CN112820845B

CN112820845B - Anode structure for improving OLED cathode fracture and preparation method thereof

Info

Publication number: CN112820845B
Application number: CN202110249976.2A
Authority: CN
Inventors: 乔程
Original assignee: Semiconductor Integrated Display Technology Co Ltd
Current assignee: Semiconductor Integrated Display Technology Co Ltd
Priority date: 2021-03-08
Filing date: 2021-03-08
Publication date: 2023-03-10
Anticipated expiration: 2041-03-08
Also published as: CN112820845A

Abstract

The invention provides an OLED anode structure for improving crosstalk and a preparation method thereof, the problem that PDL subjected to anode etching is lapped on the surface of an anode in an angle and the OLED cathode is easy to break is fully considered, and the cathode breakage of the OLED is improved by secondary deposition of a conducting layer.

Description

Anode structure for improving OLED cathode fracture and preparation method thereof

Technical Field

The invention belongs to the field of OLED (organic light emitting diode) anode structures, and particularly relates to an anode structure for improving OLED cathode fracture and a preparation method thereof.

Background

In the small-size high-resolution OLED in the industry at present, the angle after anode deposition is etched can be controlled, but after anode etching, a PDL film layer is deposited on an anode in a CVD mode, the PDL angle overlapped on the anode is large, and due to the fact that CD is small, the overlap angle can not be reduced basically through debugging, and therefore the cathode of the OLED film layer is broken seriously, and a pixel dark spot is caused. Therefore, it is difficult to improve the angle of the PDL overlapping the anode.

Disclosure of Invention

The invention aims to provide an anode structure for improving OLED cathode fracture and a preparation method thereof, the invention fully considers the problem that PDL subjected to anode etching is lapped on the surface of an anode at an angle and the OLED cathode is easy to fracture, and the conductive layer is etched through secondary deposition so as to improve the OLED cathode fracture.

The invention provides a preparation method of an anode structure for improving OLED cathode fracture, which comprises the following steps:

1) Depositing an anode structure on the surface of the substrate;

2) Etching by a dry method to form an anode pattern;

3) Depositing SiN;

4) Performing yellow light photoetching;

5) Depositing a conductive layer;

6) And (4) performing yellow lithography complementary to the yellow lithography in the step 4).

The substrate in the step 1) is a Si-based IC substrate which is a commercially available product produced by an IC factory;

in the step 1), depositing an anode structure of different metal laminations on the surface of a substrate Si base; preferably, a Ti layer is deposited to a thickness

(ii) a Depositing Al layer to a thickness

(ii) a Depositing TiN layer to a thickness

(ii) a Finally depositing an ITO layer to a thickness

(ii) a By adopting the lamination and the thickness, the anode structure is optimal and the performance is best.

Etching by the dry method in the step 2) to form an anode pattern, wherein the used dry etching machine is NAURA GSE C200, and the specific etching method comprises the following steps: sequentially performing gluing, exposure and development on the anode structure to form an anode pattern; ICP power required for etching is 400W, bias power Bias is 150W, and gas Cl used ₂ Is 15sccm, BCl ₃ At a flow rate of 20sccm, SF ₆ Etch 49s at 5sccm, at which point the etch is performed

The thickness of the anode structure is 12-16nm, and the substrate at the channel is over-etched, so that the metal anode structure can be completely disconnected;

the specific process for depositing SiN in the step 3) comprises the following steps: a 120-130nm SiN layer was deposited using AMAT PECVD at 500W SiH ₄ Flow rate 80sccm, NH ₃ Is 150sccm, N ₂ Chosen at 200sccm, deposited 72-76s, siN over the anode pixels (anode structure);

the step 4) is specifically as follows: etching SiN by yellow light photoetching to expose PDL pattern, selecting ICP power of 200-250W and eccentric power of 18-25W, CF ₄ Is set to 10-15sccm ₂ Setting the etching time to be 40-80s and 10-15sccm, wherein the SiN PDL on the anode structure is completely etched and slightly over-etched to ensure that the SiN is completely etched, and the method belongs to the conventional technology in the field; after etching, partial lapping of SiN on the surface of the anode structure is carried out;

the step 5) is specifically as follows: the deposition of the conducting layer refers to the deposition of an Al layer, an Ag layer or an anode structure completely identical to that in the step 1);

the thickness of the conducting layer is 100-130nm; after PDL patterns are exposed by filling, the height difference of SiN at the lapping position of the surface of the anode structure solves the problem of fracture caused by large PDL angle lapped on the anode; breakage can be reduced or even avoided. And the deposited film layer with high reflectivity does not influence the product performance.

