Bottom gate type thin film transistor and preparation method thereof

• Main Author: XIANG CHANGJIANG
• Format: Patent
• Language: Chinese; English
• Published: 29.06.2016
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A bottom gate type thin film transistor of the invention comprises a substrate. A gate layer, a gate insulation layer, a polycrystalline silicon semiconductor layer and a source/drain electrode layer are formed on the substrate in sequence. The substrate is provided with a depression, the gate layer is formed in the depression, and the contact face of the gate layer and the gate insulation layer is flush with the upper surface of the substrate. Because of the arrangement, the polycrystalline silicon semiconductor layer has no height difference, the uniformity in the semiconductor layer laser crystallization process is ensured, and the stability of the device is improved. 本发明所述一种底栅型薄膜晶体管，包括基板，依次在基板上形成栅极层、栅极绝缘层、多晶硅半导体层和源/漏电极层，所述基板设置有凹陷部，所述栅极层形成在所述凹陷部内，所述栅极层与所述栅极绝缘层的接触面与所述基板的上表面齐平。这样的设置使得本发明的多晶硅半导体层没有高度差，进而可以保证半导体层激光晶化过程中均匀性，从而提高了器件的稳定性。