Field-effect transistors Metal-oxide-semiconductor FETs

Different types of SiC Field Effect Transistors, Metal Oxide Semiconductor Transistors (MOSFETs), Metal Semiconductor Field Effect Transistors (MESFETs), and Junction Field Effect Transistors (JFETs) compete for future applications in high temperature and harsh environment electronics. This Datareview details these various types of FETs, the structures used and the performances obtained. Interesting recent developments and potential applications, such as FET integrated circuits, a hybrid operational amplifier and an inverter circuit are also outlined. 

Field-effect transistors (FETs) Heterojunction bipolar transistors (HBTs) High electron mobility transistors (HEMTs) Metal oxide semiconductor FETs (MOSFETs) Single-electron transistors (SETs) Single-heterojunction HBTs (SH-HBTs) Thin-film transistors (TFTs) hydrogenated amorphous silicon in, 22 135... 

The basic idea that guides the insulated-gate field-effect transistor (FET) traces back to the mid-1920s [14], but it was not until 1960 that this early concept could be successfully demonstrated, with the invention of the metal-oxide-semiconductor FET (MOSFET) [15]. Field-effect measurements on copper phthalocyanine films were... 

Field-effect transistors exist in two major types the junction FET (JFET) and the metal-oxide-semiconductor FET (MOSFET). The junction FET has a... 

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 12.12 Principle of metal-oxide-semiconductor field-effect transistor (MOS-FET). A narrow conducting channel is created when the gate is at positive voltage, allowing electrons to pass from the source to the drain.

Miniaturization of electronic devices in integrated circuits (ICs) has both technological and physical limits. Since 30-40 years only a semiconductor technology, mostly the CMOS FET (complementary metal-oxide-semiconductor field effect transistor) and the TTL (transistor-transistor logic) technologies are used for fabrication of integrated circuits in the industrial scale. Probably the CMOS technology will be used at least in the next 10-15 years. 

One real advantage of these sensors lies in the fact that an ion-selective membrane can act as a gate directly on a field effect transistor (FET) (Janata and Huber [1985]). These ion-selective field effect transistors (ISFET, shown schematically in Figure 4.3.2a) again are the analog of a solid state device, the metal oxide semiconductor field effect transistor (MOSFET, Figure 2.2.2b). 

Field effect transistors In the fabrication of some potentiometric and gas-sensitive biochemical sensors an important role is played by unipolar transistors controlled by an electrical field (field effect transistors, FET) with a conducting channel isolated from the control electrode (gate) by a thin layer of insulator (MISFET-metal insulated semiconductor FET) made of Si02 (MOSFET-metal oxide semicon-... 

The metal oxide-semiconductor field effect transistor (MOSFET) is the most important component in modem electronics, at least from the perspective of sheer numbers. A typical computer chip contains vast numbers of MOS-FETs. The basic architecture is illustrated in Eigure 1. The semiconductor is connected to a substrate on one side and to a gate contact on the other, which is separated from the semiconductor by a dielectric film. The region of semiconductor directly beneath the gate connects two contacts, the source and the drain. If the semiconductor is p-type Si, then source and drain contacts may be formed by implantation of electron-rich elements to yield shallow regions composed of n-type material. As the potential difference between the gate and the substrate is increased, the channel between the... 

The FET characteristics described here differ from those of conventional metal-oxide-semiconductor field-effect transistors (MOSFETs) [208] in the following aspects ... 

Thin film field-effect transistors are prepared by using LB films with thicknesses ranging from a monolayer to some ten monolayers as the active material (cf Sect. 3.7) [428]. Metal oxide semiconductor field-effect transistor (MOS-FET) devices work through the modulation of an accumulation layer at the... 

The MIS structure is an example of a semiconductor structure of high importance for sensor apphcations. This structure consists of three layers arranged as a stack. The sequence is metal (M), insulator (I) and semiconductor (S). Usually, the set-up starts with a substrate of a semiconductor material such as P-type silicon. This is covered first by a thin silicon oxide (Si02) layer formed by oxidation in an oxygen-containing atmosphere. Next, a thin metallic layer is applied by vapour deposition. Instead of MIS, often the abbreviation MOS is used, since the insulating layer (I) is often formed by an oxide (0). Thus, a field effect transistor (FET) in a MOS structure is called a MOSFET . 

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