Catalytic gate metal-oxide-semiconductor

Metal oxide semiconductor field effect transistors (MOSFETs) constitute other materials with applicability in the development of biosensors. Usually, a MOSFET structure consists of a metal gate on top of an oxide layer, tyqjically Si02 [189]. The catalytic properties of these sensors depend upon the type of the gate metal as well as the temperature at which the MOSFET is operated. The most used catalytic metals used as gate materials are Pd (is a good... 

In general, the semiconductor is silicon and the oxide is silicon dioxide. The potential on the gate, which is the metal, can be varied to control the charge distribution at the oxide-semiconductor interface. The catalytic gate MOSFET device differs from an ordinary MOSFET in that the gate is metalized with palladium, Pd,... 

The methods for miniaturization of chemical and biosensors are based on an extension of VLSI fabrication techniques, however with a broader range of materials [1-6], The range of materials is beyond what is normal for IC electronic devices because additional functionality is needed. These materials include electrochemi-cally active metals with catalytic properties, conductive oxides, and high-temperature materials. Examples of metal oxides include Sn02, WO3, and Ti02, and other catalytic metals include Pt, Ru, Ir, Pd, and Ag needed for electrochemical sensors [7,8]. As the dimensions of semiconductor devices continue to move to smaller gate lengths, nanoscale fabrication techniques are now developed. Hence, stmctures for sensors... 

Fig. 1.8 Classical schematic drawing illustrating the hydrogen-sensitive Schottky diode-based, capacitance-based, and field-effect transistor-based devices, in which hydrogen atoms adsoibed at the metal-semiconductor or meted oxide interface cause a shift of the electrical characteristics along the voltage axis in devices having catalytic meted (Pd) gates...

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