【摘要】：摘要：本文研究了離子注入能量對低溫多晶硅晶體管(LTPS-TFT)關(guān)態(tài)電流的影響,優(yōu)化了離子注入工藝參數(shù)；研究了退火工藝對LTPS-TFT器件性能的影響,取得以下成果： 1.本文制備了基于Si02柵絕緣層的LTPS-TFT,針對LTPS-TFT的重要特性關(guān)態(tài)電流作了重點(diǎn)研究。通過調(diào)整離子注入工藝的參數(shù)一注入能量和RF Power,分析了它們對關(guān)態(tài)電流的影響。實(shí)驗(yàn)發(fā)現(xiàn),摻雜濃度是1.6E15cm-2, RF Power從35W升高至55W時(shí),關(guān)態(tài)電流10ff升高10pA;當(dāng)RF Power增加到75W時(shí),關(guān)態(tài)電流繼續(xù)升高,但幅度較小。 2.本文按照LTPS-TFT array的標(biāo)準(zhǔn)工藝制作了完整的LTPS-TFT基板,完成了去氫退火與后氫化退火對LTPS-TFT性能的研究。結(jié)果表明： (1)通過縮短非晶硅退火的時(shí)間,在不引起氫爆的前提下,可以減少氫逸出,在后氫化退火時(shí),可以起到氫化的作用,與正常條件比較,Ion升高約20μA, Mobility提升10cm2/V.s, Vth正偏1V,電流開關(guān)比提升一個量級,達(dá)到10^6。 (2)在激光準(zhǔn)分子退火(ELA)之后沉積SiNx薄膜,400℃退火沒有達(dá)到提升TFT器件性能的目的,測得TFT特性參數(shù)與正常條件基本一致。目前不能排除SiNx薄膜中的H是否擴(kuò)散到多晶硅中,并且起到修復(fù)缺陷態(tài)的作用。Si02柵絕緣層的沉積溫度為350℃,Si-H鍵有可能斷裂,達(dá)不到修補(bǔ)懸掛鍵的作用。 (3)后氫化退火對TFT的特性有很大影響。當(dāng)退火溫度低于450℃時(shí),溫度越高,TFT特性越好。450℃退火對載流子遷移率、閾值電壓、亞閾值擺幅,開態(tài)電流影響很大,與不做后氫化退火的TFT相比,Mobility提升23cm2/V.S,Ion提升50μA,Vth正偏2V,S.S減小0.3V/dec,并且得到后氫化退火的工藝窗口應(yīng)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，

本文編號：2233809