Gallium Arsenide (GaAs) Fabrication
Gallium Arsenide (GaAs) Fabrication Techniques:
This article is used to describe the basic fabrication methods of Gallium Arsenide (GaAs), mainly using LEC Growth process.
Various methods are used for the fabrication of Gallium Arsenide (GaAs). Out of all the methods, the main growth technique that is used is the liquid-encapsulated Czochralski (LEC) growth of GaAs crystals from high purified pyrolytic boron nitride (PBN) in high pressure.
The GaAs crystals can be easily achieved from the above method as the liquid-encapsulated Czochralski material grow in the <100> direction. As a results, round (100) wafers with very large diameters are obtained. The wafers that are grown in the <100> orientation is usually selected as they have semi-insulating properties and are also know to be thermally stable.
Since the <110> cleavage planes are at a right angle, square chips can be obtained with a diamond scribe and break. This means that by adhering to the <100> growth plane most of the difficulties that occur while cutting and handling of the chips can be reduced.
The methods for making GaAs wafers is very similar to the preparation of silicon wafers. First of all, the As- grown boules are grinded to a precise diameter and then incorporatied with orientation flats. This is followed by the following steps.
• Wafering using a diamond ID saw
• Edge rounding
• Wafer Scrubbing