Low-draft filter for monitoring hydrogen gas in transformer insulating oil / ENS / EMS

摘要

The present invention relates to a low draft Pd / NiCr MISFET type sensor for monitoring hydrogen gas in a transformer insulating oil, comprising: a semiconductor substrate of a first conductivity type; A buried oxide layer formed on the semiconductor substrate; A first conductive semiconductor layer formed to be electrically insulated from the semiconductor substrate by an upper portion of the buried oxide layer; A first source and a first drain formed in a predetermined portion of the semiconductor layer by being spaced apart from each other by a predetermined distance and doped with impurities of a second conductivity type at a high concentration, A sensing transistor having a first lower portion and a first upper gate insulating layer, a first lower portion formed on top of the first upper gate insulating layer, and a first upper gate metal; A second source and a second drain formed at a predetermined distance of a predetermined portion of the semiconductor layer and formed by doping impurities of a second conductivity type at a high concentration, and a second source and a second drain formed continuously on the semiconductor layer between the second source and the second drain A reference transistor having a lower and a second upper gate insulating layer, a second lower and a second upper gate metal formed on top of the second upper gate insulating layer; A diode formed between the sensing transistor and the reference transistor of the semiconductor layer at a high concentration of the second conductivity type; A heater formed on a predetermined portion of the semiconductor layer so as to surround the sensing transistor and the reference transistor, the impurity of the second conductivity type being formed at a high concentration; And a device isolation region formed between the devices so as to electrically isolate the sensing transistor, the reference transistor, the diode, and the heater from each other.;Therefore, it is easy to maintain because of its simple structure, its characteristics can be stabilized, and it is possible to measure the concentration of hydrogen precisely. Since the hydrogen concentration can be continuously measured, it is possible to monitor in real time at a distance, It can be very cheap and mass-produced.