Affiliation:
1. TCL China Star Optoelectronics Display Technology Co. Ltd Shenzhen, Guangdong China
2. Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou China
3. Shenzhen China Star Optoelectronics Semiconductor Display Technology Co. Ltd Shenzhen, Guangdong China
Abstract
The stacked structure thin film transistors (TFT) has caused the widespread attention to achieve high mobility and reliability simultaneously. To ensure the stacked structure TFT application to mass production, it is critical to reduce the number of mask‐count. In this paper, 8‐mask‐count stacked TFT‐array process using the first semiconductor layer overlapped with the source and drain layer directly, which is the first layer on the glass substrate, is studied. By adopting this novel process, the device mobility is 25.4 cm2/Vs, which is more than twice that of conventional top‐gate self‐aligned a‐IGZO device. Besides, the ΔVth under the positive bias stress of 30V and negative bias temperature illumination stress of ‐30V for 1 h is +0.41V and ‐0.13V, respectively, achieving the stability to the level of a‐IGZO TFTs.