| Title |
A Study on the Fabrication of p-type poly-Si Thin Film Transistor (TFT) Using Sequential Lateral Solidification(SLS) |
| Authors |
이윤재(Lee, Yun-Jae) ; 박정호(Park, Jeong-Ho) ; 김동환(Kim, Dong-Hwan) |
| Keywords |
SLS process ; XeCl laser ; poly-Si TFT |
| Abstract |
This paper presents the fabrication of polycrystalline thin film transistor(TFT) using sequential lateral solidification(SLS) of amorphous silicon. The fabricated SLS TFT showed high Performance suitable for active matrix liquid crystal display(AMLCD). The SLS process involves (1) a complete melting of selected area via irradiation through a patterned mask, and (2) a precisely controlled pulse translation of the sample with respect to the mask over a distance shorter than the super lateral growth(SLG) distance so that lateral growth extended over a number of iterative steps. The SLS experiment was performed with 550 AA a-Si using 308nm XeCl laser having 2μ textrm m width. Irradiated laser energy density is 310mJ/ textrm cm^2 and pulse duration time was 25ns. The translation distance was 0.6μm/pulse, 0.8μm/pulse respectively. As a result, a directly solidified grain was obtained. Thin film transistors (TFTs) were fabricated on the poly-Si film made by SLS process. The characteristics of fabricated SLS p -type poly-Si TFT device with 2μ textrm m channel width and 2μ textrm m channel length showed the mobility of 115.5 textrm cm^2/V.s, the threshold voltage of -1.78V, subthreshold slope of 0.29V/dec, I_{off} current of 7×10^{-l4}A at V_{DS} =-0.1V and I_{on} / I_{off} ratio of 2.4×10^{7} at V_{DS} =-0.1V. As a result, SLS TFT showed superior characteristics to conventional poly-Si TFTs with identical geometry.y.y.y. |