Tft structure, array substrate and display device

Abstract

The application relates to the field of semiconductors and discloses a TFT structure, an array substrate and a display device, wherein the TFT structure comprises a drain, a source, a gate and a channel, the channel comprises a drain channel area close to the drain side and a source channel area close to the source side, and the channel width of at least part of the drain channel area and the channel width of the source channel area are different. The TFT structure, the array substrate and the display device provided by the embodiment of the application have the advantage that the warping effect of the TFT transistor can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor, in particular to a TFT structure, array substrate and display device. BACKGROUND

[0002] With the development of flat panel display, high resolution and low power consumption panel is constantly being proposed. Low temperature poly-silicon (LTPS) has been paid attention in the industry due to its high electron mobility, and is regarded as an important material to realize low cost full color flat panel display. For flat panel display, low temperature poly-silicon material has the advantages of high resolution, fast reaction speed, high brightness, high aperture ratio, low power consumption, etc. Moreover, low temperature poly-silicon can be made at low temperature and can be used to make C-MOS (Complementary Metal Oxide Semiconductor) circuit, thus it is widely studied to achieve the demand of high resolution and low power consumption panel.

[0003] The organic light emitting diode display in prior art is usually driven by thin film transistor (TFT). When the TFT transistor works, there is a relatively large electric field near the channel and source, and thus there is a serious kink effect (buckling effect, as shown in curve O in FIG. 1). Figure 1 Figure 1 The voltage-current diagram of the source and the drain is shown in FIG. 2, in which the horizontal axis is the voltage of the source or the drain, and the vertical axis is the current of the source or the drain, i.e. after the voltage of the source and the voltage of the drain exceed a fixed value, the current of the source and the drain suddenly increases with the increase of the voltage of the source and the voltage of the drain. Therefore, when the TFT transistor works for a long time or is affected by strong light, the characteristics are more likely to deviate, resulting in display abnormality.

[0004] In order to reduce the buckling effect, the light doped drain (LDD) structure is usually used in prior art to reduce the strong electric field near the source of the TFT transistor. However, the LDD structure needs an additional ion implantation process, which increases the process complexity and also increases the implantation damage to the channel. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide a TFT structure, array substrate and display device, which can effectively reduce the buckling effect of the TFT transistor. ​

[0006] To solve the above technical problems, the embodiments of the present application provide a TFT structure, comprising a drain, a source, a gate and a channel, the channel comprising a drain channel region near the side of the drain and a source channel region near the side of the source, the channel width of at least part of the drain channel region being different from the channel width of the source channel region.

[0007] The embodiments of the present application also provide an array substrate, comprising a substrate and a TFT structure as described above disposed on the substrate.

[0008] The embodiments of the present application also provide a display device, comprising an array substrate as described above and a light-emitting display unit disposed on the array substrate.

[0009] Compared with the prior art, in the embodiments of the present application, at least part of the drain channel region is set to have a channel width different from the channel width of the source channel region, the path of the current changes according to the change of the channel width at the position where the channel width is different, while the path of the electric field does not change with the change of the channel width, so that the path of the current and the path of the electric field near the drain electrode are separated, the probability of the impact ionization occurring is reduced, and thus the warpage effect of the TFT transistor is reduced.

[0010] Preferably, the drain channel region comprises a side surface connected with the drain, and the side surface is provided with a recess or a protrusion. By providing the recess or the protrusion on the side surface, the channel width of part of the drain channel region and the channel width of the source channel region can be set to be different in a relatively simple manner, so that the preparation process is simplified and the preparation cost is saved.

[0011] Preferably, the drain channel region is a curved channel, the curved channel comprising a first connecting part connected with the drain, a channel bending part connected with the first connecting part, and a second connecting part connected with the channel bending part, the extension direction of the first connecting part being different from the extension direction of the second connecting part; when the recess is provided on the side surface, the recess is provided on the channel bending part; when the protrusion is provided on the side surface, the protrusion is provided on the channel bending part. By setting the drain channel region to be a curved channel and providing the recess or the protrusion on the channel bending part of the curved channel, the recess or the protrusion can change the flow direction of the current on the first connecting part and the second connecting part at the same time, so that the path of the current and the path of the electric field are separated to a greater extent, and thus the warpage effect of the TFT transistor is reduced to a greater extent.

[0012] Preferably, the channel comprises an upper surface close to the gate and a lower surface opposite to the upper surface, and a through hole penetrating the upper surface and the lower surface. By setting the through hole penetrating the upper surface and the lower surface on the channel, the width of the drain channel region is reduced, which can effectively reduce the rigidity of the channel and improve the bending resistance of the channel, so that the TFT structure can be better applied to the flexible screen, and the application range is expanded.

