A method for growing aluminum nitride single crystal by physical vapor transport method

Abstract

The invention discloses a method for growing an aluminum nitride single crystal by a physical vapor transport method. The method comprises: S1, fixing aluminum nitride raw materials around the inner wall of a crucible; S2, fixing a seed crystal in the middle of a crystal growth chamber in the crucible Position; S3, put the crucible into a high-temperature furnace, feed high-purity nitrogen gas, raise the temperature to a preset temperature, and adjust to form a small temperature gradient around the seed crystal to grow aluminum nitride single crystal, and keep it warm for a period of time. Under the action of the temperature gradient, the surrounding gas-phase substances are transported towards the seed crystal, and a low supersaturation of Al gas pressure is formed around the seed crystal, forming a high-speed growth of the seed crystal in a high-quality laminar growth mode. The physical vapor transport method used in the present invention to prepare aluminum nitride single crystals changes the arrangement of raw materials, seed crystals, and thermal field distribution in the current traditional physical vapor transport method, and forms a good laminar growth around the seed crystals environment, and finally obtain a high-quality crystallized AlN single crystal.

Description

technical field [0001] The invention relates to the technical field of semiconductor material preparation, in particular to a method for preparing crystals by a physical vapor transport method. Background technique [0002] Aluminum nitride (AlN), as the third-generation wide bandgap semiconductor material, has high bandgap (6.2 eV), high thermal conductivity (340 W / (m∙K)), high breakdown field strength (11.7MV / cm ), good UV transmittance, chemical and thermal stability and other excellent properties, can be widely used in the manufacture of laser diodes, optical receivers, ultra-high integrated circuits, microwave devices, lasers, optoelectronics, radiation resistance, high temperature resistance and other devices. Although devices based on aluminum nitride single crystals have broad application prospects, there are great difficulties and challenges in the preparation of single crystals, and it is difficult to achieve high-quality and mass production. [0003] Currently, t...

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Problems solved by technology

Low supersaturation is conducive to growing high-quality single crystals, but often leads to low growth rate and production efficiency

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