DEVICE SENSITIVITY OF FIELD-PLATED POLYSILICON HIGH-VOLTAGE TFTS AND THEIR APPLICATION TO LOW-VOLTAGE OPERATION

The device sensitivity to the offset length variations in the recently proposed field-plated (FP) polysilicon high-voltage thin-film transistor (HVTFT) has been studied. The device characteristics of the new FP-HVTFT’s are found to be much more immune to misalignment errors, a very desirable feature especially for large-area applications. The new FP-HVTFT’s also depict lower leakage current than their conventional counterparts for up to 100-V operation. At typical low-voltage operation (e.g., 20 V), an improvement of about three orders of magnitude in the on/off current ratio can be readily achieved. These, together with a simpler processing and improved turn-on characteristics reported earlier [1], make the new FP TFT a very promising device architecture for large-area microelectronics. © 1990 IEEE