Improved Bridgman-Stockbarger method for compound semiconductor GaAs single crystal

Abstract

The invention relates to an improved falling crucible method growth method for compound semiconductor arsenide gallium monocrystal. The growth method comprises the following steps: a multi-position falling crucible furnace is used for the growth of compound semiconductor GaAs monocrystal; the furnace is designed with a plurality of positions, and can be used for the growth of a plurality of crystals; a raw material for high-purity arsenic-enriched multicrystal GaAs is synthesized first, and generally, the arsenic-enriched quantity is not more than 1mol percent; the raw material is fed into a PBN crucible with the bottom provided with crystal seed and seed crystal, and the PBN crucible is placed inside the static stable falling crucible furnace; the falling crucible furnace is designed with three temperature zones, namely a high-temperature zone T1, a gradient zone T2 and a low-temperature zone T3 which respectively plays a role in material smelting, growth and heat preservation; moreover, the furnace temperature is controlled to between 1,250 and 1,290 DEG C, and the position of the crucible is adjusted so as to ensure that the top of the seed crystal is molten; then the temperature is reduced at the speed between 0.2 and 3 millimeters/hour so as to start crystal growth; and when crystal growth is finished, in situ annealing of the crystal is carried out through adjusting the position of the crucible and controlling the furnace temperature. The improved falling crucible growth method has the advantages that the growth method combines the advantages of the prior VB method and VGF method, and adopts a plurality of crucibles so as to increase crystal yield; moreover, an in situ annealing method is adopted to overcome the disadvantage of dislocation caused by thermal stress.

Description

technical field [0001] The invention relates to an improved growth method of a compound semiconductor gallium arsenide single crystal by a crucible drop method, belonging to the field of crystal growth. Background technique [0002] Gallium arsenide (GaAs) is a typical compound semiconductor, its status is second only to Si single crystal. Compared with Si, GaAs has a larger band gap, higher electron mobility and higher saturation velocity, so electronic devices made of GaAs work faster, have a higher operating frequency and have a wider operating temperature range than corresponding Si devices. This makes GaAs replace Si as the most important semiconductor material for making modern ultra-high-speed electronic devices and circuits. In recent years, GaAs materials and related industries have developed rapidly, with an annual growth rate of more than 35%. In 2005, its output value exceeded 10 billion US dollars. In the next few decades, the GaAs industry will still maintain...

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Problems solved by technology

Generally speaking, the above growth methods have their own characteristics, but they have a common disadvantage:

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