锗预非晶化注入对镍硅(NiSi)金属栅功函数的影响研究

Study on the Impact of Germanium Preamorphization on the Work Function of Fully Silicided NiSi Gate

随着超大规模集成电路技术的发展,CMOS器件的制备过程需要同时引入金属栅和超浅结等新的先进工艺技术,因此各种新工艺的兼容性研究具有重要意义.本文研究了超浅结工艺中使用的锗预非晶化对镍硅(N iS i)金属栅功函数的影响.对具有不同剂量Ge注入的N iS i金属栅MOS电容样品的研究表明,锗预非晶化采用的Ge注入对N iS i金属栅的功函数影响很小(小于0.03eV),而且Ge注入也不会导致氧化层中固定电荷以及氧化层和硅衬底之间界面态的增加.这些结果表明,在自对准的先进CMOS工艺中,N iS i金属栅工艺和锗预非晶化超浅结工艺可以互相兼容.

As continuously scaling down the VLSI technology,it is important to investigate the compatibility of the different advanced processes integrated together in advanced CMOS process. The impact of Ge-implantation on the work function of fully silicided NiSi （ FUSI NiSi） gate is investigated. The flat band voltage （VFB） and Equivalent Oxide Thickness （EOT） data were determined by fitting the measured capacitance-voltage （C-V） curves with simulation curves. The results show that work functions of NiSi gates with and without Ge implantation vary slightly, less than 0.03eV. The increase of interface state and fixed oxide charge introduced by Ge preamorphization implantation is not observed. These results demonstrate that FUSI NiSi gate technology can be integrated with Ge preamorphization implantation in self ahgnment CMOS process.