電漿輔助化學氣相沉積法製備OLED元件氣體阻障層之研究

Fabrication of Barrier Layers for OLED by Plasma Enhanced Chemical Vapor Deposition

游清彥(Ching-In Yu)

指導教授 ： 魏大欽

中原大學/工學院/化學工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400557

摘要

有機發光二極體( OLED )是極具發展潛力之平面顯示器，但元件中的有機材料及金屬對氧氣及水氣相當敏感，所以製作完成後，需經過封裝保護處理。針對此問題，眾多學者利用多種方法( PECVD, Sputtering 和Evaporation )製備各類阻障層( 有機、無機及有機/無機複合膜 )以隔絕水氣滲透，然而有機膜阻氣效果不佳；無機膜易造成微破裂；有機/無機複合膜卻有製程複雜等多項問題。
本研究以電漿化學氣相沉積法( PECVD )製備二氧化矽複合膜作為OLED元件之氣體阻障層。在單一反應器中藉由控制TEOS/O2之流量配比來交互沉積不同性質之薄膜，其中包含阻氣效果較佳的SiO2層及較柔軟的SiOxCyHz層以消除內應力，進而有效降低水氣透過率。
實驗結果發現單層阻氣膜已有不錯之阻氣效果。而藉由改變流量配比所製備之多層複合膜更能將水氣透過率降至3.4 g/day-m2，其效果已趨近於玻璃( 1.7 g/day-m2 )，且從SIMS分析中證實改變流量配比確實能有效控制膜材之組成元素比例。此外利用CF4電漿對沉積膜進行改質易對膜材造成蝕刻效應而導致水氣透過率上昇；但CF4/CH4電漿則會沉積高度交聯之C-C鍵結使得水氣透過率些微下降。透過串聯阻力模型計算得知單層阻氣膜與多層複合膜之水氣透過量約只有基材之1/6200及1/11500。且多層複合膜製備於OLED元件上的確能有效提昇其壽命。

關鍵字

電漿化學氣相沉積 ； 有機發光二極體 ； 水氣透過率 ； 二氧化矽 ； 氣體阻障層

並列摘要

One of the advantages of organic light-emitting diodes (OLEDs) over other display technologies is the ability to fabricate them on flexible substrate. But flexible OLED need a thin-film barriers on both the bottom and top side of the device layers for sufficient lifetimes. In this study, the barriers were prepared by use of TEOS and O2 in a capacitive coupled RF PECVD system. The barriers of silica composite membrane were deposited by changing the precursor flow rate in one reactor.
The effects of operating parameters (including RF power, deposition time and precursor flow ratio) on the silica film’s structure were investigated. Under the optimal condition, the water vapor transmission rate (WVTR) of silica composite membrane was 3.4 g/day-m2, and the SIMS’s analysis demonstrated the change of barrier’s chemical composition by controlling the precursor flow ratio. Moreover, CF4 plasma post-treatment caused etching effect to barrier layers, but CF4/CH4 plasma post-treatment deposited highly cross-linked C-C films, resulting in the decreasing of WVTR. According to the series resistance model, the water vapor transmission flux of PET was 6200 and 11500 times of the monolayer barrier and the multilayer barrier, respectively. Finally, the silica composite membranes prepared on OLED were found to extend the lifetime of OLED.

並列關鍵字

Gas barrier ； PECVD ； Water vapor transmission rate ； Organic light-emitting diodes ； Silicon oxide

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