CoSi＿2／Si结构中杂质离子注入及自对准硅化物MOS器件技术

ION IMPLANTATlON THROUGH CoSi_2/Si AND SELF-ALIGNED SILICIDED MOS DEVICE TECHNOLOGY

研究了一种新型自对准硅化物ＭＯＳ晶体管制备技术，通过Ｃｏ／Ｓｉ固相反应在源漏区和栅电极表面形成一层自对准的低电阻率ＣｏＳｉ＿２薄膜，在ＣｏＳｉ＿２／Ｓｉ结构中进行杂质离子注入，用计算机模拟程序对离子注入杂质分布及损伤进行计算，选择适当的注入能量，使注入的杂质浓度峰值位于ＣｏＳｉ＿２／Ｓｉ界面附近，经快速退火，可获得界面载流子浓度较高、性能优良的增强型和耗尽型ＮＭＯＳ晶体管。该文还研究了注入在ＣｏＳｉ＿２／Ｓｉ结构中的杂质在不同的热处理条件下的分布变化，结果表明，磷在热处理过程中，存在向硅衬底较强的扩散趋势，而硼则明显不同。

A new technology for the fabrication of self-aligned silicided MOS transistorswas investigated. Self-aligned highly conductive CoSi_2 films were formed on the areas of the source/drain and gate electrode by solid state reaction of Co/Si.Dopants were implanted through CoSi_2/Si. The dopant and damage depth profileswere calculated by the eomputer program TRIM. The ion energy was properlyselected to make the peak of dopant concentration locate at the interface of CoSi_2/Si. By a rapid thermal annealing after implantation, high-performance enhancedand depletion MOS transistors were fabricated with high carrier concentrations atthe interface of CoSi_2/Si. The redistribution of the implanted dopants in thestructure of CoSi_2/Si during different thermal processes was also studied. Theresults show that phosphorous has the tendency of diffusing into Si substrate, butboron prefers to stay in CoSi_2.