A kind of method for preparing semipolar aln template

Abstract

The invention discloses a method for preparing a semipolar AlN template, which includes: inducing AlN or a twin crystal structure during the growth process of AlN, changing the growth orientation of AlN to obtain a semipolar AlN template. Through the method of the present invention, c-plane sapphire or SiC can be directly selected as the substrate instead of r-plane sapphire, so that the stacking faults in the AlN epitaxial layer can be reduced, and the cost is low; or twin structure, can change the growth orientation of AlN from [0001] to this, which makes the growth window wider and the growth conditions easier to control; at the same time, it only needs one-step growth without changing the growth conditions, so that the subsequent AlN can keep along the The growth in the semipolar direction avoids secondary pollution and is beneficial to obtain high-quality semipolar AlN templates.

Description

technical field [0001] The invention particularly relates to a method for preparing a semipolar AlN template, which belongs to the field of material science. Background technique [0002] The forbidden band of AlN and its alloys with hexagonal wurtzite structure covers the ultraviolet spectral range of 200-365nm, which is an ideal material for the preparation of deep ultraviolet optoelectronic devices and high-frequency and high-power devices. However, AlN-based materials are usually grown along the polar axis—c-axis, so that AlN and its alloys have strong spontaneous and piezoelectric polarization in the [0001] direction. This polarization effect will generate a high-intensity built-in electric field in the nitride epitaxial layer, causing the energy band to bend and tilt, so that electrons and holes are separated in space, which greatly reduces the luminous efficiency of AlN-based optoelectronic devices. Therefore, people try to improve the performance of light-emitting d...

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Problems solved by technology

However, the size of AlN materials obtained by this method is very limited, which forces researchers to try to epitaxially semipolar AlN materials on non-c-plane heterogeneous substrates such as sapphire and silicon carbide, but this technique is very difficult. Moreover, the crystal quality of AlN is poor and the dislocation density is high, which seriously restricts the efficiency of AlN-based optoelectronic devices.

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