Crystallization-induced stress in phosphorus-doped amorphous silicon thin films

The effect of phosphorus doping on the crystallization-induced stress of silicon thin films is investigated experimentally using a scanning laser microscope. Though the intrinsic stress of the phosphorus-doped amorphous silicon films and the crystallization-induced stress of the films do not change, regardless of the doped phosphorus concentration, the final residual stress of the film after full annealing depends on the phosphorus concentration. The final stress decreases by increasing the dopant concentration. In addition, phosphorus doping lowers the crystallization temperature of the amorphous silicon thin films. The existing phosphorus at the interface of the film and the base oxide film is found to change the crystallization mechanism and the magnitude of the stress developed.