Method of sensing a chemical and sensor therefor
AssigneeMotorola, Inc.
InventorsYoung Sir Chung, Keenan L. Evans
Life of this patent
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Abstract
A sensor (10) includes a gate electrode (20) overlying a channel region (34). A gap (22) between the gate electrode (20) and the channel region (34) allows a surface (28) of the gate electrode (20) to be exposed to a chemical. Upon exposure to the chemical, a surface potential or an electrical impedance of the gate electrode (20) may change. Comparing the changes in surface potential versus the changes in electrical impedance provides a method to distinguish between similar chemical species and also to extend the detection range of the sensor (10).
Claims20
A method of sensing a chemical comprising the steps of:
- providing a sensing material;
- detecting a surface potential of the sensing material;
- detecting an electrical impedance through the sensing material;
- and
- comparing the surface potential to the electrical impedance to determine a presence of the chemical.
A method of sensing a chemical comprising the steps of:
- providing a transistor having a gate electrode overlying a channel region;
- using the gate electrode to control a current in the channel region;
- measuring a resistance of the gate electrode;
- measuring a magnitude of the current;
- and
- comparing the resistance of the gate electrode to the magnitude of the current to sense the chemical.
A sensor comprising:
- a semiconductor substrate;
- a channel in the semiconductor substrate;
- a gate electrode overlying the channel, wherein a gap exists between the gate electrode and the semiconductor substrate;
- a first electrical connection coupled to the gate electrode;
- and
- a second electrical connection coupled to the gate electrode.
Dependencies are inferred from the claim text.