A New Gas Sensor Based on MOSFET Having a Horizontal Floating-Gate

A new gas sensor based on metal-oxide- semiconductor field-effect transistor was fabricated and characterized. The sensor has p-type channel, floating-gate, and control-gate formed horizontally so that various kinds of sensing material can be used in this basic sensing structure. As a sensing material in this letter, SnO
_x
was adopted to sense a target gas of NO
₂
. Measured drain current was changed by 195% at a NO
₂
gas concentration of 50 ppm. Sensing speed is <;50 s at 180 °C.