[0013] Preferably, the through hole is arranged on the drain channel region. By arranging the through hole on the drain channel region, the through hole can cause greater sound box to the current direction near the drain, thereby improving the effect of reducing the warping effect of the TFT transistor.

[0014] Preferably, the drain channel region is a curved channel, the curved channel comprises a first connecting part connected with the drain, a channel bending part connected with the first connecting part, and a second connecting part connected with the channel bending part, the extension direction of the first connecting part is different from the extension direction of the second connecting part; and the through hole is at least partially arranged on the channel bending part. By arranging the through hole on the channel bending part, the flow direction of the current on the first connecting part and the second connecting part can be changed at the same time, and the current path and the electric field path are separated to a greater extent, thereby reducing the warping effect of the TFT transistor to a greater extent.

[0015] Preferably, the through hole is a bending through hole, the bending through hole comprises a first extension part, a through hole bending part connected with the first extension part, and a second extension part connected with the through hole bending part; the first extension part is arranged on the first connecting part, the second extension part is arranged on the second connecting part, and the through hole bending part is arranged on the channel bending part.

[0016] Preferably, the extension direction of the first extension part is the same as the extension direction of the first connecting part, and the extension direction of the second extension part is the same as the extension direction of the second connecting part. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of the warping effect in the prior art;

[0018] Figure 2 is a structural schematic diagram of the TFT structure provided by the first embodiment of the present application;

[0019] Figure 3 is a structural schematic diagram of the TFT structure provided by another embodiment of the present application;

[0020] Figure 4 is a structural schematic diagram of the TFT structure provided by another embodiment of the present application;

[0021] Figure 5is a structural schematic diagram of a TFT structure provided by a second embodiment of the present application;

[0022] Figure 6 is a structural schematic diagram of a TFT structure provided by another embodiment of the present application;

[0023] Figure 7 is a sectional structural schematic diagram of a TFT structure provided by a third embodiment of the present application;

[0024] Figure 8 is a structural schematic diagram of a TFT structure provided by a third embodiment of the present application;

[0025] Figure 9 is a structural schematic diagram of a TFT structure provided by a fourth embodiment of the present application;

[0026] Figure 10 is a structural schematic diagram of an array substrate provided by a fifth embodiment of the present application;

[0027] Figure 11 is a structural schematic diagram of a display device provided by a sixth embodiment of the present application. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. However, those skilled in the art can understand that, in the embodiments of the present application, many technical details are presented to make the readers better understand the present application. However, the technical solutions claimed by the present application can be realized even without these technical details and based on various changes and modifications of the following embodiments.

[0029] A first embodiment of the present application relates to a TFT structure, and the specific structure is as shown in Figure 2 which includes a drain 10, a source 20, a channel 30 connecting the drain 10 and the source 20, and a gate 40 arranged on one side of the channel 30. The channel 30 includes a drain channel region 31 near the drain 10 side and a source channel region 32 near the source 20 side. Specifically, in the present embodiment, the drain 10 and the source 20 are arranged apart from each other and connected via the channel 30 in the middle, and there is a central axis (AA' line) between the drain 10 and the source 20. The channel 30 near the drain 10 side of the central axis AA' is the drain channel region 31, and the channel 30 near the source 20 side of the central axis AA' is the source channel region 32. At least part of the channel width of the drain channel region 31 and the channel width of the source channel region 32 are different. Figure 2 The so-called channel width is the width of the channel in the direction perpendicular to the extension direction of the channel, for example

[0030] The so-called channel width is the width of the channel in the direction perpendicular to the extension direction of the channel, for example Figure 2 The straight channel shown in FIG. 1 extends in the direction of Figure 2 In the X direction, the channel width at each point on the channel is Figure 2 For a curved channel, the channel width at each point is the width of the channel in the direction perpendicular to the extension direction at that point, for example Figure 4 As shown, the channel width at a point on the first connection portion 312 is the extension direction of the first connection portion 312 ( Figure 4 The vertical direction ( Figure 4 The width in the X direction.

[0031] Compared with the prior art, in this embodiment, the channel width of at least part of the drain channel region 31 is different from the channel width of the source channel region 32, such as Figure 2 As shown, the current path at different locations with different channel widths ( Figure 2 The solid arrow BB' in the figure will change according to the change of the channel width, and the path of the electric field ( Figure 2 The dotted arrow CC' in FIG does not change with the change of the channel width, so that the current path and the electric field path near the drain 10 are separated, reducing the probability of impact ionization, thereby reducing the warping effect of the TFT transistor.

