Gallium manufacture

GaUium prices, stable up to 1991, fluctuated in 1992 because of gallium from China and Eastern European Bloc countries. The market destablized owing to spot offers and dumping. The reHabUity of these products was a real problem, however, and the consequence of market variations was dramatic for small manufacturers. 

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. 

Uses. The main uses of gallium is in the manufacture of semiconductors which are generally obtained by the combination of Ga with P and As. Gallium arsenide is capable of converting electricity directly into coherent light (production of light-emitting diodes). 

Because of the unique property of some of its compounds, gallium is able to translate a mechanical motion into electrical impulses. This makes it invaluable for manufacturing transistors, computer chips, semiconductors, and rectifiers. 

Once germanium is recovered and formed into blocks, it is further refined by the manufacturer of semiconductors. It is melted, and the small amounts of impurities such as arsenic, gallium, or antimony, are added. They act as either electron donors or acceptors that are infused (doped) into the mix. Then small amounts of the molten material are removed and used to grow crystals of germanium that are formed into semiconducting transistors on a germanium chip. The device can now carry variable amounts of electricity because it can act as both an insulator and a conductor of electrons, which is the basis of modern computers. 

Uses/Sources. In the electronics industry to manufacture gallium arsenide and gallium arsenide phosphide for semiconductors and as a dopant produced accidentally as a result of generation of nascent hydrogen in the presence of arsenic or by the action of water on a metallic arsenide... 

Many electronic companies in the State of California create a substantial volume of arsenic waste through the processing or manufacture of gallium arsenide (GaAs) microchips. Since the concentration of arsenic in wastewaters or sludges usually exceeds disposal limits for sewer and municipal landfills, these wastes are quite often treated and disposed to a Class I hazardous landfill. This practice is undesirable environmentally and economically as a long-term mechanism for waste disposal. 

DESCRIPTION OF GALLIUM ARSENIDE MICROCHIP MANUFACTURING PROCESS... 

GALLIUM-ARSENIDE MICROCHIP MANUFACTURING ARSENIC WASTEWATER FLOW DIAGRAM... 

GALLIUM-ARSENIDE MICROCHIP MANUFACTURING ARSENIC WASTE WATER FLOW DIAGRAM PERCENT ARSENIC TO HF TREATMENT SYSTEM AND RECYCLED SOLIDS... 

TransitorAmplifiers. Most gallium-based field-effect transitor amplifiers (FETs) are manufactured using ion implantation (qv) (52), except for high microwave frequencies and low noise requirements where epitaxy is used. The majority of discrete high electron mobility transistor (HEMT) low noise amplifiers are currently produced on MBE substrates. Discrete high barrier transistor (HBT) power amplifiers use MOCVD and MBE technologies. 

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