Author_Institution :
Electr. Commun. Lab., NTT, Tokyo, Japan
Abstract :
High-voltage (>100-V) and large-transconductance poly-Si thin-film transistors (TFTs) have been fabricated on quartz substrates by the use of laser-recrystallized multiple-strip poly-Si films as semiconductors in the channel regions. The TFTs have an offset gate structure between the source and the gate (LOFF,1), and between the gate and the drain (LOFF,2). With the nonsymmetric offset gate structure at LOFF,1=3 μm and LOFF,2=15 μm, the TFTs have a large transconductance of 520 μS and exhibit low-threshold n-channel enhancement-mode characteristics. Simultaneously, a very large ON/OFF current ratio (above 107) and a low leakage current of 2×10-10 A occur at the high drain voltage of V D=100 V. The breakdown voltage VBD of the TFT depends strongly on LOFF,2, so VBD can increase with increasing LOFF,2 to 110 V at LOFF,2=10 μm, 130 V at LOFF,2 =15 μm, and 170 V at LOFF,2=20 μm
Keywords :
driver circuits; elemental semiconductors; quartz; semiconductor technology; silicon; thin film transistors; 0.2 nA; 100 V; 3 to 15 micron; 520 muS; SiO2 substrate; TFTs; breakdown voltage; channel regions; drain voltage; enhancement-mode characteristics; large ON/OFF current ratio; large-transconductance; laser recrystallised Si films; leakage current; low-threshold; multichannel structure; n-channel; nonsymmetric offset gate structure; offset gate structure; polycrystalline Si; quartz substrates; thin-film transistors; Annealing; Conductive films; Flat panel displays; Grain boundaries; Leakage current; Liquid crystal displays; Power lasers; Semiconductor films; Silicon; Thin film transistors;
