Array substrate and manufacturing method thereof, display panel and display device

Abstract

The present invention provides an array substrate and a manufacturing method thereof, a display panel and a display device. The manufacturing method of an array substrate in the present invention comprises: forming light-shielding layers on the base substrate through a patterning process by using a light-shielding layer-doping multiplexing mask plate; and performing doping of CMOS transistors by using the light-shielding layer-doping multiplexing mask plate. In the invention, two mask plates used in manufacturing the light-shielding layer and the doping process in the prior art are replaced with one light-shielding layer-doping multiplexing mask plate, therefore the number of the mask plates during manufacturing is reduced and the cost is decreased. Meanwhile, providing of the light-shielding layer below the N type transistors in the driving region of the array substrate may prevent light-induced leakage current from being generated in the conductive region.

Claims

1. A manufacturing method of an array substrate comprising a step of forming light-shielding layers on a base substrate, and a step of forming first type transistors and second type transistors above the light shielding layers, wherein the step of forming light-shielding layers on a base substrate comprises: forming a pattern of the light-shielding layers on the base substrate through a patterning process by using a light-shielding layer-doping multiplexing mask plate, wherein the light-shielding layer-doping multiplexing mask plate has a shielding portion corresponding to a conductive region of an active layer of each of the first type transistors in a driving region on the base substrate, and a shielding portion corresponding to a conductive region of an active layer of each of the first type transistors in a display region on the base substrate, the light-shielding layers are formed in positions corresponding to the conductive regions of the active layers of the first type transistors in the driving region and positions corresponding to the conductive regions of the active layers of the first type transistors in the display region, the step of forming first type transistors and second type transistors above the light-shielding layers comprises: performing a first type doping on active layers of the first type transistors and the second type transistors; and performing a second type doping on the second type transistors by shielding the conductive regions of the active layers of the first type transistors using the light-shielding layer-doping multiplexing mask plate.

2. The manufacturing method of an array substrate of claim 1, wherein performing a first type doping on active layers of the first type transistors and the second type transistors comprises: doping N type atoms into the active layers of the first type transistors and the second type transistors to form N type transistors; and doping P type atoms into the active layers of the second type transistors to form P type transistors.

3. The manufacturing method of an array substrate of claim 1, wherein performing a first type doping on active layers of the first type transistors and the second type transistors comprises: doping P type atoms into the active layers of the first type transistors and the second type transistors to form P type transistors; and doping N type atoms into the active layers of the second type transistors to form N type transistors.

4. The manufacturing method of an array substrate of claim 1, wherein the step of forming an active layer comprises following steps: depositing an amorphous silicon thin film by a low pressure chemical vapor deposition method, wherein the amorphous silicon film is crystallized into a polycrystalline silicon film as the active layer at a low temperature; or directly depositing a polycrystalline silicon film as the active layer by a low pressure chemical vapor deposition method.

5. The manufacturing method of an array substrate of claim 2, wherein the step of forming an active layer comprises following steps: depositing an amorphous silicon thin film by a low pressure chemical vapor deposition method, wherein the amorphous silicon film is crystallized into a polycrystalline silicon film as the active layer at a low temperature; or directly depositing a polycrystalline silicon film as the active layer by a low pressure chemical vapor deposition method.

6. The manufacturing method of an array substrate of claim 3, wherein the step of forming an active layer comprises following steps: depositing an amorphous silicon thin film by a low pressure chemical vapor deposition method, wherein the amorphous silicon film is crystallized into a polycrystalline silicon film as the active layer at a low temperature; or directly depositing a polycrystalline silicon film as the active layer by a low pressure chemical vapor deposition method.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a diagram illustrating a structure of an array substrate manufactured in the prior art and a using position of a light-shielding layer mask plate.

(2) FIG. 2 is a diagram illustrating a structure of an array substrate manufactured in the prior art and a using position of a doping mask plate.

(3) FIG. 3 is a diagram illustrating a structure of an array substrate manufactured in an embodiment 1 of the present invention and a using position of a light-shielding layer-doping multiplexing mask plate.

