Aluminum nitride template and preparation method thereof

Abstract

The invention discloses an aluminum nitride template and a preparation method thereof, and relates to the technical field of semiconductors. The preparation method of the aluminum nitride template comprises the steps that a sapphire substrate with a beveling angle is provided, the direction of the beveling angle of the sapphire substrate is that the c face deviates from the a axis or the m axis, and the beveling angle ranges from 0.5 degree to 6 degrees; depositing a first aluminum nitride film on the sapphire substrate to obtain a first material; carrying out first high-temperature thermal annealing treatment on the first material, cooling the first material to room temperature after the first high-temperature thermal annealing treatment, and taking out the first material; and depositing a second aluminum nitride film on one surface, far away from the sapphire substrate, of the first material. The aluminum nitride template is prepared by the preparation method of the aluminum nitride template. According to the preparation method of the aluminum nitride template, the compressive strain strength of the aluminum nitride template can be reduced, and the performance of the aluminum nitride template is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an aluminum nitride template and a preparation method thereof. Background technique [0002] The aluminum nitride template is the base material for the epitaxial growth of AlGaN-based deep ultraviolet LEDs. The crystallization quality of the AlGaN template directly determines the crystal quality of the upper layer of AlGaN. A high-quality AlN template can effectively reduce the threading dislocation density (TDDs) of AlGaN and improve the quality of LEDs grown on this material. The radiative recombination efficiency of electrons and holes in the structure improves the reliability and lifetime of LEDs. [0003] Among them, the method of secondary treatment of aluminum nitride template by ultra-high temperature (>1600°C) thermal annealing method has attracted widespread attention because it can effectively reduce its dislocation density while ensuring low cost. However,...

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Problems solved by technology

However, although the strain in AlN is completely released through misfit dislocations at the interface during ultra-high temperature annealing, which is basically a stress-free state, it will produce Compressive stress up to the order of GPa

The high-intensity compressive stress will cause the surface of the epitaxial wafer to warp, which will affect the uniformity of the composition and thickness, and will also lead to an increase in the surface roughness of the epitaxial layer, and even a high-density hillock morphology.

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