基于a-IGZO型OLED的顶栅自对准TFT结构中遮光层的研究  

Research on the Shading Layer in Self-aligned Top-gate Thin Film Transistors Based on Amorphous Oxide for OLED

作　　者：高颖 周星宇 GAO Ying;ZHOU Xingyu(Guangdong Liangyang Middle School,Guangdong 529500,CHN;Shenzhen Huaring Optoelectronic Semiconductor Display Technology Co.,Ltd.,Shenzhen Guangdong 518000,CHN)

机构地区：[1]广东两阳中学,广东阳江529500 [2]深圳市华星光电半导体显示技术有限公司,广东深圳518000

出　　处：《光电子技术》2020年第4期302-307,共6页Optoelectronic Technology

摘　　要：顶栅自对准(Top-gate self aligned)结构的a-IGZO TFT器件具有较小的寄生电容,适用于驱动OLED(Organic light emitting diode)显示器。为了增加TFT器件在光照条件下的稳定性,驱动OLED的TFT(Thin film transistors)器件通常需要加入遮光层。文章对遮光层的作用、遮光层信号连接方式、缓冲层厚度以及遮光层尺寸的选择进行了探究。结果表明:(1)遮光层可以有效降低TFT因为光照射造成的阈值电压负偏;(2)遮光层连接电讯号电性会更稳定,并且信号连接到源极,驱动电流更容易饱和,最适合驱动OLED;(3)缓冲层厚度选择400μm的器件性能较好;(4)在设计允许的情况下,遮光层应尽可能多的遮挡IGZO,以改善器件的稳定性。Top-gate self-aligned a-IGZO TFT is suitable for driving OLED displays for its tiny parasitic capacitors. In order to improve the stability of TFT device under illumination condition,the driving TFT usually needs light shading layer. In this paper,the influence of the light shading layer,the selection of its signal connection,the thickness of the buffer layer and the size of the light shading layer were explored. The results showed that:(1)the light shading layer could effectively reduce the negative bias caused by the light of TFT,(2)the light shading layer connecting signal was more stable than the floating one,and the TFT whose shading layer was connected to the source electrode was more easily saturated,which could be helpful to carry out OLED,(3)buffer layer thickness of400 μm was more favorable for device performance,(4)the light shading layer should cover IGZO,and its size should be as large as possible,which could effectively improve the device reliability.

关 键 词：顶栅自对准结构 有机发光二极管显示器 遮光层 

分 类 号：TN321.5[电子电信—物理电子学]