The step 6) is specifically as follows: and (4) performing yellow light photoetching complementary to the yellow light photoetching in the step 4), etching away the redundant conducting layer, and only keeping the conducting layer which fills and levels the thickness difference between the anode structure and the SiN film layer.

Step 6) the yellow light process specifically comprises the following steps:

coating glue, exposing, developing, etching with ICP power of 400W, bias power of 150-180W, cl used in gas ₂ Is 15-20sccm, BCl ₃ Is 20-25sccm, SF ₆ The etching time is selected to be 46s for 5-10sccm, the channel is just slightly over-etched at the time, the over-etched channel is SiN 8-12nm, the height of the leaked PDL is basically the same as that of the conductive layer after re-deposition, and the cathode breakage can be improved;

further, after the step 6), the method also comprises a step 7) of removing the photoresist, cleaning and baking;

step 7) is followed by step 8) of evaporation, specifically: sequentially depositing an HIL, an HTL, an EML, an ETL, an EIL and a cathode structure;

step 8) is followed by step 9) of packaging, wherein the packaging is sequentially packaging an ATO layer of 40nm, a SiN layer of 1000nm and an ATO layer of 40nm;

step 10) making a CF structure after packaging; the CF structure is: the structure is OC1, R, G, B, OC in sequence;

and finally, 11) performing yellow light, glue coating, exposure, development and etching on the insulator subjected to channel etching, removing the glue after etching, and lightening the insulator through MIT

The anode structure for improving the OLED cathode fracture is prepared by the method.

The invention can improve the cathode fracture of the follow-up OLED by secondarily depositing the conducting layer structure, and the mode also improves the crosstalk among pixels.

Drawings

FIG. 1 is a schematic view of the structure of the anode pattern etched in step 3) of example 1;

FIG. 2 is a schematic structural view of the SiN deposition in step 4) of example 1;

FIG. 3 is a schematic view of the structure of example 1 after step 5) of PDL yellow light process;

FIG. 4 is a schematic structural view of the conductive layer deposited in step 6) of embodiment 1;

FIG. 5 is a schematic structural view of step 7) of example 1 after complementary yellow light etching;

in the figure, 1, a substrate, 2, an anode structure, 3, a SiN layer, 4 and a conductive layer.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The test materials and reagents used in the following examples, etc., are commercially available unless otherwise specified.

The specific techniques or conditions not specified in the examples can be performed according to the techniques or conditions described in the literature in the field or according to the product specification.

Example 1

The preparation method of the anode structure for improving OLED cathode fracture specifically comprises the following steps:

1) Obtaining a Si-based IC substrate, which is a substitute for IC factories;

2) Depositing an anode structure of different metal laminations on the surface of a Si-based substrate, and depositing a Ti layer with the thickness

(ii) a Depositing Al layer to a thickness

(ii) a Depositing TiN layer to a thickness

(ii) a Finally depositing an ITO layer to a thickness

Sequentially gluing, exposing and developing the anode structure to form an anode pattern;

3) After the well-made anode photoetching, etching an anode pattern by dry etching, wherein the used dry etching machine is NAURA GSE C200, the ICP Power required by etching is 400W, the Bias Power Bias Power is 150W, and Cl used by gas ₂ Is 15sccm, BCl ₃ At a flow rate of 20sccm, SF ₆ Etch 49s at 5sccm, etch 1070A anode with 15nm SiO in the channel ₂ Over-etching; the structure is as shown in figure 1;

4) After etching, 120nm SiN is deposited on the anode by AMAT PECVD, edge covering technology is adopted, power is 500W, siH is deposited, and ₄ flow rate 80sccm, NH ₃ Is 150sccm, N ₂ Selecting 200sccm, depositing 75s, and depositing 120nm SiN partially covering the anode pixel; the structure is as shown in FIG. 2;

5) Etching PDL on NAURA by PDL yellow light wafer to make PDL leak out, the etching process selects ICP 200W, bias Power is 18W, CF ₄ Set to 10sccm, O ₂ Setting the etching time to be 40s at 10sccm, completely etching the SiN PDL on the anode pixel at the time, slightly over-etching, and partially overlapping the SiN on the surface of the anode structure after etching; the structure is shown in figure 3;

