Metal insulator semiconductor Field effect transistor

MISFET. See Metal insulator semiconductor field-effect transistor. 

Lin, H. C. Ye, P. D. Xuan, Y. Lu, G. Facchetti, A. Marks T. J. 2006. High-performance GaAs metal-insulator-semiconductor field-effect transistors enabled by self-assembled nanodiclcctrics. Appl.. Phys. Lett. 89 142101/1-142101/3. 

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. 

Brown, A.R. et al.. Precursor route pentacene metal-insulator-semiconductor field-effect transistors, J. Appl. Phys. 79, 2136-2138, 1996. 

Hu, W. et al.. The gas sensitivity of a metal-insulator-semiconductor field-effect-transistor based on Langmuir-Blodgett films of a new asymmetrically substituted phthalocyanine. Thin Solid Films, 360, 256, 2000. 

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. 

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...

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]. 

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). ... 

The process of GaAs oxidation is so complex that even after many years of work there are important issues that are still a matter of controversy. Consequently, the GaAs metal insulator semiconductor field effect transistor (MISEET) technology did not develop very weU since the electronic passivation of GaAs is not fully resolved. The challenges in the fabrication of high quality oxide layers on GaAs stimulate researchers to find out the most suitable techniques and conditions to solve the interface-related problems. 

Figure 3.25 A schematic of a typical enhancement-mode n-p-n metal-insulator-semiconductor field effect transistor. The device is normally off and eonduetion is enhanced by application of a negative gate voltage relative to the source, creating an n-type channel. The source-to-drain voltage adds to the gate bias when turned on, which is why the channel is wider at one side. The hatched area under the gate indicates an optional heavily-doped polycrystalline semiconductor region as part of the gate (see also Figure 3.27). One must further prevent current flow to the substrate as this would turn the device on as if it were a bipolar junction transistor and the base were the substrate.

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