Electrolyte transistor

Electronics Production of circuit boards (producing contacts in boreholes), modified electrolytic condensers, modified field effect transistors, molecular electronics (unidirectional conductors), photostructural lacquers based on ICPs (electron beam lithography), novel photoluminescent diodes (LED), data storage (e.g. spatially resolved eleclrochromics)... 

Valve voltmeters were widely used in the past, but have been replaced by transistor voltmeters. With instruments of this type it is possible to achieve an input resistance of 50 MQ or more, the current required to operate the instrument being of the order of 10" A. The early instruments had a tendency to zero drift on the lower ranges, but this has been overcome in the modern transistor types. Such instruments are most often used to make potential readings in extremely high-resistance electrolytes. The accuracy of such instruments is of the order of 2% full-scale deflection. It is necessary to ensure that both types are so designed that they do not respond to alternating currents. 

Ionic Chemical Systems for Electrolyte Diode and Transistors... 

Simple chemical systems with several components (HCl, KOH, KCl in hydrogel) were used for modeling mass and charge balances coupled with equations for electric field, transport processes and equilibrium reactions [146]. This served for demonstrating the chemical systems function as electrolyte diodes and transistors, so-called electrolyte-microelectronics . 

The measurement of changes of the surface potential Vo at the interface between an insulator and a solution is made possible by incorporating a thin film of that insulator in an electrolyte/insulator/silicon (EIS) structure. The surface potential of the silicon can be determined either by measuring the capacitance of the structure, or by fabricating a field effect transistor to measure the lateral current flow. In the latter case, the device is called an ion-sensitive field effect transistor (ISFET). Figure 1 shows a schematic representation of an ISFET structure. The first authors to suggest the application of ISFETs or EIS capacitors as a measurement tool to determine the surface potential of insulators were Schenck (15) and Cichos and Geidel (16). 

Note that in contrast to a solid-state transistor, hole injection from the HF electrolyte into the base is not observed independent of VBB (full diamonds in Fig. 3.2). Hole injection becomes sensible if an oxidizing agent is added to the HF, as shown in Fig. 4.12. 

The ion-selective field-effect transistor (ISFET) represents a remarkable new construction principle [7, 63], Inverse potentiometry with ion-selective electrodes is the electrolysis at the interface between two immiscible electrolyte solutions (ITIES) [28, 55],... 

Ion-selective electrodes are systems containing a membrane consisting basically either of a layer of solid electrolyte or of an electrolyte solution whose solvent is immiscible with water. The membrane is in contact with an aqueous electrolyte solution on both sides (or sometimes only on one). The ion-selective electrode frequently contains an internal reference electrode, sometimes only a metallic contact, or, for an ion-selective field-effect transistor (ISFET), an insulating and a semiconducting layer. In order to understand what takes place at the boundary between the membrane and the other phases with which it is in contact, various types of electric potential or of potential difference formed in these membrane systems must first be defined. 

Rosenblatt S, Yaish Y, Park J et al (2002) High performance electrolyte gated carbon nanotube transistors. Nano Lett 2 869-872... 

Katsura T, Yamamoto Y, Maehashi K et al (2008) High-performance carbon nanotube field-effect transistors with local electrolyte gates. Jpn J Appl Phys 47 2060-2063... 

Ion-selective field-effect transistors (ISFETs) are ion sensors that combine the electric properties of gate-insulator field-effect transistors and the electrochemical properties of ion-selective electrodes (ISEs). ISFETs have attracted much attention for clinical and biomedical fields because they could contain miniaturized multiple sensors and could be routinely used for continuous in vivo monitoring of biological fluid electrolytes (e.g., Na+, K+, Ca +, Cl", etc.) during surgical procedures or at the bedside of the patients in clinical cate unit (2). 

The knowledge of the surface potential for the dispersed systems, such as metal oxide-aqueous electrolyte solution, is based on the model calculations or approximations derived from zeta potential measurements. The direct measurement of this potential with application of field-effect transistor (MOSFET) was proposed by Schenk [108]. These measurements showed that potential is changing far less, then the potential calculated from the Nernst equation with changes of the pH by unit. On the other hand, the pHpzc value obtained for this system, happened to be unexpectedly high for Si02. These experiments ought to be treated cautiously, as the flat structure of the transistor surface differs much from the structure of the surface of dispersed particle. The next problem may be caused by possible contaminants and the surface property changes made by their presence. 

Memory devices (electrical, optical) Molecular electronics Nonlinear optics Packaging materials pH modulator Polymer/solid electrolytes Semiconducting devices p-n junctions, pho-tovoltaics, Schottky diodes, light-emitting diodes, transistors, etc. 

Electrolytic etching has been used to reveal p-n junctions (43) as well as to remove n- or p-type material preferentially from diodes and transistors (28). These processes make use of the rectifying barrier of p-n junctions as well as the hole depletion effect at the surface of n-type germanium and silicon. 

The basic building block of all CHEMFETs is the ion-sensitive field effect transistor (ISFET), introduced in 1970 by Bergveld [4]. In an ISFET the gate metal of a metal oxide semiconductor field effect transistor (MOSFET) is removed and the resulting gate oxide surface (2) is directly exposed to the electrolyte solution (Figure 1). 

Massive electrochemical attack known as galvanic corrosion [58,59] is the most severe form of copper corrosion. It can completely remove the copper from the structures (Figs. 17.25 and 17.26). It can occur when the wafers are exposed to a corrosive electrolyte for an extended period. It can also occur if the slurry does not contain enough or effective corrosion inhibitor. The source of such a galvanic potential on the patterned copper surface may be due to the fact that some copper structures connected to transistors have a different electrical potential than the rest of the wafer surface. Another possible cause of this type of galvanic potential is related to the barrier material induced metal metal battery effect. Most copper CMP slurries have been developed for Cu structures with Ta or TaN as a barrier material. In some cases, other metals may also be used in addition to the barrier metal. For example, a metal hard mask could contribute to the galvanic corrosion effects. It is also possible that some types of copper are more susceptible to corrosion that others. The grain... 

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