SEMICONDUCTOR DEVICE

摘要

THERE IS PROVIDED A SEMICONDUCTOR DEVICE IN WHICH FABRICATION STEPS CAN BE REDUCED BY CONSTRUCTING A CIRCUIT USING ONLY TFTS OF ONE CONDUCTIVITY TYPE AND IN WHICH A VOLTAGE AMPLITUDE OF AN OUTPUT SIGNAL CAN BE NORMALLY OBTAINED. A CAPACITANCE (205) IS PROVIDED BETWEEN A GATE AND A SOURCE OF A TFT (203) CONNECTED TO AN OUTPUT NODE, AND A CIRCUIT FORMED OF TFTS (201) AND (202) HAS A FUNCTION TO BRING A NODE A INTO A FLOATING STATE. WHEN THE NODE A IS IN THE FLOATING STATE, A POTENTIAL OF THE NODE A IS CAUSED HIGHER THAN VDD BY USING GATE-SOURCE CAPACITANCE COUPLING OF THE TFT (203) THROUGH THE CAPACITANCE (205), THUS AN OUTPUT SIGNAL HAVING AN AMPLITUDE OF VDD-GND CAN BE NORMALLY OBTAINED WITHOUT CAUSING AMPLITUDE ATTENUATION DUE TO THE THRESHOLD VALUE OF THE TFT. (FIG. 2A)