TFT ION SENSOR AND TFT ION SENSOR APPARATUS USING THE SAME

摘要

The ion sensors using TFT or MOSFET are low in the measurement sensitivity so that it is difficult to detect an extremely small amount of sensing-target substance. A TFT ion sensor includes both a gate electrode (a silicon substrate) and a reference electrode, in which the electrostatic capacitance of a gate insulating film (a thermal oxide film) is set to be larger than the electrostatic capacitance of an ion sensitive insulating film. Therefore, it is possible to detect the concentration of ions, hormones, and the like in a sensing-target substance from the shift in the threshold voltage of the gate-source voltage to source-drain current property.

主权项

1. A TFT ion sensor, comprising:
a semiconductor active layer to which a source electrode and a drain electrode are connected; a gate insulating film and a gate electrode provided on one of surfaces of the semiconductor active layer; an ion sensitive insulating film provided on the other surface of the semiconductor active layer; and a reference electrode provided at a position spatially isolated from the ion sensitive insulating film, wherein: an electrostatic capacitance per unit area of the ion sensitive insulating film is larger than an electrostatic capacitance per unit area of the gate insulating film; and a voltage detection unit for reading out a potential difference between the source electrode and the gate electrode is provided further.