离子注入和退火对LTPS-TFT特性的影响研究
发布时间：2018-09-10 07:40
【摘要】：摘要：本文研究了离子注入能量对低温多晶硅晶体管(LTPS-TFT)关态电流的影响,优化了离子注入工艺参数；研究了退火工艺对LTPS-TFT器件性能的影响,取得以下成果： 1.本文制备了基于Si02栅绝缘层的LTPS-TFT,针对LTPS-TFT的重要特性关态电流作了重点研究。通过调整离子注入工艺的参数一注入能量和RF Power,分析了它们对关态电流的影响。实验发现,掺杂浓度是1.6E15cm-2, RF Power从35W升高至55W时,关态电流10ff升高10pA;当RF Power增加到75W时,关态电流继续升高,但幅度较小。 2.本文按照LTPS-TFT array的标准工艺制作了完整的LTPS-TFT基板,完成了去氢退火与后氢化退火对LTPS-TFT性能的研究。结果表明： (1)通过缩短非晶硅退火的时间,在不引起氢爆的前提下,可以减少氢逸出,在后氢化退火时,可以起到氢化的作用,与正常条件比较,Ion升高约20μA, Mobility提升10cm2/V.s, Vth正偏1V,电流开关比提升一个量级,达到10^6。 (2)在激光准分子退火(ELA)之后沉积SiNx薄膜,400℃退火没有达到提升TFT器件性能的目的,测得TFT特性参数与正常条件基本一致。目前不能排除SiNx薄膜中的H是否扩散到多晶硅中,并且起到修复缺陷态的作用。Si02栅绝缘层的沉积温度为350℃,Si-H键有可能断裂,达不到修补悬挂键的作用。 (3)后氢化退火对TFT的特性有很大影响。当退火温度低于450℃时,温度越高,TFT特性越好。450℃退火对载流子迁移率、阈值电压、亚阈值摆幅,开态电流影响很大,与不做后氢化退火的TFT相比,Mobility提升23cm2/V.S,Ion提升50μA,Vth正偏2V,S.S减小0.3V/dec,并且得到后氢化退火的工艺窗口应在450℃左右。
[Abstract]:Abstract: the effect of ion implantation energy on the on-off current of low temperature polysilicon transistor (LTPS-TFT) is studied, the parameters of ion implantation are optimized, and the effect of annealing process on the performance of LTPS-TFT devices is studied. The results are as follows: 1. In this paper, LTPS-TFT, based on Si02 gate insulator is prepared to study the important characteristics of LTPS-TFT. The effects of the ion implantation parameters, the implantation energy and the RF Power, on the off-state current were analyzed by adjusting the parameters of the ion implantation process. The experimental results show that when the doping concentration is 1.6E15cm-2, when RF Power increases from 35W to 55W, the 10ff increases by 10 Pa, and when RF Power increases to 75W, the on-off current continues to increase, but the amplitude is small. In this paper, a complete LTPS-TFT substrate has been fabricated according to the standard process of LTPS-TFT array, and the properties of LTPS-TFT have been studied by dehydrogen annealing and post hydrogenation annealing. The results show that: (1) by shortening the annealing time of amorphous silicon, without causing hydrogen explosion, hydrogen escape can be reduced, and hydrogenation can be played in post hydrogenation annealing. Compared with the normal condition, the ion increases about 20 渭 A, the Mobility increases 10 cm 2 / V s, the Vth is positive 1 V, the current switching ratio increases by one order of magnitude, and reaches 10 ^ 6. (2) annealing at 400 鈩，
本文编号：2233809
[Abstract]:Abstract: the effect of ion implantation energy on the on-off current of low temperature polysilicon transistor (LTPS-TFT) is studied, the parameters of ion implantation are optimized, and the effect of annealing process on the performance of LTPS-TFT devices is studied. The results are as follows: 1. In this paper, LTPS-TFT, based on Si02 gate insulator is prepared to study the important characteristics of LTPS-TFT. The effects of the ion implantation parameters, the implantation energy and the RF Power, on the off-state current were analyzed by adjusting the parameters of the ion implantation process. The experimental results show that when the doping concentration is 1.6E15cm-2, when RF Power increases from 35W to 55W, the 10ff increases by 10 Pa, and when RF Power increases to 75W, the on-off current continues to increase, but the amplitude is small. In this paper, a complete LTPS-TFT substrate has been fabricated according to the standard process of LTPS-TFT array, and the properties of LTPS-TFT have been studied by dehydrogen annealing and post hydrogenation annealing. The results show that: (1) by shortening the annealing time of amorphous silicon, without causing hydrogen explosion, hydrogen escape can be reduced, and hydrogenation can be played in post hydrogenation annealing. Compared with the normal condition, the ion increases about 20 渭 A, the Mobility increases 10 cm 2 / V s, the Vth is positive 1 V, the current switching ratio increases by one order of magnitude, and reaches 10 ^ 6. (2) annealing at 400 鈩，
本文编号：2233809
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