Gallium arsenide doping

Consider the number of valence electrons in each element. clO-0096. Draw a band-gap diagram for gallium arsenide doped with zinc. clO-0097. Draw a band-gap diagram for germanium doped with phosphorus. 

With gallium arsenide, additional elements, such as Si, S, and Cl, are of interest because of their doping character. Impurity levels on the order of lO cm are encountered with commercial substrates, which can be readily assessed using direct TXRF." VPD-TXRF is not possible in this case because of the lack of a native oxide layer on gallium arsenide. 

Colorless gas with a mild odor described as fishy or like garlic. It is detectable at 0.5 ppm. Used as a doping agent for solid-state electronic components, in the preparation of gallium arsenide and glass dyes, and in the manufacture of light-emitting diodes. 

Moderately doped diamond demonstrates almost ideal semiconductor behavior in inert background electrolytes (linear Mott -Schottky plots, photoelectrochemical properties (see below), etc.), which provides evidence for band edge pinning at the semiconductor surface. By comparison in redox electrolytes, a metal-like behavior is observed with the band edges unpinned at the surface. This phenomenon, although not yet fully understood, has been observed with numerous semiconductor electrodes (e.g. silicon, gallium arsenide, and others) [113], It must be associated with chemical interaction between semiconductor material and redox system, which results in a large and variable Helmholtz potential drop. 

Other materials that are normally etehed in a mieroelectronics environment are poly-silieon, silicon nitride, doped poly-silieon, aluminum, gallium arsenide, and gold. The plasma chemistry involved is... 

Kressel, H. Dunse, J.U. Nelson, H. Hawrylo, F.Z. Luminescence in silicon-doped gallium arsenide grown by liquid-phase epitaxy. J. Appl. Phys. 1968, 39 (4), 2006-2011. 

A certain relationship, which exists between the bulk and surface properties of semiconducting materials and their electrochemical behavior, enables, in principle, electrochemical measurements to be used to characterize these materials. Since 1960, when Dewald was the first to determine the donor concentration in a zinc oxide electrode using Mott-Schottky plots, differential capacity measurements have frequently been used for this purpose in several materials. If possible sources of errors that were discussed in Section III.3 are taken into account correctly, the capacity method enables one to determine the distribution of the doping impurity concentration over the surface" and, in combination with the layer-by-layer etching method, also into the specimen depth. The impurity concentration profile can be constructed by this method. It has recently been developed in greatest detail as applied to gallium arsenide crystals and multilayer structures. 

A variety of problems are presented in the development of some of these technologies. Heavy doping necessary for certain areas of the devices is difficult to achieve by simple processes in gallium arsenide. In spite of these shortcomings, there are several areas in which ion implantation has already been successfully used. With... 

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