Sensing element substrate

Abstract

A sensing element substrate includes a light-transmissive substrate, a switching element, a plurality of light-sensing elements, a first insulating layer, and a first light-blocking layer. The switching element is on the light-transmissive substrate. The light-sensing elements are electrically connected to the switching element and each include a first electrode, a light-sensing layer, and a second electrode. The first electrode includes molybdenum and molybdenum oxide. The light-sensing layer is on the first electrode. The second electrode is on the light-sensing layer. The first insulating layer is on the light-sensing elements. The first light-blocking layer is on the first insulating layer, and the first light-blocking layer has a plurality of first openings, each of which overlaps each of the light-sensing elements.

Description

Technical Field

[0001] This invention relates to a sensing element substrate. Background Technology

[0002] Optical organic light-emitting diode (OLED) under-display fingerprint sensors are one of the key development areas in fingerprint sensor technology. Light source light is reflected after hitting the finger through the cover glass, then passes through the light-transmitting area of ​​the OLED, and finally reaches the fingerprint sensor after passing through a collimation structure. The fingerprint sensor first determines whether there is an incident light signal. Because different fingerprints (e.g., fingerprint peaks and valleys) reflect light at different intensities, the sensor's signal varies. After signal processing by the chip, this is converted into different grayscale displays. The higher the fingerprint sensor's sensitivity, the stronger the fingerprint sensor signal.

[0003] However, in a strong light environment, after the light penetrates the finger and reaches the fingerprint sensor, it is reflected to the light collimation structure. The light collimation structure reflects the light to external objects (such as highly reflective objects like batteries or mid-frames). The external objects cause the light to be reflected back to the light collimation structure, resulting in the fingerprint sensor receiving the light and creating stray photocurrent. Summary of the Invention

[0004] The present invention provides a sensing element substrate that can simultaneously improve the sensing sensitivity of the sensing element substrate and reduce the noise of the photosensitive element.

[0005] A sensing element substrate according to an embodiment of the present invention includes a light-transmitting substrate, a switching element, a plurality of photosensitive elements, a first insulating layer, and a first light-shielding layer. The switching element is located on the light-transmitting substrate. Each photosensitive element is electrically connected to the switching element and includes a first electrode, a photosensitive layer, and a second electrode. The first electrode is made of molybdenum and molybdenum oxide. The photosensitive layer is located on the first electrode. The second electrode is located on the photosensitive layer. The first insulating layer is located on the photosensitive element. The first light-shielding layer is located on the first insulating layer and has a plurality of first openings, each first opening overlapping each photosensitive element.

[0006] Based on the above, in a sensing element substrate according to an embodiment of the present invention, the material of the first electrode includes molybdenum and molybdenum oxide. Since the reflectivity of molybdenum oxide is lower than that of molybdenum, in a strong light environment, after light penetrates the finger and passes through the first opening of the first light-shielding layer, it hits the first electrode and will not be reflected by the first electrode back to the first light-shielding layer and then reflected to other photosensitive elements. Therefore, stray photocurrents can be avoided from being generated by each photosensitive element. In this way, both improving the sensing sensitivity of the sensing element substrate and reducing the noise of the photosensitive elements can be achieved. Attached Figure Description

[0007] The various aspects of this disclosure can be understood by reading the following detailed description and accompanying figures. It should be noted that many features in the figures are not drawn to scale according to industry standard practice. In fact, the dimensions of the described features can be arbitrarily increased or decreased for clarity of discussion.

[0008] Figure 1 This is a top view of a sensing element substrate according to an embodiment of the present invention.

[0009] Figure 2 It is along Figure 1 A cross-sectional view of section line 2-2'.

[0010] Figure 3 This is the equivalent circuit diagram of the sensing element substrate.

[0011] Figure 4 This is a schematic cross-sectional view of a sensing element substrate according to another embodiment of the present invention.

[0012] Figure 5 yes Figure 1 An enlarged schematic diagram of region R1.

[0013] Figure 6 This is a top view of a sensing element substrate according to an embodiment of the present invention.

[0014] Figure 7 It is along Figure 6 A cross-sectional view with section line 7-7'.

[0015] Figure 8 yes Figure 6 A magnified schematic diagram of region R2.

[0016] Figure 9 This is a schematic cross-sectional view of a sensing element substrate according to another embodiment of the present invention.

