Fingerprint identification unit and manufacturing method thereof, display substrate and display device

Abstract

The application provides a fingerprint identification unit, a manufacturing method thereof, a display substrate and a display device. The fingerprint identification unit comprises a thin film transistor and a photosensitive sensor. The manufacturing method comprises the following steps: forming a semiconductor layer pattern, wherein the semiconductor layer pattern comprises a first semiconductor pattern and a second semiconductor pattern, and the first semiconductor pattern is used as an active layer of the thin film transistor; and performing a conductorization treatment on the second semiconductor pattern to form a connecting electrode, wherein the connecting electrode is used for connecting the thin film transistor and the photosensitive sensor. In the embodiment of the application, the first semiconductor pattern used as the active layer of the thin film transistor and the second semiconductor pattern used for forming the connecting electrode are simultaneously formed through one patterning process, so that the number of masks of the fingerprint identification unit is reduced, and the production cost is lowered.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a fingerprint recognition unit and its manufacturing method, a display substrate and a display device. Background Technology

[0002] With the gradual adoption of full-screen displays, the demand for corresponding full-screen fingerprint recognition and touch technologies is also very urgent. A fingerprint recognition unit typically includes a thin-film transistor (TFT) and a photosensitive sensor. Please refer to [link / reference needed]. Figure 1 , Figure 1 This is an equivalent circuit diagram of a fingerprint recognition unit. The fingerprint recognition unit includes a thin-film transistor 11 and a photosensitive sensor 12. The gate of the thin-film transistor 11 is connected to a control line, which is used to control the opening of the thin-film transistor. The source of the thin-film transistor 11 is connected to a data line, and the drain is connected to the upper electrode of the photosensitive sensor 12. The lower electrode of the photosensitive sensor 12 is connected to a reference voltage. When the signal output by the control line controls the thin-film transistor to open, the current generated by the photosensitive sensor 12 is read through the data reading line, and the fingerprint is identified based on the magnitude of the current.

[0003] In related technologies, the number of masks used in the production of fingerprint recognition units is as many as 10 or more, the production process is relatively complex, and the production cost is high. Summary of the Invention

[0004] This invention provides a fingerprint recognition unit and its manufacturing method, a display substrate, and a display device, which solves the problems of complex manufacturing processes and high manufacturing costs of existing fingerprint recognition units.

[0005] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0006] In a first aspect, embodiments of the present invention provide a method for manufacturing a fingerprint recognition unit, the fingerprint recognition unit comprising a thin-film transistor and a photosensitive sensor, the manufacturing method comprising:

[0007] A semiconductor layer pattern is formed, the semiconductor layer pattern including a first semiconductor pattern and a second semiconductor pattern, wherein the first semiconductor pattern serves as the active layer of the thin-film transistor;

[0008] The second semiconductor pattern is conductiveized to form a connection electrode, which is used to connect the thin-film transistor and the photosensitive sensor.

[0009] Optionally, the process prior to forming the semiconductor layer pattern includes:

[0010] The photosensitive sensor is formed with a lower electrode, a PIN layer, and an upper electrode, wherein the connecting electrode is attached to the upper electrode.

[0011] Optionally, the connecting electrode is a transparent electrode.

[0012] Optionally, the process prior to forming the semiconductor layer pattern includes:

[0013] The lower electrode and PIN layer of the photosensitive sensor are formed, wherein the connecting electrode is a transparent electrode and is reused as the upper electrode of the photosensitive sensor.

[0014] Optionally, the connecting electrode can be reused as the lower electrode of the photosensitive sensor.

[0015] Optionally, the process prior to forming the semiconductor layer pattern includes:

[0016] A gate metal layer pattern is formed, the gate metal layer pattern including the gate of the thin film transistor and the lower electrode of the photosensitive sensor.

[0017] Optionally, after forming the semiconductor layer pattern, the method further includes:

[0018] A source / drain metal layer pattern is formed, wherein the source / drain metal layer pattern includes only the source electrode, and the connection electrode is connected to the active layer and reused as the drain electrode of the thin film transistor;

[0019] or

[0020] A source / drain metal layer pattern is formed, the source / drain metal layer pattern including a source and a drain, and the connection electrode is connected to the active layer and the drain respectively;

[0021] or

[0022] A source / drain metal layer pattern is formed, the source / drain metal layer pattern including a source and a drain, the connection electrode is disconnected from the active layer, and the drain is connected to the connection electrode.

