Block-Oxide Structure in Polycrystalline Silicon Thin-Film Transistor With Source/Drain Tie and Additional Polycrystalline Silicon Body for Analog Applications

In this paper, we for the first time demonstrate the analog performance of a block-oxide structure in polycrystalline silicon thin-film transistor with source/drain-tie and additional poly-Si body (BO-SDT-APSB TFT) experimentally and compared with the similar device with zero block-oxide structure (SDT-APSB TFT). The block-oxide in BOSDT-SDT-APSB TFT is fabricated to reduce the drain-induced barrier lowering and channel-length modulation. The source-drain tie and additional poly-silicon body region are fabricated in both devices to improve the device performance and reduce the self-heating effect. Experimental results show that the block-oxide structure can offer enhanced gate controllability over the channel, and the transconductance ( g
_m
) of the BO-SDT-APSB TFT is therefore improved. In addition, although a higher drain conductance ( g d), implying a lower output resistance r o, is observed for a BO-SDT-APSB TFT, the enhanced gm still helps to achieve the desired intrinsic voltage gain ( A
_v
= g
_m
/g
_d
) behavior.