CN114447119A - TFT substrate and manufacturing method thereof - Google Patents

Abstract

The embodiment of the application provides a TFT substrate and a manufacturing method thereof. The embodiment of the application provides a TFT base plate, include the grid through setting up the functional layer, first shading district, the second shading district, source contact zone and drain contact zone, and set up source electrode and source contact zone electric connection on through the grid insulating layer, the drain electrode passes through drain contact hole and drain contact zone electric connection on the grid insulating layer, make the side of active layer sheltered from by source electrode and drain electrode, the back of active layer is sheltered from by the functional layer, that is, carry out omnidirectional shading protection to the side and the back of active layer, avoid light from side and back to shine to the active layer and lead to producing the photogenerated carrier in the active layer, the illumination stability of TFT device has been promoted.

Description

TFT substrate and manufacturing method thereof

technical field

The present application relates to the field of display, and in particular, to a TFT substrate and a manufacturing method thereof.

Background technique

The LCD display technology driven by active matrix utilizes the bipolar polarization characteristics of liquid crystal, and controls the arrangement direction of the liquid crystal molecules by applying an electric field, so as to realize the switching effect on the traveling direction of the light path of the backlight source. Thin film transistors (TFTs) are typically used to control the electric field within each pixel. Semiconductor materials commonly used in TFTs include amorphous silicon, oxide and polysilicon, among which oxide semiconductors are used in high-order displays such as large size, high resolution and high refresh rate due to their higher mobility and simpler number of processes. Technology has unique advantages.

In the prior art, the widely used oxide TFT structure in the LCD is the back-channel etched (BCE) structure. However, the TFT using an oxide semiconductor as the active layer is sensitive to light, and it is easy to generate photogenerated light under light irradiation. The carrier is not conducive to the light stability of the TFT device.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a TFT substrate and a manufacturing method thereof. The side and back of the active layer in the TFT substrate are provided with light-shielding protection structures, which can prevent light from being irradiated to the active layer from the side and back, resulting in photo-generated generation in the active layer. carrier, which improves the light stability of the TFT device.

In a first aspect, an embodiment of the present application provides a TFT substrate, including:

substrate;

A functional layer is provided on one side of the substrate, the functional layer includes a gate electrode, a first light-shielding region, a second light-shielding region, a source contact region and a drain contact region, wherein the first light-shielding region and The second light-shielding regions are located on two sides of the gate, respectively, the source contact region is disposed on a side of the first light-shielding region away from the gate, and the drain contact region is disposed on the first light-shielding region. Two light-shielding regions are on the side away from the gate, the gate, the source contact region and the drain contact region are all conductive materials, and the first light-shielding region and the second light-shielding region are all conductive materials Insulation Materials;

a gate insulating layer, disposed on the side of the functional layer away from the substrate, and a source contact hole and a drain contact hole are arranged on the gate insulating layer;

an active layer, disposed on the side of the gate insulating layer away from the functional layer;

A source and drain layer is provided on the side of the active layer away from the gate insulating layer, the source and drain layers include a source electrode and a drain electrode, the source electrode is connected to the source electrode through the source electrode contact hole The source contact region is electrically connected, and the drain electrode is electrically connected to the drain contact region through the drain contact hole.

In some embodiments, the material of the gate electrode, the material of the source contact region, and the material of the drain contact region are all metals, and the material of the first light-shielding region and the material of the second light-shielding region are all metals. The materials are all metal oxides.

In some embodiments, the material of the gate electrode, the material of the source contact region, and the material of the drain contact region are all first metal, and the material of the first light-shielding region and the second light-shielding region The materials of the regions are all oxides of the first metal.

In some embodiments, the first metal includes one or more of molybdenum, aluminum, copper, and titanium.

In some embodiments, the TFT substrate further includes a protective layer covering the source electrode, the drain electrode and a side of the active layer away from the gate insulating layer.

In some embodiments, the material of the active layer is an oxide semiconductor.

In some embodiments, the oxide semiconductor includes one of indium gallium zinc oxide, indium tin zinc oxide, indium gallium zinc tin oxide, Nd-doped indium oxide, and Sc-doped indium oxide or more.

