiments, the sidewall spacer structure 136 extends beyond the two opposite edges 132e of the substrate 132 of the reference pixel 131 (see Figure 2 In some embodiments, the material of the sidewall spacer structure 136 may include silicon oxide, silicon nitride, silicon oxynitride, SiC, SiCN, SiC x O y N z , other suitable materials, or any combination of the foregoing materials. For example, the material of the sidewall spacer structure 136 may include silicon oxide. In some embodiments, the material of the sidewall spacer structure 136 is different from the material of the light absorbing layer 135. For example, the material of the sidewall spacer structure 136 may include silicon oxide, and the material of the light absorbing layer 135 may include silicon nitride.

[0031] At Figure 4A , the light shielding layer 137 is conformally formed on the top surface of the protruding portion 135t of the light absorbing layer 135 and the sidewall spacer structure 136, and extends to the horizontal portion 135h of the light absorbing layer 135 to reflect the light irradiated to the reference pixel 131. The light shielding layer 137 can prevent light leakage from the side of the reference pixel 131, thereby preventing the signal drift of the infrared detection structure 100, thereby improving the sensitivity of the infrared detection structure 100. Since the light shielding layer 137 can have an inverted U-shaped cross-section, it is beneficial to reflect light with different incident angles, thereby reducing the chance of light entering the reference pixel 131 and improving the accuracy of the reference pixel array 103 in operation. In some embodiments, the light shielding layer 137 extends beyond the two opposite edges 132e of the substrate 132 of the reference pixel 131 along the extension direction of the light absorbing layer 135 (see Figure 2 ). In some embodiments, the thickness T4 of the light shielding layer 137 may be less than or greater than the thickness of the light absorbing layer 135. For example, the thickness T4 of the light shielding layer 137 may be less than the thickness T1 of the protruding portion 135t of the light absorbing layer 135, and / or greater than the thickness T2 of the horizontal portion 135h of the light absorbing layer 135. In some embodiments, the material of the light shielding layer 137 includes a conductive material. For example, the material of the light shielding layer 137 may include tungsten, aluminum, copper, titanium, or other suitable materials.

[0032] Please refer to Figure 2 as well as Figure 4B .like Figure 2 As shown, the reference pixel array 103 further includes a reference pixel 141. The reference pixel 141 is adjacent to the reference pixel 131. Figure 4B As shown, the reference pixel 141 includes a substrate 142, a resistor 143, and an infrared sensing material layer 144. The materials and positional relationships of the multiple components in the reference pixel 141 are similar to Figure 3 as well as Figure 4A The materials and positional relationships of the components in the reference pixel 131 in the above description are substantially the same, and therefore, for the sake of clarity, they are not repeated here. For example, the materials and processes for the substrate 142, the resistor element 143, and the infrared sensing material layer 144 may be the same as those in the above description. Figure 3 as well as Figure 4A The substrate 132, the resistor element 133 and the infrared sensing material layer 134 shown in FIG. 1 are substantially the same. Therefore, the relevant detailed description can be referred to the above paragraphs and will not be described again here.

[0033] At Figure 2 In the embodiment, the light absorbing layer 135 located above the reference pixel 131 extends to the reference pixel 141 and covers the reference pixel 141 to absorb the light irradiated to the reference pixel 141. In some embodiments, the light absorbing layer 135 extends across two opposite edges 142e of the substrate 142 of the reference pixel 141. The sidewall spacer structure 136 located above the reference pixel 131 extends from the sidewall of the light absorbing layer 135, is located above the reference pixel 141, and crosses two opposite edges 142e of the substrate 142 of the reference pixel 141. The light shielding layer 137 located above the reference pixel 131 (see Figure 4B ) conformally extends on the top surface of the light absorbing layer 135 and the sidewall spacer structure 136, and is further located above the reference pixel 141 and crosses over two opposite edges 142e of the substrate 142 of the reference pixel 141. Therefore, the light absorbing layer 135 can provide the reference pixel 131 and the reference pixel 141 with the effect of absorbing light, while the sidewall spacer structure 136 and the light shielding layer 137 can provide the reference pixel 131 and the reference pixel 141 with the effect of shielding light.

[0034] Please refer to Figure 5 . Figure 5 Flowchart of a method M for forming an infrared detection structure 100 according to some embodiments of the present application. Figures 6 to 13 The method M for forming the infrared detection structure 100 according to some embodiments of the present application at various stages is illustrated. The method M begins with step S101, where an infrared sensing material layer is deposited on a substrate including a resistor element. Figure 6In some embodiments of step S101, an infrared sensing material layer 134 is deposited on the substrate 132 including the resistor element 133. Figure 5 The method M then proceeds to step S102 to deposit a light absorbing layer on the infrared sensing material layer. Figure 6 In some embodiments, the light absorbing layer 135 is deposited on the infrared sensing material layer 134 .