[0017] Figure 10 This is a top view of a sensing element substrate according to another embodiment of the present invention.

[0018] Figure 11 It is along Figure 10 A schematic diagram of the cross section 11-11'.

[0019] Figure 12 yes Figure 10 A magnified schematic diagram of region R3.

[0020] Figure 13 This is a schematic cross-sectional view of a sensing element substrate according to another embodiment of the present invention.

[0021] Figure 14 This is a top view of a sensing element substrate according to another embodiment of the present invention.

[0022] Figure 15 It is along Figure 14 A schematic diagram of the cross section at 15-15'.

[0023] Figure 16 yes Figure 14 An enlarged schematic diagram of region R4.

[0024] Figure 17 This is a top view of a sensing element substrate according to another embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures:

[0026] 10, 10A, 10B, 10B, 10D: Sensing element substrate

[0027] 10E, 10F, 10G: Sensor substrate

[0028] 2-2', 7-7', 11-11': Section lines

[0029] 15-15': Section

[0030] 100: Transparent substrate

[0031] 102: Passage Area

[0032] 104: Source doped region

[0033] 104a: Source region with heavy doping

[0034] 104b: Lightly doped source region

[0035] 106: Drain doped region

[0036] 106a: Drain heavily doped region

[0037] 106b: Lightly doped drain region

[0038] 108, 108A, 108C, 108D: First electrode

[0039] 108G: First Electrode

[0040] 108a: First layer

[0041] 108b: Second layer

[0042] 108c: Third layer

[0043] 110: Photosensitive layer

[0044] 112: Second electrode

[0045] 114: First flattening layer

[0046] 116: First insulating layer

[0047] 118: Second insulation layer

[0048] 120: Second flattening layer

[0049] 122: Third Insulation Layer

[0050] 124: Third flat layer

[0051] 126: Fourth Insulation Layer

[0052] 128: Microlenses

[0053] 130: Signal line

[0054] 132: Input signal line

[0055] 134: Input signal line

[0056] 136: Series wiring

[0057] 138: First route

[0058] 140: Second route

[0059] 144, 144F, 144G: Light-blocking patterns

[0060] 144a: First layer

[0061] 144b: Second layer

[0062] 144c: Third layer

[0063] 200: Path

[0064] A: Symbol

[0065] BF: Buffer layer

[0066] BM1: First light-shielding layer

[0067] BM1a: First layer

[0068] BM1b: Second layer

[0069] BM1c: Third layer

[0070] BM2: Second light-shielding layer

[0071] BM3: Third light-shielding layer

[0072] C: Capacitor

[0073] CH1: Channel layer

[0074] D1: Drain

[0075] d1: Minimum distance

[0076] F: finger

[0077] G1, G2: Gate

[0078] GI1: Gate insulation layer

[0079] H1, H2, H3, H4, H5, H6: Openings

[0080] ILD: Interlayer Insulation Layer

[0081] LVSS: Reference Voltage Line

[0082] LVDD: Power Supply Line

[0083] OP1: First opening

[0084] P1, P2: Nodes

[0085] PD: Photosensitive element

[0086] R: Resistance

[0087] R1, R2, R3, R4: Regions

[0088] S1: Source

[0089] T1: First switching element

[0090] T2: Second switching element

[0091] T2a: First end

[0092] T2b: Second end

[0093] V1, V2: Openings Detailed Implementation

[0094] As used herein, the terms “approximately,” “about,” or “nearly” generally mean within 20 percent of a given value or range, preferably within 10 percent, and more preferably within 5 percent. The quantities provided herein are approximate and, unless otherwise stated, can be expressed using the terms “approximately,” “about,” or “nearly.” The terms “substantially,” “essentially,” or “basically” as used herein reflect limitations in the process or situations where the present disclosure can still operate effectively under significant changes. Furthermore, it should be understood that when those skilled in the art implement the embodiments of the present disclosure based on its teachings, the results of their implementation may differ from those of the embodiments of the present disclosure due to limitations in the process, but those skilled in the art should recognize that their implementation results are “substantially” or “essentially” the same as those of the embodiments of the disclosure.