[0023] Secondly, embodiments of the present invention provide a fingerprint recognition unit, comprising:

[0024] A thin-film transistor, a photosensitive sensor, and a connection electrode, wherein the connection electrode is used to connect the thin-film transistor and the photosensitive sensor;

[0025] The thin-film transistor includes an active layer;

[0026] The active layer and the connecting electrode are formed from the same semiconductor layer pattern, which includes a first semiconductor pattern and a second semiconductor pattern. The first semiconductor pattern serves as the active layer, and the connecting electrode is obtained by conducting the second semiconductor pattern.

[0027] Optionally, the photosensitive sensor includes a lower electrode, a PIN layer, and an upper electrode, wherein the connecting electrode is attached to the upper electrode.

[0028] Optionally, the connecting electrode is a transparent electrode.

[0029] Optionally, the connecting electrode is a transparent electrode, which is reused as the upper electrode of the photosensitive sensor.

[0030] Optionally, the connecting electrode can be reused as the lower electrode of the photosensitive sensor.

[0031] Optionally, the thin-film transistor includes a gate, and the gate and the lower electrode of the photosensitive sensor are disposed in the same layer and made of the same material.

[0032] Optionally, the connecting electrode is connected to the active layer and reused as the drain of the thin-film transistor; or

[0033] The connecting electrodes are respectively connected to the active layer and the drain of the thin-film transistor; or

[0034] The connection electrode is disconnected from the active layer, and the drain of the thin-film transistor is connected to the connection electrode.

[0035] Thirdly, embodiments of the present invention provide a display substrate including the fingerprint recognition unit described above.

[0036] Fourthly, embodiments of the present invention provide a display device including the aforementioned display substrate.

[0037] In this embodiment of the invention, a first semiconductor pattern, which serves as the active layer of a thin-film transistor, and a second semiconductor pattern for forming connection electrodes are simultaneously formed through a single patterning process, thereby reducing the number of masks for the fingerprint recognition unit and lowering production costs. Attached Figure Description

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0039] Figure 1 This is a schematic diagram of the equivalent circuit of the fingerprint recognition unit;

[0040] Figure 2 This is a flowchart illustrating the manufacturing method of the fingerprint recognition unit according to an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the structure of a fingerprint recognition unit according to an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the structure of a fingerprint recognition unit according to another embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the structure of a fingerprint recognition unit according to another embodiment of the present invention;

[0044] Figure 6 This is a schematic diagram of the structure of a fingerprint recognition unit according to another embodiment of the present invention;

[0045] Figures 7A-7G This is a flowchart illustrating the manufacturing method of the fingerprint recognition unit according to Embodiment 1 of the present invention;

[0046] Figures 8A-8B This is a flowchart illustrating the manufacturing method of the fingerprint recognition unit according to Embodiment 2 of the present invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] In related technologies, thin-film transistors and photosensitive sensors need to be connected by connecting electrodes. However, the fabrication of connecting electrodes usually requires a separate mask process, which is not conducive to reducing the manufacturing cost of fingerprint recognition units.

[0049] To solve the above problems, please refer to... Figure 2 This invention provides a method for manufacturing a fingerprint recognition unit, the fingerprint recognition unit including a thin-film transistor and a photosensitive sensor, the manufacturing method including:

[0050] Step S11: Form a semiconductor layer pattern, the semiconductor layer pattern including a first semiconductor pattern and a second semiconductor pattern, the first semiconductor pattern serving as the active layer of the thin-film transistor;

[0051] Step S12: Conduct the second semiconductor pattern to form a connection electrode, which is used to connect the thin film transistor and the photosensitive sensor.

[0052] In this embodiment of the invention, a first semiconductor pattern, which serves as the active layer of a thin-film transistor, and a second semiconductor pattern for forming connection electrodes are formed simultaneously through a single patterning process, thereby reducing the number of masks for the fingerprint recognition unit and lowering production costs.

[0053] In some embodiments of the present invention, optionally, the process prior to forming the semiconductor layer pattern includes:

[0054] Step S0a: Form the lower electrode, PIN layer and upper electrode of the photosensitive sensor, wherein the connecting electrode is attached to the upper electrode.

[0055] Please refer to Figure 3 , Figure 3 In the embodiment shown, the lower electrode 102a, PIN layer 103 and upper electrode 104 of the photosensitive sensor are formed first, and then the active layer 106a and connection electrode 106b of the thin film transistor are formed. The connection electrode 106b is attached to the upper electrode 104 and is used to connect the thin film transistor and the photosensitive sensor.

[0056] In the existing fingerprint recognition unit manufacturing process, thin-film transistors are usually formed first, followed by the formation of a photosensitive sensor. During the formation of the photosensitive sensor, the active layer of the thin-film transistor may be damaged, thereby affecting the characteristics of the thin-film transistor.

[0057] In this embodiment of the invention, when fabricating the fingerprint recognition unit, a photosensitive sensor is formed first, and then the active layer of the thin-film transistor and other film layers are formed, thereby avoiding damage to the active layer and other layers during the formation of the photosensitive sensor.

