Method based on femtosecond laser technology for peeling GaN film and sapphire substrate

Abstract

The invention discloses a method based on a femtosecond laser technology for peeling a GaN thin film and a sapphire substrate, and the method belongs to the field of LED and power device chips. The method comprises the steps of: (1) growing the GaN thin film on the sapphire substrate by adopting chemical vapor deposition; (2) bonding a target substrate on the GaN thin film to obtain a sapphire / GaN / target substrate; (3) carrying out scanning radiation on the upper surface of the sapphire substrate by adopting femtosecond laser from the edge of the sapphire / GaN / target substrate; (4) and heating the sapphire / GaN / target substrate to not lower than 30 DEG C and removing the sapphire substrate to obtain a bilayer structure of the GaN / target substrate. The method provided by the invention has the advantages that: the method is a cold processing method, the temperature in the GaN thin film before and after femtosecond laser radiation is even and has no obvious change, the thermal stress influence on the GaN thin film is effectively reduced, and the laser peeling quality is improved; and the method increases the efficiency and yield of peeling the sapphire substrate, and overcomes the defect that the GaN thin film is liable to damage.

Description

technical field [0001] The invention relates to the field of LEDs and power device chips, in particular to a method for peeling off a GaN thin film and a sapphire substrate based on femtosecond laser technology. Background technique [0002] In recent years, among the big family of semiconductor LEDs and other power devices, the development of GaN-based LEDs is the most rapid and noticeable. With its direct bandgap and excellent optoelectronic properties, GaN-based semiconductor materials have made many major technological breakthroughs in the preparation of thin-film preparation, crystal growth and other optoelectronic devices. GaN-based semiconductor materials are therefore known as the driving force for the development of the lighting field. However, it is difficult to directly grow a thick layer of GaN, so most of the cheap sapphire is used as a heterogeneous substrate at present. However, the lattice mismatch between sapphire and GaN material is large, resulting in a h...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the defects such as low efficiency, low yield, and easy damage of GaN thin film in the method of laser stripping sapphire substrate, combined with femtosecond laser technology, the present invention proposes a method for stripping GaN thin film and sapphire based on femtosecond laser technology method

Images