Semiconductor MOS transistor

A well-known practical example of homoepitaxy is the deposition, by CVD vapor phase epitaxy, of a single crystal Si film on a Si wafer. This is one of the primary steps in the manufacture of bipolar transistors and some metal-oxide semiconductor (MOS) transistors. Explain why an epitaxial Si film on Si is deposited while the Si substrate alone could well suffice as the material for the required electronic and mechanical response ... 

John A. Copeland and Stephen Knight, Applications Utilizing Bulk Negative Resistance F.A. Padovani, The Voltage-Current Characteristics of Metal-Semiconductor Contacts P.L. Hower, W.W. Hooper, B.R. Cairns, R.D. Fairman, and D.A. Tremere, The GaAs Field-Effect Transistor Marvin H. White, MOS Transistors... 

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. 

Understanding the behavior of a MOS capacitor is useful in understanding the operation of a MOS transistor. When a negative voltage is applied to the conductor or metal, the energy bands in the p-type semiconductor... 

NMOS and PMOS (p-channel MOS) transistors are used side by side in complementary metal-oxide-semiconductor (CMOS) technology to form logic elements. These structures have the advantage of extremely low power consumption and are important in ultralarge-scale integration (ULSI) and very-large-scale integration (VLSI) (13). 

A high-resistance compound semiconductor film 13 is formed on a silicon substrate 3 at openings in an insulating film 6. A detector element 2 is composed of an n-type and a p-type HgCdTe layer 14 and 15 formed on the film 13. The detector element is connected to an electrode 24 and to a MOS transistor in the silicon substrate by a connector 21 A. 

A variety of chemical gas sensors are or could be used in electronic nose instruments. So far, successful results have been reached with conductive polymer (CP) sensors, metal oxide semiconductor (MOS) sensors, metal oxide semiconductor field effect transistor (MOSFET) sensors, quartz crystal microbalance (QCM) sensors, and infrared sensors. 

The attractiveness of silicon as a semiconductor material for ICs derives in part from the feet that this important material forms a naturally insulating surface oxide. Use is made of this fact, for example, in metal-oxide-semiconductor (MOS) field-effect transistors (FET), where the oxide serves as the gate insulator. No such naturally insulating oxide occurs with any of the compound semiconductors that offer improved performance over silicon in many device apphcations. Roberts et al. (38) demonstrated the feasibiUty of such metal-insulator-semiconductor (MIS) structures as FETs and chemical sensors shown schematically in Figure 1.23. These researchers... 

Figure 1.6. Schematic of an n-type metal-oxide-semiconductor (MOS) field transistor cross-section [19]...

The capacitor-type gas sensors are one type of the field-effect devices. The field-effect devices can be classified into two types metal-oxide-semiconductor (MOS) capacitors and transistors (MOSFETs), as shown in Figures 1.2 and 1.3, respectively... 

There is much interest in the application of PVDF in medical imaging because of its close acoustic impedance match with both tissues. Monolithic silicon-PVDF devices have been produced in which a sheet of PVDF is bonded to a silicon wafer containing an array of metal oxide semiconductor field effect transistor (MOSFET) amplifiers arranged in such a way that when an acoustic wave is detected, the electrical signal resulting from the piezoelectric action in the PVDF appears directly on the gate of an MOS transistor. The device is therefore known as a piezoelectric oxide semiconductor field effect transistor (POSFET). 

The measurement of flow rate is one of main subjects in experimental fluid mechanics. However, the thermocapacitive flow sensor may have electronic and semiconductor components, such as a capacitor, an n-channel MOS transistor, an oscillation circuit, and a microfabrication. Therefore, the thermocapacitive flow sensor is a multidisciplinary tool and some of its electronic and semiconductor components need to be explained. 

Electronic noses The so-called electronic noses consist of chemical gas sensors that are able to monitor changes in the offgas composition of fermentation processes. The different sensors of electronic noses are based on conductive polymers (CP), metal oxide semiconductors (MOS), metal oxide semiconductor field effect transistors (MOSFET), or quartz crystal microbalance (QCM). CP-based sensors use the electrochemical properties of polymers like polypyrrole or polyindole. The absorbance of selected molecules of the off-gas into the polymer film causes changes in the sensors conductivity. MOS sensors possess an electrochemically active surface of metal oxides like tin oxide or copper oxide. The sensitivity... 

Schottky barrier, metal oxide semiconductor (MOS), and held-effect transistors (MOSFETs) sensors are other types of gas sensor which involve metal films. These types of sensors were pioneered by Lundstrom et al. (1975). Besides silicon, compound semiconductors such as GaAs, InP, GaN, Ga Oj, and SiC have been alternatively employed as substrate materials for the above-mentioned... 

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