[0035] Please refer back to Figure 5 The method M then proceeds to step S103, using the first mask layer to pattern the light absorbing layer to form a strip-shaped protruding light absorbing structure covering the resistor element on the light absorbing layer. Figure 7 In some embodiments, patterning Figure 6 The light absorbing layer 135 in the infrared sensing material layer 134 is formed to form a horizontal portion 135h and a protruding portion 135t covering the resistor element. In some embodiments, a patterned mask layer 171 is formed on the light absorbing layer 135. Then, one or more etching processes are performed using the patterned mask layer 171 as an etching mask. In some embodiments, the etching process etches the portion of the light absorbing layer 135 exposed by the mask layer 171 until the thickness T2 of the aforementioned portion reaches the desired thickness to form a horizontal portion 135h and a protruding portion 135t on the infrared sensing material layer 134. In some embodiments, the etching process is performed until the infrared sensing material layer 134 located below the light absorbing layer 135 is exposed, so that the portion of the light absorbing layer 135 exposed by the patterned mask layer 171 is removed.

[0036] Please refer back to Figure 5 The method M then proceeds to step S104 to remove the patterned first mask layer. Figure 8 In some embodiments, removing Figure 7 In some embodiments, if the mask layer 171 includes a photoresist material, the mask layer 171 can be removed by an ashing process.

[0037] Please refer back to Figure 5 The method M then proceeds to step S105 to conformally deposit a sidewall spacer material on the light absorbing layer. Fig. 9 In some embodiments, the sidewall spacer material 176 is conformally deposited over the light absorbing layer 135 .

[0038] Please refer back to Figure 5 The method M then proceeds to step S106, etching the sidewall spacer material to form a sidewall spacer structure on the sidewall of the strip-shaped protruding light absorption structure. Fig.10In some embodiments, the sidewall spacer material 176 (see Fig. 9 ) to form a sidewall spacer 136 on the sidewall 135s of the protrusion 135t. In some embodiments, the etching process P1 is an anisotropic etching process to remove the sidewall spacer 136. Fig. 9 The horizontal portion of the sidewall spacer 176 is shown. The etching process P1 etches the sidewall spacer 176 at a faster etching rate than etching the light absorbing layer 135. In some embodiments, phosphoric acid (H 3 PO 4 ) to etch the sidewall spacer material 176.

[0039] Please refer back to Figure 5 The method M then proceeds to step S107 to conformally deposit a light shielding material on the light absorbing layer. Fig.11 In some embodiments, the light shielding material 177 is conformally deposited over the light absorbing layer 135 and the sidewall spacer structure 136 .

[0040] Please refer back to Figure 5 The method M then proceeds to step S108, wherein the light shielding material is patterned by the second mask layer to form a light shielding layer on the light absorbing layer and the sidewall spacer structure. Fig.12 In some embodiments, the patterned light shielding material 177 (see Fig.11 ) to form a light shielding layer 137 on the light absorbing layer 135 and the sidewall spacer structure 136. In some embodiments, a patterned mask layer 173 is formed on the light shielding material 177. Then, one or more etching processes are performed using the patterned mask layer 173 as an etching mask to form the light shielding layer 137 on the light absorbing layer 135 and the sidewall spacer structure 136.

[0041] Please refer back to Figure 5 The method M then proceeds to step S109 to remove the patterned second mask layer. Fig.13 In some embodiments, removing Fig.12 In some embodiments, if the mask layer 173 includes a photoresist material, the mask layer 173 can be removed by an ashing process.

[0042] Please refer to Figures 14 to 15C . Fig.14 A partial enlarged top view of a reference pixel array 203 in an infrared detection structure 200 according to some embodiments of the present application is shown. Fig.15A , Fig. 15B , Fig. 15C Draw along Fig.14The materials and processes used to form the infrared detection structure 200 of this embodiment are similar to those of FIG. Figures 2 to 13 The materials and processes used to form the infrared detection structure 100 in the related previous descriptions are substantially the same, and therefore, for the sake of clarity, they are not repeated here. Fig.14 ), substrate 232, resistor element 233, infrared sensing material layer 234, light absorbing layer 235, sidewall spacer structure 236, light shielding layer 237 (see Fig.15A as well as Fig. 15B ), reference pixel 241 (see Fig.14 ), substrate 242, resistor element 243 and infrared sensing material layer 244 (see Fig. 15C ) materials and processes can be compared with Figures 2 to 13 The reference pixel 131, substrate 132, resistor 133, infrared sensing material layer 134, light absorbing layer 135, sidewall spacer structure 136, light shielding layer 137, reference pixel 141, substrate 142, resistor 143 and infrared sensing material layer 144 shown in FIG. are substantially the same. Therefore, the relevant detailed description can be referred to the aforementioned paragraphs and will not be described again here.