[0095] Figure 1This is a top view of a sensing element substrate 10 according to an embodiment of the present invention. Figure 2 It is along Figure 1 A cross-sectional view of section line 2-2'. Figure 3 This is the equivalent circuit diagram of the sensing element substrate 10. Please refer to it as well. Figure 1 , Figure 2 and Figure 3 The sensing element substrate 10 includes a light-transmitting substrate 100, a first switching element T1, a second switching element T2, and a plurality of photosensitive elements PD.

[0096] The light-transmitting substrate 100 can be made of glass. However, the present invention is not limited thereto. In other embodiments, the light-transmitting substrate 100 can also be made of quartz, organic polymer, or other light-transmitting materials.

[0097] A first switching element T1 is located on a light-transmitting substrate 100, and multiple photosensitive elements PD are electrically connected to the first switching element T1. The first switching element T1 is a thin-film transistor and includes a gate G1, a source S1, a drain D1, and a channel layer CH1, with the gate G1 overlapping the channel layer CH1. The channel layer CH1 further includes a channel region 102, a source doped region 104, and a drain doped region 106. The drain doped region 106 may further include a heavily doped drain region 106a and a lightly doped drain region 106b, and the source doped region 104 may further include a heavily doped source region 104a and a lightly doped source region 104b.

[0098] The sensing element substrate 10 includes a gate insulating layer GI and an interlayer insulating layer ILD. The gate insulating layer GI is sandwiched between the gate G1 and the channel layer CH1. The interlayer insulating layer ILD covers the gate G1. The source S1 and drain D1 are disposed on the interlayer insulating layer ILD and are electrically connected to the channel layer CH1 through openings H1 and H2, respectively. Openings H1 and H2 penetrate the gate insulating layer GI and the interlayer insulating layer ILD. In some embodiments, the materials of the gate G1, source S1, and drain D1 include (but are not limited to): metallic materials or other conductive materials, wherein the metallic materials include, for example, chromium, gold, silver, copper, tin, lead, hafnium, tungsten, molybdenum, neodymium, titanium, tantalum, aluminum, zinc, or alloys of the above materials. In one embodiment, the sensing element substrate 10 includes a buffer layer BF, which is disposed between the first switching element T1 and the light-transmitting substrate 100.

[0099] In this embodiment, the first switching element T1 is exemplified by a top-gate thin-film transistor, but the invention is not limited thereto. In other embodiments, the first switching element T1 may also be a bottom-gate thin-film transistor or other types of thin-film transistors.

[0100] The photosensitive element PD is located on the interlayer insulating layer (ILD) and includes a first electrode 108, a photosensitive layer 110, and a second electrode 112. The photosensitive layer 110 is located on the first electrode 108, and the second electrode 112 is located on the photosensitive layer 110. In other words, the photosensitive layer 110 is sandwiched between the first electrode 108 and the second electrode 112. The first electrode 108 of the photosensitive element PD is electrically connected to the drain D1 of the first switching element T1. The source S1, the drain D1, and the first electrode 108 may belong to the same film layer (that is, the materials of these components may be selectively the same), but the present invention is not limited thereto.

[0101] In this embodiment, the sensing element substrate 10 further includes a first planarization layer 114, a first insulating layer 116, and a first light-shielding layer BM1. The first planarization layer 114 covers the first switching element T1 and has an opening V1 overlapping the photosensitive layer 110. The second electrode 112 of the photosensitive element PD extends into the opening V1 to cover the portion of the photosensitive layer 110 exposed by the opening V1.

[0102] In this embodiment, the photosensitive layer 110 is made of, for example, silicon-rich oxide (SRO) or other suitable materials. The second electrode 112 is, for example, a light-transmitting electrode, which is made of metal oxides, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, or other suitable oxides, or a stacked layer of at least two of the above.

