US Patent 7129521 Semiconductor device and manufacture method thereof

The problem is to provide a technology to reduce a light leakage current in order to obtain a good display. One kind or plurality kinds of elements chosen from argon, germanium, silicon, helium, neon, krypton, and xenon are implanted in a crystalline semiconductor layer, to distribute crystal defects due to the aforementioned element implantation by uniform and suitable density in the semiconductor film, making recombination centers of carriers, to thereby suppress alight sensitivity without spoiling a high degree of carrier movement included in a crystalline semiconductor layer.