[0032] Specifically, in this embodiment, if Figure 2 As shown, the drain channel region 31 includes an abutting surface 312 abutting against the drain 10 and a side surface 311 connected to the abutting surface 312, and a recess 50 is provided on the side surface 311. By providing the recess 50 on the side surface 311, it is relatively simple to set the channel width of the drain channel region 31 to be different from the channel width of the source channel region 32, thereby simplifying the preparation process and saving preparation costs. It is understandable that the aforementioned provision of the recess 50 on the side surface 311 is only a specific example of this embodiment and does not constitute a limitation. In other embodiments of the present invention, it may also be as follows Figure 3 The structure shown in which the protrusion 60 is set on the side surface 311 makes the channel width of part of the drain channel region 31 different from the channel width of the source channel region 32. The structure in which the protrusion 60 is set on the side surface 311 is also relatively simple to prepare, which can effectively reduce industrial difficulty and cost.

[0033] Preferably, in this embodiment, the protrusion 60 and the recess 50 are both arranged near the drain 10. The closer the protrusion 60 and the recess 50 are to the drain 10, the greater the impact on the current direction and electric field direction at the drain 10, and the better the effect of reducing the warping effect.

[0034] Preferably, in one embodiment of the present invention, Figure 4As shown, a plurality of protrusions 60 and / or recesses 50 can also be arranged on the side surface 311. The plurality of protrusions 60 and / or recesses 50 can be arranged on the same side of the side surface 311 or on different sides of the side surface 311, which can be flexibly arranged according to actual needs. Arranging a plurality of protrusions 60 and / or recesses 50 on the side surface 311 can have a greater impact on the direction of the current, thereby changing the direction of the current to a greater extent, making the direction of the current different from the direction of the electric field to a greater extent, and reducing the warpage effect better.

[0035] The second embodiment of the present application relates to a TFT structure. The second embodiment is substantially the same as the first embodiment, and the main difference is that in the second embodiment of the present application, as shown in Figure 5 The drain channel region 31 is a curved channel, which includes a first connecting part 312 connected with the drain 10, a channel turning part 313 connected with the first connecting part 312, and a second connecting part 314 connected with the channel turning part 313, wherein the extension direction of the first connecting part 312 is different from the extension direction of the second connecting part 314, and the recess 50 is arranged on the channel turning part 313.

[0036] The recess 50 is arranged on the side surface 311, and the recess 50 extends partially to the first connecting part 312 and partially to the second connecting part 314.

[0037] Compared with the prior art, in the TFT structure provided by the second embodiment of the present application, the drain channel region 31 is arranged as a curved channel, and the recess 50 is arranged on the channel turning part 313 of the curved channel, so that the recess 50 can change the flow direction of the current on the first connecting part 312 and the second connecting part 314 at the same time, and the path of the current and the path of the electric field are separated to a greater extent, thereby reducing the warpage effect of the TFT transistor to a greater extent.

[0038] It can be understood that the foregoing is only an example of arranging a recess 50 on the side surface, and in actual arrangement, a protrusion 60 can also be arranged on the channel turning part 313 as shown in Figure 6 Arranging a protrusion 60 on the channel turning part 313 can also achieve the effect of separating the path of the current and the path of the electric field to a greater extent, and thus can also reduce the warpage effect of the TFT transistor to a greater extent.

[0039] The third embodiment of the present application relates to a TFT structure. The third embodiment is substantially the same as the first embodiment, and the main difference is that in the third embodiment of the present application, as shown in Figure 7 , Figure 8As shown, the channel 30 includes an upper surface 33 close to the gate 40 and a lower surface 34 opposite to the upper surface 33; wherein the channel 30 is further provided with a through hole 70 penetrating the upper surface 33 and the lower surface 34.

[0040] Compared with the prior art, the third embodiment of the present application can effectively reduce the rigidity of the channel 30 and improve the bending resistance of the channel 30 while retaining the technical effects of the first embodiment, by reducing the width of the drain channel region 31 in the manner of providing the through hole 70 penetrating the upper surface 33 and the lower surface 34 on the channel 30, so that the TFT structure can be better applied to the flexible screen, thereby expanding the application range.

[0041] Preferably, in the present embodiment, the through hole 70 is provided on the drain channel region 31. By providing the through hole 70 on the drain channel region 31, the through hole 70 can have a greater impact on the current direction near the drain 10, thereby improving the effect of reducing the warpage effect of the TFT transistor.

[0042] The fourth embodiment of the present application relates to a TFT structure. The fourth embodiment is substantially the same as the third embodiment, and the main difference is that, in the fourth embodiment of the present application, as shown, Figure 9 the drain channel region 31 is a curved channel, the curved channel 31 includes a first connecting part 312 connected with the drain 10, a channel bending part 313 connected with the first connecting part 312, and a second connecting part 314 connected with the channel bending part 313, wherein the extension direction of the first connecting part 312 is different from the extension direction of the second connecting part 314, and the through hole 70 is provided on the channel bending part 313.