[0103] The first insulating layer 116 is located on the photosensitive element PD; in other words, the second electrode 112 is located between the first planarization layer 114 and the first insulating layer 116. A first light-shielding layer BM1 is located on the first insulating layer 116. The first light-shielding layer BM1 has multiple first openings OP1, each first opening OP1 overlapping the photosensitive element PD, so that light reflected from the target object (i.e., the fingerprint of finger F) can be collimated and incident on the photosensitive element PD at a predetermined angle, thus helping to improve the sensing sensitivity of the sensing element substrate 10. The material of the first electrode 108 includes molybdenum and molybdenum oxide (MoO). x In some embodiments, the first electrode 108 may be molybdenum aluminum molybdenum (Mo / Al / Mo) or molybdenum oxide (MoO). xBecause the reflectivity of molybdenum oxide is lower than that of molybdenum. For example, the reflectivity of molybdenum is about 60%, while that of molybdenum oxide is about 10%. Therefore, multiple reflections of the photosensitive element PD after being subjected to strong light incident can be avoided, preventing the generation of stray photocurrents and resulting noise. For example, in a strong light environment, light will not travel along path 200. That is, after light penetrates the finger F and passes through the first opening OP1 of the first light-shielding layer BM1, it will not be reflected by the first electrode 108 to the first light-shielding layer BM1 and then reflected to other photosensitive elements PD. Therefore, stray photocurrents can be avoided in each photosensitive element PD. In this way, the sensing sensitivity of the sensing element substrate 10 and the noise of the photosensitive elements PD can be improved at the same time.

[0104] In one embodiment, the first electrode 108 is a double-layer structure comprising a first layer 108a and a second layer 108b located on the first layer 108a. The material of the first layer 108a includes molybdenum (e.g., molybdenum-aluminum-molybdenum (Mo / Al / Mo)), and the material of the second layer 108b is molybdenum oxide. The molybdenum oxide of the second layer 108b can be obtained by oxidizing molybdenum with water, or by sputtering with a molybdenum oxide target, depending on the actual equipment.

[0105] The sensing element substrate 10 further includes a second insulating layer 118, a second planarization layer 120, a third insulating layer 122, a third planarization layer 124, and a fourth insulating layer 126 sequentially disposed on the first insulating layer 116. Furthermore, the sensing element substrate 10 also includes a second light-shielding layer BM2, a third light-shielding layer BM3, and a plurality of microlenses 128. The second insulating layer 118 is located between the first insulating layer 116 and the first light-shielding layer BM1. The second light-shielding layer BM2 is located on the third insulating layer 122 and has a plurality of openings corresponding to the photosensitive element PD. The third light-shielding layer BM3 is located on the fourth insulating layer 126 and has a plurality of openings corresponding to the photosensitive element PD.

[0106] The second light-shielding layer BM2 has a first layer BM2a and a second layer BM2b located on the first layer BM2a. The third light-shielding layer BM3 has a first layer BM3a and a second layer BM3b located on the first layer BM3a. The materials of the first layer BM2a and the first layer BM3a include molybdenum (e.g., molybdenum-aluminum-molybdenum (Mo / Al / Mo)), and the materials of the second layer BM2b and the second layer BM3b are molybdenum oxide. Since the openings of the second light-shielding layer BM2 and the third light-shielding layer BM3 overlap with each photosensitive element PD, the light reflected from the target object (i.e., the fingerprint of finger F) can be collimated and incident on the photosensitive element PD at a desired angle, which helps to improve the sensing sensitivity of the sensing element substrate 10. The microlens 128 can focus the light onto the photosensitive element PD to improve light collimation. For example, the microlens 128 in this embodiment is a plano-convex lens, with its convex surface facing away from the photosensitive element PD.

[0107] The first insulating layer 116, the second insulating layer 118, the third insulating layer 122, the fourth insulating layer 126, the first planarization layer 114, the second planarization layer 120, the third planarization layer 124, and the microlens 128 can be made of inorganic materials (e.g., silicon oxide, silicon nitride, silicon oxynitride, aluminum silicon oxide, or a stacked layer of at least two of the above materials), organic materials, or a combination thereof. Furthermore, the above layers can be a single-layer structure or a multi-layer stacked structure.

[0108] In one embodiment, the sensing element substrate 10 further includes at least one signal line 130. The area of ​​each first electrode 108 is larger than the area of ​​each photosensitive layer 110, and the minimum horizontal distance d1 between each first electrode 108 and the adjacent at least one signal line 130 is 0.1 μm to 5 μm. Therefore, the area of ​​the first electrode 108 can be increased, thereby increasing the area of ​​a single photosensitive element PD. In this way, the photosensitive signal can be increased, thereby increasing the sensing sensitivity or reducing the sensing operation voltage and reducing power consumption. Furthermore, it can prevent light from being transmitted along the path 200 in a strong light environment. That is, after the light penetrates the finger F and passes through the first opening OP1 of the first light-shielding layer BM1, it will not be reflected by the first electrode 108 to the first light-shielding layer BM1 and then reflected to other photosensitive elements PD. Therefore, stray photocurrents can be avoided in each photosensitive element PD.

