MISFET structure

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. 

Fig. 21.51 Cross section of a MISFET structure with an implanted electroactive polymer as semiconductor.

Schematic diagram for a poly(acetylene) MISFET structure. Dimensions shown are to scale, except the channel width (20 pm) and length (1.5 m). After Reference [1014], reproduced with permission.

Figure 3. Schematic diagram for a polyacetylene MISFET structure. Dimensions shown are to...

Figure 40. Difference spectra due to charge accumulation layer in a polyacetylene MISFET structure, from [14]. The solid line is the difference signal the broken line is the normal Raman spectrum. The excitation wavelength is 584 run.

We find that we can similarly model the range in properties of the solitons formed by charge injection into the accumulation region of the MIS and MISFET structures. The accumulation layer in the MIS structure is very closely localised to the interface with the insulator. For silicon-based MISFET inversion layer structures, typical confinement distances are of order 2 nm [68] and we can expect values here to be no larger for the polyacetylene devices. We can therefore expect that the accumulation layer will be very sensitive to the local structure of the polymer at the interface with the insulator. We consider that in the case where this is silicon dioxide, the polymer surface layer is significantly more disordered than in the bulk of the polymer. In contrast, where the... 

Tdie 1 Parameters obtained from absorption and i toinduced absoiptirai measurements and from electroabsoiption measurements on MIS and MISFET structures. 

Figure 41. MISFET structure with Au source and drain contacts. Shown here is Ids versus Vds for various negative values of V gs, showing channel current enhancement and saturation.

Figure 44 MISFET structure with poly n-silicon source and drain contacts with polyacetylene layer thickness of 20 nm. Shown here is the variation of Ids with Vgs for Vds =+10 V.

Figure 48 MISFET structure shown in figures 44-46. Shown here is the variation of Ids with Vds for various values of Vgs in the inversion regime. The device was held at 315 K for these experiments.

Na X, Niu W, Li H, Xie J (2002) A novel dissolved oxygen sensor based on MISFET structure with Pt-LaF3 mixture film. Sensors Actuators B Chem 87(2) 222-225. doi 10.1016/S0925-... 

Conventional electronic devices are made on silicon wafers. The fabrication of a silicon MISFET starts with the diffusion (or implantation) of the source and drain, followed by the growing of the insulating layer, usually thermally grown silicon oxide, and ends with the deposition of the metal electrodes. In TFTs, the semiconductor is not a bulk material, but a thin film, so that the device presents an inverted architecture. It is built on an appropriate substrate and the deposition of the semiconductor constitutes the last step of the process. TFT structures can be divided into two families (Fig. 14-12). In coplanar devices, all layers are on the same side of the semiconductor. Conversely, in staggered structures gate and source-drain stand on opposing sides of the semiconductor layer. 

C4.1 General remarks on GaN-based transistors and potential for high temperature/power operation C4.2 GaN FET structures MESFET, MISFET, JFET and MODFET... 

FIGURE 1 (a) A Si-doped GaN MESFET [2] (reproduced by permission of the Electrochemical Society Inc.), (b) A MISFET with Si3N4 dielectric insulator [2] (reproduced by permission of the Electrochemical Society Inc.), (c) A GaN JFE p- and n-types are formed by 40Ca and Si implantation, respectively (reproduced by permission of the authors) [4], (d) A typical group Ill-nitride MODFET layer structure. 

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. 

For MISFETs with the other type of channel, i.e. p-MISFETs, analogous rules hold. The major carriers in the n-substrate are then electrons and in the inverse conductivity layer the minor carriers are positive holes in crystallographic structure (slower than electrons). The drain current (Id < 0) rises with more negative applied voltage Ugs. 

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