铟镓锌氧化物薄膜晶体管制备及性能研究

Fabrication and Property Characterization of InGaZnO Thin Film Transistor

为了实现高质量刻蚀阻挡型InGaZnO薄膜晶体管(IGZOTFT)器件,研究了IGZO TFT关键制备工艺,其中重点探讨了IGZO成膜氧分压、退火工艺、IGZO成膜均一性对于IGZO TFT电学特性的影响。通过优化成膜和退火工艺在G6玻璃基板上制作的IGZOTFT器件,阈值电压0.72 V,亚阈值摆幅0.2 V/dec,迁移率9.57 cm^2/V·s,Ion/Ioff>10~8,IGZO TFT大基板阈值电压均一性最大偏差小于2 V。最后进行了IGZO TFT长期稳定性测试以及正负偏压应力测试,结果表明IGZO TFT器件经过长时间空气暴露会导致特性劣化,负向偏压应力劣化较为明显。所制备的刻蚀阻挡型IGZO TFT器件可以满足高质量液晶显示的要求。

The etching-stopper type InGaZnO thin film transistors（IGZO-TFT）,for high quality liquid crystal display panel,were fabricated on G6-glass substrate.The impact of the synthesis conditions of the InGaZnO coatings,including the O_2 partial pressure,annealing temperature and time,on the microstructures and IGZO-TFT characteristics was investigated.The results show that the O_2 partial pressure and annealinng significantly affect the switching characteristics of the IGZO-TFT,possibly because of oxygen vacancy.Fabricated with the uniform IGZO layers,synthesized at 25%of 02 partial pressure and annealed at 300℃ for 15 min in air,the IGZO-TFT has the properties,including a threshold voltage of 0.72 V,a subthreshold swing of 0.2 V/dec,a mobility of 9.57 cm^2/V · s,and an I_（on）/_（off） above 10^8;the maximum deviation of threshold voltage uniformity of IGZO TFT on large substrate was below 2 V.The positively/negatively biased IGZO-TFT suffered deterioration in long-time storage in air,and the deterioration was worese for the nagatively biased one.