[0058] In related technologies, there is a scheme that uses the shielding metal layer of the thin-film transistor as a bonding electrode to connect the photosensitive sensor and the thin-film transistor. While shielding the thin-film transistor, the shielding metal layer also shields part of the photosensitive sensor, reducing the light-receiving area of ​​the photosensitive sensor, thereby reducing the current of the photosensitive sensor and affecting the sensitivity of the fingerprint recognition unit.

[0059] In the above embodiments, optionally, the semiconductor layer pattern is formed using a transparent semiconductor material, thereby making the formed connection electrode a transparent electrode. Even if the connection electrode is attached to the upper electrode of the photosensitive sensor, it will not affect the light-receiving area of ​​the photosensitive sensor.

[0060] Alternatively, the transparent semiconductor material may be a metal oxide semiconductor material. As an active layer, the metal oxide semiconductor can effectively improve the characteristics of the thin film transistor.

[0061] In some other embodiments of the present invention, optionally, the connecting electrode is a transparent electrode, reused as the upper electrode of the photosensitive sensor, that is, before forming the semiconductor layer pattern, the following is included:

[0062] Step S0b: Form the lower electrode and PIN layer of the photosensitive sensor, wherein the connecting electrode is a transparent electrode and reused as the upper electrode of the photosensitive sensor.

[0063] Please refer to Figure 4 , Figure 4 In the embodiment shown, the lower electrode 202a and PIN layer 203 of the photosensitive sensor are formed first, and then the active layer 205a and connection electrode 205b of the thin film transistor are formed. The connection electrode 205b is reused as the upper electrode of the photosensitive sensor.

[0064] Optionally, the semiconductor layer pattern uses a transparent metal oxide semiconductor material. As an active layer, the metal oxide semiconductor can effectively improve the characteristics of the thin film transistor.

[0065] In this embodiment of the invention, when fabricating the fingerprint recognition unit, the lower electrode and PIN layer of the photosensitive sensor are first formed, and then the active layer of the thin-film transistor and the connection electrode that is reused as the upper electrode of the photosensitive sensor are formed. This avoids damage to the active layer and other components during the formation of the photosensitive sensor, while reducing the mask process for separately fabricating the upper electrode of the photosensitive sensor. This reduces the number of masks in the fingerprint recognition unit, lowers production costs, and also reduces the thickness of the fingerprint recognition unit.

[0066] In the above embodiments, the connecting electrode is connected to the upper electrode of the photosensitive sensor, or reused as the upper electrode of the photosensitive sensor. In other embodiments of the present invention, the connecting electrode may also be connected to the lower electrode of the photosensitive sensor, or reused as the lower electrode of the photosensitive sensor. These will be described separately below.

[0067] In some other embodiments of the present invention, optionally, the connecting electrode is reused as the lower electrode of the photosensitive sensor.

[0068] Please refer to Figure 5 , Figure 5 In the embodiment shown, the connecting electrode 303b is multiplexed as the lower electrode of the photosensitive sensor.

[0069] In this embodiment of the invention, the connecting electrode is reused as the lower electrode of the photosensitive sensor, which reduces the mask process of separately manufacturing the lower electrode of the photosensitive sensor, reduces the number of masks in the fingerprint recognition unit, and also reduces the thickness of the fingerprint recognition unit.

[0070] In other embodiments of the present invention, the connecting electrode may not be reused as the lower electrode of the photosensitive sensor, but may instead be disposed and connected to the lower electrode of the photosensitive sensor in the same layer. This structure also reduces the thickness of the fingerprint recognition unit.

[0071] In some embodiments of the present invention, optionally, the process prior to forming the semiconductor layer pattern includes:

[0072] Step S0c: Form a gate metal layer pattern, the gate metal layer pattern including the gate of the thin film transistor and the lower electrode of the photosensitive sensor.

[0073] Please refer to Figure 3 , Figure 4 and Figure 6 , Figure 3 In the embodiment shown, the gate 102b of the thin-film transistor and the lower electrode 102a of the photosensitive sensor are disposed on the same layer and made of the same material, and are formed by a single patterning process. Figure 4 In the embodiment shown, the gate 202b of the thin-film transistor and the lower electrode 202a of the photosensitive sensor are disposed on the same layer and made of the same material, and are formed by a single patterning process. Figure 6 In the embodiment shown, the gate 502b of the thin-film transistor and the lower electrode 502a of the photosensitive sensor are disposed in the same layer and made of the same material, and are formed by a single patterning process.

