The advanced low-temperature polysilicon (poly-Si) thin-film transistor with three-dimensional channels of fin-like profile has been demonstrated using excimer laser annealing and unique undercut structure without any additional patterning process. This approach provides a very narrow fin-like channel in devices with high ratio of film thickness to the width as well as a high-quality poly-Si film in channels with better crystallinity for the effect of columnar-like grain growth following the shrinkage of silicon stripe after laser irradiation. Due to that and the stronger electrical stress on the channel by the multigate, the new device with a fin-like channel structure shows good characteristics of the highest mobility up to 395 cm2/V · s, a subthreshold voltage slope below 400 mV/dec, and an ON-OFF current ratio higher than 106.
Bibliographical noteFunding Information:
Manuscript received November 28, 2005; revised February 13, 2006. This work was supported by and performed at the Samsung Advanced Institute of Technology. The review of this letter was arranged by Editor J. Sin.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering