Title |
A Study on Low Temperature Sequential Lateral Solidification(SLS) Poly-Si Thin Film Transistors(TFT′s) with Molybdenum Gate |
Keywords |
fabrication ; low temperature ; Sequential Lateral Solidification(SLS) ; poly-silicon ; thin film transistor(TFT) |
Abstract |
In this paper, we present the fabrication and the characteristic analysis of sequential lateral solidification(SLS) poly-Si thin film transistors(TFT's) with molybdenum gate for active matrix liquid displays (AMLCD's) pixel controlling devices. The molybdenum gate is applied for the purpose of low temperature processing. The maximum processing temperature is 550°C at the dopant thermal annealing step. The SLS processed poly-Si film which is reduced grain and grain boundary effect, is applied for the purpose of electrical characteristics improvements of poly-Si TFT's. The fabricated low temperature SLS poly-Si TFT's had a varying the channel length and width from 10μ{ textrm} m to 2μ{ textrm} m. And to analyze these devices, extract electrical characteristic parameters (field effect mobility, threshold voltage, subthreshold slope, on off current etc) from current-voltage transfer characteristics curve. The extract electrical characteristic of fabricated low temperature SLS poly-Si TFT's showed the mobility of 100~400cm^2/Vs, the off current of about 100pA, and the on/off current ratio of about 10^7. Also, we observed that the change of grain boundary according to varying channel length is dominant for the change of electrical characteristics more than the change of grain boundary according to varying channel width. Hereby, we comprehend well the characteristics of SLS processed poly-Si TFT's witch is recrystallized to channel length direction. |