[0074] In this embodiment of the invention, the gate of the thin-film transistor and the lower electrode of the photosensitive sensor are formed through a single patterning process, thereby further reducing the number of masks in the fingerprint recognition unit and helping to reduce the thickness of the fingerprint recognition unit.

[0075] In some embodiments of the present invention, after forming the semiconductor layer pattern, the method further includes:

[0076] Step S13a: Form a source / drain metal layer pattern, wherein the source / drain metal layer pattern includes only the source electrode, and the connecting electrode is connected to the active layer and reused as the drain electrode of the thin film transistor.

[0077] Please refer to Figure 3 , Figure 4 and Figure 5 , Figure 3 In the embodiment shown, the connection electrode 106b is reused as the drain of the thin-film transistor. Figure 4 In the illustrated embodiment, the connecting electrode 205b is simultaneously reused as the drain of the thin-film transistor and the upper electrode of the photosensitive sensor. Figure 5 In the embodiment shown, the connecting electrode 303b is simultaneously reused as the drain of the thin-film transistor and the lower electrode of the photosensitive sensor.

[0078] In some embodiments of the present invention, after forming the semiconductor layer pattern, the method further includes:

[0079] Step S13b: Form a source / drain metal layer pattern, the source / drain metal layer pattern including a source and a drain, and the connecting electrode is connected to the active layer and the drain, respectively.

[0080] Please refer to Figure 6 , Figure 6In the embodiment shown, the source / drain metal layer pattern includes a source 507a and a drain 507b, and a connecting electrode 506b is connected to the active layer 506a and the drain 507b respectively.

[0081] In this embodiment of the invention, the drain resistance can be reduced.

[0082] In other embodiments of the present invention, the active layer of the thin-film transistor may not be connected to the connection electrode, and the connection electrode may be connected to the drain electrode.

[0083] That is, after forming the semiconductor layer pattern, the process further includes:

[0084] Step S13c: Form a source / drain metal layer pattern, the source / drain metal layer pattern including a source and a drain, the connection electrode is disconnected from the active layer, and the drain is connected to the connection electrode.

[0085] In the above embodiments of the present invention, optionally, the semiconductor layer pattern is a metal oxide semiconductor, such as IGZO (indium gallium zinc oxide), ITZO (indium tin zinc oxide), IZO (indium zinc oxide), etc., to improve the performance of thin film transistors.

[0086] In the above embodiments of the present invention, the conductor-enhancing method may employ plasma treatment of the semiconductor pattern using NH3, H2, etc., or ion doping of the semiconductor pattern.

[0087] The following example illustrates the manufacturing method of the fingerprint recognition unit in an embodiment of the present invention.

[0088] Example 1

[0089] The method for manufacturing the fingerprint recognition unit in Embodiment 1 of the present invention includes the following steps:

[0090] Step S21: A gate metal layer is fabricated and patterned on the substrate 101 to form the gate 102b of the thin-film transistor and the lower electrode 102a of the photosensitive sensor, as shown below. Figure 7A As shown.

[0091] In this embodiment of the invention, the substrate can be a glass substrate or a flexible PI (polyimide) substrate, and the gate metal can be Al, Mo, AlNd, Cu, MoNb, etc.

[0092] This step uses a mask (mask1).

[0093] Step S22: A PIN process is fabricated and patterned on the lower electrode 102a to form the PIN layer 103 and the upper electrode 104 of the photosensitive sensor, as shown below. Figure 7B As shown.

[0094] The PIN layer 103 may include an intrinsic amorphous silicon layer and a p-doped amorphous silicon layer. The thickness of the intrinsic amorphous silicon layer can be 600–1200 nm, and the thickness of the p-doped amorphous silicon layer can be 10–100 nm. The upper electrode 104 may be made of a transparent metal oxide, such as ITO, with a thickness of 20–80 nm.

[0095] This step uses two masks (mask2-3).

[0096] Step S23: Deposit the gate insulating layer (GI layer) and drill holes above the upper electrode 104, such as... Figure 7C As shown.

[0097] The gate insulating layer can be SiO2, or a combination of SiNx and SiO2, with a thickness of 200-400 nm.

[0098] This step uses a mask (mask4).

[0099] Step S24: Forming a semiconductor layer pattern 106, the semiconductor layer pattern 106 including: a first semiconductor pattern 106a and a second semiconductor pattern 106b', wherein the first semiconductor pattern 106a serves as the active layer of a thin-film transistor, such as... Figure 7D As shown.

[0100] The semiconductor layer pattern 106 can be formed using metal oxide semiconductor materials such as IGZO, ITZO, and IZO. Preferably, IGZO is used, and it can be in an amorphous state, a crystalline state, or a stacked structure of both, with a thickness of 30-70 nm.

[0101] This step uses a mask (mask5).