[0109] For ease of explanation, Figure 1The interlayer insulating layer (ILD) and the first planarization layer 114 are not shown in the figure. The symbol for the opening of the ILD begins with "H", and the symbol for the opening of the first planarization layer 114 begins with "V". In one embodiment, the sensing element substrate 10 further includes input signal lines 132 and 134. The source S1 of the first switching element T1 is coupled to the reference voltage line LVSS to receive the reference voltage VSS. The gate G1 of the first switching element T1 is coupled to the input signal line 132 to receive the gate drive signal SR_R[n] that provides a reset function. The drain D1 of the first switching element T1 is coupled to node P1. One end of the photosensitive element PD is coupled to node P1, and the other end of the photosensitive element PD is coupled to the input signal line 134 through the opening V2 located in the first planarization layer 114 to receive the gate drive signal SR_W[n] that provides a write function. In this embodiment, the photosensitive element PD has a structure of a capacitor C and a resistor R (1C1R). The capacitor C and the resistor R are connected in series, so that the capacitor C can form a storage capacitor to realize the fingerprint recognition function. The sensing element substrate 10 also includes an electrode portion 133, which is electrically connected to the input signal line 134 through an opening H6. In this embodiment, the electrode portion 133, the source S1, the drain D1, and the first electrode 108 can be on the same film layer. The input signal lines 132 and 134 can be on the same film layer as the gates G1 and G2.

[0110] The gate G2 of the second switching element T2 is coupled to the photosensitive element PD through node P1. For example, the gate G2 of the second switching element T2 is coupled to the photosensitive element PD through an opening H3 located in the interlayer insulating layer (ILD). The first terminal T2a of the second switching element T2 is coupled to the power supply line LVDD through an opening H4 located in the interlayer insulating layer (ILD) to receive the power supply voltage VDD. The second terminal T2b of the second switching element T2 outputs the fingerprint determination voltage Sout[m] to the signal line 130 through node P2. For example, the second terminal T2b of the second switching element T2 is coupled to the signal line 130 through an opening H5 located in the interlayer insulating layer (ILD).

[0111] Furthermore, when the voltage at node P1 is sufficient to turn on the second switching element T2, the fingerprint determination voltage Sout[m] will rise, and the charge in capacitor C will discharge through resistor R. Since the impedance of resistor R varies depending on its perpendicular distance to the skin surface of the user's finger F, the discharge time of capacitor C will also change accordingly. Based on the above, the fingerprint determination voltage Sout[m] in this embodiment is determined by the discharge time between capacitor C and resistor R, which determines the magnitude of the rise in fingerprint determination voltage Sout[m]. Next, the fingerprint determination voltage Sout[m] in this embodiment can be compared with a threshold voltage to determine whether the fingerprint on the skin surface of the user's finger F sensed by the photosensitive element PD is a valley line or a ridge line. In this way, this embodiment can identify valley lines and ridge lines on the fingerprint by changing the impedance of resistor R.

[0112] Figure 4 This is a schematic cross-sectional view of a sensing element substrate 10A according to another embodiment of the present invention. Please refer to... Figure 4 In this embodiment, the sensing element substrate 10A and Figure 2 The difference in the sensing element substrate 10 is that the first electrode 108A is a three-layer structure including a first layer 108a, a second layer 108b and a third layer 108c. The second layer 108b is located between the first layer 108a and the third layer 108c. The material of the first layer 108a is molybdenum oxide, the material of the second layer 108b includes molybdenum (e.g., molybdenum aluminum molybdenum (Mo / Al / Mo)), and the material of the third layer 108c is molybdenum oxide.

[0113] The first layer 108a of molybdenum oxide can be prepared by sputtering with a molybdenum oxide target. The third layer 108c of molybdenum oxide can be prepared by oxidizing molybdenum with water or by sputtering with a molybdenum oxide target, depending on the actual equipment. Since the reflectivity of molybdenum oxide is lower than that of molybdenum, in a strong light environment, after light penetrates the finger, passes through the first opening OP1 of the first light-shielding layer BM1, passes through the light-transmitting substrate 100, and is reflected by an external component (not shown), such as a battery, it will not be reflected by the first electrode 108. In other words, multiple reflections between the external component and the first electrode 108 back to the first light-shielding layer BM1 and then being reflected again can be avoided, which would cause stray photocurrents to be generated in each photosensitive element PD.

