Chemistry of Aluminium, Gallium, Indium and Thallium


Book Description

Boron has all the best tunes. That may well be the first impression of the Group 13 elements. The chemical literature fosters the impression not only in the primary journals, but also in asteady outflowofbooks focussing more or less closely on boron and its compounds. The same preoccupation with boron is apparent in the coverage received by the Group 13 elements in the comprehensive and regularly updated volume of the Gmelin Handbook. Yet such an imbalance cannot be explained by any inherent lack ofvariety, interest or consequence in the 'heavier elements. Aluminium is the most abundant metal in the earth's crust; in the industrialised world the metal is second only to iron in its usage, and its compounds can justifiably be said to touch our lives daily - to the potential detriment of those and other lives, some would argue. From being chemical curios, gallium and indium have now gained considerably prominence as sources of compound semiconductors like gallium arsenide and indium antimonide. Nor is there any want ofincident in the chemistriesofthe heavier Group 13 elements. In their redox, coordination and structural properties, there is to be found music indeed, notable not always for its harmony but invariably for its richness and variety. Thisbook seeks to redress the balance with a definitive, wide-rangingand up-to-date review of the chemistry of the Group 13 metals aluminium, gallium, indium and thallium.







Properties of Lattice-matched and Strained Indium Gallium Arsenide


Book Description

The semiconductor InGaAs (indium gallium arsenide) plays a pivotal role in the study of quantum systems which provide promising applications in the fields of microelectronics and optoelectronics. This reference explores recent developments with InGaAs. Leading researchers from the USA, Europe and Japan cover such issues as structural, thermal, mechanical and vibrational properties, the band structure of lattice-matched and strained alloys, transport and surface properties, radiative and non-radiative recombinations, expitaxial growth, doping, etching of InGaAs and related heterostructures, photodetectors, FETs, double heterostructure and quantum well lasers.




Ohmic Contacts for Gallium Arsenide Devices


Book Description

A study was made of various metals and metal alloys (Ag, Ni, In, and Au-Zn) which would make ohmic contacts to p- or n-type GaAs to determine the value of contact resistivity as a function of substrate impurity concentration. Contact resistivity values for p-type material varied from 1.2 x 10 to the -4th power ohm-cm sq for 2.8 x 10 to the 17th power/cc to 7.3 x 10 to the -7th ohm-cm sq for 9 x 10 to the 19th power/cc, and for n-type material from 2.5 x 10 to the -4th power ohm-cm sq for 1 x 10 to the 17th power/cc to 1.5 x 10 to the -5th power ohm-cm sq for 3 x 10 to the 18th power/cc. The metals were applied by evaporation or plating and followed by microalloying. The improvement in contact resistivity, as substrate impurity concentration increases, indicates the desirability of incorporating a thin, heavily doped region at the surface of a device by means of diffusion or epitaxy. The improvement in power output for a typical laser diode and its modified versions resulting from the reduction in R sub s is compared. (Author).




Pure Silver Ohmic Contacts to N- and P- Type Gallium Arsenide Materials


Book Description

Disclosed is an improved process for manufacturing gallium arsenide semiconductor devices having as its components an n-type gallium arsenide substrate layer and a p-type gallium arsenide diffused layer. The improved process comprises forming a pure silver ohmic contact to both the diffused layer and the substrate layer, wherein the n-type layer comprises a substantially low doping carrier concentration.