(4) FIG. 4 is a diagram illustrating usage of the light-shielding layer-doping multiplexing mask plate in the embodiment 1 of the present invention in manufacturing the light-shielding layer.

(5) FIG. 5 is a diagram illustrating an N type channel doping performed on the array substrate in the embodiment 1 of the present invention.

(6) FIG. 6 is a diagram illustrating a P type channel doping performed on the array substrate and usage of the light-shielding layer-doping multiplexing mask plate in the embodiment 1 of the present invention.

(7) wherein:

(8) 1base substrate; 2 light-shielding layer; 3buffer layer; 4channel region of N type transistor; 5light doping region of N type transistor; 6heavy doping region of N type transistor; 7heavy doping region of P type transistor; 8channel region of P type transistor; 9insulation layer; 10gate; 11gate insulation layer; 12source; 13drain; 14planarization layer; 15light-shielding layer mask plate; 16doping mask plate; 17light-shielding layer-doping multiplexing mask plate; 18active layer; and 19conductive region.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(9) In order to make persons skilled in the art better understand solutions of the present invention, the present invention will be further described in detail below in conjunction with the drawings and embodiments.

Embodiment 1

(10) As shown in FIG. 3 to FIG. 6, the present embodiment provides an array substrate and a manufacturing method thereof.

(11) As shown in FIG. 3, the present embodiment provides an array substrate, which comprises a base substrate 1, the base substrate 1 comprises a display region for displaying and a driving region in the periphery of the display region (in a display device, the driving region is shielded by a frame), wherein the driving region of the base substrate 1 is provided with first type transistors and second type transistors, and the display region of the base substrate 1 is provided with first type transistors, and wherein a light-shielding layer 2 is provided below the conductive region of the active layer of each of the first type transistors.

(12) Specifically, in the array substrate in FIG. 3, the first type transistors correspond to N type transistors, and the second type transistors correspond to P type transistors, of course, it is possible that, the first type transistors correspond to P type transistors and the second type transistors correspond to N type transistors. As shown in FIG. 3, the array substrate comprises: a base substrate 1; and a plurality of light-shielding layers 2 provided on the base substrate 1, wherein the light-shielding layers 2 are located below the conductive regions of the active layers of the N type transistors of the array substrate, and each of the N type transistors (including the N type transistors in the display region and the driving region) has the light-shielding layer 2, and wherein the conductive region includes a channel region 4 of the N type transistor and light doping regions 5 of the N type transistor.

(13) The light-shielding layers 2 are provided with a buffer layer 3 thereon, and N type transistors and P type transistors are provided on the buffer layer 3, as shown in FIG. 3, N type transistors are provided in the display region, and an N type transistor and a P type transistor are provided in the driving region. The active layer of the N type transistor sequentially includes a conductive region 19 and heavy doping regions 6 of the N type transistor from the center to two sides thereof, the conductive region 19 includes a channel region 4 of the N type transistor, and light doping regions 5 of the N type transistor, and the active layer of the P type transistor includes a channel region 8 of the P type transistor in the center and heavy doping regions 7 of the P type transistor at ends thereof.

(14) With respect to each of the N type transistor and the P type transistor, an insulation layer 9 is provided on the active layer, a gate 10 is provided on the insulation layer 9, a source 12 and a drain 13 are provided above the gate 10, the source 12 and the drain 13 are connected to the heavy doping regions at two ends respectively, and a planarization layer 14 is provided on the source 12 and the drain 13.

(15) As shown in FIG. 3, the light-shielding layer 2 covers the channel region 4 of the N type transistor and at least a part of the light doping region 5 of the N type transistor, in the present embodiment, each of the N type transistors (including the N type transistors in the display region and the driving region) is provided with a light-shielding layer 2, the light-shielding layer 2 below the N type transistor in the display region may reduce the leakage current, and improve the display quality of the display. When light (emitted from the backlight, for example) is not shielded by a light-shielding member (light-shielding glue tape), or light is irradiated to the conductive region of the active layer of the N type transistor in the driving region due to some other reasons, the light-shielding layer 2 may shield the above light so as to prevent the light-induced leakage current from being generated in the conductive region.

