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

摘要

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 diode pumped solid-state (DPSS) CW laser Nd:YVO4, 532nm, low). 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 2μm wide and 20μm long. High performance TFTs with mobility of 410 cm{sup}2/Vs, S-value 0.20 V/dec, Vth 2.OV were obtained on non-alkali glass by fabrication process below 4500C. This crystallization uses stable diode pumped solid-state laser and realizes the high-performance Si devices on non-alkali glass substrates, which are necessary to achieve System On Glass (SOG).