Planar transistors

Before the invention of the planar transistor, many photoresist processes were developed for the manufacture of circuit boards. Experience gained in this area was rapidly transferred to silicon processing, and much of the early work in integrated circuit lithography can be traced directly to circuit board manufacturing. 

Planar transistor 1961 FINFET 2009-2013 Scaling performance power... 

Silicon chips are really planar transistors constructed from thin layers of n-type and p-type regions connected by conductors. A chip less than 1 cm wide can contain hundreds of printed circuits and be used in computers, radios, and televisions. ... 

Fulfilling multilayer and miniature structures of memory devices led to the introduction of new materials and sfrucfures. For the structure, the design rule decreases less than 70 nm and the short channel effect (SCE) phenomenon appears to have a bad influence on fhe device drive if exisf-ing planar transistor (TR) is applied. To solve this problem, studies are in progress to apply recessed charmel array TR and three-dimensional structured FinFET in DRAM and floating gate, twin SONOS, and FinFET SONOS in flash memory (Eigure 6.3). 

FIsaURS 2-17 Two types of BJTs. Constnjction details are shown in (a) for a pnp alloy BJT and in (b) for an npn planar transistor. Symbols for a pnp and npn BJT are shown in (c) and (d). respectively. (Note that alloy junction transistors may also be fabricated as npn types and planar transistors as pnp.)... 

J. Go, PR. Nair, B. Reddy Jr., B. Dorvel, R. Bashir, M.A. Alam, Coupled heterogeneous nanowire—nanoplate planar transistor sensors for giant (>10V/pH) Nemst response, ACS Nano 6 (2012) 5972-5979. 

Short intramolecular contacts between chalcogens and other chalcogens or other heteroatoms have been shown to influence molecular geometry, particularly planarity, in many structures of electroactive materials. Hence the position of the chalcogen atom in the material can profoundly affect its properties. For example Crouch et al 2 report the X-ray crystal structure of compound 24 (Figure 10), a candidate for an organic field-effect transistor, showing the effect of intramolecular S- F close contacts (in tandem with H F contacts) on the planarity of the molecule in the solid state. Note also the... 

As the integrated circuit (IC) industry has chosen chemical mechanical planarization (CMP) as one of the indispensable processes in the generations of transistor gate lengths equal to or smaller than 0.35/im, it is imperative that the CMP-related process problems be investigated and... 

Fig. 13 (a) Schematic of an electromechanical single molecule transistor, (b) Schematic of the planar version of the Cgo amplifier. (Reprinted with permission from [101])... 

A likely candidate for the role of interlevel dielectric is polyimide on the basis of its relative purity and planarizing spin-on application. In fact, planarizing metal with polymer or so-called PMP technology was pioneered by Hitachi to develop two metal level transistors. More recently, several other... 

More recently, the 5-5 heterocyclic system has found application in the preparation of -type organic field effect transistors, which are currently receiving much attention for applications such as flexible displays, low-cost electronic papers, and smart memory-sensor elements. The most recent examples are molecules prepared by Yamashita, who has prepared the planar, perfluorinated thiazolothiazole molecules 169-171 to this end <2004CL1170, 2005JA5336, 2004JMC1787>. 

Thin films (qv) of vitreous silica have been used extensively in semiconductor technology. These serve as insulating layers between conductor stripes and a semiconductor surface in integrated circuits, and as a surface passivation material in planar diodes, transistors, and injection lasers. They are also used for diffusion masking, as etchant surfaces, and for encapsulation and protection of completed electronic devices. Thin films serve an important function in multilayer conductor insulation technology where a variety of conducting paths are deposited in overlay patterns and insulating layers are required for separation. 

The imager disclosed in WO-A-9202959 comprises thin film transistors deposited on a substrate, a planarization layer deposited on the transistors followed by a mercury cadmium telluride layer and a top electrode layer. 

A plurality of thin film field effect transistors 11 are deposited onto a substrate 12. Each of the transistors has a source electrode 13, a drain electrode 14 and a gate electrode 15. Source lines 17 link the source electrodes in each row of the transistors and drain lines 18 link the drain electrodes in each column of the transistors. The source lines and drain lines are electrically isolated by a planarization layer 19. A mercury cadmium telluride layer 20 is deposited onto the planarization layer followed by a top electrode layer 23. The gate electrodes are connected with the mercury cadmium telluride layer by connectors 21. A cross-section of the imager is shown below. 

Here, 41 indicates the thin film transistors, 51 the substrate, 43 a dielectric layer, 49 polysilicon gates, 50 gate electrodes, 55 contact plugs, 56 bottom electrodes, 53 the planarization layer, 54 the mercury cadmium telluride layer and 57 the top electrode layer. The planarization layer is formed from silicon oxide, silicon nitride, silicon oxide nitride or from a polyimide. The planarization layer may be formed as a double or triple layer. 

Our choice for an Ion Sensitive Field Effect Transistor (ISFET) as a transducing element was based on the fact that the SiO surface contains reactive SiOH groups for the covalent attachment of organic molecules and polymers. In addition the FET has fast response times and can be made very small with existing planar IC technology. FIGURE 1... 

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