[0114] Please return Figure 2The first light-shielding layer BM1 has a three-layer structure comprising a first layer BM1a, a second layer BM1b, and a third layer BM1c. The second layer BM1b is located between the first layer BM1a and the third layer BM1c. The material of the first layer BM1a is molybdenum oxide, the material of the second layer BM1b includes molybdenum (e.g., molybdenum-aluminum-molybdenum (Mo / Al / Mo)), and the material of the third layer BM1c is molybdenum oxide. Since the reflectivity of molybdenum oxide is lower than that of molybdenum, in a strong light environment, after light penetrates the finger F, passes through the first opening OP1 of the first light-shielding layer BM1, passes through the light-transmitting substrate 100, and is reflected by an external component (not shown), such as a battery, it will not be reflected by the first light-shielding layer BM1 to the photosensitive element PD. Therefore, stray photocurrents can be avoided in each photosensitive element PD. The molybdenum oxide of the first layer BM1a and the third layer BM1c can be obtained by sputtering a molybdenum oxide target.

[0115] Figure 5 yes Figure 1 Please refer to the enlarged diagram of region R1 as well. Figure 5 and Figure 2 The sensing element substrate 10 also includes multiple serial wirings 136. Figure 5 Only the first electrode 108, the second electrode 112, and the series connection 136 are shown; the remaining components are omitted. Each series connection 136 connects two adjacent second electrodes 112, and a portion of each first electrode 108 does not overlap with the series connection 136 in the vertical direction. Therefore, the parasitic capacitance between the first electrode 108 and the second electrode 112 can be reduced.

[0116] For example, the symbol A indicates the overlap between the series trace 136 and the first electrode 108; in other words, this overlap represents the series area of ​​the series trace 136. In this embodiment, the series trace 136 includes a plurality of first traces 138 and a plurality of second traces 140, wherein the extension direction of each first trace 138 is perpendicular to the extension direction of each second trace 140 and the arrangement direction of the two adjacent second electrodes 112 connected by the second trace 140. With this configuration, the total series area of ​​the series trace 136 can be reduced. For example, it can be reduced by approximately 84.3%. In this way, the parasitic capacitance between the first electrode 108 and the series trace 136 can be reduced.

[0117] Figure 6 This is a top view schematic diagram of a sensing element substrate 10B according to an embodiment of the present invention. Figure 7 It is along Figure 6 A cross-sectional view with section line 7-7'. Figure 8 yes Figure 6 An enlarged schematic diagram of region R2, and Figure 8 Only the first electrode 108, the second electrode 112, and the series connection line 136 are shown; the remaining components are omitted. Please refer to [reference needed]. Figures 6 to 8 In this embodiment, the sensing element substrate 10B and Figure 1 The difference in the sensing element substrate 10 is that each first electrode 108B overlaps the serial trace 136 in the vertical direction. Therefore, the area of ​​the first electrode 108B and the serial trace 136 can be reduced, decreasing the parasitic capacitance between them. With this configuration, the total serial area of ​​the serial trace 136 can be reduced. For example, it can be reduced by approximately 45.7%. In this way, the parasitic capacitance between the first electrode 108B and the serial trace 136 can be reduced.

[0118] Figure 9 This is a cross-sectional schematic diagram of the sensing element substrate 10C according to another embodiment of the present invention. Please refer to... Figure 9 The sensing element substrate 10C and in this embodiment Figure 7 The difference in the sensing element substrate 10B is that the first electrode 108C is a three-layer structure including a first layer 108a, a second layer 108b and a third layer 108c. The second layer 108b is located between the first layer 108a and the third layer 108c. The material of the first layer 108a is molybdenum oxide, the material of the second layer 108b includes molybdenum (e.g., molybdenum aluminum molybdenum (Mo / Al / Mo)), and the material of the third layer 108c is molybdenum oxide.