[0043] Compared with the prior art, the TFT structure provided by the fourth embodiment of the present application can change the current flow direction on the first connecting part 312 and the second connecting part 314 at the same time while retaining all the technical effects of the third embodiment, by providing the through hole 70 on the channel bending part 313, thereby more greatly separating the current path and the electric field path, and more greatly reducing the warpage effect of the TFT transistor.

[0044] Preferably, in the present embodiment, the through hole 70 is a bending through hole, the bending through hole 70 includes a first extension part 71, a through hole bending part 72 connecting the first extension part 71, and a second extension part 73 connected with the through hole bending part 72, the first extension part 71 is provided on the first connecting part 312, the second extension part 73 is provided on the second connecting part 314, and the through hole bending part 72 is provided on the channel bending part 313.

[0045] In the present embodiment, the extension direction of the first extension part 71 is the same as the extension direction of the first connecting part 312, and the extension direction of the second extension part 73 is the same as the extension direction of the second connecting part 314.

[0046] It can be understood that the foregoing is only an example of the application in the embodiment by changing the width of the drain channel region 31 so that the channel width of at least part of the drain channel region 31 is different from the channel width of the source channel region 32, and in actual application, it can also be by changing the channel width of the source channel region 32 so that the channel width of at least part of the drain channel region 31 is different from the channel width of the source channel region 32, for example, setting a structure such as a protrusion, a recess, and a perforation on the source channel region 32, which can be specifically referred to the foregoing description, and will not be repeated here.

[0047] The fifth embodiment of the present application relates to an array substrate, as shown in the accompanying drawings, comprising: a substrate 100 and a TFT structure 200 provided on the substrate 100, as provided in the foregoing embodiments. Figure 10

[0048] Compared with the prior art, the array substrate provided by the fifth embodiment of the present application is provided with the TFT structure 200 provided in the foregoing embodiments, so it also has the technical effects of the foregoing embodiments, which will not be repeated here.

[0049] The sixth embodiment of the present application relates to a display device, as shown in the accompanying drawings, comprising: an array substrate 300 provided in the foregoing embodiments and a light-emitting display unit 400 provided on the array substrate 300. Figure 11

[0050] Compared with the prior art, the display device provided by the sixth embodiment of the present application is provided with the array substrate 300 provided in the foregoing embodiments, so it also has the technical effects of the foregoing embodiments, which will not be repeated here.

[0051] It can be understood by those skilled in the art that the above embodiments are specific embodiments for implementing the present application, and in actual application, various changes can be made in form and details without departing from the spirit and scope of the present application.​​

Claims

1. A TFT structure, characterized in that: include: A drain, a source, a gate, and a channel, wherein the channel includes a drain channel region near the drain and a source channel region near the source, and the channel width of at least a portion of the drain channel region is different from the channel width of the source channel region; The drain channel region includes an abutting surface abutting the drain and a side surface connected to the abutting surface, wherein a depression or a protrusion is provided on the side surface; Alternatively, the channel includes an upper surface close to the gate, a lower surface opposite to the upper surface, and a through-hole penetrating the upper surface and the lower surface, wherein the through-hole is provided in the drain channel region.

2. The TFT structure according to claim 1, wherein: The drain channel region is a curved channel, comprising a first connecting portion connected to the drain, a channel bending portion connected to the first connecting portion, and a second connecting portion connected to the channel bending portion, wherein an extending direction of the first connecting portion is different from an extending direction of the second connecting portion; When the recess is provided on the side surface, the recess is provided on the channel bend; When the protrusion is provided on the side surface, the protrusion is provided on the channel bending portion.

3. The TFT structure according to claim 1, wherein: The through hole is provided in the drain channel region.

4. The TFT structure according to claim 3, wherein: The drain channel region is a curved channel, comprising a first connecting portion connected to the drain, a channel bending portion connected to the first connecting portion, and a second connecting portion connected to the channel bending portion, wherein an extending direction of the first connecting portion is different from an extending direction of the second connecting portion; The through hole is at least partially arranged on the channel bending portion.

5. The TFT structure according to claim 4, wherein: The perforation is a bent perforation, and the bent perforation includes a first extension portion, a perforation bent portion connected to the first extension portion, and a second extension portion connected to the perforation bent portion; The first extending portion is arranged on the first connecting portion, the second extending portion is arranged on the second connecting portion, and the perforated bending portion is arranged on the channel turning portion.

6. The TFT structure according to claim 5, wherein: An extending direction of the first extending portion is the same as an extending direction of the first connecting portion, and an extending direction of the second extending portion is the same as an extending direction of the second connecting portion.

7. An array substrate, characterized in that: The invention comprises: a substrate and a TFT structure according to any one of claims 1 to 6, which is arranged on the substrate.

8. A display device, characterized in that: include: The array substrate according to claim 7 and the light-emitting display unit arranged on the array substrate.

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