Title :
A novel self-aligned double-gate TFT technology
Author :
Zhang, Shengdong ; Han, Ruqi ; Sin, Johnny K O ; Chan, Mansun
Author_Institution :
Inst. of Microelectron., Beijing Univ., China
Abstract :
In this letter, a novel self-aligned double-gate (SADG) thin-film transistor (TFT) technology is proposed and experimentally demonstrated for the first time. The self-alignment between the top-gate (TG) and bottom-gate (BG) is realized by a noncritical chemical-mechanical polishing (CMP) step. An ultrathin channel and a thick source/drain, that allow better device performance and lower source/drain resistance, are also automatically achieved. N-channel poly-Si TFTs are fabricated with maximum processing temperature below 600/spl deg/C. Metal induced unilateral crystallization (MIUC) is used for poly-Si grain size enhancement. The fabricated SADG TFT exhibits symmetrical bidirectional transfer characteristics when the polarity of source/drain bias is interchanged. The on-current under double-gate operation is more than two times the sum of that under TG and BG operation.
Keywords :
chemical mechanical polishing; crystallisation; elemental semiconductors; grain size; silicon; thin film transistors; 600 C; N-channel polysilicon TFT; Si; chemical-mechanical polishing; grain size; metal induced unilateral crystallization; self-aligned double-gate thin film transistor technology; Chemical technology; Crystallization; Displays; Fabrication; Glass; Grain size; Semiconductor films; Silicon compounds; Temperature; Thin film transistors;
Journal_Title :
Electron Device Letters, IEEE