In a second aspect, an embodiment of the present application provides a method for fabricating a TFT substrate, including:

providing a substrate, depositing a metal layer on the substrate, and patterning the metal layer to obtain a functional layer;

A gate electrode, a first light-shielding region, a second light-shielding region, a source contact region and a drain contact region are defined on the functional layer, wherein the first light-shielding region and the second light-shielding region are respectively located in the On both sides of the gate, the source contact region is arranged on a side of the first shielding region away from the gate, and the drain contact region is arranged at a side of the second shielding region away from the gate. side; performing oxidation treatment on the first light-shielding area and the second light-shielding area, so that the material of the first light-shielding area and the second light-shielding area is converted from a conductive metal material to a non-conductive metal oxide;

A gate insulating layer is provided on the side of the functional layer away from the substrate, and a source contact hole and a drain contact hole are formed on the gate insulating layer;

An active layer is provided on a side of the gate insulating layer away from the functional layer;

A source-drain layer is provided on a side of the active layer away from the gate insulating layer, the source-drain layer includes a source electrode and a drain electrode, and the source electrode is connected to the source electrode through the source electrode contact hole The electrode contact region is electrically connected, and the drain electrode is electrically connected to the drain contact region through the drain contact hole.

In some embodiments, the method for fabricating the TFT substrate further includes: forming a protective layer on a side of the source electrode, the drain electrode and the active layer away from the gate insulating layer, the protective layer covering the source electrode, the drain electrode and the active layer.

The TFT substrate provided by the embodiment of the present application includes a gate electrode, a first light-shielding region, a second light-shielding region, a source contact region and a drain contact region by arranging a functional layer, and the source electrode is arranged to pass through the source electrode on the gate insulating layer. The contact hole is electrically connected to the source contact area, and the drain is electrically connected to the drain contact area through the drain contact hole on the gate insulating layer, so that the side of the active layer is shielded by the source and drain, and the active layer The back of the active layer is blocked by the functional layer, that is to say, the side and back of the active layer are protected from light in an all-round way to prevent light from being irradiated to the active layer from the side and back, resulting in the generation of photogenerated carriers in the active layer. Illumination stability of TFT devices.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a schematic structural diagram of a TFT substrate provided by an embodiment of the present application.

FIG. 2 is a flowchart of a method for fabricating a TFT substrate according to an embodiment of the present application.

FIG. 3 is a schematic diagram of step S100 of a method for fabricating a TFT substrate provided by an embodiment of the present application.

FIG. 4 is a schematic diagram of step S200 of the method for fabricating a TFT substrate according to an embodiment of the present application.

FIG. 5 is a schematic diagram of step S300 of a method for fabricating a TFT substrate provided by an embodiment of the present application.

FIG. 6 is a schematic diagram of step S400 of a method for fabricating a TFT substrate provided by an embodiment of the present application.

FIG. 7 is a schematic diagram of step S500 of a method for fabricating a TFT substrate provided by an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of this application.

Please refer to FIG. 1 . FIG. 1 is a schematic structural diagram of a TFT substrate provided by an embodiment of the present application. An embodiment of the present application provides a TFT substrate 100 including a substrate 10 , a functional layer 20 , a gate insulating layer 30 , and an active layer 40 and the source and drain layers 50 .

The functional layer 20 is disposed on one side of the substrate 10 , and the functional layer 20 includes a gate 21 , a first light-shielding region 22 , a second light-shielding region 23 , a source contact region 24 and a drain contact region 25 , wherein the first light-shielding region 22 and the second light-shielding region 23 are respectively located on both sides of the gate 21, the source contact region 24 is provided on the side of the first light-shielding region 22 away from the gate 21, and the drain contact region 25 is provided in the second light-shielding region 23 away from the gate On one side of the electrode 21 , the gate electrode 21 , the source contact region 24 and the drain contact region 25 are all conductive materials, and the first light shielding region 22 and the second light shielding region 23 are all insulating materials.

