Tilted back exposure for lightly doped drain structure in metal induced lateral crystallization poly Si thin film transistors.
It has been known that LDD is essential to reduce the leakage current in poly TFTs, which has been regarded as one of the most important issues in poly TFT characteristics. However, according to the conventional process, an extra mask is needed solely for the LDD formation, which is not only complicated but also difficult to maintain the reproducibility. In this work, a simple method has been introduced for formation of LDD structure in poly Si TFTs, Tilted Back Exposure (TBE) technique. It has been found that asymmetry patterns can be realized with TBE process and submicron accuracy can be easily achieved by adjusting the angle between the substrate and light source. The LDD TFTs using TBE process shows almost the same electrical properties as the LDD TFTs using an additional separate LDD Mask.
Research Institute of Advanced Materials, Department of Materials Science and Engineering, College of Engineering, Seoul National University, Gwanak-gu, Seoul 151-742, Korea.
Se Wan
SW
Son
Chang Woo
CW
Byun
Yong Woo
YW
Lee
Jae Hyo
JH
Park
Seung Ki
SK
Joo