To realize TFT enabling high-speed operation by fabricating a crystalline semiconductor film in which positions and sizes of crystal grains are controlled and using the crystalline semiconductor film in a channel forming region of TFT, a film thickness is stepped by providing a stepped difference in...http://www.google.de/patents/US6746901?utm_source=gb-gplus-sharePatent US6746901 - Semiconductor device and method of fabricating thereof