[0102] Step S25: Conduct the second semiconductor pattern 1062 to form a connecting electrode 106b, such as... Figure 7E As shown.

[0103] Conducting methods can involve plasma treatment of semiconductor patterns using NH3, H2, etc., or ion doping of semiconductor patterns.

[0104] This step uses a mask (mask6).

[0105] Step S26: Form a source / drain metal layer pattern, wherein the source / drain metal layer pattern only includes the source electrode 107, and no source / drain metal layer pattern is formed on the connecting electrode 106b, such as... Figure 7F As shown.

[0106] The source / drain metal can be Al, Mo, AlNd, Cu, MoNb, or any combination of two or more of the above metals, and the thickness of the source / drain metal layer can be 300-500 nm.

[0107] This step uses a mask (mask7).

[0108] Step S27: Form a passivation protection (PVX) layer 108, such as Figure 7G As shown.

[0109] The PVX layer can be made of SiO2, SiON, or a combination of SiO2 and SiON, and its thickness can be [missing information].

[0110] Example 2

[0111] The method for manufacturing the fingerprint recognition unit in Embodiment 2 of the present invention includes the following steps:

[0112] Steps S31-S35 are the same as steps S21-S25 in Implementation 1, and will not be described again.

[0113] Step S36: Form the source / drain metal layer pattern, wherein the source / drain metal layer pattern includes only the source 507a and the drain 507b, as shown below. Figure 8A As shown.

[0114] The source / drain metal can be Al, Mo, AlNd, Cu, MoNb, or any combination of two or more of the above metals, and the thickness of the source / drain metal layer can be 300-500 nm.

[0115] In this embodiment of the invention, a drain electrode 507b is fabricated on the connecting electrode 506b, which can reduce its resistance.

[0116] Step S37: Form a passivation protection (PVX) layer 508, such as Figure 7G As shown.

[0117] The PVX layer can be made of SiO2, SiON, or a combination of SiO2 and SiON, with a thickness of [missing information].

[0118] In the two embodiments of the present invention described above, a first semiconductor pattern serving as the active layer of a thin-film transistor and a second semiconductor pattern for forming connection electrodes are simultaneously formed through a single patterning process, thereby reducing the number of masks for the fingerprint recognition unit and lowering production costs. Furthermore, the photosensitive sensor is fabricated first, followed by the gate insulating layer, active layer, source / drain metal patterns, and PVX process related to the thin-film transistor, to reduce the impact of the photosensitive sensor process on the characteristics of the thin-film transistor. The use of transparent metal oxides to form the semiconductor layer pattern makes the formed connection electrodes transparent, which can increase the light-receiving area of ​​the photosensitive sensor. The bottom electrode of the photosensitive sensor and the gate of the thin-film transistor share the same metal layer, reducing the film layer structure. The 7-mask process is used, which significantly reduces the process flow compared to existing processes.

[0119] This invention also provides a fingerprint recognition unit, comprising:

[0120] A thin-film transistor, a photosensitive sensor, and a connection electrode, wherein the connection electrode is used to connect the thin-film transistor and the photosensitive sensor;

[0121] The thin-film transistor includes an active layer;

[0122] The active layer and the connecting electrode are formed from the same semiconductor layer pattern, which includes a first semiconductor pattern and a second semiconductor pattern. The first semiconductor pattern serves as the active layer, and the connecting electrode is obtained by conducting the second semiconductor pattern.

[0123] In this embodiment of the invention, an active layer serving as a thin-film transistor and a semiconductor pattern for forming connection electrodes can be formed simultaneously through a single patterning process, thereby reducing the number of masks for the fingerprint recognition unit and lowering production costs.

[0124] In some embodiments of the present invention, optionally, the photosensitive sensor includes: a lower electrode, a PIN layer and an upper electrode, wherein the connecting electrode is attached to the upper electrode.

[0125] Optionally, the semiconductor layer pattern is formed using a transparent semiconductor material, thereby making the formed connection electrode a transparent electrode. Even if the connection electrode is attached to the upper electrode of the photosensitive sensor, it will not affect the light-receiving area of ​​the photosensitive sensor.

[0126] Alternatively, the transparent semiconductor material may be a metal oxide semiconductor material. As an active layer, the metal oxide semiconductor can effectively improve the characteristics of the thin film transistor.

[0127] Please refer to Figure 3 , Figure 3 In the illustrated embodiment, the fingerprint recognition unit includes:

[0128] Substrate 101; The substrate can be a glass substrate or a flexible PI (polyimide) substrate;

[0129] The gate metal layer pattern includes the gate 102b of the thin-film transistor and the lower electrode 102a of the photosensitive sensor; the gate metal can be Al, Mo, AlNd, Cu, MoNb, etc.

