Semi-insulating GaAs (gallium arsenide) crystal with low defects and dopants can be offered by PAM-XIAMEN, one of gallium arsenide producers. Semi-insulating GaAs crystal refers that there is excess arsenic during the GaAs crystal growth process, leading to crystallographic defects, which is arsenic antisite defects. The electronic properties of such defects can interact with other defects, and then make Fermi level fixed near GaAs band gap center. Therefore, the semi-insulating GaAs ingot has a very low concentration of holes and electrons. GaAs crystal lattice structure is Zinc blende. Details about the semi insulating GaAs crystals are as following:
1. Specification of GaAs Crystal (PAM210618-GAAS)
|Item||GaAs Single Crystal|
|Size||3” and 4”|
2. GaAs Crystal Properties
GaAs crystals have a unique property anisotropy, which also displays this property during crystal growth. In general, GaAs crystal growth tends to preferentially grow on the crystal face with the densest arrangement of atoms. For gallium arsenide crystals, the GaAs crystal planes with the densest arrangement of atoms are the (111) crystal plane. Gallium and arsenic atoms are arranged in a hexagonal close-packed arrangement on the (111) plane. When crystal grows, it expands horizontally on a dense plane of atoms, which is faster than the growth of new nuclei perpendicular to this plane. The GaAs crystal is a polar crystal, so the polarity also affects the GaAs boule growth. The GaAs formula is shown as the picture:
The properties of GaAs crystal at room temperature, like GaAs crystal structure, GaAs band gap, GaAs lattice constant, and etc. are shown as in the picture below:
The GaAs crystal resistivity is ranging from 107 Ω·cm to 109 Ω·cm.
The following diagram shows the relationship of GaAs band structure and carrier concentration:
3. GaAs Single Crystal Industry Standards
As for PAM-XIAMEN’s semi insulating GaAs single crystal, the inspection of conductivity type, carrier concentration, mobility, resistivity, dislocation density and crystal orientation of single crystals all meet the relevant industry standards. Details please see below:
Semi insulating GaAs crystal produced by PAM-XIAMEN is free of pores, cracks and twinning lines.
Single crystal growth direction: <111> and <100>, or the required special direction is determined by negotiation between the supplier and the buyer.
The GaAs single crystal dislocation density classification is in accordance with the following table:
|Diameter(mm)||Dislocation density level and requirements|
4. GaAs Crystal Applications
GaAs ingot has high electron mobility, so it is easy to realize ultra-high-speed and ultra-high-frequency performance of the device and reduce power consumption and volume. In addition, GaAs direct band gap with high luminous efficiency is widely used in light-emitting and laser devices.
5. GaAs Crystal Market
Undoped SI GaAs boule is the basic material of GaAs integrated circuits (GaAs IC’s). There are many GaAs crystal growth techniques, including LEC, VB, VGF and etc. Among them, usually we use LEC method to prepare the GaAs single crystal, and has formed an industrial production scale. In order to improve the performance-price ratio of GaAs IC’s and develop the commercial market, we have developed high-quality SI-GaAs single crystal materials with larger diameter, improved the purity of SI-GaAs ingot, improved micro-area uniformity, and reduced dislocation and micro defect density.