[0043] This embodiment and Figures 2 to 13 The difference between the embodiments in FIG. 1 and FIG. 2 is that the light absorbing layer 235 (see FIG. 235 ) located above the reference pixel 231 Fig.14 ) does not extend to the adjacent reference pixel 241. In other words, the light absorbing layer 235 does not cover the adjacent reference pixel 241. Fig.14 As shown in the top view of FIG. 2 , the light absorbing layer 235 is a block structure. The sidewall spacer structure 236 surrounds the light absorbing layer 235 and does not cover the adjacent reference pixel 241. Fig.15A as well as Fig. 15B As shown in the cross-sectional view of FIG. 2 , the protrusion 235t of the light absorbing layer 235 has substantially the same width in different cross-sectional views. Fig. 15C As shown, the infrared detection structure 200 further includes a light absorbing layer 245, a sidewall spacer structure 246, and a light shielding layer 247. The light absorbing layer 245 is located above the infrared sensing material layer 244. The sidewall spacer structure 246 is located above the infrared sensing material layer 244 and extends to the sidewall of the light absorbing layer 245. The light shielding layer 247 is conformally formed on the top surface of the light absorbing layer 245 and the sidewall spacer structure 246. The light absorbing layer 245, the sidewall spacer structure 246, and the light shielding layer 247 do not cover the adjacent reference pixel 231 (see Fig.14 ).

[0044] The features of the aforementioned multiple embodiments enable those skilled in the art to better understand various aspects of the present invention. Those skilled in the art should understand that in order to achieve the same purpose and / or the same advantages of the embodiments mentioned in the present invention, they can easily use the present invention as a basis to further design or modify other processes and structures. Those skilled in the art should also understand that such identical structures do not deviate from the spirit and scope of the present invention, and that various changes, substitutions and modifications can be made here without departing from the spirit and scope of the present invention.

[0045]

Explanation of symbols

[0046] 100, 200: Infrared detection structure

[0047] 101: Base material

[0048] 102: Active pixel array

[0049] 103: Reference pixel array

[0050] 131, 231: reference pixels

[0051] 132, 232: Substrate

[0052] 132e, 142e: Edge

[0053] 133, 143, 233, 243: Resistor elements

[0054] 134, 234: infrared sensing material layer

[0055] 135, 235: light absorption layer

[0056] 135e: long side

[0057] 135h: horizontal position

[0058] 135s: Sidewall

[0059] 135t, 235t: protruding part

[0060] 136, 236: Side wall spacer structure

[0061] 137, 237: light shielding layer

[0062] 141, 241: Reference pixels

[0063] 142, 242: Substrate

[0064] 143, 243: Resistor

[0065] 144, 244: infrared sensing material layer

[0066] 245: Light absorbing layer

[0067] 246: Side wall spacer structure

[0068] 247: Light shielding layer

[0069] 151, 153: Support arm

[0070] 155, 157: Support columns

[0071] 171, 173: Mask layer

[0072] 176: Sidewall spacer material

[0073] 177:Light-shielding material

[0074] M: Method

[0075] S101, S102, S103, S104, S105, S106, S107, S108, S109: Steps

[0076] T1, T2, T3, T4: thickness

[0077] W: width.

Claims

1. An infrared detection structure, characterized in that: Include: Base material; an active pixel array, located on the substrate; A reference pixel array is located on the substrate and adjacent to the active pixel array, and has a first reference pixel. The first reference pixel includes: a first substrate; A first resistor element is located on the first substrate; as well as A first infrared sensing material layer is located above the first resistor element; A first light absorbing layer, located above the first reference pixel; A first sidewall spacer structure is located above the first reference pixel and extends to a sidewall of the first light absorbing layer; as well as The first light shielding layer is conformally formed above the first light absorbing layer and the first sidewall spacer structure.

2. The infrared detection structure according to claim 1, characterized in that: The first light absorbing layer extends beyond two opposite edges of the first substrate.

3. The infrared detection structure according to claim 2, characterized in that: The reference pixel array further includes a second reference pixel, which is adjacent to the first reference pixel. The first light absorption layer extends to the second reference pixel and covers the second reference pixel.

4. The infrared detection structure according to claim 1, characterized in that: The reference pixel array further includes a second reference pixel, the second reference pixel is adjacent to the first reference pixel, and the first light absorption layer does not cover the second reference pixel.

5. The infrared detection structure according to claim 4, characterized in that: The second reference pixel comprises: a second substrate; A second resistor element is located on the second substrate; and A second infrared sensing material layer is located above the second resistor element, and the infrared detection structure further comprises: A second light absorbing layer, located above the second reference pixel; A second sidewall spacer structure is located above the second reference pixel and extends to a sidewall of the second light absorbing layer; as well as The second light shielding layer is conformally formed above the second light absorbing layer and the second sidewall spacer structure.

6. The infrared detection structure according to claim 1, characterized in that: The material of the first sidewall spacer structure is different from the material of the first light absorbing layer.

7. The infrared detection structure according to claim 1, characterized in that: The material of the first sidewall spacer structure includes silicon oxide, and the material of the first light absorption layer includes silicon nitride.

8. The infrared detection structure according to claim 1, characterized in that: The first light shielding layer has an inverted U-shaped cross section.

9. The infrared detection structure according to claim 1, characterized in that: The material of the first light shielding layer includes a conductive material.

10. The infrared detection structure according to claim 1, characterized in that: The material of the first infrared sensing material layer includes vanadium oxide.

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