Lateral diffusion of phosphorus ions by excimer laser annealing in the poly-Si film on silicon dioxide film

The paper reports the lateral diffusion of phosphorus ions by excimer laser annealing in the poly-Si film on silicon dioxide film. Implanted phosphorus ions in the 80 nm thick poly-Si film are diffused in liquid phase during melt duration of 100 ns. The diffusion length is measured by comparing the total resistance of the lateral poly-Si resistors fabricated by the lateral diffusion of phosphorus ions using excimer laser. Uniformly doped poly-Si resistors with different doping concentration are also fabricated as a reference. By evaluation it is found that the diffusion length by lower energy density (200 J/cm²) excimer laser is saturated while that by the high energy density (300 J/cm²) is increased, as the number of laser shot increases. Increasing the number of laser shot, the dopants at the poly-Si region is gradually increased by lateral diffusion and its concentration is increased to be of the order of 10¹⁹#/cm³.