Dopants hydride

It is often necessary to iatroduce dopant atoms iato the epitaxial (epi) layers. Typically, the dopant sources are hydrides (qv) of the impurity atoms. Common dopants are boron hydride, ie, diborane(6) [19287-45-7] 2 6 p-ty e dopiag, and arsiae [7784-42-17, AsH, and phosphoms hydrides for n-ty e dopiag (11). For example ... 

Dopant species can be codeposited with the Si02 by introducing small amounts of the dopants in hydride or haUde form. P-doped Si02, called P-glass, functions as an insulator between polysiUcon gates and the top metallisation layer of ICs. It is also used as a final passivation layer over devices, and as agettering source (17). 

Boron creates an electron deficiency in the siHcon lattice resulting in a -type semiconductor forp—n junctions. Boron compounds are more commonly used as the dopant, however (see Boron hydrides). 

Diborane(6), B2H. This spontaneously flammable gas is consumed primarily by the electronics industry as a dopant in the production of siHcon wafers for use in semiconductors. It is also used to produce amine boranes and the higher boron hydrides. Gallery Chemical Co., a division of Mine Safety AppHances Co., and Voltaix, Inc., are the main U.S. producers of this substance. Several hundred thousand pounds were manufactured worldwide in 1990. 

Titanium nitride-based nanoparticles are also efficient dopants for NaAlH4 in hydrogen storage applications [12, 13]. The black solid TiN powder can be dispersed into the hydride via ball milling. Addition of titanium nitride-based na-... 

The theoretical hmit of 5.4% (NaAlH4+2 mol% TiN) for the two subsequent decomposition reactions is in both cases only observed in the first cycle. The reason for the decrease in capacity is stiU unknown and litde is known about the mechanism of alanate activation via titanium dopants in the sohd state. Certainly, the ease of titanium hydride formation and decomposition plays a key role in this process, but whether titanium substitution in the alanate or the formation of a titanium aluminum alloys, i.e., finely dispersed titanium species in the decomposition products is crucial, is stiU under debate [41]. 

Group 14 (IV) elements as, 22 232 high throughput experimentation, 7 382t, 414t hydrides in, 13 609 introduction of dopants into, 14 428 ion dose for, 14 427 photon interaction with, 23 33—34 as photosensitive materials, 22 716 scanning capacitance microscopy,... 

J. Wang, A.D. Ebner, R. Zidan, J.A. Ritter, Synergistic effects of co-dopants on the dehydrogenation kinetics of sodium aluminum hydride , J. Alloys Compd. 391 (2005) 245-255. 

In order to control the condnctivity type and carrier concentration of the epitaxial layers, dopants are added to the reactant gases (cf. Section 6.1.1.5). Dopants are typically introduced in the form of hydrides (e.g., B2H6, PH3, and AsHs) in low concentrations (10-1000 ppm). There are no simple mles to relate the incorporation of dopant atoms from the gas phase into the Si film, since the incorporation depends on many factors, including snbstrate temperatnre, deposition rate, dopant molar volume, and reactor geometry. Thus, the dopanl/Si ratio in the film is different from that in the... 

Metalloids Intermediate. Altered by dopants (semiconductors) No (brittle) Varies Varies (oxides). Low (hydrides, halides)... 

Malleable materials can be beaten into sheets. Ductile materials can be pulled into wires. Lustrous materials have a shine. Oxides, hydrides, and halides are compounds with 0, H, and halogens respectively. Measures of intermolecular attractions other than melting point are also higher for metal oxides, hydrides, and halides than for the nonmetal compounds. A dopant is a small quantity of an intentionally added impurity. The controlled movement of electrons in doped silicon semiconductors carries digital information in computer circuitry. 

In recent years transition metal fiuorides have attained more and more attention as effective dopant precursors for complex hydrides [66, 67]. It is well known that aluminum hydrides, as well as borohydrides, react with fluorine to form fluorides [68]. In addition, many fluorides and hydrides are isotypic. One example is... 

Direct gas sources provide an easy way of introducing impurities into a diffusion furnace, and they can be diluted by a carrier gas, (e.g., dopant trihalides or hydrides can be diluted with nitrogen mixed with oxygen). The vapor phase reactions produce on the semiconductor surfaces dopant oxides from which diffusion can occur. 

Comparative studies of other metal halides as dopant precursors for treating NaAlIij have shown that similar levels of kinetic enhancement of the reversible dehydrogenation can be achieved upon doping with chlorides of zirconium, vanadium, and several lanthanides. Lower levels of catalytic activity have been reported to occur in hydride that was charged with FeCl2 and... 

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