Crystal Plasticity Analysis of Dislocation Accumulation in Impurity Doped-ULSI Cells

Several atomic level problems such as uneven oxidation film or generation of lattice defects take place in the fabrication processes of nano-meter order devices. Among them，dislocation accumulation is a serious problem. Generation and accumulation of dislocations are known to take place during the cooling processes of device fabrication due to its thermo-plastic deformation. Dislocations accumulated in the electron channel have an enormous effect on the electronic state of the device，increase the signal delay and obstruct devices from normal operation. Therefore，it is important to understand the deformation and the dislocation accumlation for the fabrications of nano-mater order devices. On the other hand, impurity doping is an indispensable process fof the device fabrication, and also important in dislocation accumulation. In this study, we make numerical models of ULSI cells where impurities are doped at some limited areas. Dislocation accumulation in the models during cooling processes of device fabrication is analysed by employing a technique of crystal plasticity analysis and evaluate the thermal stress, plastic slip deformation and accumulation of dislocations when the temprature drops from the initial value of 1000°C. Possibilities for the control of deslocation accumulation in impurity doped-ULSI cells are discussed.本文データは学協会の許諾に基づきCiNiiから複製したものであ