Thin film transistor having enhanced charge carrier mobility and method for manufacturing the same

PURPOSE: A thin film transistor with improved charge mobility and a manufacturing method thereof are provided to increase a field effect by forming a main active layer which is shorter than a channel. CONSTITUTION: A gate insulation layer(300) is formed on a gate electrode(200). A main active layer(400a) is formed on a part of the gate insulation layer. A sub active layer(400b) surrounds the front side of the main active layer. A source electrode(500) and a drain electrode(600) come in contact with both sides of the sub active layer. The carrier concentration of the main active layer is higher than the carrier concentration of the sub active layer. The main active layer is shorter than a channel.