[0119] Figure 10 This is a top view of a sensing element substrate 10D according to another embodiment of the present invention. Figure 11 It is along Figure 10 A schematic diagram of the cross section 11-11'. Figure 12 yes Figure 10 An enlarged schematic diagram of region R3, and Figure 12 Only the first electrode 108D, the second electrode 112, and the series connection trace 136 are shown; the remaining components are omitted. Please refer to [the documentation / reference needed]. Figures 10 to 12 In this embodiment, the sensing element substrate 10D and Figure 1 The difference between the sensing element substrate 10 and the sensing element substrate 10D is that the sensing element substrate 10D further includes at least one light-shielding pattern 144. The light-shielding pattern 144 is located between two adjacent first electrodes 108, and the at least one light-shielding pattern 144 is spaced apart from the two adjacent first electrodes 108 in the horizontal direction.

[0120] In one embodiment, the material of the light-shielding pattern 144 is the same as the material of the first electrode 108. For example, the light-shielding pattern 144 is a double-layer structure including a first layer 144a and a second layer 144b located on the first layer 144a. The material of the first layer 144a includes molybdenum (e.g., molybdenum-aluminum-molybdenum (Mo / Al / Mo)), and the material of the second layer 144b is molybdenum oxide. Since the reflectivity of molybdenum oxide is lower than that of molybdenum, multiple reflections of light between the first light-shielding layer BM1 and the first electrode 108 can be avoided. The serial area of ​​the serial connection trace 136 in this embodiment is the same as... Figure 1 The serial area of ​​the serial wiring 136 on the sensing element substrate 10 will not be described in detail here. In other embodiments, the material of the light-shielding pattern 144 may be black matrix resin.

[0121] Figure 13 This is a cross-sectional schematic diagram of the sensing element substrate 10E according to another embodiment of the present invention. Please refer to... Figure 13 The sensing element substrate 10E and in this embodiment Figure 11 The difference between the sensing element substrate 10D and the original is that the light-shielding pattern 144E of the sensing element substrate 10E in this embodiment is a three-layer structure including a first layer 144a, a second layer 144b, and a third layer 144c. The second layer 144b is located between the first layer 144a and the third layer 144c. The material of the first layer 144a is molybdenum oxide, the material of the second layer 144b includes molybdenum (e.g., molybdenum aluminum molybdenum (Mo / Al / Mo)), and the material of the third layer 144c is molybdenum oxide. Since the reflectivity of molybdenum oxide is lower than that of molybdenum, in a strong light environment, after light penetrates the finger, passes through the first opening OP1 of the first light-shielding layer BM1, passes through the light-transmitting substrate 100, and is reflected by an external component (not shown), such as a battery, it will not be reflected by the first light-shielding layer BM1 to the photosensitive element PD. Therefore, stray photocurrents can be avoided from being generated by each photosensitive element PD.

[0122] Figure 14 This is a top view of a sensing element substrate 10F according to another embodiment of the present invention. Figure 15 It is along Figure 14 A schematic diagram of the cross section at 15-15'. Figure 16 yes Figure 14 Please refer to the enlarged diagram of region R4 as well. Figures 14 to 16 In this embodiment, the sensing element substrate 10F and Figure 10The difference in the sensing element substrate 10D is that each first electrode 108F overlaps the series trace 136 in the vertical direction. Therefore, the area of ​​the first electrode 108F and the series trace 136 can be reduced, decreasing the parasitic capacitance between them. With this configuration, the total series area of ​​the series trace 136 can be reduced. For example, it can be reduced by approximately 45.7%. This reduces the parasitic capacitance between the first electrode 108F and the series trace 136. The light-shielding pattern 144F in this embodiment is a two-layer structure including a first layer 144a and a second layer 144b located on the first layer 144a.

[0123] Figure 17 This is a schematic cross-sectional view of the sensing element substrate 10G according to another embodiment of the present invention. Please refer to... Figure 17 The sensing element substrate 10G and in this embodiment Figure 15 The difference between the sensing element substrate 10F and the original is that the light-shielding pattern 144G of the sensing element substrate 10G in this embodiment is a three-layer structure including a first layer 144a, a second layer 144b, and a third layer 144c. The second layer 144b is located between the first layer 144a and the third layer 144c. The material of the first layer 144a is molybdenum oxide, the material of the second layer 144b includes molybdenum (e.g., molybdenum aluminum molybdenum (Mo / Al / Mo)), and the material of the third layer 144c is molybdenum oxide. Since the reflectivity of molybdenum oxide is lower than that of molybdenum, in a strong light environment, after light penetrates the finger, passes through the first opening OP1 of the first light-shielding layer BM1, passes through the light-transmitting substrate 100, and is reflected by an external component (not shown), such as a battery, it will not be reflected by the first light-shielding layer BM1 to the photosensitive element PD. Therefore, stray photocurrents can be avoided from being generated by each photosensitive element PD.

