Ni全硅化金属栅功函数调节技术研究

摘要

Through fabricating Ni-FUSI metal gate capacitors and analyzing their C-V and Vfb-EOT characteristics,it is found that Ga or Yb has more favorable modulation ability than conventional dopants.The work function of Ni-FUSI metal gate is modulated close to the top of valince band and the bottom of conduction band,which meets the requirement of high performance CMOS devices.The high modulation abilities of Ga and Yb are explained by dipole theory.Moreover,it is found that the capacitance value of Ni-FUSI metal gate capacitor increases after incorporating Ga or Yb into Ni-FUSI metal gate,but the gate leakage current decreases.And the detailed explanation for the above phenomena is also included in this article by analyzing C-V and gate leakage current characteristics.%通过制备栅内不同掺杂条件的Ni全硅化金属栅电容并分析其C-V和Vfb-EOT特性发现,Ga和Yb较常规的杂质而言具有更好的栅功函数调节能力,能够分别将Ni全硅化金属栅电极功函数调节到价带顶和导带底附近,满足高性能体硅平面互补金属氧化物半导体（CMOS）器件对栅电极功函数的要求.同时根据电偶极子（Dipole）理论分析了Ga和Yb具有较强栅功函数调节能力的原因.另外,研究发现栅内掺入Ga或Yb杂质后的Ni全硅化金属栅电容的电容值变大、栅极泄漏电流反而变小,通过对C-V和栅极泄漏电流特性进行分析,对这一现象进行了解释.