[0130] PIN layer 103; PIN layer 103 may include an intrinsic amorphous silicon layer and a P-doped amorphous silicon layer, wherein the thickness of the intrinsic amorphous silicon layer may be 600-1200 nm and the thickness of the P-doped amorphous silicon layer may be 10-100 nm.

[0131] Upper electrode 104; the upper electrode 104 can be made of transparent metal oxide such as ITO, and the thickness can be 20-80 nm;

[0132] The gate insulating layer 105 has a through hole located above the upper electrode 104. The gate insulating layer can be SiO2 or a combination of SiNx and SiO2 film, and the thickness can be 200-400nm.

[0133] An active layer 106a and a connecting electrode 106b are formed from the same semiconductor layer pattern. The semiconductor layer pattern includes a first semiconductor pattern and a second semiconductor pattern. The first semiconductor pattern serves as the active layer 106a. The connecting electrode 106b is obtained by conducting the second semiconductor pattern. The connecting electrode 106b is connected to the upper electrode 104 of the photosensitive sensor through a via on the gate insulating layer 105. The connecting electrode 106b is a transparent electrode. The semiconductor layer pattern can be formed using metal oxide semiconductor materials such as IGZO, ITZO, and IZO. Preferably, IGZO is used, and it can be in an amorphous state, a crystalline state, or a stacked structure of both. The thickness can be 30-70 nm.

[0134] The source / drain metal layer pattern includes a source electrode 107; the source / drain metal can be Al, Mo, AlNd, Cu, MoNb, etc., or any combination of two or more of the above metals, and the thickness of the source / drain metal layer can be 300-500 nm.

[0135] PVX layer 108; PVX layer 108 can be made of SiO2, SiON, or a combination of SiO2 and SiON, and its thickness can be [missing information].

[0136] In some other embodiments of the present invention, optionally, the connecting electrode is a transparent electrode, which is reused as the upper electrode of the photosensitive sensor.

[0137] Optionally, the semiconductor layer pattern uses a transparent metal oxide semiconductor material. As an active layer, the metal oxide semiconductor can effectively improve the characteristics of the thin film transistor.

[0138] Please refer to Figure 4 , Figure 4 In the illustrated embodiment, the fingerprint recognition unit includes:

[0139] Substrate 201; The substrate can be a glass substrate or a flexible PI (polyimide) substrate;

[0140] The gate metal layer pattern includes the gate 202b of the thin-film transistor and the lower electrode 202a of the photosensitive sensor; the gate metal can be Al, Mo, AlNd, Cu, MoNb, etc.

[0141] PIN layer 203; PIN layer 203 may include an intrinsic amorphous silicon layer and a P-doped amorphous silicon layer, wherein the thickness of the intrinsic amorphous silicon layer can be 600-1200 nm and the thickness of the P-doped amorphous silicon layer can be 10-100 nm.

[0142] The gate insulating layer 204 has a through hole located above the PIN layer 203. The gate insulating layer 204 can be made of SiO2, or a combination of SiNx and SiO2 film, with a thickness of 200-400nm.

[0143] The active layer 205a and the connecting electrode 205b are formed from the same semiconductor layer pattern. The semiconductor layer pattern includes a first semiconductor pattern and a second semiconductor pattern. The first semiconductor pattern serves as the active layer 205a, and the connecting electrode 205b is obtained by conducting the second semiconductor pattern. The connecting electrode 205b is a transparent electrode and is reused as the upper electrode of a photosensitive sensor. The semiconductor layer pattern can be formed using metal oxide semiconductor materials such as IGZO, ITZO, and IZO. Preferably, IGZO is used, and it can be in an amorphous state, a crystalline state, or a stacked structure of both. The thickness can be 30-70 nm.

[0144] The source / drain metal layer pattern includes a source electrode 206; the source / drain metal can be Al, Mo, AlNd, Cu, MoNb, etc., or any combination of two or more of the above metals, and the thickness of the source / drain metal layer can be 300-500 nm.

[0145] PVX layer 207; PVX layer 207 can be made of SiO2, SiON, or a combination of SiO2 and SiON, and its thickness can be [missing information].

[0146] In the above embodiments, the connecting electrode is connected to the upper electrode of the photosensitive sensor, or reused as the upper electrode of the photosensitive sensor. In other embodiments of the present invention, the connecting electrode may also be connected to the lower electrode of the photosensitive sensor, or reused as the lower electrode of the photosensitive sensor. These will be described separately below.

[0147] In some other embodiments of the present invention, optionally, the connecting electrode is reused as the lower electrode of the photosensitive sensor.

