Selective single-crystalline-silicon growth at the pre-defined active regions of TFTs on a glass by a scanning CW laser irradiation

We have developed a new Si crystallization method, which makes possible to form single-crystalline-silicon (Si) film in channel region of TFTs on non-alkali glass without introducing thermal damage into it, using a scanning solid-state CW laser (10 W). The peculiar characteristics of this crystallization method are introduction of pre-defined thick capping Si layer on the pre-patterned channel region and laser irradiation from back surface. We succeeded in formation of single-crystalline-Si with 1.5 /spl mu/m wide and 20 /spl mu/m long. High performance TFTs with mobility of 300 cm/sup 2//Vs, S-value 0.41 V/dec, Vth -0.5 V, and low off-current, were obtained by fabrication process below 450/spl deg/C. This crystallization uses stable solid-state laser and realizes the high-performance Si devices on non-alkali glass substrates, which are necessary to achieve System On Glass (SOG).