(16) It should be understood that, in special applications, the above N type transistors and P type transistors may be exchangeable, and in the present embodiment, although the N type transistors and P type transistors are made by low temperature polycrystalline silicon doping, in fact, complementary metal oxide semiconductor transistors (CMOS transistors) may also be used.

(17) The manufacturing method of the above array substrate, as shown in FIG. 4 to FIG. 6, comprises:

(18) S01, forming the light-shielding layers on the base substrate 1 through a patterning process by using a light-shielding layer-doping multiplexing mask plate 17.

(19) The patterning process in the present invention includes a part or all of photoresist application, mask, exposure, development, etching, photoresist peeling off and the like, and the present embodiment is explained by taking the positive photoresist as an example. The above patterning process belongs to the prior art and will not be repeated herein. The above light-shielding layers 2 may be made of various metal materials, such as chrome, gold, aluminum, copper and the like, which can shield light.

(20) As shown in FIG. 4 and FIG. 5, the light-shielding layers 2 are formed on the base substrate 1 through a patterning process by using a light-shielding layer-doping multiplexing mask plate 17. The light-shielding layer-doping multiplexing mask plate 17 includes a shielding portion corresponding to the conductive region of the active layer of the N type transistor in the driving region, so that, in this step, the conductive region of the active layer of each N type transistor is formed with a light-shielding layer 2 therebelow, that is, the light-shielding layer 2 is also formed at the conductive region of the active layer of each N type transistor in the driving region.

(21) In the prior art, since the conductive region of the active layer of the N type transistor in the driving region is usually not irradiated by light, no light-shielding layer 2 is provided thereat, however, apparently, there is no adverse effect if the light-shielding layer 2 is added there, and the light-shielding layer 2 may prevent the light-induced leakage current from being generated in the conductive region, and meanwhile, with the light-shielding layer-doping multiplexing mask plate 17, the number of mask plates to be used in sequential steps can be reduced, and the manufacturing cost of the array substrate can be decreased.

(22) A buffer layer 3 is formed on the light-shielding layers 2, and the process for forming the buffer layer 3 may be an existing process, and will not be repeated herein.

(23) S02, manufacturing the active layer.

(24) As shown in FIG. 5, by using silane gas as a material, an a-Si:H film is deposited through a low pressure chemical vapor deposition method at a temperature about 550, next, the film is melted at a high temperature more than 600 and then generates crystal nucleuses by lowering the temperature, the melt silicon continues to crystallize on the crystal nucleuses with the temperature's lowering so that the crystalline grains are enlarged, so that the film is converted into a polycrystalline silicon film, thus the active layer 18 is formed.

(25) The polycrystalline silicon film may also be formed by a direct method, that is, the silane gas is directly deposited on the base substrate 1, the deposition parameters are as follows: the pressure of the silane gas is 13.326.6 Pa, the deposition temperature is 580630 and the growth speed is 510 nm/min.

(26) It should be understood that, the low temperature polycrystalline silicon may also be prepared through other processes, for example, an excimer laser crystallization, a rapid thermal annealing method and the like, which will not be discussed herein.

(27) S03, performing N type doping on the active layer.

(28) As shown in FIG. 5, N type atoms are doped into the active layer 18, a threshold voltage of the active layer 18 may become a threshold voltage required by the N type transistor through thus doping, and then a pattern of the active layer 18 is formed by a patterning process. The N type doping refers to doping phosphorus atoms or antimony atoms into the active layer 18 using an existing diffusing method or ion implantation method.

(29) S04, performing P type doping on the active layer.

