Boron and Phosphorus Diffusion in MOS Transistors: Simulation and analyze in both 2D and 3D

Boron Phosphorus and Arsenic atoms used as doping for the polysilicon gate they can cause crucial problem of metal-oxide- Semiconductor (MOS) devices.     In this work, in order to improve the electrical parameters of... [ view full abstract ]

Boron Phosphorus and Arsenic atoms used as doping for the polysilicon gate they can cause crucial problem of metal-oxide- Semiconductor (MOS) devices.

    In this work, in order to improve the electrical parameters of MOS transistor such as, threshold voltage and flat band voltage, we have simulated Boron, Phosphorus and Arsenic Diffusion profiles in three dimensions in a polysilicon layer using the simulator Athena based on Pearson type IV models. We have study profile of dopant in 3-D before and after thermal annealing in a highly doped polysilicon film. The model takes into account the distribution of vacancy mechanism by associating parameters and effects related to high concentrations, such as the formation of clusters by trapping and exceeding the solid solubility limit. Based on the literature the model is solved under windows seven, following a well-defined algorithm.

also We have studied the influence of some parameters, like concentration, temperature, time, dose and energy on implantation profiles of Boron, Phosphorus and Arsenic.

     The results have analyzed and discussed in order to extract depth of doping (Phosphorus Arsenic and boron) and it has been able to optimize the silicon oxide thickness, to reduce the penetration of doping. This theoretical analyses show that technological conditions preserve the quality of the silicon oxide structure studied. The model is validated with the help of simulation results obtained from Matlab.