Method for reducing the stress between the GaN single crystal film and heterogeneous substrate

Abstract

The provided reducing-stress method comprises: growing GaN thin film on sapphire or other heterogeneous substrate, applying laser to pass through the sapphire and irradiate the film to obtain preliminary-decomposed layer on film bottom and release the stress. This invention is benefit to obtain crystal material with better quality.

Description

technical field [0001] The invention relates to the field of photoelectric materials and devices, in particular to a method for reducing the stress between a GaN single crystal film and a heterogeneous substrate. Background technique [0002] Gallium nitride (GaN)-based semiconductor materials have a wide band gap, good optoelectronic properties (higher carrier concentration, mobility, electron saturation velocity, breakdown electric field and lower dielectric constant, etc. ) and physical and chemical properties (high temperature resistance, corrosion resistance, etc.), known as the third generation of semiconductor materials after the first generation of Si, Ge element semiconductor materials, second generation GaAs, InP semiconductor materials, or "post-silicon devices The main representative of "era materials" is an ideal material for the production of high-frequency, high-temperature, high-voltage, high-power integrated circuit (IC) microelectronic devices and short-wav...

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Problems solved by technology

[0003] Due to the extremely high melting temperature and high nitrogen saturation vapor pressure of GaN materials, it is quite difficult to prepare GaN bulk single crystals by conventional methods. Therefore, GaN-based alloy materials are mostly grown on heterogeneous substrates, such as sapphire, silicon, GaAs, SiC, etc., especially economical and cheap sapphire, but due to the large lattice mismatch between sapphire and GaN and the large difference in thermal expansion coefficient, on the one hand, the defect density in GaN crystal is high. Currently, the defect density of GaN crystal grown on sapphire is Usually in 10 10 / cm 2 Even with lateral epitaxy, multi-buffer layers and other technologies, it is best to only reach 10 6 / cm 2 , the crystal quality of the GaAs material system grown on a homogeneous substrate is still far away, which prevents the excellent performance of GaN-based materials from being fully utilized, and the performance of corresponding GaN-based optoelectronic and microelectronic devices has been greatly affected. limits

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