Semiconductor breakdown

In the case of semiconductors, the idea of electron tunneling has been used by Zener [42] to describe the so-called interband tunneling. Such tunneling represents one of the possible mechanisms of semiconductor breakdown. To understand the nature of interband tunneling, we shall first follow Ziman [43] and consider the one-dimensional motion of an electron in a separate band under the influence of an electric field. If we use the scheme of repeated bands, then the electron motion in momentum space is an up and down motion along the OABC periodic curve (Fig. 16). In the coordinate space, the electron, starting from point O, accelerates then slows down as it approaches point A here, the direction of the motion is changed to the... 

Silicon wafer has been extensively used in the semiconductor industry. CMP of silicon is one of the key technologies to obtain a smooth, defect-free, and high reflecting silicon surfaces in microelectronic device patterning. Silicon surface qualities have a direct effect on physical properties, such as breakdown point, interface state, and minority carrier lifetime, etc. Cook et al. [54] considered the chemical processes involved in the polishing of glass and extended it to the polishing of silicon wafer. They presented the chemical process which occurs by the interaction of the silicon layer and the... 

Electric Breakdown in Anodic Oxide Films Physics and Applications of Semiconductor Electrodes Covered with Metal Clusters Analysis of the Capacitance of the Metal-Solution Interface. Role of the Metal and the Metal-Solvent Coupling Automated Methods of Corrosion Measurement... 

On the other hand, Switzer et al. proposed a different model for the oscillation. They attributed the oscillation to repetitive build-up and breakdown of a thin CU2O layer, which is a p-type semiconductor and acts as a thin rectifying (passivating) layer [24]. Disappearance of the oscillation under irradiated condition supports this model. Light will generate electron-hole pairs in the CU2O and lower the rectifying barrier at the semiconductor/solution interface. 

Flame Photometry and Gas Chromatography (CyTerra) -Aerodynamic Particle Size and Shape Analysis (BIRAL) -Flow Cytometry (Luminex, LLNL) -Semiconductor-Based Ultraviolet Light (DARPA) -Polymer Fluorochrome (Echo Technology) -Laser-Induced Breakdown Spectroscopy -Raman Scattering -Infrared Absorption -Terahertz Spectroscopy -UV LIDAR... 

Grain boundary defects are primarily responsible for the operation of zinc oxide (ZnO) varistors, a shortened form of variable resistor. The varistor behaves like an insulator or poor semiconductor at lower electrical field strengths, but at a critical breakdown voltage the resistance decreases enormously and the material behaves like an electrical conductor (Fig. 3.36). When a varistor is connected in parallel with electrical equipment, negligible power flows through it under normal low... 

A variety of photocatalyzed decarboxylation reactions on Ti02 powder including the decomposition of acetate to methane and carbon dioxide and the breakdown of benzoic acid yielding predominantly CO2 have been reported by Bard and coworkers (23,24). Evidence for the occurrence of these "photo-Kolbe" reactions has stimulated the search for other organic reactions that might be photochemically initiated by excitation of semiconductors and extensive work in this area is in progress (25). 

Many of the commercial applications of semiconductor photocatalysis involve the oxidative breakdown of organic pollutants in aqueous solution or of volatile organic compounds in air by oxygen, a process called photomineralisation. 

Significant reverse currents at semiconductor electrodes are not only observed for breakdown but also under illumination. For the latter case a quantum efficiency q, the number of exchanged holes and electrons n e per incident photons np, can be defined ... 

The next point to realize is that the best emitter is a metal. Many forms of carbon initially studied are semiconductors or even insulators, including nanodiamond [8-11] and diamond-like carbon (DLC) [12-13,4]. Combine this with local field enhancement means that there is never uniform emission from a flat carbon surface, it emits from local regions of field enhancement, such as grain boundaries [8-11] or conductive tracks burnt across the film in a forming process akin to electrical breakdown [13]. Any conductive track is near-metallic and is able to form an internal tip, which provides the field enhancement within the solid state [4]. Figure 13.2 shows the equipoten-tials around an internal tip due to grain boundaries or tracks inside a less conductive region. 

Surface layers of silicon oxide are important in semiconductor device fabrication as interlayer dielectrics for capacitors, isolation of conducting layers, or as masking materials. However, anodic oxides, due to their relatively poor electrical properties, breakdown voltage, and leakage current, have not yet found much use in device technology, and cannot compete with thermal oxides obtained at high temperatures of 700 to 900 °C. 

The thermal conductivity of diamond at 300 K is higher than that of any other material, and its thermal expansion coefficient at 300 K is 0.8 x 10". lower than that of Invar (an Fe-Ni alloy). Diamond is a very widc-band gap semiconductor Eg = 5.5 eV), has a high breakdown voltage (I07V cm-1), and its saturation velocity of 2.7 x I01 cm s-1 is considerably greater than that of silicon, gallium arsenide, or indium phosphide. 

An interesting effect has been observed in p-GaP.(25) If the cathodic breakdown regime is attained (10 V or greater vs SCE) in the dark at cathodic currents of 10 mA or greater, luminescence is observed from the electrode. This luminescence is associated with the injection of ions into the semiconductor. The luminescence is broad band and occurs both above and below the band gap as illustrated in Figure 14a. Table II illustrates the depen-... 

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