High-temperature bonding method for aluminum nitride seed crystals

Abstract

The invention discloses a high-temperature bonding method for aluminum nitride seed crystals. The aluminum nitride seed crystal, a seed crystal supporting piece and a high-purity aluminum nitride raw material are placed in a crucible of a closed structure, the seed crystal supporting piece and the seed crystal are placed at the bottom of the crucible, and the aluminum nitride raw material is fixed to the position above the seed crystal; and bonding is completed in a high-temperature furnace. The bonding method mainly comprises the following steps that (1) vacuumizing a high-temperature furnace, introducing high-purity nitrogen, and increasing the temperature to a certain temperature, wherein the seed crystal temperature in the process is higher than the raw material temperature; (2) continuously raising the temperature while the temperature raising speed of the raw material is greater than that of the seed crystal to form a gradient that the temperature of the seed crystal is less than that of the raw material, keeping the temperature after raising the temperature to a set high temperature, thermally bonding the seed crystal and the seed crystal support during the temperature keeping period, and depositing aluminum nitride on the surface of the seed crystal; and (3) finally cooling to room temperature. The high-temperature bonding method provided by the invention solves the technical problems that the seed crystal is easy to fall off, holes are formed, the seed crystal is polluted by impurities, the growth surface is damaged and the like in the chemical bonding and mechanical fixing methods of the seed crystal.

Description

Technical field [0001] The present invention relates to the technical field of semiconductor material preparation, and more particularly to a seed crystal fixation method in a physical gas phase transmission method. Background technique [0002] Aluminum nitride (ALN) is a wide-proof zone semiconductor material with potential, with a width of 6.2 eV, and has a high hitting field, high saturated electron drift rate and excellent thermal conductivity, anti-radiation performance It is an ideal substrate material for the optimum substrate material and GaN power devices of ultraviolet / deep UV LEDs. There is a rich Al-E element in nature, but there is no natural form of AlN minerals. At present, the physical gas phase transfer method (PVT) is recognized as the best method for preparing AlN crystals, wherein the homogeneous epitaxial process based on high quality AlN seed crystals is the ideal way to obtain high quality and large size AlN crystals. [0003] The seed epitaxial growth b...

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Problems solved by technology

[0004]Based on the above problems in the prior art, the present invention intends to provide a high-temperature bonding method for aluminum nitride seed crystals to solve the problem of chemical bonding and mechanical fixation of the seed crystals. The technical problems mentioned above are easy to fall off, form holes, be polluted by impurities, and damage the growth surface.

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