Yh. Byun et al., AN AMORPHOUS-SILICON TFT WITH ANNULAR-SHAPED CHANNEL AND REDUCED GATE-SOURCE CAPACITANCE, I.E.E.E. transactions on electron devices, 43(5), 1996, pp. 839-841
An amorphous silicon Thin-Film Transistor (a-Si TFT) with an annular-s
haped channel is presented, The Annular-Channel TFT (AC-TFT) is fabric
ated using standard design rules with 4 mu m minimum feature size whic
h is common in large area applications such as Active Matrix LCD's. Th
e AC-TFT has two times smaller gate-to-source capacitance of about 50
fF in the on-state as compared to a conventional Rectangular-Channel T
FT (RC-TFT) which has the same on-current of more than 10 mu A at V-gs
= 20 V and V-ds = 10 V, Its off-current under illumination from the g
ate side is about ten times lower than that of the RC-TFT.