Gallium arsenide has some better electronic properties than Si, so GaAs can be used in occasions higher than 250 GHz. If the equivalent GaAs and Si elements operate at high frequency at the same time, GaAs will produce less noise. Also because GaAs has a high collapse voltage, GaAs is more suitable for operation in high power occasions than the same Si element. Because of these characteristics, GaAs circuits can be used in mobile phones, satellite communications, microwave point-to-point connections, radar systems and so on. GaAs has been used to make Gann diodes, microwave diodes and Gunn diodes to emit microwaves.Another advantage of GaAs: it is a direct energy gap material, so it can be used to emit light. Si is an indirect energy gap material, which can only emit very weak light. (however, recent technologies have been able to make LEDs from Si and use them in lasers.)
Silicon has long held its place as the key material in semiconductors. However, gallium arsenide, along with other compounds like GaAs cells and silicon carbide, are now sharing the stage. So what is GaAs cells and how does it differ from other compounds? Let's explore this compound and take a look at how it's being used as a semiconductor material.
Gallium arsenide cells is a compound built from the elements gallium and arsenic. It is always related to as a III-V compound because gallium and arsenic are in the III group and V group of the periodic table respectively.
Patterning process with photo-resist (PR) is inevitable. And for leaving the PR, an etching process with oxygen plasma is generally used. A compound semiconductor, but undergoes severe surface modification as compositional gradient resulted from the surface oxidation during the etching process. The surface treatment with these reagents induces the formation of passivation layer with sulfur and is usually wont to reduce the surface state density on the facets of optical devices and at the regrown interface. This sulfidation is revealed to stop adsorption impurities like oxygen atoms and metallic impurities to the clean compound semiconductor surface, even in small quantities. this system is applied to device fabrication and clearly shows the improved electrical properties.