SELF-ALIGNED OFFSET GATED POLY-SI TFTS WITH A FLOATING SUB-GATE

We have fabricated a self-aligned offset-gated poly-Si thin film trans istor (TFT) by employing a novel photoresist reflow process. The gate structure of the new device is consisted of two unique patterns: A mai n-gate and a sub-gate, The new fabrication method extends the gate-oxi de over the offset region. With the assistance of the sub-gate and ref lowed photoresist a self-aligned offset region is successfully obtaine d due to the offset oxide acting as an implantation mask, The poly-Si TFT with symmetrical offsets is easily fabricated and the new method d oes not require any additional offset mask step, Compared with the mis aligned offset gated poly-Si TFT's, excellent symmetric electrical cha racteristics are obtained.