Metal Oxide Semiconductor MOS Capacitor

Schottky-barrier diode and metal-oxide-semiconductor (MOS) capacitor gas sensors have established themselves as extremely sensitive, versatile solid state sensors. 

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... 

Nakano and Jimbo investigated the interface electronic properties of thermally oxidized n-type GaN metal-oxide-semiconductor (MOS) capacitors [230]. The formation of an intermediate gallium oxide nitride layer vith a graded composition could provide the origin of a small capacitance transient observed experimentally. 

An insnlating layer of Si02 is grown onto a crystalline silicon substrate, and thin conducting electrodes are placed on top of the silica layer to create metal-oxide-semiconductor (MOS) capacitors. The crystalline silicon has Si-Si bonds arranged in a 3D lattice. A bond can be broken by... 

The plates of the capacitors of integrated circuits (Fig. 2.50(b)) in most modem technologies (AUstot and Black, 1983) are formed by two heavily doped polysfiicon layers. The dielectric is usually a thin layer of silicon oxide. The whole capacitor is formed on a layer ofthick (field) oxide. The capacitors are temperature stable, their temperature coefficient is about 20 ppm/°C. A detailed comparative evaluation of the different metal oxide semiconductor (MOS) capacitor structures can be found in AUstot and Black (1983). 

To understand metal-oxide-semiconductor (MOS) Capacitor CV curves, a high frequency (HF) CV curve for an n-type semiconductor substrate is illustrated in Figure 8. A CV curve can be divided into three regions accumulation, depletion, and inversion. Each of the three regions is described for an n-type complementary MOS (CMOS). This application is conducted using the Keithley Model 4200-SPAS to make C-V measurements. 

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. 

The source and drain are both p-type if the current flowing is holes. Surface field effect transistors have become the dominant type of transistor used in integrated circuits, which can contain up to one billion transistors plus resistors, capacitors, and the very thinnest of deposited connection wires made from aluminum, copper, or gold. The field effect transistors are simpler to produce than junction transistors and have many fevorable electrical characteristics. The names of various field effect transistors go by the abbreviations MOS (metal-oxide semiconductor), PMOS (p-type metal-oxide semiconductor), NMOS (n-type metal-oxide semiconductor), CMOS (complementary metal-oxide semiconductor—uses both p-type unipolar and n-type unipolar). 

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