Combustible gas diode sensor
AssigneeFord Global Technologies, LLC
InventorsAmer Mohammad Khaled Samman, Samuel Admassu Gebremariam, Lajos Rimai
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Abstract
A combustible gas sensor diode including a SiC semiconductor substrate, on top of which an AlN layer and a catalytic metal “gate” electrode are deposited is disclosed. The combustible gas sensor diode can be operated in either a D.C. forward conduction mode or an A.C. reverse bias mode. Methods of detecting combustibles in both D.C. and A.C. modes are further disclosed.
Claims13
A combustible gas sensor diode structure comprising:
- a SiC semiconductor substrate;
- a metal back contact juxtaposed to the SiC semiconductor substrate;
- an AlN layer deposited on the SiC semiconductor substrate;
- and
- a catalytically active metal “gate” electrode deposited on the AlN layer.
A method of detecting combustibles in a gas stream, comprising:
- placing a reverse biased diode sensor in contact with the gas stream, wherein the diode sensor comprises:
- a SiC semiconductor substrate;
- a metal back contact juxtaposed to the SiC semiconductor substrate;
- an AlN layer deposited on the SiC semiconductor substrate;
- and
- a catalytically active metal gate deposited on the AlN layer;
- measuring the capacitance of the diode sensor at frequencies between 100 and 1000 KHz;
- and
- detecting a shift in the capacitance versus voltage characteristics of the diode sensor.
A method of detecting combustibles in a gas stream comprising:
- placing a forward biased diode sensor in contact with the gas stream, wherein the diode sensor comprises:
- a SiC semiconductor substrate;
- a metal back contact juxtaposed to the SiC semiconductor substrate;
- an AlN layer deposited on the SiC semiconductor substrate;
- and
- a catalytically active metal gate deposited on the AlN layer;
- applying a constant forward current to the diode sensor;
- and
- measuring a change in the voltage drop across the diode sensor in response to changes in gas stream composition.
A method of detecting combustibles in a gas stream comprising:
- placing a forward biased diode sensor in contact with the gas stream, wherein the diode sensor comprises:
- a SiC semiconductor substrate;
- a metal back contact juxtaposed to the SiC semiconductor substrate;
- an AlN layer deposited on the SiC semiconductor substrate;
- and
- a catalytically active metal gate deposited on the AlN layer;
- applying a constant forward voltage to the diode sensor;
- and
- measuring the change in the current through the diode sensor in response to changes in gas stream composition.
Dependencies are inferred from the claim text.