Crystallization-induced stress in silicon thin films

Residual stress change in silicon thin films during crystallization of amorphous silicon is discussed experimentally by detecting the wafer curvature change using a scanning laser microscope. The as-deposited amorphous-silicon film shows compressive stress of about 200 MPa. During a crystallization reaction at about 650°C, a large tensile stress of about 1000 MPa develops in the film due to film shrinkage. The final residual stress of polycrystalline film depends on the film formation process.