MISFET insulator semiconductor

MISFET. See Metal insulator semiconductor field-effect transistor. 

Figure 14-7. A MISFET in operation, (a) VK>V l/j=0 an n-lypc channel of constant thickness forms at the insulator-semiconductor interlace, (b) V, > V , Vlt - Vy, the channel is pinched ofl at the drain contact. The white area that separates the p-lype substrate from the ii-lypc contacts and channel represents the depletion layer.

MISFETs), 22 162, 192. See also Field effect transistors (FETs) Metal-insulator-semiconductor junction, 23 34... 

Gallium arsenide s native oxide is found to be a mixture of nonstoichiometric galhum and arsenic oxides and elemental arsenic. Thus, the electronic band structure is found to be severely disrupted, causing a breakdown in normal semiconductor behavior on the GaAs surface. As a consequence, the GaAs MISFET (metal insulator semiconductor field-effect transistor) equivalent to the technologically important Si-based MOSFET (metal-oxide semiconductor field-effect transistor) is, therefore, presently unavailable. 

Figure 14-6. Schematic view of three kinds of field-effect transistors (FET) (a) metal-insulator-semiconductor FET (MISFET), (b) metal-semiconductor FET (MESFET), (c) thin-film transistor (TFT).

Miyahara et al. (1985) developed an integrated enzyme FET based on a silicon-on-sapphire (SOS) sensor for simultaneous determination of glucose and urea. Three ISFETs and two metal insulator semiconductor FETs (MISFETs) were integrated on a surface area of 2.5 mm x 2.5 mm (Fig. 54). One of the ISFETs served as reference sensor in order to compensate the signals caused by pH changes of the solution the two others were covered by GOD and urease, respectively. The MISFETs can be used as pH electrodes. For enzyme immobilization the chip was covered with a laminated photosensitive layer of 75 pm thickness and,... 

The MIS capacitor represents the heart of most field effect sensor devices, and the physics of MIS capacitors is of importance and is treated in semiconductor physics and other sensor books (Sze, 1981 Lundstrom, 1995 Dimitrijev, 2000). Here, we will only give the basic physical principles regarding the metal insulator semiconductor field effect transistor (MISFET), since this is the ultimate transducer for commercial sensor devices. 

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-... 

Fig. 5. Metal-insulated semiconductor field effect transistor with n-channel (n-MISFET). (A) the state with uncharged G-I-Su capacitor, (B) open transistor with charged G-I-Su capacitor. Abbreviations S, source electrode D, drain electrode G, gate electrode Su, substrate Al, aluminium contact I, insulator (dielectric) n-Si, p-Si, n- or p-type of silicone...

The use of semiconducting conjugated polymers as an electro-active material in microelectronic devices is a rapidly growing area. Burroughes et al. [248] reported the first examples of high-performance Schottky diodes, metal-insulator semiconductor (MIS) diodes and the MIS-field effect transistor (MISFET) structure involving conjugated polymers. 

Electrically conducting polymers can be used as the active element in metal-insulator-semiconductor field-effect transistors (MISFET). MISFETs are generally produced by spin-coating a solution of a polymer onto the surface of oxidized silicon onto which metal electrodes have previously been deposited to form source and drain contacts (Fig. 21) [765]. 

MISFET metal-insulator-semiconductor field effect diode... 

One of the earliest examples of a conjugated polymer electronic device used transpolyacetylene which had been prepared by the Durham route. Precursor polyma- 2 has very good film-forming properties, and it is simple to control the thickness of the final polyacetylene film. Durham polyacetylene has electrical characteristics that are well suited to device fabrication. The carrier concentration (of the order 10 cm-s) results from unintentional doping, most likely from immobile catalyst residues that are chemically bound to the polymer chain ends. The undoped polymer can take over the role of the semiconductor in a metal-insulator-semiconductor field-effect transistor (MISFET). ... 

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