In one embodiment, a chemical sensor is described. The chemical sensor includes a chemically-sensitive field effect transistor including a floating gate conductor having an upper surface, a first opening extending through a first material and through a portion of a second material located on the first material and a second opening extending from the bottom of the first opening to the top of a liner layer located on the upper surface of the floating gate conductor.

The described semiconductor device can include a two-transistor pixel array. Each pixel in the two-transistor pixel array can include a chemical detection pixel comprising a chemically-sensitive transistor and a row-selection transistor connected between a current source and a chemically-sensitive transistor. The source of the chemically-sensitive transistor can be coupled to a column line, and the drain of the chemically-sensitive transistor can be coupled to the source of the row selection transistor. The gate of the row selection transistor can be couple to a row line. When a row line is activated, the row selection transistor can couple the chemically-sensitive transistor to the column line.

A field effect transistor sensor includes: a source-drain channel, a semiconductor layer on said source-drain channel, a first gate electrode arranged above said semiconductor layer, a first well enclosing said source-drain channel, said semiconductor layer and said first gate electrode, the first well being configured to be filled, in use, with a first liquid, particularly a gating electrolyte, a second gate electrode arranged above the first gate electrode and exposed to an interior of the first well. Also disclosed is an array device including an array of field effect transistor sensors according to the above.

A sensing device including a transistor, at least one response electrode, and a selective membrane is provided. The transistor includes a gate end, a source end, a drain end, and a semiconductor layer, wherein the source end and the drain end are located on the semiconductor layer, and the gate end is located between the source end and the drain end. The at least one response electrode is disposed opposite to the gate end of the transistor and spaced apart from the transistor. The selective membrane is located on the at least one response electrode or on the transistor.

The described embodiments may provide a chemical detection circuit that may comprise a plurality of first output circuits at a first side and a plurality of second output circuits at a second side of the chemical detection circuit. The chemical detection circuit may further comprise a plurality of tiles of pixels each placed between respective pairs of first and second output circuits. Each tile may include four quadrants of pixels. Each quadrant may have columns with designated first columns interleaved with second columns. Each first column may be coupled to a respective first output circuit in first and second quadrants, and to a respective second output circuit in third and fourth quadrants. Each second column may be coupled to a respective second output circuit in first and second quadrants, and to a respective first output circuit in third and fourth quadrants.

The described embodiments may provide a chemical detection circuit that may comprise a plurality of first output circuits at a first side and a plurality of second output circuits at a second side of the chemical detection circuit. The chemical detection circuit may further comprise a plurality of tiles of pixels each placed between respective pairs of first and second output circuits. Each tile may include four quadrants of pixels. Each quadrant may have columns with designated first columns interleaved with second columns. Each first column may be coupled to a respective first output circuit in first and second quadrants, and to a respective second output circuit in third and fourth quadrants. Each second column may be coupled to a respective second output circuit in first and second quadrants, and to a respective first output circuit in third and fourth quadrants.

In one embodiment, a chemical sensor is described. The chemical sensor includes a chemically-sensitive field effect transistor including a floating gate conductor having an upper surface, a first opening extending through a first material and through a portion of a second material located on the first material and a second opening extending from the bottom of the first opening to the top of a liner layer located on the upper surface of the floating gate conductor.

A FET type gas-sensitive device has a floating electrode formed in a horizontal direction. The device achieves noise reduction, process simplification, pollution control, sensing speed improvement, various sensing material applicability and mechanical stability etc. in comparison with a gas-sensitive device that is vertically stacked with a floating electrode, a sensing material layer and a control electrode. The device can be assembled easily with a plurality of gas-sensitive devices being operated by various sensing mechanisms in one substrate.

Provided is a sensing method of a FET-type sensor using electric charge storage engineering. The sensing method comprises the following steps to improve reactivity and selectivity to a gas to be sensed: (a) applying a preset erase voltage (Erase bias) or program voltage (Program bias) to the control gate according to the type of gas to be sensed to change a threshold voltage of the FET transducer and control the charge at an interface between the passivation layer and the sensing material layer; and (b) in the recovery phase where the gas detection reaction is terminated and the original state is returned, applying a pre-bias greater or less than a read voltage to the control gate according to the type of gas detected, and then applying the read voltage to the drain and the source of the FET transducer to increase the desorption rate of the detected gas.

The described embodiments may provide a chemical detection circuit that may comprise a plurality of first output circuits at a first side and a plurality of second output circuits at a second side of the chemical detection circuit. The chemical detection circuit may further comprise a plurality of tiles of pixels each placed between respective pairs of first and second output circuits. Each tile may include four quadrants of pixels. Each quadrant may have columns with designated first columns interleaved with second columns. Each first column may be coupled to a respective first output circuit in first and second quadrants, and to a respective second output circuit in third and fourth quadrants. Each second column may be coupled to a respective second output circuit in first and second quadrants, and to a respective first output circuit in third and fourth quadrants.