Metal—oxide—semiconductor field-effect

Metal oxide semiconductor field-effect transistor pOSFEQ... 

Gate oxide dielectrics are a cmcial element in the down-scaling of n- and -channel metal-oxide semiconductor field-effect transistors (MOSEETs) in CMOS technology. Ultrathin dielectric films are required, and the 12.0-nm thick layers are expected to shrink to 6.0 nm by the year 2000 (2). Gate dielectrics have been made by growing thermal oxides, whereas development has turned to the use of oxide/nitride/oxide (ONO) sandwich stmctures, or to oxynitrides, SiO N. Oxynitrides are formed by growing thermal oxides in the presence of a nitrogen source such as ammonia or nitrous oxide, N2O. Oxidation and nitridation are also performed in rapid thermal processors (RTP), which reduce the temperature exposure of a substrate. 

A novel development of the use of ion-selective electrodes is the incorporation of a very thin ion-selective membrane (C) into a modified metal oxide semiconductor field effect transistor (A) which is encased in a non-conducting shield (B) (Fig. 15.4). When the membrane is placed in contact with a test solution containing an appropriate ion, a potential is developed, and this potential affects the current flowing through the transistor between terminals Tt and T2. 

The ISFET is an electrochemical sensor based on a modification of the metal oxide semiconductor field effect transistor (MOSFET). The metal gate of the MOSFET is replaced by a reference electrode and the gate insulator is exposed to the analyte solution or is coated with an ion-selective membrane as illustrated in Fig. 

The operation principle of these TFTs is identical to that of the metal-oxide-semiconductor field-effect transistor (MOSFET) [617,618]. When a positive voltage Vg Is applied to the gate, electrons are accumulated in the a-Si H. At small voltages these electrons will be localized in the deep states of the a-Si H. The conduction and valence bands at the SiN.v-a-Si H interface bend down, and the Fermi level shifts upward. Above a certain threshold voltage Vth a constant proportion of the electrons will be mobile, and the conductivity is increased linearly with Vg - Vih. As a result the transistor switches on. and a current flows from source to drain. The source-drain current /so can be expressed as [619]... 

Palmour, J. W., H. S. Kong, and R. F. Davis, Characterization of Device Parameters in High-Temperature Metal-Oxide-Semiconductor Field-Effect Transistors in fi-SiC Thin Films, J. of Applied Physics, Vol. 64, No. 4, August 15, 1988, pp. 2168-2177. 

MOSFETs. A type of semiconductor device that utilizes oxide ceramics is a metal-oxide-semiconductor field-effect transistor, abbreviated as MOSFET. Just like the semiconductor junction devices of Section 6.1.1.6, the MOSFET is composed of n-and / -type semiconductor regions within a single device, as illustrated in Figure 6.36. 

Metal oxide semiconductor field-effect transistors (MOSFETs) are field effect transistors with a thin film of silicon dioxide between the gate electrode and the semiconductor. The charge on the silicon dioxide controls the size of the depletion zone in the polype semiconductor. MOSFETs are easier to mass produce and are used in integrated circuits and microprocessors for computers and in amplifiers for cassette players. Traditionally, transistors have been silicon based but a recent development is field-effect transistors based on organic materials. 

Metal Oxide Semiconductor Field-Effect Transistor... 

MOS metal oxide sensor, MOSFET metal oxide semiconductor field-effect transistor, IR infrared, CP conducting polymer, QMS quartz crystal microbalance, IMS ion mobility spectrometry, BAW bulk acoustic wave, MS mass spectrometry, SAW siuface acoustic wave, REMPI-TOFMS resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry... 

Ion-Selective Field Effect Transistors [22b,c,d] An ion-selective field effect transistor (ISFET) is a hybrid of an ion-selective electrode and a metal-oxide semiconductor field effect transistor (MOSFET), the metal gate of the MOSFET being replaced by or contacted with a thin film of a solid or liquid ion-sensitive material. The ISFET and a reference electrode are immersed in the solution containing ion i, to which the ISFET is sensitive, and electrically connected as in Fig. 5.37. A potential which varies with the activity of ion i, o(i), as in Eq. (5.38), is developed at the ion-sensitive film ... 

Figure 19.8—A selective electrode designed from a MOSFET (metal oxide semiconductor field effect transistor). A specific reaction can be monitored by putting an enzyme in contact with the electrodes. This schematic shows the three electrodes used for amperometric measurement.

MOSFETs. The metal-oxide-semiconductor field effect transistor (MOSFET or MOS transistor) (8) is the most important device for very-large-scale integrated circuits, and it is used extensively in memories and microprocessors. MOSFETs consume little power and can be scaled down readily. The process technology for MOSFETs is typically less complex than that for bipolar devices. Figure 12 shows a three-dimensional view of an n-channel MOS (NMOS) transistor and a schematic cross section. The device can be viewed as two p-n junctions separated by a MOS capacitor that consists of a p-type semiconductor with an oxide film and a metal film on top of the oxide. 

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