Preparation of InAs, InP, GaAs, and GaP by Chemical Methods

Zinc‐and cadmium‐doped gallium phosphide crystals have been grown by an open tube halogen transport process at 805°–875°C. The zinc‐doping varied from 1017 to 1019 cm−3 while cadmium could be incorporated at levels ranging from 1016 to 1018 cm−3. We observed a linear dependence of zinc and cadmium concentration on the partial pressure of the dopant in the growth ambient. This linear dependence is evidence for a nonequilibrium, kinetically controlled process. The structural and electrical properties are compared with the properties of crystals grown by the wet hydrogen process. A study of the gallium consumption as a function of experimental variables yielded a Ga to PCl3 ratio of 2.5±0.2 , independent of PCl3 feed rate and carrier gas flow. A ratio of 2.64 is predicted from thermodynamic data provided the species GaCl2false(normalgfalse) can be neglected in the initial reaction between normalHCl and Ga.

Section: Transport Mechanism--in a Recent Paper Seki Andsupporting

confidence: 84%

Epitaxial Growth of Zinc- and Cadmium-Doped Gallium Phosphide by Gallium Chloride Vapor Transport

Luther¹,

Roccasecca²

1968

“…The Growth of Pure Epitaxiat Layers of GaAs Choice o~ system.---It has been shown that Group III-V compounds may be prepared and transported by vapor phase reactions in a number of ways (1,12). In the case of GaAs the following systems are equivalent: (a) GaAs, HC1; (b) GaC18, Ga, As, H2; and (c) Ga, AsCI~, H2.…”

Section: Growth Of Sn-doped Layersmentioning

confidence: 99%

Epitaxial Growth of Doped and Pure GaAs in an Open Flow System

Effer¹

1965

107

The basic parameters for the transport and epitaxial growth of normalGaAs in an open flow system have been studied using hydrogen chloride as the transport agent. Selenium‐ and tin‐doped normalGaAs layers were grown in this system, the maximum doping levels achieved being 3.7×1.018 electrons cm−3 and 3.2×1018 electrons cm−3 , respectively. Pure layers of normalGaAs have been grown by means of the AsCl3/normalGa/H2 reaction. The best layer had a room temperature carrier concentration of 1.75×1015 electrons cm−3 and a mobility of 8800 cm2/v‐sec. At 77°K the mobility value was 38,000 cm2/v‐sec.

“…Iron (0.1 ppm) and chlorine (0.2 ppm) are the most noticeable impurities detected by the mass spectrometer. The effect of both these elements is uncertain although it has been shown in this laboratory that very high concentrations of chlorine can be tolerated in indium arsenide with little or no change in the measured electrical properties (10,11,12).…”

Section: Discussionmentioning

confidence: 96%

Preparation of High-Purity Indium Arsenide

Effer¹

1961

The purest indium arsenide so far reported has a carrier concentration of about 1.3.1016 electrons/cm3 at room temperature. This is several times the intrinsic value and it has been suggested that the limiting impurity may be sulfur originating in the arsenic component. Arsenic has been prepared by the thermal decomposition of highly purified arsine gas and has been combined with samples of indium purified by a variety of processes. Mass spectrographic analysis of the resultant ingots showed in all cases a sulfur content less than 0.05 ppm. The purest sample had a Hall coefficient of 795 cm3/coulomb at 77°K, corresponding to an electron concentration of 8.1015/cm3 while the Hall mobility was 75,700 cm2/v/sec. Analytical techniques failed to detect the prime source of the free electron concentration, but it is concluded that sulfur is not the dominant impurity in these samples.