This paper discusses the influence uf variuus photoresist protectors on the electrical properties of the bottom gated TFT,which is with a-IGZO as the active layer deposited by Pulsed DC sputtering. The investigation found that the photoresist can maintain the electric properties in a short period with the protector. Then, the electrical properties begin to deteriorate, especially the threshold voltages decay obviously, and the work modes change from enhancement to depletion when the protected devices are placed in the air for a time. It's inferred that, the dissolvant in the photoresist contacts with the IGZO channel and the chemical reaction between them causes desorption of oxygen, which makes the earner concentration increase. Besides that,the investigation found that the electrical properties are smaller in decay and higher in stability with SU-8 photorisist as the protector than the others.%采用脉冲直流溅射的方式沉积IGZO膜层作为底栅结构TFT的有源层,并在背沟道上涂覆不同类型的光刻胶作为保护层,探讨不同保护层对器件电学特性的影响.经考察发现:采用光刻胶作为保护层时,保护层制作后短期内可维持器件的电学特性基本不变；但涂胶后暴露在空气中一定时间后,器件的电学特性开始衰退,尤其是阈值电压变化较明显,器件工作模式由增强型变为耗尽型,并推断光刻胶中溶剂接触到背沟道中IGZO,其化学反应导致沟道中氧脱附,载流子浓度增加.实验还发现:使用SU-8负性光刻胶作为保护层的器件,其电学特性衰退较小,在空气中放置一段时间后表现最稳定.
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