Internal stress change of phosphorus-doped amorphous silicon thin films during crystallization

Internal stress change of phosphorus-doped silicon thin films during crystallization is measured by detecting substrate curvature change using a scanning laser microscope. The films are deposited in an amorphous phase by chemical vapor deposition using Si₂H₆ gas. The deposited films have compressive stress of about 200 MPa. The internal stress changes significantly to a tensile stress of about 800 MPa at about 600 °C due to shrinkage of the films during crystallization. The high tensile stress can be relaxed by annealing above 800 °C. The phosphorus doping changes the crystallization process of the films and their final residual stress.