Of GaAs

Figure B3.2.5. The imaginary part of the dieleetrie fiinetion of GaAs, aeeording to tire AFC ELAPW-/c p method (solid eiirve) [195] and the experiment (dashed enrve) [196], To eorreet for the band gap underestimated by the loeal density approximation, the eonduetion bands have been shifted so that tlie 2 peaks agree in theory and experiment.

Pulci O, Onida G, Shkrebtii A I, Del Sole R and Adolph B 1997 Plane-wave pseudopotential calculation of the optical properties of GaAs Phys. Rev. B 55 6685... 

Eckstein FI, Schattke W, Reigrotzki M and Redmer R 1996 Variational quantum Monte Carlo ground state of GaAs Phys. Rev. B 54 5512-15... 

Olshavsky M A, Goldstein A N and Alivisatos A P 1990 Organometallic synthesis of GaAs orystallites exhibiting quantum oonfinement J. Am. Chem. Soc. 112 9438... 

The dangling bonds of a Si surface abstract one F atom from an incident F2 molecule while the complementary F atom is scattered back into the gas phase [20]. This abstractive mechanism leads to F adsorjDtion at single sites rather than at adjacent pairs of sites, as observed directly by scanning tunnelling microscopy [21]. Br atoms adsorb only to Ga atoms in the second layer of GaAs(001)-(2 x 4) where empty dangling bonds on the Ga atoms can be filled by electrons from the Br atoms [22]. 

Gillis H P, Choutov D A, Martin K P and Song L 1996 Low energy electron enhanced etching of GaAs(IOO) in chlorine-hydrogen DC plasma Appl. Phys. Lett. 68 2255-7... 

Yu M L 1993 A modei for the atomic iayer epitaxy of GaAs Thin Solid Films 225 7-11... 

Creighton J R and Bansenauer B A 1993 The surface chemistry and kinetics of GaAs atomic iayer epitaxy Thin Solid Films 225 17-25... 

Early injection lasers were small rectangular parallelepipeds made by cutting a wafer of GaAs. Feedback was provided by mirrors polished on two edges or by cleaving. The wafer had ap—n junction incorporated into it and broad area or stripe contacts were provided. Laser stmctures have since evolved to satisfy a wide range of appHcation specific requirements. 

Two different high efficiency types of GaAs cell stmctures ate being developed. These are GaAs homojunctions with a top window layer of Ga ... 

Eig. 1. Representation of the band stmcture of GaAs, a prototypical direct band gap semiconductor. Electron energy, E, is usually measured in electron volts relative to the valence, band maximum which is used as the 2ero reference. Crystal momentum, is in the first BriUouin 2one in units of 27r/a... 

An extensive compilation of the properties of compound semiconductors may be found in the Landolt-Bn mstein reference books (13,14). Various subvolumes in the series cover the properties of elemental. III—V, II—V, and other less common semiconductors. Information may also be found concerning semiconductor technology. Another useful source of information is the EMIS data review series (15). These books describe the properties and technology of GaAs, HgCdTe, InP, AlGaAs, InGaAs, and the III—V nitride compounds. 

A powerful feature of wet etching is the abiUty to achieve excellent etch selectivities of one material over another. This can be extremely useful in the fabrication of epitaxial devices with different material layers. Because selective etching allows the removal of specific layers, the final accuracy of the etch can approach that of the epitaxial layers. Etch selectivities of >100 1 have been achieved for citric acid H202 etching of GaAs—AlGaAs and InGaAs—InP stmctures (133). 

Film Contamination from Bulk Phase. The contamination of an epitaxial film of GaAs from an oven charge can be corrected by doping... 

The reactions can also be initiated tlrrough the application of a shock wave from a mechanical source, and syntlresis of GaAs has been achieved without any external heating, which would lead to arsenic evaporation, being applied to the mixture of the elements. 

Figure 8 Spectroscopic study of GaAs(110). With a positive voltage on the STM tip, the left-hand image represents As atoms, while the corresponding negative tip voltage on the right shows Ga atoms. (Courtesy of Y. Yang and J.H. Weaver, University of Minnesota)...

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