Method for reducing GaN epitaxial defects through wet etching

Abstract

The invention provides a method for reducing GaN epitaxial defects through wet etching. The method comprises the following steps that (1) non-doped gallium nitride is grown on a sapphire wafer; (2) the sapphire wafer is placed into an acid solution and then taken out to be cleaned through ionized water and spin-dried; (3) the sapphire wafer cleaned and spin-dried in the step (2) is made to grow again; (4) a GaN base is bonded on a silicon substrate and the sapphire wafer is peeled off by using high-temperature lattice mismatching stress. According to the method for reducing the GaN epitaxial defects through wet etching, the acid solution is used, and screw dislocation and mixed dislocation can be avoided.

Description

technical field [0001] The invention relates to the technical field of LED epitaxial growth, in particular to a method for reducing GaN epitaxial defects by wet etching. Background technique [0002] GaN is usually grown on a sapphire substrate with a relatively high defect density of 1x10 8-9 / cm 2 , due to the large lattice mismatch between GaN and sapphire. Material defects are an important limiting factor in LED device characteristics; this problem becomes more serious when the emission wavelength is extended from blue to ultraviolet or green. From the reported technology, the method to solve this problem is epitaxial lateral overgrowth (ELOG, Epitaxial Lateral Over Growth), defect blocking layer (DBL, Defect Blocking La x er) and sapphire patterned substrate (PSS, Pattern Sapphire Substrate). [0003] The ELOG approach uses an oxide-patterned GaN template, which reduces defect density by 1-2 orders of magnitude. However, defect reduction occurs only in oxide-covere...

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Problems solved by technology

Alkaline solution corrosion can resolve edge dislocations and mixed dislocations, but cannot alleviate screw dislocations

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