[0148] Please refer to Figure 5 , Figure 5 In the illustrated embodiment, the fingerprint recognition unit includes:

[0149] Substrate 301; Substrate 301 can be a glass substrate or a flexible PI (polyimide) substrate;

[0150] Buffer layer 302;

[0151] The active layer 303a, the connecting electrode 303b, and the source connection region 303c are formed from the same semiconductor layer pattern. The semiconductor layer pattern includes a first semiconductor pattern, a second semiconductor pattern, and a third semiconductor pattern. The first semiconductor pattern serves as the active layer 303a. The connecting electrode 303b is obtained by conducting the second semiconductor pattern, and the source connection region 303c is obtained by conducting the third semiconductor pattern. The connecting electrode 303b is reused as the drain of a thin-film transistor and the lower electrode of a photosensitive sensor. The semiconductor layer pattern can be formed using metal oxide semiconductor materials such as IGZO, ITZO, and IZO. Preferably, IGZO is used, and it can be in an amorphous state, a crystalline state, or a stacked structure of both. The thickness can be 30-70 nm.

[0152] PIN layer 304; PIN layer 304 may include an intrinsic amorphous silicon layer and a P-doped amorphous silicon layer, wherein the thickness of the intrinsic amorphous silicon layer can be 600-1200 nm and the thickness of the P-doped amorphous silicon layer can be 10-100 nm.

[0153] Upper electrode 305; Upper electrode 305 can be made of transparent metal oxide such as ITO, with a thickness of 20-80 nm;

[0154] The gate insulating layer 306 has a through hole located above the upper electrode 305. The gate insulating layer can be SiO2 or a combination of SiNx and SiO2 film, with a thickness of 200-400 nm.

[0155] The gate metal layer pattern includes the gate 307 of the thin-film transistor; the gate metal can be Al, Mo, AlNd, Cu, MoNb, etc.

[0156] Interlayer dielectric layer (ILD) 308, with through holes formed on the interlayer dielectric layer 308, the through holes being located above the through holes on the gate insulating layer 306 and communicating with the through holes on the gate insulating layer 306;

[0157] The first connection portion 309 is connected to the upper electrode 305 through through holes in the interlayer dielectric layer 308 and the gate insulating layer 306.

[0158] The source / drain metal layer pattern includes a source electrode 310a and a second connection portion 310b. The source / drain metal can be Al, Mo, AlNd, Cu, MoNb, or any combination of two or more of the above metals. The thickness of the source / drain metal layer can be 300-500 nm. In some embodiments of the present invention, the first connection portion 309 may not be included, and the second connection portion 310b may be directly connected to the upper electrode 305 through the through-holes on the interlayer dielectric layer 308 and the gate insulating layer 306.

[0159] PVX layer 311; PVX layer 311 can be made of SiO2, SiON, or a combination of SiO2 and SiON, and its thickness can be [missing information].

[0160] In this embodiment of the invention, the connecting electrode is reused as the lower electrode of the photosensitive sensor, which reduces the mask process of separately manufacturing the lower electrode of the photosensitive sensor, reduces the number of masks in the fingerprint recognition unit, and also reduces the thickness of the fingerprint recognition unit.

[0161] In other embodiments of the present invention, the connecting electrode may not be reused as the lower electrode of the photosensitive sensor, but may instead be disposed and connected to the lower electrode of the photosensitive sensor in the same layer. This structure also reduces the thickness of the fingerprint recognition unit.

[0162] In some embodiments of the present invention, the thin-film transistor includes a gate, and the gate and the lower electrode of the photosensitive sensor are disposed in the same layer and of the same material. Please refer to [reference needed]. Figure 3 , Figure 4 and Figure 6 . Figure 3In the embodiment shown, the gate 102b of the thin-film transistor and the lower electrode 102a of the photosensitive sensor are disposed on the same layer and made of the same material, and are formed by a single patterning process. Figure 4 In the embodiment shown, the gate 202b of the thin-film transistor and the lower electrode 202a of the photosensitive sensor are disposed on the same layer and made of the same material, and are formed by a single patterning process. Figure 6 In the embodiment shown, the gate 502b of the thin-film transistor and the lower electrode 502a of the photosensitive sensor are disposed in the same layer and made of the same material, and are formed by a single patterning process.

[0163] In this embodiment of the invention, the gate of the thin-film transistor and the lower electrode of the photosensitive sensor are formed through a single patterning process, thereby further reducing the number of masks in the fingerprint recognition unit and helping to reduce the thickness of the fingerprint recognition unit.