The gate insulating layer 30 is disposed on the side of the functional layer 20 away from the substrate 10 , and the gate insulating layer 30 is provided with a source contact hole 31 and a drain contact hole 32 .

The active layer 40 is disposed on the side of the gate insulating layer 30 away from the functional layer 20 .

The source and drain layers 50 are disposed on the side of the active layer 40 away from the gate insulating layer 30 . The source and drain layers 50 include a source electrode 51 and a drain electrode 52 , and the source electrode 51 is connected to the source electrode contact region 24 through the source electrode contact hole 31 . Electrically connected, the drain 52 is electrically connected to the drain contact region 25 through the drain contact hole 32 .

It can be understood that the TFT substrate 100 provided by the embodiment of the present application includes a gate electrode 21 , a first light shielding region 22 , a second light shielding region 23 , a source contact region 24 and a drain contact region 25 by setting the functional layer 20 , and The source electrode 51 is arranged to be electrically connected to the source contact region 24 through the source contact hole 31 on the gate insulating layer 30 , and the drain electrode 52 is electrically connected to the drain contact region 25 through the drain contact hole 32 on the gate insulating layer 30 . so that the side of the active layer 40 is blocked by the source electrode 51 and the drain electrode 52, and the back side of the active layer 40 is blocked by the functional layer 20, that is to say, the side and back side of the active layer 40 are all-round. The shading protection can prevent light from being irradiated to the active layer 40 from the side and back surface, resulting in the generation of photo-generated carriers in the active layer 40 , which improves the illumination stability of the TFT device.

In the prior art, the active layer 40 widely used in oxide TFTs with a BCE structure is IGZO. IGZO conducts electricity mainly through oxygen vacancies generated by defect states. (O) will be released, so the TFT using IGZO as the active layer 40 is more sensitive to light, and photogenerated carriers are easily generated under light, which is not conducive to the light stability of the TFT device. However, in the present application, the light stability of the TFT device can be significantly improved by comprehensively shielding the side and back of the active layer 40 from light.

Exemplarily, the material of the gate electrode 21 , the material of the source contact region 24 and the material of the drain contact region 25 are all metals, and the materials of the first light shielding region 22 and the material of the second light shielding region 23 are both metal oxides.

Exemplarily, the material of the gate electrode 21 , the material of the source contact region 24 and the material of the drain contact region 25 are all the first metal, and the material of the first light-shielding region 22 and the material of the second light-shielding region 23 are all the first metal. Metal oxides. Illustratively, the first metal includes one or more of molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti). In the embodiments of the present application, multiple refers to two or more, such as three, four, five, and the like.

Please refer to FIG. 1 , the TFT substrate 100 may further include a protective layer 60 covering the source electrode 51 , the drain electrode 52 and the side of the active layer 40 away from the gate insulating layer 30 .

Exemplarily, the material of the protective layer 60 may include one or more of silicon oxide (SiOx) and silicon nitride (SiNx).

Exemplarily, the material of the active layer 40 may be an oxide semiconductor, such as indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), indium gallium zinc tin oxide (IGZTO), Nd-doped oxide Indium oxide (NdInOx), Sc-doped indium oxide (ScInOx), etc.

Please refer to FIG. 1 , the source electrode 51 and the drain electrode 52 are respectively overlapped on both sides of the active layer 40 , that is, the source electrode 51 and the drain electrode 52 are both electrically connected to the active layer 40 .

Exemplarily, the TFT substrate 100 may further include a flat layer, a common electrode, an insulating layer, and a pixel electrode sequentially stacked on the protective layer 60, wherein the protective layer 60, the flat layer, and the insulating layer are provided with overlapping holes, so that the The pixel electrode is electrically connected to the source electrode 51 or the drain electrode 52 through the tap hole; for example, the material of the flat layer may include soluble polytetrafluoroethylene (PFA), and the material of the common electrode and the pixel electrode may both be indium tin oxide (ITO), the material of the insulating layer may be silicon nitride (SiN _x ).