[0124] In summary, the sensing element substrate of the present invention uses molybdenum and molybdenum oxide (MoO) as materials for the first electrode. x Because molybdenum oxide has a lower reflectivity than molybdenum. For example, molybdenum has a reflectivity of approximately 60%, while molybdenum oxide has a reflectivity of approximately 10%. Therefore, multiple reflections of strong light from the photosensitive element can prevent the generation of stray photocurrents that would cause noise. For example, in a strong light environment, after light penetrates a finger and passes through the first opening of the first light-shielding layer, it will not be reflected by the first electrode back to the first light-shielding layer and then reflected to other photosensitive elements. Therefore, stray photocurrents can be avoided from each photosensitive element. In this way, both the sensing sensitivity of the sensing element substrate and the noise of the photosensitive element can be improved.

Claims

1. A sensing element substrate, comprising: a light-transmissive substrate; A switching element is located on the light-transmitting substrate; Multiple photosensitive elements are electrically connected to the switching element, and each photosensitive element includes: a first electrode, a photosensitive layer, and a second electrode. The material of the first electrode includes molybdenum and molybdenum oxide. The photosensitive layer is located on the first electrode. The second electrode is located on the photosensitive layer; A first insulating layer is located on the photosensitive elements; and A first light-shielding layer is located on the first insulating layer, wherein the first light-shielding layer has a plurality of first openings, each of the first openings overlapping the photosensitive element in the normal direction of the light-transmitting substrate.

2. The sensing element substrate of claim 1, wherein the first electrode is a double-layer structure comprising a first layer and a second layer located on the first layer, the material of the first layer comprising molybdenum, and the material of the second layer comprising molybdenum oxide.

3. The sensing element substrate as claimed in claim 1, wherein the first electrode is a three-layer structure comprising a first layer, a second layer and a third layer, the second layer being located between the first layer and the third layer, the first layer being made of molybdenum oxide, the second layer being made of molybdenum, and the third layer being made of molybdenum oxide.

4. The sensing element substrate as claimed in claim 1, wherein the first light-shielding layer is a three-layer structure comprising a first layer, a second layer and a third layer, the second layer being located between the first layer and the third layer, the first layer being made of molybdenum oxide, the second layer being made of molybdenum, and the third layer being made of molybdenum oxide.

5. The sensing element substrate as claimed in claim 1, further comprising: Multiple serial traces connect two adjacent second electrodes respectively, wherein each first electrode does not overlap with the serial traces in the vertical direction.

6. The sensing element substrate of claim 5, wherein the serial traces include a plurality of first traces and a plurality of second traces, the extension direction of each first trace being perpendicular to the extension direction of each second trace and the arrangement direction of two adjacent second electrodes connected by the second trace.

7. The sensing element substrate as claimed in claim 1, further comprising: Multiple serial traces connect two adjacent second electrodes, wherein each first electrode overlaps the serial traces in the vertical direction.

8. The sensing element substrate as claimed in claim 1, further comprising: At least one light-shielding pattern is located between two adjacent first electrodes, wherein the at least one light-shielding pattern is horizontally spaced from the two adjacent first electrodes, and the at least one light-shielding pattern is a double-layer structure comprising a first layer and a second layer located on the first layer, wherein the material of the first layer includes, and the material of the second layer is molybdenum oxide.

9. The sensing element substrate as claimed in claim 1, further comprising: At least one light-shielding pattern is located between two adjacent first electrodes, wherein the at least one light-shielding pattern is horizontally spaced from the two adjacent first electrodes, and the at least one light-shielding pattern is a three-layer structure comprising a first layer, a second layer and a third layer, wherein the second layer is located between the first layer and the third layer, wherein the material of the first layer is molybdenum oxide, the material of the second layer includes molybdenum, and the material of the third layer is molybdenum oxide.

10. The sensing element substrate of claim 1, further comprising: At least one signal line, wherein the area of ​​each of the first electrodes is larger than the area of ​​each of the photosensitive layers, and the minimum horizontal distance between each of the first electrodes and the adjacent at least one signal line is 0.1µm to 5µm.

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