(30) Specifically, as shown in FIG. 6, the conductive regions 19 of the active layers of all of the N type transistors on the array substrate are shielded using the above light-shielding layer-doping multiplexing mask plate 17 (size of the light-shielding layer-doping multiplexing mask plate 17 matches with that of the conductive regions 19), P type doping is performed on the active layers, which are in corresponding regions, of the exposed P type transistors and the active layers, which are in corresponding regions, of the partially exposed N type transistors, wherein the P type doping refers to doping indium atoms or boron atoms into the active layers 18 using an existing diffusing method or ion implantation method. Since the light-shielding layer-doping multiplexing mask plate 17 shields the conductive regions 19 of all of the N type transistors, the P type doping may be performed on the non-shielded regions to form a threshold voltage required by the P type transistor, which is convenient to adjust. It can be seen that, the light-shielding layer-doping multiplexing mask plate 17 in the present embodiment can be used to not only manufacture the light-shielding layers 2, but also perform doping on the N type transistors, that is, a single mask plate may be used in two steps, so that the number of the mask plates is reduced by one, and the manufacturing cost is decreased.

(31) While parts of the active layers of the partially exposed N type transistors are doped to be of weak P type, they can be compensated through subsequent N type heavy doping.

(32) S05, with reference to FIG. 5, an N type heavy doping is performed on the active layers, wherein the N type heavy doping means using the above N type doping method and increasing the concentrations of the phosphorus atoms or antimony atoms doped into the active layers. Through the N type heavy doping, the active layers, which are doped to be of weak P type, of the N type transistors in the step S04 can be compensated for N type heavy doping, and finally, a channel region 4 of the N type transistor and light doping regions 5 of the N type transistor may be formed in each of the conductive regions of the active layers of the N type transistors; heavy doping regions 6 of the N type transistor are formed at ends of the active layer of each N type transistor; next, a channel region 8 and heavy doping regions 7 of the P type transistor at two ends of the channel region 8 are formed in the active layer of each P type transistor; and an insulation layer 9, gates 10, a gate insulation layer 11, sources 12, drains 13 and a planarization layer 14 are formed on the active layers.

(33) It should be understood that, in the above manufacturing method, except the common light-shielding layer-doping multiplexing mask plate 17 is used in step S01 and step S04, methods and materials used in other steps may be existing methods and materials.

(34) In the array substrate and the manufacturing method thereof, two mask plates used in manufacturing the light-shielding layer and the doping process in the prior art are replaced with one light-shielding layer-doping multiplexing mask plate, therefore the number of the mask plates during manufacturing is reduced and the cost is decreased. Meanwhile, providing the light-shielding layers below the N type transistors in the driving region of the array substrate may prevent light-induced leakage current from being generated in the conductive region.

Embodiment 2

(35) The present embodiment provides a display panel comprising the above array substrate.

(36) In manufacturing the display panel of the present invention, two mask plates used in manufacturing the light-shielding layer and the doping process in the prior art are replaced with one light-shielding layer-doping multiplexing mask plate, therefore the number of the mask plates during manufacturing is reduced and the cost is decreased. Meanwhile, providing of the light-shielding layer below the N type transistors in the driving region of the array substrate may prevent light leakage current from being generated in the conductive region.

Embodiment 3

(37) The present embodiment provides a display device comprising the above display panel.

(38) In manufacturing the display device of the present invention, two mask plates used in manufacturing the light-shielding layer and the doping process in the prior art are replaced with one light-shielding layer-doping multiplexing mask plate, therefore the number of the mask plates during manufacturing is reduced and the cost is decreased. Meanwhile, providing of the light-shielding layer below the N type transistor in the driving region of the array substrate may prevent light-induced leakage current from being generated in the conductive region.

(39) It should be noted that, FIG. 1 to FIG. 6 of the present invention only show the relative position relationship between the mask plates and the light-shielding layers and the active layers, which does not mean that the mask plates are used in the situation shown in the drawings, for example, the light-shielding layer-doping multiplexing mask plate 17 in FIG. 3 is used to form the light-shielding layers 2 on the base substrate 1 without any other structure thereon, rather than form the light-shielding layers 2 after other structures have been formed on the base substrate 1.

(40) It should be understood that, the above embodiments are only exemplary embodiments used to explain the principle of the present invention and the protection scope of the present invention is not limited thereto. The person skilled in the art can make various variations and modifications without departing from the spirit and scope of the present invention, and these variations and modifications should be considered to belong to the protection scope of the invention.