Please refer to FIG. 2 , which is a flowchart of a method for fabricating a TFT substrate according to an embodiment of the present application. An embodiment of the present application provides a method for fabricating a TFT substrate, and the fabrication method can fabricate the TFT substrate 100 in any of the above embodiments. The fabrication method includes:

S100 , referring to FIG. 3 , a substrate 10 is provided, a metal layer is deposited on the substrate 10 , and the metal layer is patterned to obtain a functional layer 20 .

Illustratively, the substrate 10 is a glass substrate.

Exemplarily, the material of the metal layer may include one or more of molybdenum (Mo), aluminum (Al), copper (Cu), and titanium (Ti).

S200 , please refer to FIG. 4 , a gate electrode 21 , a first light-shielding region 22 , a second light-shielding region 23 , a source contact region 24 and a drain contact region 25 are defined on the functional layer 20 , wherein the first light-shielding region 22 and the drain contact region 25 are defined. The second light-shielding regions 23 are respectively located on both sides of the gate 21 , the source contact region 24 is disposed on the side of the first light-shielding region 22 away from the gate 21 , and the drain contact region 25 is disposed in the second light-shielding region 23 away from the gate 21 . The first shading area 22 and the second shading area 23 are oxidized, so that the material of the first shading area 22 and the second shading area 23 is converted from a conductive metal material to a non-conductive metal oxide.

S300 , please refer to FIG. 5 , a gate insulating layer 30 is provided on the side of the functional layer 20 away from the substrate 10 , and a source contact hole 31 and a drain contact hole 32 are formed on the gate insulating layer 30 .

Exemplarily, the gate insulating layer 30 may be prepared by chemical vapor deposition (CVD), and the gate insulating layer 30 may be a silicon oxide (SiO _x ) layer or a silicon nitride (SiN _x ) layer, or an oxide layer. A stacked structure of a silicon (SiO _x ) layer and a silicon nitride (SiN _x ) layer.

S400 , please refer to FIG. 6 , the active layer 40 is disposed on the side of the gate insulating layer 30 away from the functional layer 20 .

Exemplarily, the active layer 40 may be deposited by physical vapor deposition (PVD), and the active layer 40 may be annealed. Exemplarily, the material of the active layer 40 may be an oxide semiconductor, such as indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), indium gallium zinc tin oxide (IGZTO), Nd-doped oxide Indium oxide (NdInO _x ), Sc-doped indium oxide (ScInO _x ), and the like.

S500 , please refer to FIG. 7 , a source-drain layer 50 is provided on the side of the active layer 40 away from the gate insulating layer 30 , the source-drain layer 50 includes a source electrode 51 and a drain electrode 52 , and the source electrode 51 passes through the source contact hole 31 is electrically connected to the source contact region 24 , and the drain 52 is electrically connected to the drain contact region 25 through the drain contact hole 32 .

Exemplarily, the material of the source and drain layers 50 may include one or more of molybdenum (Mo), aluminum (Al), copper (Cu), and titanium (Ti).

After S500, the manufacturing method of the TFT substrate provided by the embodiment of the present application may further include:

S600 , referring to FIG. 1 , a protective layer 60 is formed on the side of the source electrode 51 , the drain electrode 52 and the active layer 40 away from the gate insulating layer 30 , and the protective layer 60 covers the source electrode 51 , the drain electrode 52 and the active layer 40 .

Exemplarily, after S600, the manufacturing method of the TFT substrate provided in the embodiment of the present application may further include:

S700, a flat layer, a common electrode, and an insulating layer are sequentially stacked on the protective layer 60, and overlapping holes are provided on the protective layer 60, the flat layer, and the insulating layer;

S800 , a pixel electrode is arranged on the insulating layer on a side away from the common electrode, so that the pixel electrode is electrically connected to the source electrode 51 or the drain electrode 52 through a lap hole.

Exemplarily, the material of the flat layer may include soluble polytetrafluoroethylene (PFA), the material of the common electrode and the pixel electrode may be indium tin oxide (ITO), and the material of the insulating layer may be silicon nitride (SiN _x ).

