反应生成的TiSi_2薄膜特性及TiSi_2/poly Si栅结构特性、TiSi_2/n~+-Si接触特性和形貌的研究

<正> 一、引言 随着集成电路的发展,集成度的提高,器件尺寸将逐渐缩小,此时RC延迟时间及接触电阻的影响将越来越显著。目前广泛应用的多晶硅栅材料在亚微米技术中已不再适用,取代它的有硅化物/多晶硅栅。由于TiSi_2的电阻率低,形成温度低,因此是人们最重视的硅化物。本文对反应生成的TiSi_2/poly Si栅结构及TiSi_2/n~+-Si的接触特性进行了系统研究,有助于

The Characteristics and Morphologies of Reactiveiy Formed TiSi_2 Films and TiSi_2/poly Si,TiSi_2 /n~+-Si Bilayer Structures

With SEM and TEM the characteristics and morphologies of reactively formed TiSi2films and TiSi2/poly Si, TiSi2/n+-Si bilayer structures, the influence of thickness of polysilicon layer on the MOS structures have been investigated thoroughly. TEM(cross-section) has been employed to observa the formation of the defects and stress of this gate structure during thermal annealing in situ. The micrographes show that, when the residual polysilicon layer was below 1500A, the defects and stress in the interface between the gate oxide and the silicon substrate were generated. C-V characteristies measured at different signal frequence manifest new interface states formed. The contact resistance of TiNx/TiSi2/n+-Si structure formed by sintering Ti on n+ -Si substrate, as a function of anaealing temperature has also been investigated. The results show that when the annealing temperature was below 900 ℃, the contact resistance decreases as the temperature increases and that when the temperature was above 900℃, the contact resistance increases as the temperature increases. A thin TiNx layer on the surface formed during the thermal annealing in N2 can effectively prevent the dopant outdiffusion through the formed silicide