Unlock instant, AI-driven research and patent intelligence for your innovation.

A method for preparing high-precision silver electrodes by self-limiting wet etching

A wet etching and self-limiting technology, which is applied in the manufacture of circuits, electrical components, cables/conductors, etc., can solve the problems of long etching time, low reflectivity of aluminum, and poor conductivity of aluminum, so as to reduce CDloss and high Reflective properties, the effect of a simple method

Active Publication Date: 2022-02-01
ANHUI SEMICON INTEGRATED DISPLAY TECH CO LTD
View PDF0 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Because the reflectivity of Ag is as high as 98%, it is widely used in top-emitting organic light-emitting diode devices, but because silver (Ag) can only use wet etching process, CD loss is large (>1μm), so the Ag electrode structure cannot be applied To ultra-high resolution displays such as silicon-based microscopes and digital micromirror devices (DMDs)
At present, ultra-high resolution displays mainly use aluminum (Al) electrodes, but the reflectivity of aluminum is low (about 91%), and Al is easy to cause hillocks and pits due to stress concentration and release during the annealing process, and the surface flatness Poor; Aluminum has poor conductivity and severe electromigration, especially the resistance becomes larger and larger as the pixel size becomes smaller, electromigration becomes more and more serious, and electrical reliability deteriorates
Ag does not have the problem of poor surface flatness caused by stress changes, and Ag has good conductivity, so the development of high-precision, high reflectivity, and high-conductivity silver electrodes is very meaningful for ultra-high resolution displays.
[0003] At present, the Ag electrode mainly uses the ITO / Ag / ITO structure, and the nitrification mixed acid (nitric acid, phosphoric acid, acetic acid) one-step etching process, the nitrification mixed acid ITO etching rate is slow, the Ag etching rate is fast, and the etching time is long when etching the lower layer ITO. It will lead to a large amount of Ag over-etching; at the same time, because the Ag etching rate of nitrated mixed acid is very fast (300-500A / s), it is difficult to control over-etching, resulting in a large Ag CD loss

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A method for preparing high-precision silver electrodes by self-limiting wet etching
  • A method for preparing high-precision silver electrodes by self-limiting wet etching
  • A method for preparing high-precision silver electrodes by self-limiting wet etching

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] A method for preparing high-precision silver electrodes by self-limiting wet etching, comprising the following steps:

[0036] 1) Deposit a 50A ITO layer by PVD sputtering on the silicon substrate first, then deposit a 500A Ag layer, and finally deposit an ITO layer with a thickness of 50A;

[0037] 2) Photolithography, PR thickness 1μm, energy 100mj;

[0038] 3) Wet etching the upper layer of ITO oxalic acid that is not protected by photoresist, using 2wt% oxalic acid aqueous solution, wet etching for 5s;

[0039] 4) Ag self-limiting oxidation, using a hydrogen peroxide solution with a volume fraction of 2%, oxidizing for 2s;

[0040] 5) Ag self-limiting etching, using 1% nitric acid solution, wet etching for 5s;

[0041] 6) Repeat step 4) and step 5) several times in sequence until the Ag etching is completed, the silver is bright silver, and the disappearance of the bright silver on the surface of the substrate indicates that the etching is complete;

[0042] 7) T...

Embodiment 2

[0046] A method for preparing high-precision silver electrodes by self-limiting wet etching, comprising the following steps:

[0047] 1) First deposit a 500A ITO layer by PVD sputtering on the silicon substrate, then deposit a 3000A Ag layer, and finally deposit a thickness of 500A;

[0048] 2) Photolithography, PR thickness 5μm, energy 500mj;

[0049] 3) Wet etching of the upper layer of ITO with oxalic acid, the part not coated with photoresist was wet-etched with 10% aqueous solution of oxalic acid for 2s;

[0050] 4) After oxalic acid wet etching, use Ag self-limiting oxidation, use APM solution with a volume fraction of 30% hydrogen peroxide: 38% concentrated hydrochloric acid: water = 1:1:5 volume ratio, and oxidize for 2s;

[0051] 5) Perform Ag self-limiting etching again, and then use 2wt% nitric acid solution for wet etching for 4s;

[0052] 6) Repeat step 4) and step 5) several times in sequence until the Ag etching is completed, the silver is bright silver, and the...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a method for preparing a high-precision silver electrode by self-limiting wet etching. First, an oxidizing solvent such as hydrogen peroxide solution or diluted APM solution is used to oxidize the surface silver. After the surface silver is completely oxidized, the oxidation reaction does not proceed; The silver oxide on the surface is etched with dilute nitric acid. The reaction between dilute nitric acid and silver is very slow. After the surface silver oxide is etched, the etching reaction is terminated. The self-limited etching process will be terminated after the etchant is etched, and the CD loss will not be too large due to over-etching. The self-limited Ag etching CD loss is related to the Ag film thickness, which is approximately equal to the Ag film thickness. Oxalic acid is a special etchant for metal oxides and does not react with Ag, so it will not cause Ag CD loss when etching the upper and lower ITO layers. Through the above method, the CD loss of Ag electrode etching can be reduced from >1 μm in one-step wet etching to about 0.1 μm, which meets the demand for ultra-high resolution display.

Description

technical field [0001] The invention belongs to the field of new display technologies, in particular to Ag electrodes used in display industries including organic light-emitting diodes, silicon-based microdisplays, and digital micromirror chips, and in particular to a method for preparing high-precision silver electrodes by self-limiting wet etching. Background technique [0002] Because the reflectivity of Ag is as high as 98%, it is widely used in top-emitting organic light-emitting diode devices, but because silver (Ag) can only use wet etching process, CD loss is large (>1μm), so the Ag electrode structure cannot be applied To ultra-high resolution displays such as silicon-based microscopes and digital micromirror devices (DMDs). At present, ultra-high resolution displays mainly use aluminum (Al) electrodes, but the reflectivity of aluminum is low (about 91%), and Al is easy to cause hillocks and pits due to stress concentration and release in the annealing process, a...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): H01L21/3213
CPCH01B13/00H01B1/08H01B1/02C23F1/02C23F1/30
Inventor 吕迅刘胜芳刘晓佳王志超
Owner ANHUI SEMICON INTEGRATED DISPLAY TECH CO LTD