The TFT substrate and the fabrication method thereof provided by the embodiments of the present application are described in detail above. The principles and implementations of the present application are described herein by using specific examples, and the descriptions of the above embodiments are only used to help the understanding of the present application. At the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific embodiments and application scope. To sum up, the content of this specification should not be construed as a limitation to the present application.

Claims (10)

1. A TFT substrate, comprising:

a substrate;

the functional layer is arranged on one side of the substrate and comprises a grid electrode, a first shading area, a second shading area, a source electrode contact area and a drain electrode contact area, wherein the first shading area and the second shading area are respectively positioned on two sides of the grid electrode, the source electrode contact area is arranged on one side, far away from the grid electrode, of the first shading area, the drain electrode contact area is arranged on one side, far away from the grid electrode, of the second shading area, the grid electrode, the source electrode contact area and the drain electrode contact area are all made of conducting materials, and the first shading area and the second shading area are all made of insulating materials;

the grid insulating layer is arranged on one side, far away from the substrate, of the functional layer, and a source contact hole and a drain contact hole are formed in the grid insulating layer;

the active layer is arranged on one side, far away from the functional layer, of the gate insulating layer;

the source drain layer is arranged on one side, far away from the grid insulating layer, of the active layer and comprises a source electrode and a drain electrode, the source electrode is electrically connected with the source electrode contact area through the source electrode contact hole, and the drain electrode is electrically connected with the drain electrode contact area through the drain electrode contact hole.

2. The TFT substrate of claim 1, wherein the gate electrode, the source contact region, and the drain contact region are all made of metal, and the first light-shielding region and the second light-shielding region are all made of metal oxide.

3. The TFT substrate of claim 2, wherein the gate electrode, the source contact region, and the drain contact region are all made of a first metal, and the first light-shielding region and the second light-shielding region are all made of an oxide of the first metal.

4. The TFT substrate of claim 3, wherein the first metal comprises one or more of molybdenum, aluminum, copper, and titanium.

5. The TFT substrate of claim 1, further comprising a protective layer covering the source electrode, the drain electrode, and a side of the active layer facing away from the gate insulating layer.

6. The TFT substrate according to claim 1, wherein a material of the active layer is an oxide semiconductor.

7. The TFT substrate of claim 6, wherein the oxide semiconductor comprises one or more of indium gallium zinc oxide, indium tin zinc oxide, indium gallium zinc tin oxide, Nd doped indium oxide, Sc doped indium oxide.

8. A method for manufacturing a TFT substrate is characterized by comprising the following steps:

providing a substrate, depositing a metal layer on the substrate, and carrying out graphical processing on the metal layer to obtain a functional layer;

defining a grid electrode, a first shading area, a second shading area, a source electrode contact area and a drain electrode contact area on the functional layer, wherein the first shading area and the second shading area are respectively positioned at two sides of the grid electrode, the source electrode contact area is arranged at one side of the first shading area far away from the grid electrode, and the drain electrode contact area is arranged at one side of the second shading area far away from the grid electrode; carrying out oxidation treatment on the first light-shielding area and the second light-shielding area, so that materials of the first light-shielding area and the second light-shielding area are converted into non-conductive metal oxides from conductive metal materials;

arranging a grid electrode insulating layer on one side of the functional layer far away from the substrate, and forming a source electrode contact hole and a drain electrode contact hole on the grid electrode insulating layer;

an active layer is arranged on one side, far away from the functional layer, of the gate insulating layer;

and arranging a source drain layer on one side of the active layer, which is far away from the gate insulating layer, wherein the source drain layer comprises a source electrode and a drain electrode, the source electrode is electrically connected with the source electrode contact area through the source electrode contact hole, and the drain electrode is electrically connected with the drain electrode contact area through the drain electrode contact hole.

9. The method of claim 8, wherein the metal layer comprises one or more of molybdenum, aluminum, copper, and titanium.

10. The method of manufacturing a TFT substrate as claimed in claim 8, further comprising: and forming a protective layer on the source electrode, the drain electrode and one side of the active layer, which is far away from the gate insulating layer, wherein the protective layer covers the source electrode, the drain electrode and the active layer.

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