6) Then depositing a conducting layer on the wafer, wherein the thickness is 120nm; the structure is as shown in FIG. 4;

7) Then, yellow light which is opposite to the PDL yellow light process in the step 5) is made on the well-made structure, and the yellow light is coatedGluing, exposing and developing; etching the conductive layer with ICP power of 400W and Bias power of 150W, and Cl gas ₂ Is 15sccm, BCl ₃ At a flow rate of 20sccm, SF ₆ The etching time is selected to be 46s for 5sccm, slight over-etching is just performed on the channel at the time, the channel SiN is over-etched by 10nm, the height of the leaked PDL is basically the same as that of the conducting layer, and cathode breakage can be improved; the structure is as shown in FIG. 5;

8) Removing photoresist, cleaning and baking after etching until evaporation;

9) Evaporation is used as an evaporation structure, and an HIL, an HTL, an EML, an ETL, an EIL and a cathode structure are sequentially deposited;

10 Then making a normal packaging structure, sequentially ATO40nm, siN 1000nm and ATO40nm;

11 Preparing CF structure on the wafer, and sequentially preparing OC1 and R, G, B, OC structures;

12 Making pad open yellow light, gluing, exposing, developing, etching, removing glue after etching, lightening through MIT, and remarkably reducing the cathode fracture of OLED.

Claims

1. The preparation method of the anode structure for improving OLED cathode fracture is characterized by comprising the following steps:

1) Depositing an anode structure on the surface of the substrate;

2) Etching by a dry method to form an anode pattern;

3) Depositing SiN;

4) Performing yellow light photoetching: etching the SiN by adopting a yellow light photoetching process to expose PDL patterns; after etching, partial lapping of SiN on the surface of the anode pattern is carried out;

5) Depositing a conductive layer;

6) Performing yellow light photoetching complementary to the yellow light photoetching in the step 4);

the step 5) is specifically as follows: the deposition of the conducting layer refers to the deposition of an Al layer, an Ag layer or a material which has the same structure as the anode in the step 1);

the step 6) is specifically as follows: and (4) performing yellow light photoetching complementary to the yellow light photoetching in the step 4), etching away the redundant conducting layer, and only keeping the conducting layer which fills and levels the thickness difference between the anode pattern and the SiN film layer.

2. The method according to claim 1, wherein in step 1), an anode structure of a stack of different metals is deposited on the Si-based surface of the substrate; depositing a Ti layer with the thickness of 100A; depositing an Al layer with the thickness of 800A; depositing a TiN layer with the thickness of 20 ANG; finally an ITO layer is deposited with a thickness of 150 a.

3. The preparation method according to claim 1 or 2, wherein the anode pattern is etched by the dry etching in the step 2), and the specific etching method comprises: sequentially performing gluing, exposure and development on the anode structure to form an anode pattern; ICP power required for etching is 400W, bias power Bias is 150W, and gas Cl used ₂ Is 15sccm, BCl ₃ At a flow rate of 20sccm, SF ₆ Etch 49s at 5sccm, at which time the anode structure thickness of 1070a is etched, with a substrate over-etch at the channel having a thickness of 12-16 nm.

4. The method according to claim 1 or 2, wherein the specific process for depositing SiN in step 3) is as follows: the deposition power was 500W, siH ₄ Flow rate 80sccm, NH ₃ Is 150sccm, N ₂ A layer of SiN of 120-130nm is deposited for 72-76s, chosen at 200 sccm.

5. The preparation method according to claim 1 or 2, wherein step 4) is specifically: the step 4) is specifically as follows: etching SiN by yellow light photoetching to expose PDL pattern, selecting ICP power of 200-250W and eccentric power of 18-25W, CF ₄ Is set to 10-15sccm ₂ The concentration is set to 10-15sccm, and the etching time is set to 40-80s.

6. The method according to claim 1, wherein the conductive layer of step 5) has a thickness of 100 to 130nm.

7. The preparation method according to claim 1 or 2, wherein the step 6) yellow light process is specifically:

coating glue, exposing, developing, etching with ICP power of 400W, bias power of 150-180W, cl used in gas ₂ Is 15-20sccm, BCl ₃ Is 20-25sccm, SF ₆ The etching time is selected to be 46s for 5-10sccm, the channel is slightly over-etched, and the over-etched channel is SiN 8-12nm.

8. An anode structure for improving OLED cathode rupture prepared by the method of any one of claims 1-7.