V Semiconductors

X in GaAsj. P. Substrate A/nm Observed colour or region of spectrum 

Thin films of GaAs are deposited commercially using CVD techniques by reactions such as 27.13. Slow hydrolysis of GaAs in moist air means that films must be protectively coated. 

The commercial production of GaAS] P requires the epitaxial growth of the crystalline material on a substrate. 

Epitaxial growth of a crystal on a substrate crystal is such that the growth follows the crystal axis of the substrate. 

The proportions of the group 15 hydrides entering the reactor can be varied as required they thermally decompose by reaction 27.15 giving elemental components for the ternary semiconductor at the substrate surface. High-purity reagents are essential for the deposition of films that are of acceptable commercial grade. 

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Fig. 5. A gas manifold for the production of epitaxial layers of Group 111—V semiconductors by OMCVD where [...

The main use of elemental As is in alloys with Pb and to a lesser extent Cu. Addition of small concentrations of As improves die properties of Pb/Sb for storage batteries (see below ), up to 0.75% improves the hardness and castabilily of type metal, and 0 5-2.0% improves the sphericity of Pb ammunition. Automotive body solder is Pb (92%),, Sb (5 0%), Sn (2.5%) and As (0.5%). Intcrnxitallic compounds with Al, Ga and In give the 111-V semiconductors (p 255) of which GaAs and InAs are of particular value for light-emitting diodes (LEDs), tunnel diodes, infrared emitters, laser windows and Hall-effect devices (p. 258). 

N. Holonyak, Jr. and M. H. Lee, Photopumped 111-V Semiconductor Lasers Henry Kressel and Jerome K. Butler, Heterojunction Laser Diodes... 

Guzelian, A.A. (1996) Synthesis and Characterization of 111-V Semiconductor Nanocrystals, Ph.D. Thesis, University of California at Berkeley. 

Table 11. Summary of experimental results obtained for halogen adsorption on zinc blende 111-V semiconductor surfaces. The colunm headings are the same as defined for Table 1. ...

GaAs is probably the most familiar example of 111-V compound semiconductors, used for both highspeed electronics and for optoelectronic devices. Optoelectronics has taken advantage of ternary and quaternary 111-V semiconductors to establish optical wavelengths and to achieve a variety of novel device structures. The ternary semiconductors have the general form A, (with two group III... 

In contrast to single element elemental semiconductors (for which the positioning of each atom on a lattice site is not relevant), 111-V semiconductors require very good control of stoichiometry (i.e., the ratio of the two atomic species) during crystal growth. For example, each Ga atom must reside on a Ga (and... 

Walker, R.G. 1991. High-speed 111-V semiconductor intensity modulators. IEEE J. Quan. Elec. 27 654-667. 

A very nice example of the power of Mossbauer spectroscopy was the demonstration [37] of site selective doping of compound 111-V semiconductors such as GaAs, where it was concluded from the measured Sn isomer shift that implanted In and Sb radioactive parent ions selectively populate 111 and V sites respectively. 

Tip-based oxidation experiments were first performed on Si(lll) and polycrystaline tantalum faces. - Since then a large number of materials have been locally oxidized, such as compound 111-V semiconductors silicon carbide several metals such as titanium, tantalum, aluminum, molybdenum, nickel, and niobium perovskite manganite thin films dielectrics such as silicon nitride... 

Concerning 111-V semiconductors, mainly GaAs, GaP, and InP have been studied. In all cases, it has been found that six charges are required for the anodic decomposition of one semiconductor molecule. As an example taking GaAs, with which most investigations have been performed, the overall reaction is given... 

This section of the chapter will consider only the electrodeposition of the Group IV semiconductors (Si and Ge), Group 11-VI semiconductors (e.g. CdS, CdSe, CdTe, ZnSe, ZnTe), Group 111-V semiconductors (e.g. GaAs, GaP, and InP) and some alloys using the voltammetry technic... 

The resulting stability curves are ellipses or squared ellipses in the quaternary phase space. Each ellipse becomes smaller at higher temperature as the spinodal decomposition region shrinks (as is the case in Figure 4.18c), driven by the stronger entropy contribution. Onabe [8] carried out calculations for all of the common 111-V semiconductor ternary and quaternary alloys. Selected results are shown in Figure 6.7. 

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