An Experimental Study of Block-Oxide Source/Drain-Tied Polycrystalline-Silicon Thin-Film Transistors With Additional Polycrystalline-Silicon Body

This paper presents an experimental comparison of the block-oxide (BO) source/drain-tied (SDT) (BOSDT) polycrystalline-silicon (poly-Si) thin-film transistor (poly-Si TFT) with additional poly-Si body (APSB) against the zero-BO (ZBO) SDT (ZBOSDT) poly-Si TFT with APSB. The APSB scheme is created when the isolation process takes place after annealing of the source/drain regions. The experimental results show the superior electrical characteristics of the BOSDT-APSB poly-Si TFT over the ZBOSDT-APSB poly-Si TFT. The BO scheme is indeed useful in reducing the source and drain charge sharing. Although the ZBOSDT-APSB poly-Si TFT exhibits worse electrical properties, the combination of a ZBO (a buried oxide layer only under the poly-Si body) with an APSB can still be used to keep diminishing the charge-sharing effect. Furthermore, both devices can increase the cooling capability through their source/drain-tied structure.