Method for preparing high-precision silver electrode by side wall protection process

A sidewall protection, high-precision technology, applied in circuits, electrical components, electrical solid-state devices, etc., can solve the problems of inability to apply Ag electrode structure, large AgCDloss, poor aluminum conductivity, etc., to meet the needs of ultra-high-resolution display , The effect of reducing CDloss

Active Publication Date: 2021-02-12
ANHUI SEMICON INTEGRATED DISPLAY TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Since 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, the 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 (-91%), and Al is easy to cause hillocks and pits due to stress concentration and release during the annealing process, and the surface is even. 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. Will lead to a large Ag CDloss

Method used

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  • Method for preparing high-precision silver electrode by side wall protection process
  • Method for preparing high-precision silver electrode by side wall protection process
  • Method for preparing high-precision silver electrode by side wall protection process

Examples

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Embodiment 1

[0034] A method for preparing a high-precision silver electrode by a sidewall protection process, comprising the following steps:

[0035] 1) The ITO / Ag / ITO structure is a three-layer sandwich structure, which is ITO layer, Ag layer and ITO layer from bottom to top, and its thickness is 100A, 1000A, 100A from bottom to top; photolithography is performed first, and PR Thickness 1μm, curing energy 50mj;

[0036] 2), then wet etching the upper layer ITO not protected by the photoresist, using 8wt% oxalic acid etching, time 20s to remove the upper layer ITO, and then wet etching the Ag layer with nitric acid / phosphoric acid / acetic acid mixture for 10s to remove the Ag layer; Nitric acid / phosphoric acid / acetic acid mixture, the mass fraction ratio is 20%:40%:40%.

[0037] 3), and then proceed to C 4 f 8 Deposit passivation layer, process parameters: time 10s, power supply power 300W, C 4 f 8 The flow rate is 10sccm, the pressure is 5mt, and the temperature is 50°C; it is used ...

Embodiment 2

[0043] A method for preparing a high-precision silver electrode by a sidewall protection process, comprising the following steps:

[0044] 1) The ITO / Ag / ITO structure is a three-layer sandwich structure, and its thickness is 500A, 5000A, and 500A in turn; for photolithography, the PR thickness is 2μm, and the curing energy is 500mj;

[0045] 2) Remove the upper layer of ITO at the position not protected by the photoresist, use 4wt% oxalic acid wet etching for 50s, remove the upper layer of ITO; then perform Ag wet etching, nitric acid / phosphoric acid / acetic acid mixed solution wet etching for 20s, remove the Ag layer; The nitric acid / phosphoric acid / acetic acid mixed acid used has a mass fraction ratio of 30%:30%:40%.

[0046] 3), C 4 f 8 Deposit passivation layer, process parameters: time 30s, power supply power 500W, C 4 f 8 The flow rate is 20sccm, the pressure is 10mt, and the temperature is 50°C. Both the photoresist surface and the exposed Ag surface area on the und...

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Abstract

The invention provides a method for preparing a high-precision silver electrode by a side wall protection process, which utilizes a side wall protection mechanism of a Bosch process and undercut morphology after Ag wet etching, deposits a passivation polymer by the Bosch process C4F8 after Ag etching, etches polymers at the bottom and the top by SF6, reserves a side wall passivation layer polymeras a protection layer, and protects Ag from being etched during bottom ITO etching so as to reduce CD loss. By using the Bosch side wall protection etching process, the CD loss can be reduced from more than 1 micron of one-step wet etching to less than 0.1 micron, and the ultra-high resolution display requirement is met.

Description

technical field [0001] The invention belongs to the field of silicon-based Micro OLED microdisplays, and in particular relates to a method for preparing a high-precision silver electrode by a side wall protection process. Background technique [0002] Since 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, the 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 (-91%), and Al is easy to cause hillocks and pits due to stress concentration and release during the annealing process, and the surface is even. Poor; aluminum has poor conductivity and severe electromigration, especially the resistance becomes large...

Claims

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Application Information

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IPC IPC(8): H01B13/00H01L51/56
CPCH01B13/00H10K71/00
Inventor 吕迅刘胜芳刘晓佳王志超
Owner ANHUI SEMICON INTEGRATED DISPLAY TECH CO LTD
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