标题: | 铜/二氧化矽系统可靠性之研究 Reliability of Cu/SiO2 system |
作者: | 王弘毅 Hong-I Wang 陈茂杰 Mao-Chieh Chen 电子研究所 |
关键字: | 铜,二氧化矽,铜离子;Cu, Silicon Dioxide, Cu Mobile Ion |
公开日期: | 1994 |
摘要: | 本文分别以介电质劣化,及铜闸极金氧半结构中的铜离子迁移,来探讨 铜/二氧化矽/矽系统之热稳定性。我们测量铜/二氧化矽/矽结构经快速退 火后, 介电强度及矽/二氧化矽介面能阶密度的变化, 来观察此系统的 热稳定性。 此结构经 300℃ 60 秒快速退火后, 电性便生劣化,其程度 随退火温度升高而加剧。 劣化原因可能来自退火过程中, 溶于二氧化矽 层中带正电的铜离子。 铜离子在二氧化矽中的移动率则以加温偏压法求 之, 并以此法求得经快速退火处理后,铜离子在铜闸极金氧半结构的二 氧化矽层中之分布。 我们发现铜离子在二氧化矽层中移动迅速,并可能在 到达二氧化矽/矽介面后扩散至矽基板中. Thermal stability of the Cu/SiO2/Si system was investigated with respect to the dielectric degradation and Cu ion migration in the Cu-gate MOS capacitor. We used the rapid thermal annealing (RTA) and the technique of bias-temperature stress in conjunction with the dielectric breakdown field (Ebd) and SiO2/ Si interface state density (Dit) measurements to characterize the thermal stability of the Cu/SiO2/Si system. We found that the Ebd degradation started to occur after Cu/SiO2/Si structure was annealed with 60 sec RTA at a temperature as low as 300℃; and the dielectric strength deteriorated progressively with the increase of annealing temperature. The dielectric degradation is presumably due to Cu dissolution in SiO2 layer in the form of positive ion. The mobility of Cu ion in the SiO2 layer was evaluated using the data obtained from the bias- temperature stress. The Cu ion concentration in the SiO2 layer of Cu-gate MOS capacitor resulting from RTA anneal was also evaluated using a simple extractation scheme. It is also concluded that Cu is a fast diffusion specises in SiO2 and may diffuse into Si substrate once it arrives at the SiO2/Si interface. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#NT830430094 http://hdl.handle.net/11536/59286 |
显示于类别: | Thesis |