[0164] In some embodiments of the present invention, the connection electrode is connected to the active layer and reused as the drain of the thin-film transistor. Please refer to... Figure 3 , Figure 4 and Figure 5 , Figure 3 In the embodiment shown, the connection electrode 106b is reused as the drain of the thin-film transistor. Figure 4 In the illustrated embodiment, the connecting electrode 205b is simultaneously reused as the drain of the thin-film transistor and the upper electrode of the photosensitive sensor. Figure 5 In the embodiment shown, the connecting electrode 303b is simultaneously reused as the drain of the thin-film transistor and the lower electrode of the photosensitive sensor.

[0165] In some embodiments of the present invention, the connection electrode is connected to both the active layer and the drain of the thin-film transistor. Please refer to... Figure 6 , Figure 6 In the illustrated embodiment, the source / drain metal layer pattern includes a source 507a and a drain 507b, and a connecting electrode 506b is connected to the active layer 506a and the drain 507b, respectively. This structure can reduce the drain resistance.

[0166] In some embodiments of the present invention, the connection electrode is disconnected from the active layer, and the drain of the thin-film transistor is connected to the connection electrode.

[0167] In the above embodiments of the present invention, optionally, the semiconductor layer pattern is a metal oxide semiconductor, such as IGZO (indium gallium zinc oxide), ITZO (indium tin zinc oxide), IZO (indium zinc oxide), etc., to improve the performance of thin film transistors.

[0168] This invention also provides a display substrate, including the fingerprint recognition unit in any of the above embodiments.

[0169] This invention also provides a display device, including the above-described display substrate.

[0170] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A method for manufacturing a fingerprint recognition unit, the fingerprint recognition unit comprising a thin-film transistor and a photosensitive sensor, characterized in that, The manufacturing method includes: A semiconductor layer pattern is formed, the semiconductor layer pattern including a first semiconductor pattern and a second semiconductor pattern, wherein the first semiconductor pattern serves as the active layer of the thin-film transistor; The second semiconductor pattern is conductively processed to form a connection electrode, which is used to connect the thin film transistor and the photosensitive sensor. The connection electrode is disposed on the same layer as the active layer. The process prior to forming the semiconductor layer pattern includes: The lower electrode and PIN layer of the photosensitive sensor are formed, wherein the connecting electrode is attached to the upper electrode of the photosensitive sensor and is connected to the upper electrode through an opening in the gate insulating layer; or, the connecting electrode is reused as the upper electrode of the photosensitive sensor and is connected to the PIN layer through an opening in the gate insulating layer. The process after forming the semiconductor layer pattern also includes: A source / drain metal layer pattern is formed, the source / drain metal layer pattern including a source and a drain, and the connection electrode is connected to the active layer and the drain respectively, wherein the drain is fabricated on the connection electrode.

2. The method as described in claim 1, characterized in that, The connecting electrode is a transparent electrode.

3. The method as described in claim 1, characterized in that, Alternatively, the connecting electrode can be reused as the lower electrode of the photosensitive sensor.

4. The method as described in claim 1, characterized in that, The process prior to forming the semiconductor layer pattern includes: A gate metal layer pattern is formed, the gate metal layer pattern including the gate of the thin film transistor and the lower electrode of the photosensitive sensor.

5. A fingerprint recognition unit, characterized in that, include: A thin-film transistor, a photosensitive sensor, and a connection electrode, wherein the connection electrode is used to connect the thin-film transistor and the photosensitive sensor; The thin-film transistor includes an active layer; The active layer and the connecting electrode are formed from the same semiconductor layer pattern. The connecting electrode is disposed in the same layer as the active layer. The semiconductor layer pattern includes a first semiconductor pattern and a second semiconductor pattern. The first semiconductor pattern serves as the active layer. The connecting electrode is obtained by conducting the second semiconductor pattern. The photosensitive sensor includes a lower electrode and a PIN layer, wherein the connecting electrode is attached to the upper electrode of the photosensitive sensor and is connected to the upper electrode through an opening in the gate insulating layer; or, the connecting electrode is reused as the upper electrode of the photosensitive sensor and is connected to the PIN layer through an opening in the gate insulating layer. The connection electrodes are respectively connected to the active layer and the drain of the thin-film transistor; wherein the drain is fabricated on the connection electrodes.

6. The fingerprint recognition unit as described in claim 5, characterized in that, The connecting electrode is a transparent electrode.

7. The fingerprint recognition unit as described in claim 5, characterized in that, Alternatively, the connecting electrode can be reused as the lower electrode of the photosensitive sensor.

8. The fingerprint recognition unit as described in claim 5, characterized in that, The thin-film transistor includes a gate, and the gate and the lower electrode of the photosensitive sensor are disposed in the same layer and made of the same material.

9. A display substrate, characterized in that, Includes the fingerprint recognition unit as described in any one of claims 5-8.

10. A display device, characterized in that, Includes the display substrate as described in claim 9.

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