High-voltage poly-Si TFTs with multichannel structure

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 (L/sub OFF,1/), and between the gate and the drain (L/sub OFF,2/). With the nonsymmetric offset gate structure at L/sub OFF,1/=3 mu m and L/sub OFF,2/=15 mu m, the TFTs have a large transconductance of 520 mu S and exhibit low-threshold n-channel enhancement-mode characteristics. Simultaneously, a very large ON/OFF current ratio (above 10/sup 7/) and a low leakage current of 2*10/sup -10/ A occur at the high drain voltage of V/sub D/=100 V. The breakdown voltage V/sub BD/ of the TFT depends strongly on L/sub OFF,2/, so V/sub BD/ can increase with increasing L/sub OFF,2/ to 110 V at L/sub OFF,2/=10 mu m, 130 V at L/sub OFF,2/=15 mu m, and 170 V at L/sub OFF,2/=20 mu m.<>