The invention relates to vWF cleaving entities having a molecular weight of 180 kD, 170 kD, 160 kD, 120 kD or 110 kD and an N-terminal amino acid sequence of AAGGILHLELLV, vWF cleaving complexes and methods for their production. The head portion is generally tear-drop in shape and has a width no greater than 12 inches. By irradiating pulse laser beams to heat the SiNx film, hydrogen in the SiNx film is diffused into the polycrystalline Si film to hydrogenate it and reduce the trap density along crystal grain boundaries in the polycrystalline Si film.